Background Nitrogen-Use-Efficiency(NUE)in lactating dairy cows,defined as milk nitrogen(N)output as a proportion of N consumed,is low,with the majority of excess N excreted in manure.Excreted N can be lost to the envi...Background Nitrogen-Use-Efficiency(NUE)in lactating dairy cows,defined as milk nitrogen(N)output as a proportion of N consumed,is low,with the majority of excess N excreted in manure.Excreted N can be lost to the environment as ammonia gas leading to environmental acidification and nutrient enrichment of sensitive habitats,and to watercourses contributing to aquatic eutrophication.While there is much evidence that NUE can be improved by reducing the crude protein(CP)content of dairy cow diets,the long-term impacts of feeding lower protein diets on cow performance and the rumen microbiome are less well understood.This study examined the effects of reducing the CP contents of dairy cow diets on cow performance,NUE,the relationship between NUE and residual feed intake(RFI),and the rumen microbiome.Results Dietary CP content did not affect feed intake,milk yield or milk composition(P>0.05),except for milk urea N(MUN),which increased with increasing diet CP content(P<0.05).The mean NUE was 34%,34%and 31%for the LCP(low-protein,15%),MCP(medium-protein,16%),and HCP(high-protein,17%)diets,respectively.RFI was negatively correlated with NUE(r=−0.57,P<0.001).The rumen ammonia-N concentrations increased with increasing dietary CP;however,the ruminal pH and volatile fatty acid(VFA)content of the rumen fluid remained constant.Predicted urinary N excretion was greater in the HCP and MCP diets than in the LCP diet.Reducing dietary CP content in dairy cow diets did not affect microbial composition,diversity and functional profiles.The family Bacteroidaceae was more abundant in HE(high-efficiency)cows,whereas the Methanobacteriaceae and the genus Methanobrevibacter were more abundant in LE(low-efficiency)cows.Additionally,propanoate metabolism,cysteine and methionine metabolism and amino acid biosynthesis pathways were more abundant in HE cows,whilst the methane(CH4)metabolism pathway was upregulated in LE cows.Conclusions The results demonstrate that diet CP can be reduced with no loss in cow performance,but with an associated reduction in N excretion.The abundance of microbial populations differed between low and high efficiency cows,which may contribute to the differences in efficiency observed.展开更多
[Objective] The aim of this study was to investigate the efficacy of the herbal feed additive Zengrujianniusan on the milk production of dairy cows. [Method] Thirty-two black-white lactating cows were randomly divided...[Objective] The aim of this study was to investigate the efficacy of the herbal feed additive Zengrujianniusan on the milk production of dairy cows. [Method] Thirty-two black-white lactating cows were randomly divided into four groups, and were fed with forage supplemented with 0 （control group）, 0.2%, 0.4% and 0.6% Zengrujianniusan for 60 d. During this period, the contents of fat, protein and non-fat solid in milk were measured every 20 d. [Result] The milk production of the cows whose forage was added with 0.2 %, 0.4 % and 0.6% Zengrujianniusan was 4.02%, 12.50%, 14.00% higher than that of the control （P〉0.05）. The herbal feed additive had no significant influence on the contents of fat, milk and non-fat solid in milk, but significantly reduced the number of somatic cells. [Conclusion] The study will provide reference for developing feed additives which is safe and non-toxic to cows and their milk.展开更多
Background The objective was to characterize the colostrum proteome of primiparous Holstein cows in association with immunoglobulin G(IgG)content.Immediately after calving,colostrum samples were collected from 18 cows...Background The objective was to characterize the colostrum proteome of primiparous Holstein cows in association with immunoglobulin G(IgG)content.Immediately after calving,colostrum samples were collected from 18 cows to measure IgG concentration.Based on colostrum IgG content,samples were classified through cluster analysis and were identified as poor,average,and excellent quality.The proteome was assessed with quantitative shotgun proteomics;abundance data were compared among the colostrum types;enrichment analysis of metabolic processes and proteins classes was performed as well.We also tested correlations between this proteome and blood globulin level of cows and passive immunity level of calves.Results On average,428 proteins were identified per sample,which belonged mainly to cellular process,biological regulation,response to stimulus,metabolic process,and immune system process.Most abundant proteins were complement C3(Q2UVX4),alpha-S1-casein(P02662),Ig-like domain-containing protein(A0A3Q1M032),albumin(A0A140T897),polymeric immunoglobulin receptor(P81265),lactotransferrrin(P24627),and IGHG1*01(X167014).Colostrum of excellent quality had greater(P<0.05)abundance of serpin A3-7(A2I7N3),complement factorl(A0A3Q1 MIF4),lipocalin/cytosolic fatty-acid binding domain-containing protein(A0A3Q1 MRQ2),complement C3(E1B805),complement component 4 binding protein alpha(A0AAF6ZHP5),and complement component C6(F1MM86).However,colostrum of excellent quality had lower(P<0.05)abundance of HGF activator(E1BCW0),alpha-S1-casein(P02662),and xanthine dehydrogenase/oxidase(P80457).This resulted in enrichment of the biological processes predominantly for complement activation alternative pathway,complement activation,complement activation classical pathway,humoral immune response,leukocyte mediated immunity,and negative regulation of endopeptidase activity in excellent-quality colostrum.Additionally,some colostrum proteins were found to be correlated with the blood globulin level of cows and with the passive immunity level of calves(P<0.05;r≥0.57).Conclusions This study provides new insights into the bovine colostrum proteome,demonstrating associations between IgG levels and the abundance of other proteins,as well as the enrichment of metabolic processes related to innate immune response.Thus,results suggest that the colostrum proteomic profile is associated with the content of IgG.Future research should deeply explore the association of these findings with pre-calving nutrition status and blood composition of the cow,and with passive immunity transfer to the calf.展开更多
Background During the transition period,cows are prone to negative energy balance,which can lead to a decline in production performance and health in severe cases.In recent years,it has been discovered that bile acids...Background During the transition period,cows are prone to negative energy balance,which can lead to a decline in production performance and health in severe cases.In recent years,it has been discovered that bile acids(BAs)can act not only as fat emulsifiers but also as signaling molecules to regulate body metabolism.Although BAs have been used to some extent in monogastric and aquatic animals,their role in ruminants,particularly in transition cows,remains unclear.Therefore,this study aimed to determine the effects of BAs on the production performance,milk and plasma fatty acid and BA composition,and fecal microbiota in transition dairy cows.Results Forty-six healthy transition Holstein dairy cows with similar conditions were randomly divided into two groups and supplemented with 0 or 20 g/d of BAs from 21 d before the expected calving to 21 d after calving.The production performance was tracked until 60 d after calving.The results indicated that BA supplementation significantly improved postpartum milk fat content and yields as well as the yields of unsaturated fatty acids,monounsaturated fatty acids,and polyunsaturated fatty acids in milk.There was a significant increase in the concentration of triglyceride and the proportion of C≤16 fatty acids in the plasma of cows supplemented with BAs,while the concentration of β-hydroxybutyrate and the proportion of C>16 fatty acids in the plasma decreased significantly.BA supplementation significantly altered the composition of the fecal bacterial community and increased the relative abundance of bacteria beneficial for BA metabolism and transformation(Romboutsia,Clostridium sensu_stricto_6,and Clostridium sensu_stricto_1).Functional prediction analysis showed that the relative abundance of bile salt hydrolase,7 α-hydroxysteroid dehydrogenase,and BA inducible E as well as the pathways related to BA metabolism also significantly increased in cows supplemented BAs.In addition,BA supplementation significantly altered the composition of plasma and fecal BAs,particularly increasing circulating secondary BA concentration,which might induce the complete oxidation of fatty acids in the liver and further reduce the concentration of β-hydroxybutyrate.Conclusions These findings highlight the potential benefits of BA supplementation in improving milk yields and quality,as well as influencing metabolic pathways in transition dairy cows.Meanwhile,further studies are needed to elucidate the underlying mechanisms and explore the broader implications of these results by using more tissue samples.展开更多
Background： Metabolic profile was initially designed as a presymptomatic diagnostic aid based on statistical analyses of blood metabolites to provide an early warning of certain types of metabolic disorder. However, ...Background： Metabolic profile was initially designed as a presymptomatic diagnostic aid based on statistical analyses of blood metabolites to provide an early warning of certain types of metabolic disorder. However, there is little metabolic profile data available about Korean Hanwoo cows. Therefore, this study aimed to determine the reference intervals of metabolic profile for Korean Hanwoo cows. Methods： Healthy animals （2,205） were selected and divided into early （day 1 to 95）, middle （day 96 to 190） and late （day 191 to 285） period according to their gestating period. Metabolic profile including total protein （TP）, albumin （AIb）, urea （UREA）, glucose （Glu）, total cholesterol （T-Cho）, long-chain fatty acid （LCFA）, aspartate aminotransferase （AST）, gamma-glutamyl transpeptidase （GGT）, creatinine （Crea）, calcium （Ca）, inorganic phosphorous （iP） and magnesium （Mg） were analyzed using a TBA-4OFR automatic biochemical analyzer. The data of Korean Hanwoo cows were then compared to those of the Japanese Wagyu cows. Results： Most of the data of the Korean Hanwoo cows were relatively higher than those of Japanese Wagyu cows, with the exception of Glu and GGT. This may indicate that the nutritional level of feed for the Korean Hanwoo cows was higher than that of the Japanese Wagyu cows because of the different feeding system. In particular, relatively higher levels of UREA and LCFA were observed in the Korean Hanwoo cows, and this may also contribute to the low reproduction efficiency. Conclusions： These findings may provide some theoretical basis for understanding the reproductive and feeding situation of Korean Hanwoo cows.展开更多
Elevated concentrations of plasma fatty acids in transition dairy cows are significantly associated with increased disease susceptibility and poor lactation performance. The main source of plasma fatty acids throughou...Elevated concentrations of plasma fatty acids in transition dairy cows are significantly associated with increased disease susceptibility and poor lactation performance. The main source of plasma fatty acids throughout the transition period is lipolysis from adipose tissue depots. During this time, plasma fatty acids serve as a source of calories mitigating the negative energy balance prompted by copious milk synthesis and limited dry matter intake.Past research has demonstrated that lipolysis in the adipose organ is a complex process that includes not only the activation of lipolytic pathways in response to neural, hormonal, or paracrine stimuli, but also important changes in the structure and cellular distribution of the tissue in a process known as adipose tissue remodeling. This process involves an inflammatory response with immune cell migration, proliferation of the cellular components of the stromal vascular fraction, and changes in the extracellular matrix. This review summarizes current knowledge on lipolysis in dairy cattle, expands on the new field of adipose tissue remodeling, and discusses how these biological processes affect transition cow health and productivity.展开更多
Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperaturehumidity index（THI） is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is di...Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperaturehumidity index（THI） is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines（leptin and adiponectin）, AMP-activated protein kinase（AMPK）, and heat shock signal molecules（heat shock transcription factor（HSF） and heat shock proteins（HSP）） in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment： eighteen lactating Holstein dairy cows were used. The treatments were： heat stress（HS, THI average=81.7, n=9） and cooling（CL, THI average=53.4, n=9）. Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment： HS treatment cows（n=9） from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90（P〈0.05）. Adiponectin is strongly associated with AMPK. The increases of adiponectin and AMPK may be one of the mechanisms to maintain homeostasis in heat-stressed dairy cows. When heat stress treatment lasted 8 weeks, a higher expression of HSF and HSP70 was observed under moderate heat stress. Serum HSF and HSP70 are sensitive and accurate in heat stress and they could be potential indicators of animal response to heat stress. We recommend serum HSF and HSP70 as meaningful biomarkers to supplement the THI and evaluate moderate heat stress in dairy cows in the future.展开更多
Background:Due to the high prevalence and complex etiology,bovine mastitis(BM)is one of the most important diseases to compromise dairy cow health and milk quality.The shift in milk compositions has been widely invest...Background:Due to the high prevalence and complex etiology,bovine mastitis(BM)is one of the most important diseases to compromise dairy cow health and milk quality.The shift in milk compositions has been widely investigated during mastitis,but recent studies suggested that gastrointestinal microorganism also has a crucial effect on the inflammation of other peripheral tissues and organs,including the mammary gland.However,research focused on the variation of rumen inner-environment during mastitis is still limited.Therefore,the ruminal microbial profiles,metabolites,and milk compositions in cows with different udder health conditions were compared in the present study.Furthermore,the correlations between udder health status and ruminal conditions were investigated.Based on the somatic cell counts(SCC),California mastitis test(CMT)parameters and clinical symptoms of mastitis,60 lactating Holstein dairy cows with similar body conditions(excepted for the udder health condition)were randomly divided into 3 groups(n=20 per group)including the healthy(H)group,the subclinical mastitis(SM)group and the clinical mastitis(CM)group.Lactation performance and rumen fermentation parameters were recorded.And rumen microbiota and metabolites were also analyzed via 16S rRNA amplicon sequencing and untargeted metabolomics,respectively.Results:As the degree of mastitis increased,rumen lactic acid(LA)(P<0.01),acetate,propionate,butyrate,valerate(P<0.001),and total volatile fatty acids(TVFAs)(P<0.01)concentrations were significantly decreased.In the rumen of CM cows,the significantly increased bacteria related to intestinal and oral inflammation,such as Lachnospiraceae(FDR-adjusted P=0.039),Moraxella(FDR-adjusted P=0.011)and Neisseriaceae(FDR-adjusted P=0.036),etc.,were accompanied by a significant increase in 12-oxo-20-dihydroxy-leukotriene B4(FDR-adjusted P=5.97×10^(−9))and 10beta-hydroxy-6beta-isobutyrylfuranoeremophilane(FDR-adjusted P=3.88×10^(−10)).Meanwhile,in the rumen of SM cows,the Ruminiclostridium_9(FDR-adjusted P=0.042)and Enterorhabdus(FDR-adjusted P=0.043)were increased along with increasing methenamine(FDR-adjusted P=6.95×10^(−6)),5-hydroxymethyl-2-furancarboxaldehyde(5-HMF)(FDR-adjusted P=2.02×10^(−6))and 6-methoxymellein(FDR-adjusted P=2.57×10^(−5)).The short-chain fatty acids(SCFAs)-producing bacteria and probiotics in rumen,including Prevoterotoella_1(FDRadjusted P=0.045)and Bifidobacterium(FDR-adjusted P=0.035),etc.,were significantly reduced,with decreasing 2-phenylbutyric acid(2-PBA)(FDR-adjusted P=4.37×10^(−6)).Conclusion:The results indicated that there was a significant shift in the ruminal microflora and metabolites associated with inflammation and immune responses during CM.Moreover,in the rumen of cows affected by SM,the relative abundance of several opportunistic pathogens and the level of metabolites which could produce antibacterial compounds or had a competitive inhibitory effect were all increased.展开更多
Background: Residual feed intake(RFI) in dairy cattle typically calculated at peak lactation is a measure of feed efficiency independent of milk production level. The objective of this study was to evaluate difference...Background: Residual feed intake(RFI) in dairy cattle typically calculated at peak lactation is a measure of feed efficiency independent of milk production level. The objective of this study was to evaluate differences in ruminal bacteria, biopolymer hydrolyzing enzyme activities, and overall performance between the most-and the leastefficient dairy cows during the peripartal period. Twenty multiparous Holstein dairy cows with daily ad libitum access to a total mixed ration from d-10 to d 60 relative to the calving date were used. Cows were classified into most-efficient(i.e. with low RFI, n = 10) and least-efficient(i.e. with high RFI, n = 10) based on a linear regression model involving dry matter intake(DMI), fat-corrected milk(FCM), changes in body weight(BW), and metabolic BW.Results: The most-efficient cows had ~ 2.6 kg/d lower DMI at wk 4, 6, 7, and 8 compared with the least-efficient cows. In addition, the most-efficient cows had greater relative abundance of total ruminal bacterial community during the peripartal period. Compared with the least-efficient cows, the most-efficient cows had 4-fold greater relative abundance of Succinivibrio dextrinosolvens at d-10 and d 10 around parturition and tended to have greater abundance of Fibrobacter succinogenes and Megaspheara elsdenii. In contrast, the relative abundance of Butyrivibrio proteoclasticus and Streptococcus bovis was lower and Succinimonas amylolytica and Prevotella bryantii tended to be lower in the most-efficient cows around calving. During the peripartal period, the most-efficient cows had lower enzymatic activities of cellulase, amylase, and protease compared with the least-efficient cows.Conclusions: The results suggest that shifts in ruminal bacteria and digestive enzyme activities during the peripartal period could, at least in part, be part of the mechanism associated with better feed efficiency in dairy cows.展开更多
This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were r...This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were randomly assigned to one of two treatments according to a completely randomized design. Half of the cows were allocated to the HS group in August(summer season), and the other half were assigned to the HS-free group in November(autumn season). HS reduced(P<0.01) dry matter intake(DMI), milk yield, milk protein and milk urea nitrogen(MUN) of cows compared with HSfree control, but increased(P<0.01) milk somatic cell counts(SCC). We determined the HS-induced metabolic alterations and the relevant mechanisms in dairy cows using liquid chromatography mass spectrometry combined with multivariate analyses. Thirty-four metabolites were identified as potential biomarkers for the diagnosis of HS in dairy cows. Ten of these metabolites, glucose, lactate, pyruvate, lactose, β-hydroxybutyrate, citric acid, α-ketoglutarate, urea, creatine, and orotic acid, had high sensitivity and specificity for HS diagnoses, and seven metabolites were also identified as potential biomarkers of HS in plasma, milk, and liver. These substances are involved in glycolysis, lactose, ketone, tricarboxylic acid(TCA), amino acid and nucleotide metabolism, indicating that HS mainly affects lactose, energy and nucleotide metabolism in the mammary gland of lactating dairy cows. This study suggested that HS might affect milk production and composition by affecting the feed intake and substance metabolisms in the mammary gland tissue of lactating dairy cows.展开更多
Background: Residual feed intake(RFI) is an inheritable measure of feed efficiency that is independent on level of production. However, physiological and metabolic mechanisms underlying divergent RFI are not fully elu...Background: Residual feed intake(RFI) is an inheritable measure of feed efficiency that is independent on level of production. However, physiological and metabolic mechanisms underlying divergent RFI are not fully elucidated.This study was conducted to investigate dietary nitrogen(N) partitioning and microbial protein synthesis in lactating dairy cows divergent in phenotypic RFI.Results: Thirty Holstein dairy cows(milk yield = 35.3 ± 4.71 kg/d;milk protein yield = 1.18 ± 0.13 kg/d;mean ± standard deviation) were selected for the experiment to derive RFI. After the RFI measurement period of 50 d, the 10 lowest RFI cows and 8 highest RFI cows were selected. The low RFI cows had lower dry matter intake(DMI, P < 0.05) than the high RFI cows, but they produced similar energy-corrected milk. The ratios of milk to DMI(1.41 vs. 1.24, P < 0.01) and energy-corrected milk to DMI(1.48 vs. 1.36, P < 0.01) were greater in low RFI cows than those in the high RFI cows. The low RFI cows had lower milk urea nitrogen than that in the high RFI cows(P = 0.05). Apparent digestibility of nutrients did not differ between two groups(P > 0.10). Compared with high RFI animals, the low RFI cows had a lower retention of N(5.72 vs. 51.4 g/d, P < 0.05) and a higher partition of feed N to milk N(29.7% vs. 26.5%, P < 0.05).Conclusions: The results suggest that differences in N partition, synthesis of microbial protein, and utilization of metabolizable protein could be part of the mechanisms associated with variance in the RFI.展开更多
In order to further study the postpartum care technology of dairy cows,the effects of oral administration of propylene glycol or Ca-P-Mg mixture and compound oral rehydration salts on milk quality and SCC of dairy cow...In order to further study the postpartum care technology of dairy cows,the effects of oral administration of propylene glycol or Ca-P-Mg mixture and compound oral rehydration salts on milk quality and SCC of dairy cows after birth were investigated. The results showed that the milk fat and dry matter contents in the dairy cows administered with Ca-P-Mg mixture and compound oral rehydration salts were higher than those in the dairy cows administered with propylene glycol（P 〈0.05）. However, there were no significant differences in milk sugar and protein contents and SCC between the two administration groups.展开更多
The aim of this study was to investigate the feasibility of stimulating ovarian fol icle development in order to improve fertility in water buffalo cows by immunization against inhibin. The experiment was carried out ...The aim of this study was to investigate the feasibility of stimulating ovarian fol icle development in order to improve fertility in water buffalo cows by immunization against inhibin. The experiment was carried out in early summer (May) and included 24 multi-parity crossbred Murrah-Swamp buffaloes that were divided into immunized (n=11) and control (n=13) groups. Each immunized cow was administered with a 2-mL immunogen of mineral oil adjuvant containing 2 mg of recombinant inhibinα-subunit fusion protein. The controls were treated with the adjuvant only. Al animals received Ovsynch protocol treatment, starting on the day of the antigen administration, and they were artiifcial y inseminated upon behavioral estrus. As a result, al of the immunized buffaloes generated antibodies against inhibin during the experimental period and had higher plasma concentrations of fol icle-stimulating hormone (FSH), activin, and estradiol (E2) related to estrous expression. A higher proportion of immunized animals expressed estrus behavior than did the controls (72%vs. 30%, P<0.05). On aver-age, inhibin-immunized buffaloes had signiifcantly more large fol icles (≥9 mm in diameter) than the controls (mean±SEM;1.2±0.1 vs. 0.84±0.1, respectively;P<0.05) and a slightly higher mean total number of fol icles (≥2 mm;11.4±0.7 vs. 9.0±1.1, respectively;P=0.09) and smal (2–4 mm) fol icles (8.81±0.6 vs. 6.84±1.0, respectively;P=0.12). A higher percentage of cows ovulated in the immunized group than in the control group (91%(10/11) vs. 54%(7/13), respectively;P<0.05). Moreover, inhibin-immunized cows had slightly larger corpus luteum (CL) than the controls 9 days after ovulation and signiifcantly higher (P<0.01) post-ovulation peak plasma progesterone (P4) concentrations. Immunization against inhibin also mar-ginal y increased the conception rate 42 days after insemination (45.8%vs. 15.4%;P>0.05). These results demonstrate that immunization against inhibin, coupled with the treatment with the Ovsynch protocol, can constitute a new technique to increase fertility in water buffalo cows.展开更多
Background Sustainable strategies for enteric methane(CH_(4))mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure.The present study aimed to in...Background Sustainable strategies for enteric methane(CH_(4))mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure.The present study aimed to investigate the effects of dietary xylooligosaccharides(XOS)and exogenous enzyme(EXE)supplementation on milk production,nutrient digestibility,enteric CH_(4) emissions,energy utilization efficiency of lactating Jersey dairy cows.Forty-eight lactating cows were randomly assigned to one of 4 treatments:(1)control diet(CON),(2)CON with 25 g/d XOS(XOS),(3)CON with 15 g/d EXE(EXE),and(4)CON with 25 g/d XOS and 15 g/d EXE(XOS+EXE).The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period.The enteric CO_(2)and CH_(4) emissions and O2 consumption were measured using two GreenFeed units,which were further used to determine the energy utilization efficiency of cows.Results Compared with CON,cows fed XOS,EXE or XOS+EXE significantly(P<0.05)increased milk yield,true protein and fat concentration,and energy-corrected milk yield(ECM)/DM intake,which could be reflected by the significant improvement(P<0.05)of dietary NDF and ADF digestibility.The results showed that dietary supplementation of XOS,EXE or XOS+EXE significantly(P<0.05)reduced CH_(4) emission,CH_(4)/milk yield,and CH_(4)/ECM.Furthermore,cows fed XOS demonstrated highest(P<0.05)metabolizable energy intake,milk energy output but lowest(P<0.05)of CH_(4) energy output and CH_(4) energy output as a proportion of gross energy intake compared with the remaining treatments.Conclusions Dietary supplementary of XOS,EXE or combination of XOS and EXE contributed to the improvement of lactation performance,nutrient digestibility,and energy utilization efficiency,as well as reduction of enteric CH_(4) emissions of lactating Jersey cows.This promising mitigation method may need further research to validate its long-term effect and mode of action for dairy cows.展开更多
Dry matter intake （DMI） prediction models of NRC （2001）, Fox et aL （2004） and Fuentes-Pila et aL （2003） were targeted in the present study, and the objective was to evaluate their prediction accuracy with feed...Dry matter intake （DMI） prediction models of NRC （2001）, Fox et aL （2004） and Fuentes-Pila et aL （2003） were targeted in the present study, and the objective was to evaluate their prediction accuracy with feeding trial data of 32 lactating Holstein cows fed two total mixed rations with different forage source. Thirty-two cows were randomly assigned to one of two total mixed ration groups： a ration containing a mixed forage （MF） of 3.7% Chinese wildrye, 28.4% alfalfa hay and 26.5% corn silage diet and another ration containing 33.8% corn stover （CS） as unique forage source. The actual DMI was greater in MF group than in CS group （P=0.064）. The NRC model to predict DMI resulted in the lowest root mean square prediction error for both MF and CS groups （1.09 kg d-1 vs. 1.28 kg d-1） and the highest accuracy and precision based on concordance correlation coefficient for both MF and CS diet （0.89 vs. 0.87）. Except the NRC model, the other two models presented mean and linear biases in both MF and CS diets when prediction residuals were plotted against predicted DMI values （P〈0.001）. The DMI variation in MF was caused by week of lactation （55.6%）, milk yield （13.9%）, milk fat percentage （7.1%） and dietary neutral detergent fiber （13.3%）, while the variation in CS was caused by week of lactation （50.9%）, live body weight （28.2%）, milk yield （8.4%）, milk fat percentage （5.2%） and dietary neutral detergent fibre （3.8%）. In a brief, the NRC model to predict DMI is comparatively acceptable for lactating dairy cows fed two total mixed rations with different forage source.展开更多
Background: Corn stover(CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohy...Background: Corn stover(CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohydrate(NFC)might limit the utilization of a CS diet by lactating dairy cows. Thus, this study was conducted to investigate the lactation performance and rumen fermentation characteristics in lactating cows consuming CS with two contents of NFC compared to an alfalfa hay-containing diet. Twelve Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments:(1) low-NFC diet(NFC = 35.6%, L-NFC),(2) high-NFC diet(NFC = 40.1%,H-NFC), and(3) alfalfa hay diet(NFC = 38.9%, AH).Results: Intake of DM was lower for cows fed H-NFC compared to L-NFC and AH, while the milk yield was higher in AH than in H-NFC and L-NFC(P < 0.01). The feed efficiency(milk yield/DM intake, 1.15 vs. 1.08, P < 0.01) were greater for cows fed H-NFC than L-NFC. The contents of milk protein and lactose were not different among the groups(P > 0.11), but milk fat content was higher for cows fed H-NFC and L-NFC compared to AH(P < 0.01). The rumen ammonia nitrogen concentration and the concentrations of urea nitrogen in blood and milk were lower for cows fed H-NFC and AH compared to L-NFC(P < 0.05). The concentrations of rumen propionate and total volatile fatty acids were different among groups(P < 0.05) with higher concentration for cows fed AH compared to H-NFC and L-NFC, and acetate concentration tended to be different among groups(P = 0.06).Conclusions: From the results obtained in this study, it was inferred that the increased NFC content in a diet containing corn stover can improve the feed efficiency and benefit the nitrogen conversion.展开更多
Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolite...Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolites,as well as the host metabolism,contribute to regulating the milk protein yield(MPY).Methods The rumen fluid,serum and milk of 12 Holstein cows with the same diet(45%coarseness ratio),parity(2–3 fetuses)and lactation days(120–150 d)were used for the microbiome and metabolome analysis.Rumen metabolism(rumen metabolome)and host metabolism(blood and milk metabolome)were connected using a weighted gene co-expression network(WGCNA)and the structural equation model(SEM)analyses.Results Two different ruminal enterotypes,with abundant Prevotella and Ruminococcus,were identified as type1 and type2.Of these,a higher MPY was found in cows with ruminal type2.Interestingly,[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae(the differential bacteria)were the hub genera of the network.In addition,differential ruminal,serum and milk metabolome between enterotypes were identified,where the cows with type2 had higher L-tyrosine of rumen,ornithine and L-tryptophan of serum,and tetrahydroneopterin,palmitoyl-L-carnitine,S-lactoylglutathione of milk,which could provide more energy and substrate for MPY.Further,based on the identi-fied modules of ruminal microbiome,as well as ruminal serum and milk metabolome using WGCNA,the SEM analysis indicated that the key ruminal microbial module1,which contains the hub genera of the network([Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae)and high abundance of bacteria(Prevotella and Ruminococcus),could regulate the MPY by module7 of rumen,module2 of blood,and module7 of milk,which contained L-tyrosine and L-tryptophan.Therefore,in order to more clearly reveal the process of rumen bacterial regulation of MPY,we established the path of SEM based on the L-tyrosine,L-tryptophan and related components.The SEM based on the metabolites suggested that[Ruminococcus]gauvreauii group could inhibit the energy supply of serum tryptophan to MPY by milk S-lactoylglutathione,which could enhance pyruvate metabolism.Norank_f_Ruminococcaceae could increase the ruminal L-tyrosine,which could provide the substrate for MPY.Conclusion Our results indicated that the represented enterotype genera of Prevotella and Ruminococcus,and the hub genera of[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae could regulate milk protein synthesis by affecting the ruminal L-tyrosine and L-tryptophan.Moreover,the combined analysis of enterotype,WGCNA and SEM could be used to connect rumen microbial metabolism with host metabolism,which provides a fundamental understanding of the crosstalk between host and microorganisms in regulating the synthesis of milk composition.展开更多
This experiment was conducted to evaluate the effects of Bupleurum extract （BE） on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were rando...This experiment was conducted to evaluate the effects of Bupleurum extract （BE） on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg-1 dry matter. Supplementation with BE decreased （P〈0.05） blood urea nitrogen （BUN） contents and increased blood total protein （TP） and albumin （ALB） levels compared with control cows, but it had no effects （P〉0.05） on blood glucose （GLU）, nonesterified fatty acid （NEFA）, total triglycedde （TG）, low-density lipoprotein cholesterol （LDL-C）, and high density lipoprotein cholesterol （HDL-C）. Compared with control cows, cows fed BE had higher （P〈0.05） superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） activity. However, supplementation with BE had no effect （P〉0.05） on total antioxidant capacity （T-AOC） or malondialdehyde （MDA） levels. The immunoglobulin （Ig） A and G contents increased （P〈0.05） in cows fed 0.25 or 0.5 g of BE kg-1. Interleukin （IL）-2 and IL-4 levels were higher （P〈0.05） in cows fed 0.5 and 1.0 g of BE kg-1, and IL-6 was significantly elevated （P〈0.05） in cows fed 0.5 g of BE kg-1. There were no treatment effects （P〉0.05） on the CD4＋ and CD8＋ T lymphocyte ratios, CD4＋/CD8＋ratio, or tumor necrosis factor-α （TNF-α） level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.展开更多
Background:This study investigated greenhouse gas(GHG)emission characteristics of lactating Holstein dairy cows in East China and provided a basis for formulating GHG emission reduction measures.GreenFeed system was u...Background:This study investigated greenhouse gas(GHG)emission characteristics of lactating Holstein dairy cows in East China and provided a basis for formulating GHG emission reduction measures.GreenFeed system was used to measure the amount of methane(CH_(4))and carbon dioxide(CO_(2))emitted by the cows through respiration.Data from a commercial cow farm were used to observe the effects of parity,body weight,milk yield,and milk component yield on CH_(4) and CO_(2) emissions.Results:Mean herd responses throughout the study were as follows:111 cows completed all experimental processes,while 42 cows were rejected because they were sick or had not visited the GreenFeed system 20 times.On average,lactating days of cows was 138±19.04 d,metabolic weight was 136.5±9.5 kg,parity was 2.8±1.0,dry matter intake(DMI)was 23.1±2.6 kg/d,and milk yield was 38.1±6.9 kg/d.The GreenFeed system revealed that CH_(4) production(expressed in CO_(2) equivalent,CO_(2)-eq)was found to be 8304 g/d,CH_(4)_(CO_(2)−eq)/DMI was 359 g/kg,CH_(4)_(CO_(2)−eq)/energy-corrected milk(ECM)was 229.5 g/kg,total CO_(2) production(CH_(4) production plus CO_(2) production)was 19,201 g/d,total CO_(2)/DMI was 831 g/kg,and total CO_(2)/ECM was 531 g/kg.The parity and metabolic weight of cows had no significant effect on total CO_(2) emissions(P>0.05).Cows with high milk yield,milk fat yield,milk protein yield,and total milk solids yield produced more total CO_(2)(P<0.05),but their total CO_(2) production per kg of ECM was low(P<0.05).The total CO_(2)/ECM of the medium and high milk yield groups was 17%and 27%lower than that of the low milk yield group,respectively.Conclusions:The parity and body condition had no effect on total CO_(2) emissions,while the total CO_(2)/ECM was negatively correlated with milk yield,milk fat yield,milk protein yield,and total milk solids yield in lactating Holstein dairy cows.Measurement of total CO_(2) emissions of dairy cows in the Chinese production system will help establish regional or national GHG inventories and develop mitigation approaches to dairy production regimes.展开更多
基金funded by UK Research and Innovation(UKRI)doctoral training grant no:BB/T008776/1the Department of Agriculture,Environment and Rural Affairs(DAERA)by Trouw Nutrition and by John Thompsons and Sons Ltd.
文摘Background Nitrogen-Use-Efficiency(NUE)in lactating dairy cows,defined as milk nitrogen(N)output as a proportion of N consumed,is low,with the majority of excess N excreted in manure.Excreted N can be lost to the environment as ammonia gas leading to environmental acidification and nutrient enrichment of sensitive habitats,and to watercourses contributing to aquatic eutrophication.While there is much evidence that NUE can be improved by reducing the crude protein(CP)content of dairy cow diets,the long-term impacts of feeding lower protein diets on cow performance and the rumen microbiome are less well understood.This study examined the effects of reducing the CP contents of dairy cow diets on cow performance,NUE,the relationship between NUE and residual feed intake(RFI),and the rumen microbiome.Results Dietary CP content did not affect feed intake,milk yield or milk composition(P>0.05),except for milk urea N(MUN),which increased with increasing diet CP content(P<0.05).The mean NUE was 34%,34%and 31%for the LCP(low-protein,15%),MCP(medium-protein,16%),and HCP(high-protein,17%)diets,respectively.RFI was negatively correlated with NUE(r=−0.57,P<0.001).The rumen ammonia-N concentrations increased with increasing dietary CP;however,the ruminal pH and volatile fatty acid(VFA)content of the rumen fluid remained constant.Predicted urinary N excretion was greater in the HCP and MCP diets than in the LCP diet.Reducing dietary CP content in dairy cow diets did not affect microbial composition,diversity and functional profiles.The family Bacteroidaceae was more abundant in HE(high-efficiency)cows,whereas the Methanobacteriaceae and the genus Methanobrevibacter were more abundant in LE(low-efficiency)cows.Additionally,propanoate metabolism,cysteine and methionine metabolism and amino acid biosynthesis pathways were more abundant in HE cows,whilst the methane(CH4)metabolism pathway was upregulated in LE cows.Conclusions The results demonstrate that diet CP can be reduced with no loss in cow performance,but with an associated reduction in N excretion.The abundance of microbial populations differed between low and high efficiency cows,which may contribute to the differences in efficiency observed.
基金Supported by Science and Technology Development Program of Shijiazhuang City(08150132A)China Spark Program(2012GA6200025)~~
文摘[Objective] The aim of this study was to investigate the efficacy of the herbal feed additive Zengrujianniusan on the milk production of dairy cows. [Method] Thirty-two black-white lactating cows were randomly divided into four groups, and were fed with forage supplemented with 0 （control group）, 0.2%, 0.4% and 0.6% Zengrujianniusan for 60 d. During this period, the contents of fat, protein and non-fat solid in milk were measured every 20 d. [Result] The milk production of the cows whose forage was added with 0.2 %, 0.4 % and 0.6% Zengrujianniusan was 4.02%, 12.50%, 14.00% higher than that of the control （P〉0.05）. The herbal feed additive had no significant influence on the contents of fat, milk and non-fat solid in milk, but significantly reduced the number of somatic cells. [Conclusion] The study will provide reference for developing feed additives which is safe and non-toxic to cows and their milk.
基金supported by Austrian Federal Ministry for Digital and Economic Affairsthe National Foundation for Research,Technology and Developmentsupported using resources of the Vet Core Facility(Mass Spectrometry)of the University of Veterinary Medicine Vienna。
文摘Background The objective was to characterize the colostrum proteome of primiparous Holstein cows in association with immunoglobulin G(IgG)content.Immediately after calving,colostrum samples were collected from 18 cows to measure IgG concentration.Based on colostrum IgG content,samples were classified through cluster analysis and were identified as poor,average,and excellent quality.The proteome was assessed with quantitative shotgun proteomics;abundance data were compared among the colostrum types;enrichment analysis of metabolic processes and proteins classes was performed as well.We also tested correlations between this proteome and blood globulin level of cows and passive immunity level of calves.Results On average,428 proteins were identified per sample,which belonged mainly to cellular process,biological regulation,response to stimulus,metabolic process,and immune system process.Most abundant proteins were complement C3(Q2UVX4),alpha-S1-casein(P02662),Ig-like domain-containing protein(A0A3Q1M032),albumin(A0A140T897),polymeric immunoglobulin receptor(P81265),lactotransferrrin(P24627),and IGHG1*01(X167014).Colostrum of excellent quality had greater(P<0.05)abundance of serpin A3-7(A2I7N3),complement factorl(A0A3Q1 MIF4),lipocalin/cytosolic fatty-acid binding domain-containing protein(A0A3Q1 MRQ2),complement C3(E1B805),complement component 4 binding protein alpha(A0AAF6ZHP5),and complement component C6(F1MM86).However,colostrum of excellent quality had lower(P<0.05)abundance of HGF activator(E1BCW0),alpha-S1-casein(P02662),and xanthine dehydrogenase/oxidase(P80457).This resulted in enrichment of the biological processes predominantly for complement activation alternative pathway,complement activation,complement activation classical pathway,humoral immune response,leukocyte mediated immunity,and negative regulation of endopeptidase activity in excellent-quality colostrum.Additionally,some colostrum proteins were found to be correlated with the blood globulin level of cows and with the passive immunity level of calves(P<0.05;r≥0.57).Conclusions This study provides new insights into the bovine colostrum proteome,demonstrating associations between IgG levels and the abundance of other proteins,as well as the enrichment of metabolic processes related to innate immune response.Thus,results suggest that the colostrum proteomic profile is associated with the content of IgG.Future research should deeply explore the association of these findings with pre-calving nutrition status and blood composition of the cow,and with passive immunity transfer to the calf.
基金supported by the National Center of Technology Innovation for Dairy(No.2024-JSGG-021)the National Natural Science Foundation of China(No.32102570)the Key Research and Development Project of Ningxia(No.2024BBF01006).
文摘Background During the transition period,cows are prone to negative energy balance,which can lead to a decline in production performance and health in severe cases.In recent years,it has been discovered that bile acids(BAs)can act not only as fat emulsifiers but also as signaling molecules to regulate body metabolism.Although BAs have been used to some extent in monogastric and aquatic animals,their role in ruminants,particularly in transition cows,remains unclear.Therefore,this study aimed to determine the effects of BAs on the production performance,milk and plasma fatty acid and BA composition,and fecal microbiota in transition dairy cows.Results Forty-six healthy transition Holstein dairy cows with similar conditions were randomly divided into two groups and supplemented with 0 or 20 g/d of BAs from 21 d before the expected calving to 21 d after calving.The production performance was tracked until 60 d after calving.The results indicated that BA supplementation significantly improved postpartum milk fat content and yields as well as the yields of unsaturated fatty acids,monounsaturated fatty acids,and polyunsaturated fatty acids in milk.There was a significant increase in the concentration of triglyceride and the proportion of C≤16 fatty acids in the plasma of cows supplemented with BAs,while the concentration of β-hydroxybutyrate and the proportion of C>16 fatty acids in the plasma decreased significantly.BA supplementation significantly altered the composition of the fecal bacterial community and increased the relative abundance of bacteria beneficial for BA metabolism and transformation(Romboutsia,Clostridium sensu_stricto_6,and Clostridium sensu_stricto_1).Functional prediction analysis showed that the relative abundance of bile salt hydrolase,7 α-hydroxysteroid dehydrogenase,and BA inducible E as well as the pathways related to BA metabolism also significantly increased in cows supplemented BAs.In addition,BA supplementation significantly altered the composition of plasma and fecal BAs,particularly increasing circulating secondary BA concentration,which might induce the complete oxidation of fatty acids in the liver and further reduce the concentration of β-hydroxybutyrate.Conclusions These findings highlight the potential benefits of BA supplementation in improving milk yields and quality,as well as influencing metabolic pathways in transition dairy cows.Meanwhile,further studies are needed to elucidate the underlying mechanisms and explore the broader implications of these results by using more tissue samples.
基金supported by Bioindustry Technology Development Program (313020041SB010) for Ministry of Agriculture, Food and Rural Affairs, Republic of Korea and Concentrated Research Professor Program for Konkuk University, Seoul, Republic of Korea
文摘Background： Metabolic profile was initially designed as a presymptomatic diagnostic aid based on statistical analyses of blood metabolites to provide an early warning of certain types of metabolic disorder. However, there is little metabolic profile data available about Korean Hanwoo cows. Therefore, this study aimed to determine the reference intervals of metabolic profile for Korean Hanwoo cows. Methods： Healthy animals （2,205） were selected and divided into early （day 1 to 95）, middle （day 96 to 190） and late （day 191 to 285） period according to their gestating period. Metabolic profile including total protein （TP）, albumin （AIb）, urea （UREA）, glucose （Glu）, total cholesterol （T-Cho）, long-chain fatty acid （LCFA）, aspartate aminotransferase （AST）, gamma-glutamyl transpeptidase （GGT）, creatinine （Crea）, calcium （Ca）, inorganic phosphorous （iP） and magnesium （Mg） were analyzed using a TBA-4OFR automatic biochemical analyzer. The data of Korean Hanwoo cows were then compared to those of the Japanese Wagyu cows. Results： Most of the data of the Korean Hanwoo cows were relatively higher than those of Japanese Wagyu cows, with the exception of Glu and GGT. This may indicate that the nutritional level of feed for the Korean Hanwoo cows was higher than that of the Japanese Wagyu cows because of the different feeding system. In particular, relatively higher levels of UREA and LCFA were observed in the Korean Hanwoo cows, and this may also contribute to the low reproduction efficiency. Conclusions： These findings may provide some theoretical basis for understanding the reproductive and feeding situation of Korean Hanwoo cows.
基金supported in part by USDA-NIFA(Washington,DC)grants 2014-68004-21972 and 2015-67015-23207Department of Large Animal Clinical Sciences(East Lansing,MI)+2 种基金the Michigan State University Elwood Kirkpatrick Dairy Science Research Endowment(East Lansing,MI)Michigan Alliance for Animal Agriculture(East Lansing,Michigan)Michigan Animal Health Foundation
文摘Elevated concentrations of plasma fatty acids in transition dairy cows are significantly associated with increased disease susceptibility and poor lactation performance. The main source of plasma fatty acids throughout the transition period is lipolysis from adipose tissue depots. During this time, plasma fatty acids serve as a source of calories mitigating the negative energy balance prompted by copious milk synthesis and limited dry matter intake.Past research has demonstrated that lipolysis in the adipose organ is a complex process that includes not only the activation of lipolytic pathways in response to neural, hormonal, or paracrine stimuli, but also important changes in the structure and cellular distribution of the tissue in a process known as adipose tissue remodeling. This process involves an inflammatory response with immune cell migration, proliferation of the cellular components of the stromal vascular fraction, and changes in the extracellular matrix. This review summarizes current knowledge on lipolysis in dairy cattle, expands on the new field of adipose tissue remodeling, and discusses how these biological processes affect transition cow health and productivity.
基金Project supported by the National Basic Research Program(973)of China(No.2011CB100805)the Modern Agro-Industry Technology Research System of China(No.nycytx-04-01)the Agricultural Science and Technology Innovation Program(No.ASTIP-IAS12),China
文摘Heat stress affects feed intake, milk production, and endocrine status in dairy cows. The temperaturehumidity index（THI） is employed as an index to evaluate the degree of heat stress in dairy cows. However, it is difficult to ascertain whether THI is the most appropriate measurement of heat stress in dairy cows. This experiment was conducted to investigate the effects of heat stress on serum insulin, adipokines（leptin and adiponectin）, AMP-activated protein kinase（AMPK）, and heat shock signal molecules（heat shock transcription factor（HSF） and heat shock proteins（HSP）） in dairy cows and to research biomarkers to be used for better understanding the meaning of THI as a bioclimatic index. To achieve these objectives, two experiments were performed. The first experiment： eighteen lactating Holstein dairy cows were used. The treatments were： heat stress（HS, THI average=81.7, n=9） and cooling（CL, THI average=53.4, n=9）. Samples of HS were obtained on August 16, 2013, and samples of CL were collected on April 7, 2014 in natural conditions. The second experiment： HS treatment cows（n=9） from the first experiment were fed for 8 weeks from August 16, 2013 to October 12, 2013. Samples for moderate heat stress, mild heat stress, and no heat stress were obtained, respectively, according to the physical alterations of the THI. Results showed that heat stress significantly increased the serum adiponectin, AMPK, HSF, HSP27, HSP70, and HSP90（P〈0.05）. Adiponectin is strongly associated with AMPK. The increases of adiponectin and AMPK may be one of the mechanisms to maintain homeostasis in heat-stressed dairy cows. When heat stress treatment lasted 8 weeks, a higher expression of HSF and HSP70 was observed under moderate heat stress. Serum HSF and HSP70 are sensitive and accurate in heat stress and they could be potential indicators of animal response to heat stress. We recommend serum HSF and HSP70 as meaningful biomarkers to supplement the THI and evaluate moderate heat stress in dairy cows in the future.
基金This study was funded by the National Key R&D Program of China(Grant No.2018YFD0500703,2017YFD0701604)Beijing Dairy Industry Innovation Team(bjcystx-ny-1).
文摘Background:Due to the high prevalence and complex etiology,bovine mastitis(BM)is one of the most important diseases to compromise dairy cow health and milk quality.The shift in milk compositions has been widely investigated during mastitis,but recent studies suggested that gastrointestinal microorganism also has a crucial effect on the inflammation of other peripheral tissues and organs,including the mammary gland.However,research focused on the variation of rumen inner-environment during mastitis is still limited.Therefore,the ruminal microbial profiles,metabolites,and milk compositions in cows with different udder health conditions were compared in the present study.Furthermore,the correlations between udder health status and ruminal conditions were investigated.Based on the somatic cell counts(SCC),California mastitis test(CMT)parameters and clinical symptoms of mastitis,60 lactating Holstein dairy cows with similar body conditions(excepted for the udder health condition)were randomly divided into 3 groups(n=20 per group)including the healthy(H)group,the subclinical mastitis(SM)group and the clinical mastitis(CM)group.Lactation performance and rumen fermentation parameters were recorded.And rumen microbiota and metabolites were also analyzed via 16S rRNA amplicon sequencing and untargeted metabolomics,respectively.Results:As the degree of mastitis increased,rumen lactic acid(LA)(P<0.01),acetate,propionate,butyrate,valerate(P<0.001),and total volatile fatty acids(TVFAs)(P<0.01)concentrations were significantly decreased.In the rumen of CM cows,the significantly increased bacteria related to intestinal and oral inflammation,such as Lachnospiraceae(FDR-adjusted P=0.039),Moraxella(FDR-adjusted P=0.011)and Neisseriaceae(FDR-adjusted P=0.036),etc.,were accompanied by a significant increase in 12-oxo-20-dihydroxy-leukotriene B4(FDR-adjusted P=5.97×10^(−9))and 10beta-hydroxy-6beta-isobutyrylfuranoeremophilane(FDR-adjusted P=3.88×10^(−10)).Meanwhile,in the rumen of SM cows,the Ruminiclostridium_9(FDR-adjusted P=0.042)and Enterorhabdus(FDR-adjusted P=0.043)were increased along with increasing methenamine(FDR-adjusted P=6.95×10^(−6)),5-hydroxymethyl-2-furancarboxaldehyde(5-HMF)(FDR-adjusted P=2.02×10^(−6))and 6-methoxymellein(FDR-adjusted P=2.57×10^(−5)).The short-chain fatty acids(SCFAs)-producing bacteria and probiotics in rumen,including Prevoterotoella_1(FDRadjusted P=0.045)and Bifidobacterium(FDR-adjusted P=0.035),etc.,were significantly reduced,with decreasing 2-phenylbutyric acid(2-PBA)(FDR-adjusted P=4.37×10^(−6)).Conclusion:The results indicated that there was a significant shift in the ruminal microflora and metabolites associated with inflammation and immune responses during CM.Moreover,in the rumen of cows affected by SM,the relative abundance of several opportunistic pathogens and the level of metabolites which could produce antibacterial compounds or had a competitive inhibitory effect were all increased.
基金supported by Hatch funds under project ILLU-538-914,National Institute of Food and Agriculture(Washington,DC)
文摘Background: Residual feed intake(RFI) in dairy cattle typically calculated at peak lactation is a measure of feed efficiency independent of milk production level. The objective of this study was to evaluate differences in ruminal bacteria, biopolymer hydrolyzing enzyme activities, and overall performance between the most-and the leastefficient dairy cows during the peripartal period. Twenty multiparous Holstein dairy cows with daily ad libitum access to a total mixed ration from d-10 to d 60 relative to the calving date were used. Cows were classified into most-efficient(i.e. with low RFI, n = 10) and least-efficient(i.e. with high RFI, n = 10) based on a linear regression model involving dry matter intake(DMI), fat-corrected milk(FCM), changes in body weight(BW), and metabolic BW.Results: The most-efficient cows had ~ 2.6 kg/d lower DMI at wk 4, 6, 7, and 8 compared with the least-efficient cows. In addition, the most-efficient cows had greater relative abundance of total ruminal bacterial community during the peripartal period. Compared with the least-efficient cows, the most-efficient cows had 4-fold greater relative abundance of Succinivibrio dextrinosolvens at d-10 and d 10 around parturition and tended to have greater abundance of Fibrobacter succinogenes and Megaspheara elsdenii. In contrast, the relative abundance of Butyrivibrio proteoclasticus and Streptococcus bovis was lower and Succinimonas amylolytica and Prevotella bryantii tended to be lower in the most-efficient cows around calving. During the peripartal period, the most-efficient cows had lower enzymatic activities of cellulase, amylase, and protease compared with the least-efficient cows.Conclusions: The results suggest that shifts in ruminal bacteria and digestive enzyme activities during the peripartal period could, at least in part, be part of the mechanism associated with better feed efficiency in dairy cows.
基金supported financially by the National Key Research and Development Program of China (2016YFD0500503)the Shanghai Science and Technology Promotion Project for Agriculture (Shanghai Agriculture Science Promotion Project (2019) No. 1-2)
文摘This experiment was conducted to investigate the effects of heat stress(HS) on the feed intake, milk production and composition and metabolic alterations in the mammary gland of dairy cows. Twenty Holstein cows were randomly assigned to one of two treatments according to a completely randomized design. Half of the cows were allocated to the HS group in August(summer season), and the other half were assigned to the HS-free group in November(autumn season). HS reduced(P<0.01) dry matter intake(DMI), milk yield, milk protein and milk urea nitrogen(MUN) of cows compared with HSfree control, but increased(P<0.01) milk somatic cell counts(SCC). We determined the HS-induced metabolic alterations and the relevant mechanisms in dairy cows using liquid chromatography mass spectrometry combined with multivariate analyses. Thirty-four metabolites were identified as potential biomarkers for the diagnosis of HS in dairy cows. Ten of these metabolites, glucose, lactate, pyruvate, lactose, β-hydroxybutyrate, citric acid, α-ketoglutarate, urea, creatine, and orotic acid, had high sensitivity and specificity for HS diagnoses, and seven metabolites were also identified as potential biomarkers of HS in plasma, milk, and liver. These substances are involved in glycolysis, lactose, ketone, tricarboxylic acid(TCA), amino acid and nucleotide metabolism, indicating that HS mainly affects lactose, energy and nucleotide metabolism in the mammary gland of lactating dairy cows. This study suggested that HS might affect milk production and composition by affecting the feed intake and substance metabolisms in the mammary gland tissue of lactating dairy cows.
基金supported by grants from the National Natural Science Foundation of China(No.31872380)the China Agricultural Research System(Beijing,China No.CARS-36)
文摘Background: Residual feed intake(RFI) is an inheritable measure of feed efficiency that is independent on level of production. However, physiological and metabolic mechanisms underlying divergent RFI are not fully elucidated.This study was conducted to investigate dietary nitrogen(N) partitioning and microbial protein synthesis in lactating dairy cows divergent in phenotypic RFI.Results: Thirty Holstein dairy cows(milk yield = 35.3 ± 4.71 kg/d;milk protein yield = 1.18 ± 0.13 kg/d;mean ± standard deviation) were selected for the experiment to derive RFI. After the RFI measurement period of 50 d, the 10 lowest RFI cows and 8 highest RFI cows were selected. The low RFI cows had lower dry matter intake(DMI, P < 0.05) than the high RFI cows, but they produced similar energy-corrected milk. The ratios of milk to DMI(1.41 vs. 1.24, P < 0.01) and energy-corrected milk to DMI(1.48 vs. 1.36, P < 0.01) were greater in low RFI cows than those in the high RFI cows. The low RFI cows had lower milk urea nitrogen than that in the high RFI cows(P = 0.05). Apparent digestibility of nutrients did not differ between two groups(P > 0.10). Compared with high RFI animals, the low RFI cows had a lower retention of N(5.72 vs. 51.4 g/d, P < 0.05) and a higher partition of feed N to milk N(29.7% vs. 26.5%, P < 0.05).Conclusions: The results suggest that differences in N partition, synthesis of microbial protein, and utilization of metabolizable protein could be part of the mechanisms associated with variance in the RFI.
基金Supported by Technology Research,Demonstration and Promotion Project of Beijing Vocational College of Agriculture(XY-YF-14-17,XY-YF-14-11)~~
文摘In order to further study the postpartum care technology of dairy cows,the effects of oral administration of propylene glycol or Ca-P-Mg mixture and compound oral rehydration salts on milk quality and SCC of dairy cows after birth were investigated. The results showed that the milk fat and dry matter contents in the dairy cows administered with Ca-P-Mg mixture and compound oral rehydration salts were higher than those in the dairy cows administered with propylene glycol（P 〈0.05）. However, there were no significant differences in milk sugar and protein contents and SCC between the two administration groups.
基金supported by the National Key Technology R&D Program of China (2011BAD19B02-6)the Open Grant of Guangxi Provincial Key Laboratory of Water Buffalo Genetics, Breeding and Reproduction, China (SNKF-2012-04)
文摘The aim of this study was to investigate the feasibility of stimulating ovarian fol icle development in order to improve fertility in water buffalo cows by immunization against inhibin. The experiment was carried out in early summer (May) and included 24 multi-parity crossbred Murrah-Swamp buffaloes that were divided into immunized (n=11) and control (n=13) groups. Each immunized cow was administered with a 2-mL immunogen of mineral oil adjuvant containing 2 mg of recombinant inhibinα-subunit fusion protein. The controls were treated with the adjuvant only. Al animals received Ovsynch protocol treatment, starting on the day of the antigen administration, and they were artiifcial y inseminated upon behavioral estrus. As a result, al of the immunized buffaloes generated antibodies against inhibin during the experimental period and had higher plasma concentrations of fol icle-stimulating hormone (FSH), activin, and estradiol (E2) related to estrous expression. A higher proportion of immunized animals expressed estrus behavior than did the controls (72%vs. 30%, P<0.05). On aver-age, inhibin-immunized buffaloes had signiifcantly more large fol icles (≥9 mm in diameter) than the controls (mean±SEM;1.2±0.1 vs. 0.84±0.1, respectively;P<0.05) and a slightly higher mean total number of fol icles (≥2 mm;11.4±0.7 vs. 9.0±1.1, respectively;P=0.09) and smal (2–4 mm) fol icles (8.81±0.6 vs. 6.84±1.0, respectively;P=0.12). A higher percentage of cows ovulated in the immunized group than in the control group (91%(10/11) vs. 54%(7/13), respectively;P<0.05). Moreover, inhibin-immunized cows had slightly larger corpus luteum (CL) than the controls 9 days after ovulation and signiifcantly higher (P<0.01) post-ovulation peak plasma progesterone (P4) concentrations. Immunization against inhibin also mar-ginal y increased the conception rate 42 days after insemination (45.8%vs. 15.4%;P>0.05). These results demonstrate that immunization against inhibin, coupled with the treatment with the Ovsynch protocol, can constitute a new technique to increase fertility in water buffalo cows.
基金the Key Program for International S&T Cooperation Projects of China(2022YFE0130100)Central Public-interest Scientific Institution Basal Research Fund of Chinese Academy of Agricultural Sciences(Y2022GH12).
文摘Background Sustainable strategies for enteric methane(CH_(4))mitigation of dairy cows have been extensively explored to improve production performance and alleviate environmental pressure.The present study aimed to investigate the effects of dietary xylooligosaccharides(XOS)and exogenous enzyme(EXE)supplementation on milk production,nutrient digestibility,enteric CH_(4) emissions,energy utilization efficiency of lactating Jersey dairy cows.Forty-eight lactating cows were randomly assigned to one of 4 treatments:(1)control diet(CON),(2)CON with 25 g/d XOS(XOS),(3)CON with 15 g/d EXE(EXE),and(4)CON with 25 g/d XOS and 15 g/d EXE(XOS+EXE).The 60-d experimental period consisted of a 14-d adaptation period and a 46-d sampling period.The enteric CO_(2)and CH_(4) emissions and O2 consumption were measured using two GreenFeed units,which were further used to determine the energy utilization efficiency of cows.Results Compared with CON,cows fed XOS,EXE or XOS+EXE significantly(P<0.05)increased milk yield,true protein and fat concentration,and energy-corrected milk yield(ECM)/DM intake,which could be reflected by the significant improvement(P<0.05)of dietary NDF and ADF digestibility.The results showed that dietary supplementation of XOS,EXE or XOS+EXE significantly(P<0.05)reduced CH_(4) emission,CH_(4)/milk yield,and CH_(4)/ECM.Furthermore,cows fed XOS demonstrated highest(P<0.05)metabolizable energy intake,milk energy output but lowest(P<0.05)of CH_(4) energy output and CH_(4) energy output as a proportion of gross energy intake compared with the remaining treatments.Conclusions Dietary supplementary of XOS,EXE or combination of XOS and EXE contributed to the improvement of lactation performance,nutrient digestibility,and energy utilization efficiency,as well as reduction of enteric CH_(4) emissions of lactating Jersey cows.This promising mitigation method may need further research to validate its long-term effect and mode of action for dairy cows.
基金financially supported by the National Natural Science Foundation of China(31572435)the National Key Research and Development Plan(2016YFD0700205,2016YFD0700201)
文摘Dry matter intake （DMI） prediction models of NRC （2001）, Fox et aL （2004） and Fuentes-Pila et aL （2003） were targeted in the present study, and the objective was to evaluate their prediction accuracy with feeding trial data of 32 lactating Holstein cows fed two total mixed rations with different forage source. Thirty-two cows were randomly assigned to one of two total mixed ration groups： a ration containing a mixed forage （MF） of 3.7% Chinese wildrye, 28.4% alfalfa hay and 26.5% corn silage diet and another ration containing 33.8% corn stover （CS） as unique forage source. The actual DMI was greater in MF group than in CS group （P=0.064）. The NRC model to predict DMI resulted in the lowest root mean square prediction error for both MF and CS groups （1.09 kg d-1 vs. 1.28 kg d-1） and the highest accuracy and precision based on concordance correlation coefficient for both MF and CS diet （0.89 vs. 0.87）. Except the NRC model, the other two models presented mean and linear biases in both MF and CS diets when prediction residuals were plotted against predicted DMI values （P〈0.001）. The DMI variation in MF was caused by week of lactation （55.6%）, milk yield （13.9%）, milk fat percentage （7.1%） and dietary neutral detergent fiber （13.3%）, while the variation in CS was caused by week of lactation （50.9%）, live body weight （28.2%）, milk yield （8.4%）, milk fat percentage （5.2%） and dietary neutral detergent fibre （3.8%）. In a brief, the NRC model to predict DMI is comparatively acceptable for lactating dairy cows fed two total mixed rations with different forage source.
基金financially supported by the China Agriculture(Dairy)Research System(CARS-36)
文摘Background: Corn stover(CS) is an abundant source of feed for livestock in China. However, it is low in nutritional value that we have been seeking technologies to improve. Previous studies show that non-fiber carbohydrate(NFC)might limit the utilization of a CS diet by lactating dairy cows. Thus, this study was conducted to investigate the lactation performance and rumen fermentation characteristics in lactating cows consuming CS with two contents of NFC compared to an alfalfa hay-containing diet. Twelve Holstein cows were used in a replicated 3 × 3 Latin square design with three dietary treatments:(1) low-NFC diet(NFC = 35.6%, L-NFC),(2) high-NFC diet(NFC = 40.1%,H-NFC), and(3) alfalfa hay diet(NFC = 38.9%, AH).Results: Intake of DM was lower for cows fed H-NFC compared to L-NFC and AH, while the milk yield was higher in AH than in H-NFC and L-NFC(P < 0.01). The feed efficiency(milk yield/DM intake, 1.15 vs. 1.08, P < 0.01) were greater for cows fed H-NFC than L-NFC. The contents of milk protein and lactose were not different among the groups(P > 0.11), but milk fat content was higher for cows fed H-NFC and L-NFC compared to AH(P < 0.01). The rumen ammonia nitrogen concentration and the concentrations of urea nitrogen in blood and milk were lower for cows fed H-NFC and AH compared to L-NFC(P < 0.05). The concentrations of rumen propionate and total volatile fatty acids were different among groups(P < 0.05) with higher concentration for cows fed AH compared to H-NFC and L-NFC, and acetate concentration tended to be different among groups(P = 0.06).Conclusions: From the results obtained in this study, it was inferred that the increased NFC content in a diet containing corn stover can improve the feed efficiency and benefit the nitrogen conversion.
基金the National Natural Science Foundation of China(32272829,32072761,31902184)Shaanxi Provincial Science and Technology Association Young Talents Lifting Program Project(20220203).
文摘Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolites,as well as the host metabolism,contribute to regulating the milk protein yield(MPY).Methods The rumen fluid,serum and milk of 12 Holstein cows with the same diet(45%coarseness ratio),parity(2–3 fetuses)and lactation days(120–150 d)were used for the microbiome and metabolome analysis.Rumen metabolism(rumen metabolome)and host metabolism(blood and milk metabolome)were connected using a weighted gene co-expression network(WGCNA)and the structural equation model(SEM)analyses.Results Two different ruminal enterotypes,with abundant Prevotella and Ruminococcus,were identified as type1 and type2.Of these,a higher MPY was found in cows with ruminal type2.Interestingly,[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae(the differential bacteria)were the hub genera of the network.In addition,differential ruminal,serum and milk metabolome between enterotypes were identified,where the cows with type2 had higher L-tyrosine of rumen,ornithine and L-tryptophan of serum,and tetrahydroneopterin,palmitoyl-L-carnitine,S-lactoylglutathione of milk,which could provide more energy and substrate for MPY.Further,based on the identi-fied modules of ruminal microbiome,as well as ruminal serum and milk metabolome using WGCNA,the SEM analysis indicated that the key ruminal microbial module1,which contains the hub genera of the network([Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae)and high abundance of bacteria(Prevotella and Ruminococcus),could regulate the MPY by module7 of rumen,module2 of blood,and module7 of milk,which contained L-tyrosine and L-tryptophan.Therefore,in order to more clearly reveal the process of rumen bacterial regulation of MPY,we established the path of SEM based on the L-tyrosine,L-tryptophan and related components.The SEM based on the metabolites suggested that[Ruminococcus]gauvreauii group could inhibit the energy supply of serum tryptophan to MPY by milk S-lactoylglutathione,which could enhance pyruvate metabolism.Norank_f_Ruminococcaceae could increase the ruminal L-tyrosine,which could provide the substrate for MPY.Conclusion Our results indicated that the represented enterotype genera of Prevotella and Ruminococcus,and the hub genera of[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae could regulate milk protein synthesis by affecting the ruminal L-tyrosine and L-tryptophan.Moreover,the combined analysis of enterotype,WGCNA and SEM could be used to connect rumen microbial metabolism with host metabolism,which provides a fundamental understanding of the crosstalk between host and microorganisms in regulating the synthesis of milk composition.
基金supported financially by the National Key Research and Development Program of China (2016YFD0500503)the Agricultural Science and Technology Innovation Program, China (ASTIP-IAS12)the Anhui International Science and Technology Cooperation Plan Program, China (1503062019)
文摘This experiment was conducted to evaluate the effects of Bupleurum extract （BE） on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg-1 dry matter. Supplementation with BE decreased （P〈0.05） blood urea nitrogen （BUN） contents and increased blood total protein （TP） and albumin （ALB） levels compared with control cows, but it had no effects （P〉0.05） on blood glucose （GLU）, nonesterified fatty acid （NEFA）, total triglycedde （TG）, low-density lipoprotein cholesterol （LDL-C）, and high density lipoprotein cholesterol （HDL-C）. Compared with control cows, cows fed BE had higher （P〈0.05） superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） activity. However, supplementation with BE had no effect （P〉0.05） on total antioxidant capacity （T-AOC） or malondialdehyde （MDA） levels. The immunoglobulin （Ig） A and G contents increased （P〈0.05） in cows fed 0.25 or 0.5 g of BE kg-1. Interleukin （IL）-2 and IL-4 levels were higher （P〈0.05） in cows fed 0.5 and 1.0 g of BE kg-1, and IL-6 was significantly elevated （P〈0.05） in cows fed 0.5 g of BE kg-1. There were no treatment effects （P〉0.05） on the CD4＋ and CD8＋ T lymphocyte ratios, CD4＋/CD8＋ratio, or tumor necrosis factor-α （TNF-α） level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.
基金funded by the Central Public-interest Scientific Institution Basal Research Fund of Chinese Academy of Agricultural Sciences(No.Y2022GH12)the Agricultural Science and Technology Innovation Program(CAAS-ASTIP-2017-FRI-04).
文摘Background:This study investigated greenhouse gas(GHG)emission characteristics of lactating Holstein dairy cows in East China and provided a basis for formulating GHG emission reduction measures.GreenFeed system was used to measure the amount of methane(CH_(4))and carbon dioxide(CO_(2))emitted by the cows through respiration.Data from a commercial cow farm were used to observe the effects of parity,body weight,milk yield,and milk component yield on CH_(4) and CO_(2) emissions.Results:Mean herd responses throughout the study were as follows:111 cows completed all experimental processes,while 42 cows were rejected because they were sick or had not visited the GreenFeed system 20 times.On average,lactating days of cows was 138±19.04 d,metabolic weight was 136.5±9.5 kg,parity was 2.8±1.0,dry matter intake(DMI)was 23.1±2.6 kg/d,and milk yield was 38.1±6.9 kg/d.The GreenFeed system revealed that CH_(4) production(expressed in CO_(2) equivalent,CO_(2)-eq)was found to be 8304 g/d,CH_(4)_(CO_(2)−eq)/DMI was 359 g/kg,CH_(4)_(CO_(2)−eq)/energy-corrected milk(ECM)was 229.5 g/kg,total CO_(2) production(CH_(4) production plus CO_(2) production)was 19,201 g/d,total CO_(2)/DMI was 831 g/kg,and total CO_(2)/ECM was 531 g/kg.The parity and metabolic weight of cows had no significant effect on total CO_(2) emissions(P>0.05).Cows with high milk yield,milk fat yield,milk protein yield,and total milk solids yield produced more total CO_(2)(P<0.05),but their total CO_(2) production per kg of ECM was low(P<0.05).The total CO_(2)/ECM of the medium and high milk yield groups was 17%and 27%lower than that of the low milk yield group,respectively.Conclusions:The parity and body condition had no effect on total CO_(2) emissions,while the total CO_(2)/ECM was negatively correlated with milk yield,milk fat yield,milk protein yield,and total milk solids yield in lactating Holstein dairy cows.Measurement of total CO_(2) emissions of dairy cows in the Chinese production system will help establish regional or national GHG inventories and develop mitigation approaches to dairy production regimes.
