Background Nursery pigs undergo stressors in the post-weaning period that result in production and welfare chal-lenges.These challenges disproportionately impact the offspring of primiparous sows compared to those of ...Background Nursery pigs undergo stressors in the post-weaning period that result in production and welfare chal-lenges.These challenges disproportionately impact the offspring of primiparous sows compared to those of mul-tiparous counterparts.Little is known regarding potential interactions between parity and feed additives in the post-weaning period and their effects on nursery pig microbiomes.Therefore,the objective of this study was to investigate the effects of maternal parity on sow and offspring microbiomes and the influence of sow parity on pig fecal microbi-ome and performance in response to a prebiotic post-weaning.At weaning,piglets were allotted into three treat-ment groups:a standard nursery diet including pharmacological doses of Zn and Cu(Con),a group fed a commercial prebiotic only(Preb)based on an Aspergillus oryzae fermentation extract,and a group fed the same prebiotic plus Zn and Cu(Preb+ZnCu).Results Although there were no differences in vaginal microbiome composition between primiparous and mul-tiparous sows,fecal microbiome composition was different(R^(2)=0.02,P=0.03).The fecal microbiomes of primiparous offspring displayed significantly higher bacterial diversity compared to multiparous offspring at d 0 and d 21 post-weaning(P<0.01),with differences in community composition observed at d 21(R^(2)=0.03,P=0.04).When analyzing the effects of maternal parity within each treatment,only the Preb diet triggered significant microbiome distinc-tions between primiparous and multiparous offspring(d 21:R^(2)=0.13,P=0.01;d 42:R^(2)=0.19,P=0.001).Composi-tional differences in pig fecal microbiomes between treatments were observed only at d 21(R^(2)=0.12,P=0.001).Pigs in the Con group gained significantly more weight throughout the nursery period when compared to those in the Preb+ZnCu group.Conclusions Nursery pig gut microbiome composition was influenced by supplementation with an Aspergillus oryzae fermentation extract,with varying effects on performance when combined with pharmacological levels of Zn and Cu or for offspring of different maternal parity groups.These results indicate that the development of nursery pig gut microbiomes is shaped by maternal parity and potential interactions with the effects of dietary feed additives.展开更多
This paper summarizes the current knowledge regarding the possible modes of action and nutritional factors involved in the use of essential oils （EOs） for swine and poultry. EOs have recently attracted increased int...This paper summarizes the current knowledge regarding the possible modes of action and nutritional factors involved in the use of essential oils （EOs） for swine and poultry. EOs have recently attracted increased interest as feed additives to be fed to swine and poultry, possibly replacing the use of antibiotic growth promoters which have been prohibited in the European Union since 2006. In general, EOs enhance the production of digestive secretions and nutrient absorption, reduce pathogenic stress in the gut, exert antioxidant properties and reinforce the animal＇s immune status, which help to explain the enhanced performance observed in swine and poultry. However, the mechanisms involved in causing this growth promotion are far from being elucidated, since data on the complex gut ecosystem, gut function, in vivo oxidative status and immune system are still lacking. In addition, limited information is available regarding the interaction between EOs and feed ingredients or other feed additives （especially pro- or prebiotics and organic acids）. This knowledge may help feed formulators to better utilize EOs when they formulate diets for poultry and swine.展开更多
Feed security is a prerequisite for safe animal food products.In this study,13 groups of feed and feed ingredients,totaling 2067 samples,were collected in the period of 2011 to 2014 from China.The highest mean level o...Feed security is a prerequisite for safe animal food products.In this study,13 groups of feed and feed ingredients,totaling 2067 samples,were collected in the period of 2011 to 2014 from China.The highest mean level of polychlorinated dibenzo-p-dioxins and dibenzofurans（PCDD/Fs） was found in fish meals and shell powders,with a concentration of 60.35 ng/kg,followed by mineral origin materials.In terms of the toxicity equivalent concentration,the fish oil group showed the highest PCDD/F levels because of their bio-accumulation through the aquatic food chain,with an average concentration of 1.26 ng WHO-TEQ/kg,while the lowest level was observed in compound feed for chickens and pigs,with an average value of0.16 ng WHO-TEQ/kg.OCDD and OCDF were the predominant congeners in all groups except fish oils,in which the primary congeners were 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF.For zinc chloride samples,different from other zinc-based compound samples,the main congeners were 1,2,3,4,6,7,8-HpCDF（17%）,1,2,3,4,7,8,9-HpCDF（15%）,1,2,3,4,7,8-HxCDF（12%） and OCDF（30%）.Considering toxicity equivalency factors,the dominant congeners were 2,3,4,7,8-PeCDF,1,2,3,4,7,8-HxCDF,2,3,7,8-TCDF and 1,2,3,7,8-PeCDD,and the contribution to the total TEQwas29%,16%,14%and 12%,respectively.Overall,2.1%（43 out of 2067） of all the analyzed samples exceeded the different individual ＇European Union maximum limited levels for PCDD/Fs.This study is beneficial for the determination of the status of contamination levels of feed and feed ingredients.展开更多
Background:This study was conducted to investigate the effects of each phytogenic feed additive(PFA;PFA1,bitter citrus extract;PFA2,a microencapsulated blend of thymol and carvacrol;PFA3,a mixture of bitter citrus ext...Background:This study was conducted to investigate the effects of each phytogenic feed additive(PFA;PFA1,bitter citrus extract;PFA2,a microencapsulated blend of thymol and carvacrol;PFA3,a mixture of bitter citrus extract,thymol,and carvacrol;PFA4,a premixture of grape seed,grape marc extract,green tea,and hops;PFA5,fenugreek seed powder)on the growth performance,nutrient digestibility,intestinal morphology,and immune response in weaned pigs infected with Escherichia coli(E.coli).Results:A total of 634-week-old weaned pigs were placed in individual metabolic cages and assigned to seven treatment groups.The seven treatments were as follows:1)NC;basal diet without E.coli challenge,2)PC;basal diet with E.coli challenge,3)T1;PC+0.04%PFA1,4)T2;PC+0.01%PFA2,5)T3;PC+0.10%PFA3,6)T4;PC+0.04%PFA4,7)T5;PC+0.10%PFA5.The experiments lasted in 21 d,including 7 d before and 14 d after the first E.coli challenge.In the E.coli challenge treatments,all pigs were orally inoculated by dividing a total of 10 mL of E.coli F18 for 3 consecutive days.The PFA-added groups significantly increased(P<0.05)average daily gain and feed efficiency and decreased(P<0.05)the fecal score at d 0 to 14 post-inoculation(PI).Tumor necrosis factorαwas significantly lower(P<0.05)in the PFA-added groups except for T1 in d 14 PI compared to the PC treatment.The T3 had a higher(P<0.05)immunoglobulin G and immunoglobulin A concentration compared to the PC treatment at d 7 PI.Also,T3 showed significantly higher(P<0.05)villus height:crypt depth and claudin 1 expression in ileal mucosa,and significantly downregulated(P<0.05)the expression of calprotectin compared to the PC treatment.Conclusions:Supplementation of PFA in weaned pigs challenged with E.coli alleviated the negative effects of E.coli and improved growth performance.Among them,the mixed additive of bitter citrus extract,thymol,and carvacrol showed the most effective results,improving immune response,intestinal morphology,and expression of tight junctions.展开更多
[ Objectivel To investigate the effects of three different levels of feed additives on fur production performance of Rex rabbit. [ Method] A total of 60 healthy American strain Rex rabbits at the age of 60 d （female...[ Objectivel To investigate the effects of three different levels of feed additives on fur production performance of Rex rabbit. [ Method] A total of 60 healthy American strain Rex rabbits at the age of 60 d （female：male =1：1 ） were randomly divided into group I, group II and group III. The Rex rabbits in the group I were fed basal diet containing nutritional substances; those in the group II were fed basal diet containing nutdtionai substances and Chinese herbal additive; and those in the group III were fed basal diet containing nutritional substances, Chinese herbal additive and enzyme. The trial lasted for 100 d. After slaughtering, the fur area, fur thickness, wool density, wool fineness and coarse wool rate were determined. [Result] The fur production performance of group III was significantly higher than that of group I （ P 〈 0.05）. There was no significant difference between group III and group II. [ Conclusion] Supplementing Chinese herbal additive and enzyme in diet can improve the fur production performance of Rex rabbit.展开更多
The Camellia oleifera meal(COM),a primary byproduct of oil-tea processing,often being discarded or used as a low-grade fertilizer due to its low value.The underutilization has become a significant bottleneck hindering...The Camellia oleifera meal(COM),a primary byproduct of oil-tea processing,often being discarded or used as a low-grade fertilizer due to its low value.The underutilization has become a significant bottleneck hindering the high-quality development of the oil-tea industry.In this study,the production of antibiotic-free feed additives through the solid-state fermentation of COM by Acremonium terricola was investigated.Our findings revealed that a saponin concentration of 5 mg/mL significantly enhanced the production of cordycepic acid(70.4 mg/g),ergosterol(3.32 mg/g),and chitin(110 mg/g)by A.terricola.This concentration also promoted chitin production and the activities of peroxidase(POD)and Na+/K+-ATPase,thereby maintaining cellular homeostasis and energy balance in A.terricola.Solid-state fermented rice bran(RB),wheat bran(WB),and desaponificated COM(containing 2.6 mg/100 g of tea saponin)were all found to be beneficial for increasing the production of cordycepic acid and ergosterol.The blend of COM,RB,and WB in the ratio of 15:65:20 was particularly advantageous for the production and accumulation of cordycepic acid and ergosterol,yielding 1.54 and 1.43 times,1.27 and 1.37 times,and 1.98 and 5.52 times more than those produced by WB,RB,and COM alone,respectively.Meantime,the difference in contents of sugar and protein in A.terricola cultures(ATCs)using combination were not significant compared to RB and WB.These results indicated that COM can partially replace foodstuffs or food by-products to prepare antibiotic-free feed additives by A.terricola.展开更多
The use of antibiotics in animal production raises great public safety concerns;therefore,there is an urgent need for the development of substitutes for antibiotics.In recent decades,plant-derived feed additives have ...The use of antibiotics in animal production raises great public safety concerns;therefore,there is an urgent need for the development of substitutes for antibiotics.In recent decades,plant-derived feed additives have been widely investigated as antibiotic alternatives for use in animal health and production because they exert multiple biological functions and are less likely to induce resistance development.This review summarizes the research history and classification of phytogenic feed additives and their main functions,potential modes of action,influencing factors,and potential negative effects.Further,we highlight the challenges in developing sustainable,safe,and affordable plant-derived antibiotic alter-natives for use in livestock production.展开更多
In vitro model provides alternatives to the use of live animals in research.In pig nutrition,there has been a tremendous increase in in vivo research over the decades.Proper utilization of in vitro models could provid...In vitro model provides alternatives to the use of live animals in research.In pig nutrition,there has been a tremendous increase in in vivo research over the decades.Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies,research duration,cost,and the use of animals and feeds.This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives.Seven feedstuffs(corn,corn distillers dried grains with solubles[corn DDGS],barley,wheat,soybean meal,soy protein concentrates,and Corynebacterium glutamicum cell mass[CGCM]),feed enzymes(xylanase and phytase),and supplemental amino acids(arginine,methionine,and tryptophan),were used in this in vitro evaluation for their efficacy on digestibility,digesta characteristics,and intestinal health compared with the results from previously published in vivo studies.All in vitro evaluations were triplicated.Data were analyzed using Mixed procedure of SAS9.4.Evaluations included(1)nutrient di-gestibility of feedstuffs,(2)the effects of feed enzymes,xylanase and phytase,on digestibility of feed-stuffs and specific substrates,and(3)the effects of amino acids,arginine,tryptophan,and methionine,on anti-inflammatory,anti-oxidative,and anti-heat stress statuses showing their effects(P<0.05)on the measured items.Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected(P<0.05),including xylo-oligosaccharide profiles and phosphorus release from phytate.Supplementation of arginine,tryptophan,and methionine modulated(P<0.05)cellular inflammatory and oxidative stress responses.The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P<0.05.This indicates in vitro models can have increased precision and consistency compared with in vivo animal studies.展开更多
Background Post-weaning diarrhea(PWD)in piglets,often caused by F4^(+)enterotoxigenic Escherichia coli(ETEC),poses significant challenges in pig production.Traditional solutions like antibiotics and zinc oxide face in...Background Post-weaning diarrhea(PWD)in piglets,often caused by F4^(+)enterotoxigenic Escherichia coli(ETEC),poses significant challenges in pig production.Traditional solutions like antibiotics and zinc oxide face increasing restrictions due to growing concerns over antibiotic resistance and environmental sustainability.This study investigates the application of bivalent heavy chain variable domain(V_(H)H)constructs(BL1.2 and BL2.2)targeting ETEC virulence factors,administered in feed to mitigate ETEC-induced PWD in weaned piglets.Results The supplementation of BL1.2 and BL2.2 in both mash and pelleted feed significantly reduced the diarrhea incidence and fecal shedding of F4^(+)ETEC in challenged piglets.Pelleted feed containing V_(H)H constructs helped to preserve gut barrier integrity by maintaining levels of the tight junction protein occludin in the small intestine.Additionally,the constructs maintained blood granulocyte counts at a similar level to the non-challenged control group,including neutrophils,and ameliorated the acute phase protein response after challenge.Notably,even at low feed intake immediately after weaning,V_(H)H constructs helped maintain piglet health by mitigating ETEC-induced inflammation and the resulting diarrhea.Conclusions Our findings demonstrated that using V_(H)H constructs as feed additives could serve as an effective strategy to help manage ETEC-associated PWD,by reducing F4^(+)ETEC gut colonization and supporting gut barrier function of weaned piglets.The high stability of these V_(H)H constructs supports their incorporation into industrial feed manufacturing processes,offering a more sustainable preventive strategy compared to traditional antimicrobial interventions,which could contribute to sustainable farming practices.展开更多
Background Isoacids are the product of branched-chain amino acid fermentation and are naturally producedin the hindgut by microbial fermentation. In ruminants, supplementation of isoacids as a feed additive improvesfi...Background Isoacids are the product of branched-chain amino acid fermentation and are naturally producedin the hindgut by microbial fermentation. In ruminants, supplementation of isoacids as a feed additive improvesfiber utilization, with a positive impact on animal productivity. However, information on how isoacids impact nutrientdigestibility in swine is limited. The objective of this experiment was to determine the optimal inclusion levelof an isoacid blend product based on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD)of nutrients and fermentation products in the ileal digesta and feces of growing pigs fed a corn-soybean meal diet.Methods Twelve ileal cannulated pigs (20.9 ± 0.6 kg) were used in a 5-period crossover design with 6 diets and 2replicate pigs in each period. Dietary treatments consisted of increasing levels (0%, 0.5%, 0.75%, 1%, 1.25%, and 1.5%)of an isoacid blend (isobutyrate, isovalerate, and 2-methyl butyrate, 1:1:1) added to a corn-soybean meal basal diet.Each experimental period consisted of 14 d: 10 d for acclimatization to the diets, 2 d for fecal collection, and 2 dfor digesta collection.Results Isoacids supplementation quadratically improved the AID of hemicellulose (P < 0.05) and tended to improvethe AID of crude fiber (P < 0.1). The AID of most indispensable amino acids (except Met + Cys, Trp, and Val) as wellas the ATTD of crude protein, gross energy, neutral detergent fiber, and hemicellulose improved or tended to improvelinear or quadratically (P < 0.05 or P < 0.1). In addition, the ATTD values of Arg, His, Ile, Leu, Met + Cys, Phe, Thr, and Valincreased quadratically (P < 0.05). Collectively, 1% of isoacids inclusion resulted in the greatest response. Furthermore,isoacids supplementation tended to increase (P = 0.071, quadratically) the concentration of ammonia and decreased(P < 0.05) the concentrations of acetic acid and total volatile fatty acids with a tendency to decrease (P = 0.064) isovalericacid in the ileal digesta. In fecal samples, the proportion of acetic acid decreased (P < 0.05) quadratically, whereas the proportionsof propionic, valeric, and caproic acids tended to increase linearly and/or quadratically (P < 0.1).Conclusions Isoacids supplementation at 1% in swine diets can improve nutrient digestibility, particularly aminoacids and fiber at the ileal level and ATTD of crude protein, gross energy, and hemicellulose.展开更多
[ Objective] The aim of this study was to provide a theoretical basis for population and application of Chinese herbal feed additive in the rex rabbit breeding. [ Methyl] 108 weaned -rex rabbits aged 40 days were divi...[ Objective] The aim of this study was to provide a theoretical basis for population and application of Chinese herbal feed additive in the rex rabbit breeding. [ Methyl] 108 weaned -rex rabbits aged 40 days were divided into three groups with thirty -six each group. Group A were fed basal diet, while group B were fed basal diet supplemented with 0.3% Chinese herbal feed additive and group C were fed basal diet supplemented with 0.4% Chinese herbal feed additive. The meat quality indexes were measured when feeding to 150 age in days. [ Result] There was significant difference among pH value, water loss rate, storing loss rate and crude protein content in each group （P〈0.05）, but no significant difference was found in tenderness, cooking percentage, moisture content and crude fat content （ P 〉 0.05）. The total content of ami- no acids, essential amino acids and semi essential amino acids as well as main delicious amino acids was highest in group C accounting for 23.84%, 11.47% and 8.32% respectively, next came group B accounting for 20.94%, 10.64% and 6.81% respectively, and lowest in group C （ control group） accounting for 19.06%, 9.61% and 6.46% respectively. [ Conclusion] The Chinese herbal feed additive can improve meat quality of rex rabbit the best addition of 0.4%.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
At Baiyin dairy farm, the Chinese herbal additive was added into feed which was then fed to dairy cows from August to October, 2014, and the changes in milk production and quality were observed. The test showed that t...At Baiyin dairy farm, the Chinese herbal additive was added into feed which was then fed to dairy cows from August to October, 2014, and the changes in milk production and quality were observed. The test showed that the additive added into the feed had obvious milk-increasing effect, the milk production was im- proved by 12.67%-17.26%, and the milk quality was improved. The additive has the effects of preventing miscarriage, expelling parasite and preventing diseases. The nutritional components in the feed additive were determined, and the results showed that the contents of protein, crude fat, Ca and P in the additive were 12.29%, 2.66%, 1.8% and 0.22%, respectively.展开更多
Background Maintaining intestinal health is crucial for the overall well-being and productivity of livestock,as it impacts nutrient absorption,immune function,and disease resistance.Oxidative stress and inflammation a...Background Maintaining intestinal health is crucial for the overall well-being and productivity of livestock,as it impacts nutrient absorption,immune function,and disease resistance.Oxidative stress and inflammation are key threats to intestinal integrity.This study explored the antioxidant,anti-inflammatory,and barrier-strengthening properties of a fermented plant macerate(FPM)derived from 45 local herbs,using a specifically developed fermentation process utilizing the plants'inherent microbiota to enhance bioactivity and sustainability.Results In vitro experiments with IPEC-J2 cells showed that FPM significantly reduced intracellular reactive oxygen species(ROS)levels,improved barrier integrity,and enhanced cell migration under stress.Similar antioxidant effects were observed in THP-1 macrophages,where FPM reduced ROS production and modulated inflammatory responses by decreasing pro-inflammatory cytokines[tumor necrosis factor alpha(TNF-α),monokine induced by gamma interferon(MIG),interferon-inducible T cell alpha chemoattractant(I-TAC),macrophage inflammatory proteins(MIP)-1αand-1β]and increasing anti-inflammatory interleukin(IL)-10 levels.Mechanistic studies with HEK-Blue reporter cell lines revealed that FPM inhibited nuclear factor kappa B(NF-κB)activation via a toll-like receptor(TLR)4-independent pathway.In vivo,FPM significantly reduced ROS levels in Drosophila melanogaster and improved activity and LT50 values in Caenorhabditis elegans under oxidative stress,although it did not affect intestinal barrier integrity in these models.Conclusion The findings indicate that FPM shows promising application as a functional feed supplement for improving intestinal health in livestock by mitigating oxidative stress and inflammation.Further studies,including livestock feeding trials,are recommended to validate these results.展开更多
Slow-release non-protein nitrogen feed has a large market demand. It has a long research history, but its production technology needs further improvement in order to realize the industrial production of slow-release n...Slow-release non-protein nitrogen feed has a large market demand. It has a long research history, but its production technology needs further improvement in order to realize the industrial production of slow-release non-protein nitrogen extruded feed. By designing the best formula and using chelating and emulsifying process, the slow-release non-protein nitrogen extruded feed additives were produced. This product increases milk yield and improves milk quality, thus increasing economic efficiency.展开更多
Yeast culture is a kind of green feed additive. It has been researched and applied widely in the feed industry. In this paper, the functions of yeast culture and its application in the actual production were discussed...Yeast culture is a kind of green feed additive. It has been researched and applied widely in the feed industry. In this paper, the functions of yeast culture and its application in the actual production were discussed. It can be concluded that yeast culture has a great application prospect.展开更多
Coarse columnar β grains result in anisotropic mechanical properties in Ti alloys deposited by additive manufacturing. This study reports that Ti-6Al-4V alloy fabricated by coaxial electron beam wire feeding additive...Coarse columnar β grains result in anisotropic mechanical properties in Ti alloys deposited by additive manufacturing. This study reports that Ti-6Al-4V alloy fabricated by coaxial electron beam wire feeding additive manufacturing presents a weak anisotropy, high strength and ductility. The superior tensile property arises from a microstructure with fine equiaxed β grains(EGβ), discontinuous grain boundary α phase and short intragranular α lamellae. A large region of fine EGβ arises from a special combination of the temperature gradient and solidification rate, and attractive α morphology is caused by solid phase transformations during interpass thermal cycling and post heat treatments.展开更多
[Objectives]To explore the effects of nano compound Chinese herbal medicine feed additive on growth performance,meat quality and disease resistance of chickens.[Methods]Chickens were fed with nano compound Chinese her...[Objectives]To explore the effects of nano compound Chinese herbal medicine feed additive on growth performance,meat quality and disease resistance of chickens.[Methods]Chickens were fed with nano compound Chinese herbal medicine feed additive developed by Hunan Polytechnic of Environment and Biology,including 120 chickens in the treatment group and 120 chickens in the control group(CK).The growth performance indices(body weight gain,feed to gain ratio and slaughter index),meat quality indices(pH value,color,drip loss,shear force)and disease resistance indices(morbidity and mortality)of the chickens in the treatment and CK groups were recorded and determined,respectively.[Results]The inclusion of 2%nano compound Chinese herbal medicine feed additive in the diet significantly increased the growth rate,reduced the feed-to-gain ratio and improved the meat quality of the chickens.Supplementing Chinese herbal medicine could increase the pH value and reduce the drip loss and shear force of chicken meat.At the same time,the body's immune function,antioxidant level and resistance against diseases of the chickens fed with nano compound Chinese herbal medicine feed additive were improved.[Conclusions]The inclusion of nano compound Chinese herbal medicine feed additive in the diet can improve the growth performance,meat quality and disease resistance of chickens.展开更多
The objective of this study was to investigate the influence ofa phytogenic feed additive （PFA） to late-gestation （d 90） and lactation sows on their reproduction performance. Sixty Large White × Landrace prim...The objective of this study was to investigate the influence ofa phytogenic feed additive （PFA） to late-gestation （d 90） and lactation sows on their reproduction performance. Sixty Large White × Landrace primiparous sows were divided into four groups （fifteen sows per group）. The control group was fed with basal diet, the others were fed with basal diet supplemented with 0.02%, 0.04% and 0.06% PFA, respectively. Compared with the control, the sows in 0.04% PFA group had higher feed intake during lactation and higher litter weaning weight （P 〈 0.05）. At farrowing, glucose level in 0.04% PFA sows was higher than the control and sows in 0.02% PFA had the highest IgG content among the treatments （P 〈 0.05）. On day 7 of lactation, serum urea nitrogen contents were lower in response to PFA supplementation compared to the control （P 〈 0.05）. At the same time, sows fed the 0.06% PFA diet increased the lysozyme activity （P 〈 0.05）. The levels of milk lactose and IgG were increased in 0.02% and 0.04% PFA groups （P 〈 0.05）. In conclusion, feeding PFA improved sows and litter performance, serum metabolite concentrations, lgG level and lysozyme activity at postpartum and milk quality.展开更多
In this work,a novel conjugate of ractopamine and bovine serum albumin(RAC–BSA)has been developed via the Mannich reaction,with a mole coupling ratio for RAC–BSA of 9:1.The proposed conjugation method provides a sim...In this work,a novel conjugate of ractopamine and bovine serum albumin(RAC–BSA)has been developed via the Mannich reaction,with a mole coupling ratio for RAC–BSA of 9:1.The proposed conjugation method provides a simple and one-step method with the use of fewer reagents compared with other conjugation methods for competitive immunoassays.RAC–BSA conjugation was used to fabricate a competitive lateral flow strip test for RAC detection in animal feed.For sample preparation,RAC was spiked in swine feed purchased from the local markets in Thailand,and methanol and running buffer at a volume ratio of 10:90 was used as extraction buffer.The procedures for sample preparation were completed within 25 min.Under optimal conditions,the limit of detection(LOD),assessed by the naked eye within 5 min,was found to be 1 ng/g.A semi-quantitative analysis was also conducted using a smart phone and computer software,with a linearity of 0.075–0.750 ng/g,calculated LOD of 0.10 ng/g,calculated limit of quantitation of 0.33 ng/g,and good correlation of 0.992.The recoveries were found in the range of 96.4%–103.7%with a relative standard deviation of 2.5%–3.6%for intra-and inter-assays.Comparison of the results obtained by the strip test with those obtained by enzyme-linked immunosorbent assay had a good agreement in terms of accuracy.Furthermore,this strip test exhibited highly specific RAC detection without cross reactivity with related compounds.Therefore,the RAC–BSA conjugation via the Mannich reaction can be accepted as a one-step and easy conjugation method and applied to the competitive lateral flow strip test.展开更多
基金This study was partially supported by funds from the Agricultural Research,Education,Extension and Technology Transfer(AGREETT)and MNDrive Global Food Ventures Programs,both from the University of MinnesotaPartial funding was supplied by BioZyme,Inc,St.Joseph,Missouri,USA and New Fashion Pork,Jackson,MN,USA.
文摘Background Nursery pigs undergo stressors in the post-weaning period that result in production and welfare chal-lenges.These challenges disproportionately impact the offspring of primiparous sows compared to those of mul-tiparous counterparts.Little is known regarding potential interactions between parity and feed additives in the post-weaning period and their effects on nursery pig microbiomes.Therefore,the objective of this study was to investigate the effects of maternal parity on sow and offspring microbiomes and the influence of sow parity on pig fecal microbi-ome and performance in response to a prebiotic post-weaning.At weaning,piglets were allotted into three treat-ment groups:a standard nursery diet including pharmacological doses of Zn and Cu(Con),a group fed a commercial prebiotic only(Preb)based on an Aspergillus oryzae fermentation extract,and a group fed the same prebiotic plus Zn and Cu(Preb+ZnCu).Results Although there were no differences in vaginal microbiome composition between primiparous and mul-tiparous sows,fecal microbiome composition was different(R^(2)=0.02,P=0.03).The fecal microbiomes of primiparous offspring displayed significantly higher bacterial diversity compared to multiparous offspring at d 0 and d 21 post-weaning(P<0.01),with differences in community composition observed at d 21(R^(2)=0.03,P=0.04).When analyzing the effects of maternal parity within each treatment,only the Preb diet triggered significant microbiome distinc-tions between primiparous and multiparous offspring(d 21:R^(2)=0.13,P=0.01;d 42:R^(2)=0.19,P=0.001).Composi-tional differences in pig fecal microbiomes between treatments were observed only at d 21(R^(2)=0.12,P=0.001).Pigs in the Con group gained significantly more weight throughout the nursery period when compared to those in the Preb+ZnCu group.Conclusions Nursery pig gut microbiome composition was influenced by supplementation with an Aspergillus oryzae fermentation extract,with varying effects on performance when combined with pharmacological levels of Zn and Cu or for offspring of different maternal parity groups.These results indicate that the development of nursery pig gut microbiomes is shaped by maternal parity and potential interactions with the effects of dietary feed additives.
文摘This paper summarizes the current knowledge regarding the possible modes of action and nutritional factors involved in the use of essential oils （EOs） for swine and poultry. EOs have recently attracted increased interest as feed additives to be fed to swine and poultry, possibly replacing the use of antibiotic growth promoters which have been prohibited in the European Union since 2006. In general, EOs enhance the production of digestive secretions and nutrient absorption, reduce pathogenic stress in the gut, exert antioxidant properties and reinforce the animal＇s immune status, which help to explain the enhanced performance observed in swine and poultry. However, the mechanisms involved in causing this growth promotion are far from being elucidated, since data on the complex gut ecosystem, gut function, in vivo oxidative status and immune system are still lacking. In addition, limited information is available regarding the interaction between EOs and feed ingredients or other feed additives （especially pro- or prebiotics and organic acids）. This knowledge may help feed formulators to better utilize EOs when they formulate diets for poultry and swine.
基金supported by the National Natural Science Foundation of China(No.21525730)the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB14030401 and XDB14030402)
文摘Feed security is a prerequisite for safe animal food products.In this study,13 groups of feed and feed ingredients,totaling 2067 samples,were collected in the period of 2011 to 2014 from China.The highest mean level of polychlorinated dibenzo-p-dioxins and dibenzofurans（PCDD/Fs） was found in fish meals and shell powders,with a concentration of 60.35 ng/kg,followed by mineral origin materials.In terms of the toxicity equivalent concentration,the fish oil group showed the highest PCDD/F levels because of their bio-accumulation through the aquatic food chain,with an average concentration of 1.26 ng WHO-TEQ/kg,while the lowest level was observed in compound feed for chickens and pigs,with an average value of0.16 ng WHO-TEQ/kg.OCDD and OCDF were the predominant congeners in all groups except fish oils,in which the primary congeners were 2,3,4,7,8-PeCDF and 2,3,7,8-TCDF.For zinc chloride samples,different from other zinc-based compound samples,the main congeners were 1,2,3,4,6,7,8-HpCDF（17%）,1,2,3,4,7,8,9-HpCDF（15%）,1,2,3,4,7,8-HxCDF（12%） and OCDF（30%）.Considering toxicity equivalency factors,the dominant congeners were 2,3,4,7,8-PeCDF,1,2,3,4,7,8-HxCDF,2,3,7,8-TCDF and 1,2,3,7,8-PeCDD,and the contribution to the total TEQwas29%,16%,14%and 12%,respectively.Overall,2.1%（43 out of 2067） of all the analyzed samples exceeded the different individual ＇European Union maximum limited levels for PCDD/Fs.This study is beneficial for the determination of the status of contamination levels of feed and feed ingredients.
基金carried out with the support of“Cooperative Research Program for Agriculture Science&Technology Development(Project No.PJ01622001)”Rural Development Administration,Korea。
文摘Background:This study was conducted to investigate the effects of each phytogenic feed additive(PFA;PFA1,bitter citrus extract;PFA2,a microencapsulated blend of thymol and carvacrol;PFA3,a mixture of bitter citrus extract,thymol,and carvacrol;PFA4,a premixture of grape seed,grape marc extract,green tea,and hops;PFA5,fenugreek seed powder)on the growth performance,nutrient digestibility,intestinal morphology,and immune response in weaned pigs infected with Escherichia coli(E.coli).Results:A total of 634-week-old weaned pigs were placed in individual metabolic cages and assigned to seven treatment groups.The seven treatments were as follows:1)NC;basal diet without E.coli challenge,2)PC;basal diet with E.coli challenge,3)T1;PC+0.04%PFA1,4)T2;PC+0.01%PFA2,5)T3;PC+0.10%PFA3,6)T4;PC+0.04%PFA4,7)T5;PC+0.10%PFA5.The experiments lasted in 21 d,including 7 d before and 14 d after the first E.coli challenge.In the E.coli challenge treatments,all pigs were orally inoculated by dividing a total of 10 mL of E.coli F18 for 3 consecutive days.The PFA-added groups significantly increased(P<0.05)average daily gain and feed efficiency and decreased(P<0.05)the fecal score at d 0 to 14 post-inoculation(PI).Tumor necrosis factorαwas significantly lower(P<0.05)in the PFA-added groups except for T1 in d 14 PI compared to the PC treatment.The T3 had a higher(P<0.05)immunoglobulin G and immunoglobulin A concentration compared to the PC treatment at d 7 PI.Also,T3 showed significantly higher(P<0.05)villus height:crypt depth and claudin 1 expression in ileal mucosa,and significantly downregulated(P<0.05)the expression of calprotectin compared to the PC treatment.Conclusions:Supplementation of PFA in weaned pigs challenged with E.coli alleviated the negative effects of E.coli and improved growth performance.Among them,the mixed additive of bitter citrus extract,thymol,and carvacrol showed the most effective results,improving immune response,intestinal morphology,and expression of tight junctions.
基金supported by Science and Technology Development Projects of Hebei Province (06220404)
文摘[ Objectivel To investigate the effects of three different levels of feed additives on fur production performance of Rex rabbit. [ Method] A total of 60 healthy American strain Rex rabbits at the age of 60 d （female：male =1：1 ） were randomly divided into group I, group II and group III. The Rex rabbits in the group I were fed basal diet containing nutritional substances; those in the group II were fed basal diet containing nutdtionai substances and Chinese herbal additive; and those in the group III were fed basal diet containing nutritional substances, Chinese herbal additive and enzyme. The trial lasted for 100 d. After slaughtering, the fur area, fur thickness, wool density, wool fineness and coarse wool rate were determined. [Result] The fur production performance of group III was significantly higher than that of group I （ P 〈 0.05）. There was no significant difference between group III and group II. [ Conclusion] Supplementing Chinese herbal additive and enzyme in diet can improve the fur production performance of Rex rabbit.
基金financially supported by Hunan Province Forestry Science and Technology Innovation Foundation(XLK202445)plan of Hunan Province Key Research and Development(2023NK2034)Program for Science&Technology Innovation Talents of Hunan Province(2019TP1029).
文摘The Camellia oleifera meal(COM),a primary byproduct of oil-tea processing,often being discarded or used as a low-grade fertilizer due to its low value.The underutilization has become a significant bottleneck hindering the high-quality development of the oil-tea industry.In this study,the production of antibiotic-free feed additives through the solid-state fermentation of COM by Acremonium terricola was investigated.Our findings revealed that a saponin concentration of 5 mg/mL significantly enhanced the production of cordycepic acid(70.4 mg/g),ergosterol(3.32 mg/g),and chitin(110 mg/g)by A.terricola.This concentration also promoted chitin production and the activities of peroxidase(POD)and Na+/K+-ATPase,thereby maintaining cellular homeostasis and energy balance in A.terricola.Solid-state fermented rice bran(RB),wheat bran(WB),and desaponificated COM(containing 2.6 mg/100 g of tea saponin)were all found to be beneficial for increasing the production of cordycepic acid and ergosterol.The blend of COM,RB,and WB in the ratio of 15:65:20 was particularly advantageous for the production and accumulation of cordycepic acid and ergosterol,yielding 1.54 and 1.43 times,1.27 and 1.37 times,and 1.98 and 5.52 times more than those produced by WB,RB,and COM alone,respectively.Meantime,the difference in contents of sugar and protein in A.terricola cultures(ATCs)using combination were not significant compared to RB and WB.These results indicated that COM can partially replace foodstuffs or food by-products to prepare antibiotic-free feed additives by A.terricola.
基金supported by the National Key R&D Program of China(grant No.2022YFD130040311)the National Natural Science Foundation of China(grant No.31972576,31972575)+1 种基金the Special Program on Science and Technology Innovation Capacity Building of BAAFS(grant No.KJCX 20240339)the innovation and development project of the Institute of Animal Husbandry and Veterinary Medicine,Beijing Academy of Agriculture and Forestry Sciences(grant No.XMS202303).
文摘The use of antibiotics in animal production raises great public safety concerns;therefore,there is an urgent need for the development of substitutes for antibiotics.In recent decades,plant-derived feed additives have been widely investigated as antibiotic alternatives for use in animal health and production because they exert multiple biological functions and are less likely to induce resistance development.This review summarizes the research history and classification of phytogenic feed additives and their main functions,potential modes of action,influencing factors,and potential negative effects.Further,we highlight the challenges in developing sustainable,safe,and affordable plant-derived antibiotic alter-natives for use in livestock production.
基金technical supports from all members of the Application Center at the CJ Blossom Park(Suwon,Republic of Korea)and Kim Lab at North Carolina State University(Raleigh,NC,USA)financial supports from North Carolina Agricultural Foundation(Raleigh,NC,USA)and CJ BIO(Seoul,Republic of Korea).
文摘In vitro model provides alternatives to the use of live animals in research.In pig nutrition,there has been a tremendous increase in in vivo research over the decades.Proper utilization of in vitro models could provide a screening tool to reduce the needs of in vivo studies,research duration,cost,and the use of animals and feeds.This study aimed to develop a multi-step porcine in vitro system to simulate nutrient digestion and intestinal epithelial immune responses affected by feedstuffs and feed additives.Seven feedstuffs(corn,corn distillers dried grains with solubles[corn DDGS],barley,wheat,soybean meal,soy protein concentrates,and Corynebacterium glutamicum cell mass[CGCM]),feed enzymes(xylanase and phytase),and supplemental amino acids(arginine,methionine,and tryptophan),were used in this in vitro evaluation for their efficacy on digestibility,digesta characteristics,and intestinal health compared with the results from previously published in vivo studies.All in vitro evaluations were triplicated.Data were analyzed using Mixed procedure of SAS9.4.Evaluations included(1)nutrient di-gestibility of feedstuffs,(2)the effects of feed enzymes,xylanase and phytase,on digestibility of feed-stuffs and specific substrates,and(3)the effects of amino acids,arginine,tryptophan,and methionine,on anti-inflammatory,anti-oxidative,and anti-heat stress statuses showing their effects(P<0.05)on the measured items.Differences in dry matter and crude protein digestibility among the feedstuffs as well as effects of xylanase and phytase were detected(P<0.05),including xylo-oligosaccharide profiles and phosphorus release from phytate.Supplementation of arginine,tryptophan,and methionine modulated(P<0.05)cellular inflammatory and oxidative stress responses.The use of this in vitro model allowed the use of 3 experimental replications providing sufficient statistical power at P<0.05.This indicates in vitro models can have increased precision and consistency compared with in vivo animal studies.
基金financially supported by the Green Development and Demonstration Programme(GUDP)(case number 34009-19-1585)。
文摘Background Post-weaning diarrhea(PWD)in piglets,often caused by F4^(+)enterotoxigenic Escherichia coli(ETEC),poses significant challenges in pig production.Traditional solutions like antibiotics and zinc oxide face increasing restrictions due to growing concerns over antibiotic resistance and environmental sustainability.This study investigates the application of bivalent heavy chain variable domain(V_(H)H)constructs(BL1.2 and BL2.2)targeting ETEC virulence factors,administered in feed to mitigate ETEC-induced PWD in weaned piglets.Results The supplementation of BL1.2 and BL2.2 in both mash and pelleted feed significantly reduced the diarrhea incidence and fecal shedding of F4^(+)ETEC in challenged piglets.Pelleted feed containing V_(H)H constructs helped to preserve gut barrier integrity by maintaining levels of the tight junction protein occludin in the small intestine.Additionally,the constructs maintained blood granulocyte counts at a similar level to the non-challenged control group,including neutrophils,and ameliorated the acute phase protein response after challenge.Notably,even at low feed intake immediately after weaning,V_(H)H constructs helped maintain piglet health by mitigating ETEC-induced inflammation and the resulting diarrhea.Conclusions Our findings demonstrated that using V_(H)H constructs as feed additives could serve as an effective strategy to help manage ETEC-associated PWD,by reducing F4^(+)ETEC gut colonization and supporting gut barrier function of weaned piglets.The high stability of these V_(H)H constructs supports their incorporation into industrial feed manufacturing processes,offering a more sustainable preventive strategy compared to traditional antimicrobial interventions,which could contribute to sustainable farming practices.
基金financially supported by Zinpro Corporation(grant number:SA2300029,2022–2025).
文摘Background Isoacids are the product of branched-chain amino acid fermentation and are naturally producedin the hindgut by microbial fermentation. In ruminants, supplementation of isoacids as a feed additive improvesfiber utilization, with a positive impact on animal productivity. However, information on how isoacids impact nutrientdigestibility in swine is limited. The objective of this experiment was to determine the optimal inclusion levelof an isoacid blend product based on apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD)of nutrients and fermentation products in the ileal digesta and feces of growing pigs fed a corn-soybean meal diet.Methods Twelve ileal cannulated pigs (20.9 ± 0.6 kg) were used in a 5-period crossover design with 6 diets and 2replicate pigs in each period. Dietary treatments consisted of increasing levels (0%, 0.5%, 0.75%, 1%, 1.25%, and 1.5%)of an isoacid blend (isobutyrate, isovalerate, and 2-methyl butyrate, 1:1:1) added to a corn-soybean meal basal diet.Each experimental period consisted of 14 d: 10 d for acclimatization to the diets, 2 d for fecal collection, and 2 dfor digesta collection.Results Isoacids supplementation quadratically improved the AID of hemicellulose (P < 0.05) and tended to improvethe AID of crude fiber (P < 0.1). The AID of most indispensable amino acids (except Met + Cys, Trp, and Val) as wellas the ATTD of crude protein, gross energy, neutral detergent fiber, and hemicellulose improved or tended to improvelinear or quadratically (P < 0.05 or P < 0.1). In addition, the ATTD values of Arg, His, Ile, Leu, Met + Cys, Phe, Thr, and Valincreased quadratically (P < 0.05). Collectively, 1% of isoacids inclusion resulted in the greatest response. Furthermore,isoacids supplementation tended to increase (P = 0.071, quadratically) the concentration of ammonia and decreased(P < 0.05) the concentrations of acetic acid and total volatile fatty acids with a tendency to decrease (P = 0.064) isovalericacid in the ileal digesta. In fecal samples, the proportion of acetic acid decreased (P < 0.05) quadratically, whereas the proportionsof propionic, valeric, and caproic acids tended to increase linearly and/or quadratically (P < 0.1).Conclusions Isoacids supplementation at 1% in swine diets can improve nutrient digestibility, particularly aminoacids and fiber at the ileal level and ATTD of crude protein, gross energy, and hemicellulose.
文摘[ Objective] The aim of this study was to provide a theoretical basis for population and application of Chinese herbal feed additive in the rex rabbit breeding. [ Methyl] 108 weaned -rex rabbits aged 40 days were divided into three groups with thirty -six each group. Group A were fed basal diet, while group B were fed basal diet supplemented with 0.3% Chinese herbal feed additive and group C were fed basal diet supplemented with 0.4% Chinese herbal feed additive. The meat quality indexes were measured when feeding to 150 age in days. [ Result] There was significant difference among pH value, water loss rate, storing loss rate and crude protein content in each group （P〈0.05）, but no significant difference was found in tenderness, cooking percentage, moisture content and crude fat content （ P 〉 0.05）. The total content of ami- no acids, essential amino acids and semi essential amino acids as well as main delicious amino acids was highest in group C accounting for 23.84%, 11.47% and 8.32% respectively, next came group B accounting for 20.94%, 10.64% and 6.81% respectively, and lowest in group C （ control group） accounting for 19.06%, 9.61% and 6.46% respectively. [ Conclusion] The Chinese herbal feed additive can improve meat quality of rex rabbit the best addition of 0.4%.
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.
文摘At Baiyin dairy farm, the Chinese herbal additive was added into feed which was then fed to dairy cows from August to October, 2014, and the changes in milk production and quality were observed. The test showed that the additive added into the feed had obvious milk-increasing effect, the milk production was im- proved by 12.67%-17.26%, and the milk quality was improved. The additive has the effects of preventing miscarriage, expelling parasite and preventing diseases. The nutritional components in the feed additive were determined, and the results showed that the contents of protein, crude fat, Ca and P in the additive were 12.29%, 2.66%, 1.8% and 0.22%, respectively.
基金funded by Christian Doppler Forschungsgesellschaft(Josef Ressel Center for Phytogenic Drug Research,Wels,Austria)funded by a research project of the Austrian Competence Centre for Feed and Food Quality,Safety and Innovation(FFoQSI,FFG#881882)+1 种基金funded by the Austrian federal ministries BMK and BMDW and the Austrian provinces of Lower Austria,Upper Austria and Vienna within the scope of COMET-Competence Centers for Excellent TechnologiesThe COMET program is handled by the Austrian Research Promotion Agency FFG。
文摘Background Maintaining intestinal health is crucial for the overall well-being and productivity of livestock,as it impacts nutrient absorption,immune function,and disease resistance.Oxidative stress and inflammation are key threats to intestinal integrity.This study explored the antioxidant,anti-inflammatory,and barrier-strengthening properties of a fermented plant macerate(FPM)derived from 45 local herbs,using a specifically developed fermentation process utilizing the plants'inherent microbiota to enhance bioactivity and sustainability.Results In vitro experiments with IPEC-J2 cells showed that FPM significantly reduced intracellular reactive oxygen species(ROS)levels,improved barrier integrity,and enhanced cell migration under stress.Similar antioxidant effects were observed in THP-1 macrophages,where FPM reduced ROS production and modulated inflammatory responses by decreasing pro-inflammatory cytokines[tumor necrosis factor alpha(TNF-α),monokine induced by gamma interferon(MIG),interferon-inducible T cell alpha chemoattractant(I-TAC),macrophage inflammatory proteins(MIP)-1αand-1β]and increasing anti-inflammatory interleukin(IL)-10 levels.Mechanistic studies with HEK-Blue reporter cell lines revealed that FPM inhibited nuclear factor kappa B(NF-κB)activation via a toll-like receptor(TLR)4-independent pathway.In vivo,FPM significantly reduced ROS levels in Drosophila melanogaster and improved activity and LT50 values in Caenorhabditis elegans under oxidative stress,although it did not affect intestinal barrier integrity in these models.Conclusion The findings indicate that FPM shows promising application as a functional feed supplement for improving intestinal health in livestock by mitigating oxidative stress and inflammation.Further studies,including livestock feeding trials,are recommended to validate these results.
基金funded by the Higher Vocational Colleges and Higher Junior Colleges Research Project of Heilongjiang Provincial Education Department (11515077)
文摘Slow-release non-protein nitrogen feed has a large market demand. It has a long research history, but its production technology needs further improvement in order to realize the industrial production of slow-release non-protein nitrogen extruded feed. By designing the best formula and using chelating and emulsifying process, the slow-release non-protein nitrogen extruded feed additives were produced. This product increases milk yield and improves milk quality, thus increasing economic efficiency.
文摘Yeast culture is a kind of green feed additive. It has been researched and applied widely in the feed industry. In this paper, the functions of yeast culture and its application in the actual production were discussed. It can be concluded that yeast culture has a great application prospect.
基金supported by the internal funding source from University of Shanghai for Science and Technology.
文摘Coarse columnar β grains result in anisotropic mechanical properties in Ti alloys deposited by additive manufacturing. This study reports that Ti-6Al-4V alloy fabricated by coaxial electron beam wire feeding additive manufacturing presents a weak anisotropy, high strength and ductility. The superior tensile property arises from a microstructure with fine equiaxed β grains(EGβ), discontinuous grain boundary α phase and short intragranular α lamellae. A large region of fine EGβ arises from a special combination of the temperature gradient and solidification rate, and attractive α morphology is caused by solid phase transformations during interpass thermal cycling and post heat treatments.
基金Project of Hunan Province for Science of Education during 13th Five-Year Plan Period[XJK18BZY066]Hengyang Social Science Foundation Project[2017B(1)010].
文摘[Objectives]To explore the effects of nano compound Chinese herbal medicine feed additive on growth performance,meat quality and disease resistance of chickens.[Methods]Chickens were fed with nano compound Chinese herbal medicine feed additive developed by Hunan Polytechnic of Environment and Biology,including 120 chickens in the treatment group and 120 chickens in the control group(CK).The growth performance indices(body weight gain,feed to gain ratio and slaughter index),meat quality indices(pH value,color,drip loss,shear force)and disease resistance indices(morbidity and mortality)of the chickens in the treatment and CK groups were recorded and determined,respectively.[Results]The inclusion of 2%nano compound Chinese herbal medicine feed additive in the diet significantly increased the growth rate,reduced the feed-to-gain ratio and improved the meat quality of the chickens.Supplementing Chinese herbal medicine could increase the pH value and reduce the drip loss and shear force of chicken meat.At the same time,the body's immune function,antioxidant level and resistance against diseases of the chickens fed with nano compound Chinese herbal medicine feed additive were improved.[Conclusions]The inclusion of nano compound Chinese herbal medicine feed additive in the diet can improve the growth performance,meat quality and disease resistance of chickens.
文摘The objective of this study was to investigate the influence ofa phytogenic feed additive （PFA） to late-gestation （d 90） and lactation sows on their reproduction performance. Sixty Large White × Landrace primiparous sows were divided into four groups （fifteen sows per group）. The control group was fed with basal diet, the others were fed with basal diet supplemented with 0.02%, 0.04% and 0.06% PFA, respectively. Compared with the control, the sows in 0.04% PFA group had higher feed intake during lactation and higher litter weaning weight （P 〈 0.05）. At farrowing, glucose level in 0.04% PFA sows was higher than the control and sows in 0.02% PFA had the highest IgG content among the treatments （P 〈 0.05）. On day 7 of lactation, serum urea nitrogen contents were lower in response to PFA supplementation compared to the control （P 〈 0.05）. At the same time, sows fed the 0.06% PFA diet increased the lysozyme activity （P 〈 0.05）. The levels of milk lactose and IgG were increased in 0.02% and 0.04% PFA groups （P 〈 0.05）. In conclusion, feeding PFA improved sows and litter performance, serum metabolite concentrations, lgG level and lysozyme activity at postpartum and milk quality.
基金Project Project supported by the Thailand Research Fund through the International Research Network(No.PHD58W0001)the Thailand Research Fund through Research Team Promotion Grant the Ratchadaphisaksomphot Endowment Fund of Chulalongkorn University(No.RTA6080002),Thailand
文摘In this work,a novel conjugate of ractopamine and bovine serum albumin(RAC–BSA)has been developed via the Mannich reaction,with a mole coupling ratio for RAC–BSA of 9:1.The proposed conjugation method provides a simple and one-step method with the use of fewer reagents compared with other conjugation methods for competitive immunoassays.RAC–BSA conjugation was used to fabricate a competitive lateral flow strip test for RAC detection in animal feed.For sample preparation,RAC was spiked in swine feed purchased from the local markets in Thailand,and methanol and running buffer at a volume ratio of 10:90 was used as extraction buffer.The procedures for sample preparation were completed within 25 min.Under optimal conditions,the limit of detection(LOD),assessed by the naked eye within 5 min,was found to be 1 ng/g.A semi-quantitative analysis was also conducted using a smart phone and computer software,with a linearity of 0.075–0.750 ng/g,calculated LOD of 0.10 ng/g,calculated limit of quantitation of 0.33 ng/g,and good correlation of 0.992.The recoveries were found in the range of 96.4%–103.7%with a relative standard deviation of 2.5%–3.6%for intra-and inter-assays.Comparison of the results obtained by the strip test with those obtained by enzyme-linked immunosorbent assay had a good agreement in terms of accuracy.Furthermore,this strip test exhibited highly specific RAC detection without cross reactivity with related compounds.Therefore,the RAC–BSA conjugation via the Mannich reaction can be accepted as a one-step and easy conjugation method and applied to the competitive lateral flow strip test.
