This paper introduced the difficulties in the handling of infected pig carcasses,such as difficulty in finding,difficulty in collection and transportation,difficulty in facility construction,and difficulty in monitori...This paper introduced the difficulties in the handling of infected pig carcasses,such as difficulty in finding,difficulty in collection and transportation,difficulty in facility construction,and difficulty in monitoring and supervision,etc.The reasons for these difficulties are shortcomings in the top-level design of the policy to the specific measures at the grassroots level.In view of these shortcomings,the author came up with some pertinent recommendations,including improving relevant regulations and policy measures,establishing a sound system and network for the collection,transportation and processing of infected pig carcasses,reinforcing punishment and strengthening linkage and cooperation between departments.展开更多
<strong>Objectives:</strong> This study aimed to conduct a comparative assessment of bacterial cross-contamination in commercial and non-commercial processing plants including associated risk factors for b...<strong>Objectives:</strong> This study aimed to conduct a comparative assessment of bacterial cross-contamination in commercial and non-commercial processing plants including associated risk factors for bacterial contamination. <strong>Study Design</strong><strong>:</strong> This was analytic cross sectional survey on bacterial contamination of broiler carcasses between different processing systems. <strong>Introduction:</strong> Zambia, like most African and Asian Countries, still practices “live-open non-commercial broiler carcass processing systems” besides the “closed abattoir based systems”. However, shelf life, spoilage and hygiene levels have been postulated to vary based on the type of processing system. Live-open non-commercial processing systems are popular among majority consumers owing to their perceived “freshness”, compared to commercially dressed chickens. In between, consumers have to balance freshness and quality assurance. Ultimately, this becomes inert, remotely but an important public health issue. However, lack of empirical evidence on safety levels to guide consumer product selection leaves them to speculation. It is this need to close this gap that created an impetus for us to undertake this study. <strong>Methods:</strong> Biological samples were collected before carcass wash and after carcass wash alongside a structured questionnaire that gathered risk-associated data. Standard microbiological enumeration methods were used to isolate bacteria and enumerate contamination. <strong>Results:</strong> Broiler carcasses processed from “open” non-commercial systems were more contaminated (45.6%) than “closed-abattoir” commercially processed systems (35%). <em>Escherichia coli</em> were major contaminants (71.3%) and few <em>Salmonella</em> spices (typhi or para-typhi) in 1.3%. Risk analysis indicates washing (method) of carcasses at commercial systems was significantly more risky for contamination than non-commercial ones. Major sources of contamination were “distance from water sources”. Increased volume of slaughters per day (>15,000 birds) for commercial systems accounted for increased cross-contamination, particularly, distance from water source was a ma-jor risk factor for contamination.展开更多
The objective of the study was to determine the level of Bruising and Dark Firm Dry on Arsi, Boran and Harar cattle breeds in Ethiopia. A total of 39 beef bulls from three different breeds (14 Boran, 14 Harar, and 11 ...The objective of the study was to determine the level of Bruising and Dark Firm Dry on Arsi, Boran and Harar cattle breeds in Ethiopia. A total of 39 beef bulls from three different breeds (14 Boran, 14 Harar, and 11 Arsi cattle breeds) were used in this study. Based on the present finding, from 39 slaughtered beef bulls 66.7% was bruised and 30.77% produced DFD meat. Harar breed had the highest (39.1%) overall level of bruising while Boran and Arsi had the lowest level. However, Harar breed had the lowest level of DFD (14.29%). Age groups 3 - 6 and 6 - 9 years had the highest level of a bruise (29.70% and 28.10%, respectively) compared to age groups 2 - 3 years. The mean number of bruises per carcass was 1.96 ± 0.25 while the bruise score per carcass was 3.58 ± 0.68. A linear bruise was the most observed (33.33%) shape of a bruise. It was concluded that the level of bruising and DFD was higher compared to some other abattoir studies in other countries which indicated the possible presence of poor handling practice of cattle from farm to abattoir gates. To minimize the incidence of DFD and bruising, it was recommended that proper handling of cattle during loading, transport, unloading, at lairriage and during slaughter need to be practiced.展开更多
A carcass is the innermost layer of a deep-sea unbonded flexible pipe,which is in direct contact with the gas/liquid-solid multi-phase flow.Considering that stress-accelerated erosion is common for carcasses,this stud...A carcass is the innermost layer of a deep-sea unbonded flexible pipe,which is in direct contact with the gas/liquid-solid multi-phase flow.Considering that stress-accelerated erosion is common for carcasses,this study proposes a general model and simulation method for stress-accelerated erosion(SE)of carcasses under external water pressure.First,an SE model suitable for 316 stainless steel was developed,which was then used for stress-erosion simulation for an external pressurized carcass,and the solid domain,fluid domain and rough inner surface of the carcass were carefully considered.Moreover,a simplified model(equivalent smooth pipe)was also established on the basis of the main geometric characteristics of the carcass,and the stress-erosion characteristics under different operating conditions,including the effects of the elastic stress level,flow velocity,particle diameter and concentration,were carefully compared,and the key factors governing the elastic stress-erosion of the carcass were discussed.Finally,a modified geometry factor(GF)for carcasses was proposed considering the stress acceleration effect.展开更多
The carcass layer is the innermost structure of flexible marine risers and is responsible for resisting external pressure.It has an“S”section with a spiral interlocking feature.After the multi-pass roll forming of a...The carcass layer is the innermost structure of flexible marine risers and is responsible for resisting external pressure.It has an“S”section with a spiral interlocking feature.After the multi-pass roll forming of a flat steel strip,a carcass layer is formed by lock forming.During roll forming,the steel strip undergoes significant plastic deformation,and its local area accumulates residual stress owing to multiple loading and unloading cycles.These phenomena complicate the design and analysis of the carcass layer multi-pass roll forming(CLMRF)process and cause issues in the carcass layer during manufacturing,such as strip fracture and low forming quality.Thus,herein,CLMRF was investigated to clarify the stress distribution,and a parameter analysis was performed.First,the CLMRF process was designed on the basis of classical roll-forming design theory.Second,a finite element model was established,and CLMRF was simulated.Third,the distributions of the forming stress and residual stress of the strip during CLMRF were investigated.Finally,the influences of the strip thickness,roll gap,roll distance,and angular increment were investigated.The conclusions of this study can be used to provide technical guidance in the manufacturing of flexible risers.展开更多
The degradation of animal carcasses can lead to rapid waste release(e.g.,pathogenic bacteria,viruses,prions,or parasites)and also result in nutrient accumulation in the surrounding environment.However,how viral profil...The degradation of animal carcasses can lead to rapid waste release(e.g.,pathogenic bacteria,viruses,prions,or parasites)and also result in nutrient accumulation in the surrounding environment.However,how viral profile responds and influences nutrient pool(carbon(C),nitrogen(N),phosphorus(P)and sulfur(S))in polluted water caused by animal carcass decomposition had not been explored.Here,we combined metagenomic analysis,16S rRNA gene sequencing and water physicochemical assessment to explore the response of viral communities under different temperatures(23℃,26℃,29℃,32℃,and 35℃)in water polluted by cadaver,as well as compare the contribution of viral/bacterial communities on water nutrient pool.We found that a total of 15,240 viral species were classified and mainly consisted of Siphoviridae.Both temperature and carrion reduced the viral diversity and abundance.Only a small portion of the viruses(∼8.8%)had significant negative correlations with temperature,while most were not sensitive.Our results revealed that the viruses had lager contribution on nutrient pool than bacteria.Besides,viral-related functional genes involved in C,N,P and S cycling.These functional genes declined during carcass decomposition and covered part of the central nutrient cycle metabolism(including carbon sugar transformation,denitrification,P mineralization and extracelluar sulfate transfer,etc.).Our result implies that human regulation of virus communities may be more important than bacterial communities in regulating and managing polluted water quality and nutrition.展开更多
This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks wer...This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks were randomly divided into four groups with six replicates and 20 ducks per replicate and fed the basal diet to the control group.The experimental groups were fed the basal diet with 400,600 and 800 mg·kg^(-1) guanidinoacetic acid,respectively.The trial lasted 48 days.Compared with the control group,(1)the body weight at 90 days and average daily gain were increased(P<0.05),the feed conservation ratio was decreased(P<0.05);(2)the dressing percentage and breast muscle percentage were increased(P<0.05);(3)the total amino acid content,polyunsaturated fatty acids to monounsaturated fatty acids ratio were increased(P<0.05)in breast and thigh muscles;(4)activities of superoxide dismutase,catalase and glutathione peroxidase enzyme were increased(P<0.05)in thigh muscles;(5)the relative expressions of superoxide dismutase 1,glutathione peroxidase 1,and catalase were significantly increased(P<0.05)in the liver.In this study,the optimum dosage of 600 mg·kg^(-1) guanidinoacetic acid improved the growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.展开更多
Background The protein sources in pig diets strongly rely on soybean meal,but its production has been associated with soil degradation,deforestation and loss of biodiversity.Microalga Spirulina can be a potentially mo...Background The protein sources in pig diets strongly rely on soybean meal,but its production has been associated with soil degradation,deforestation and loss of biodiversity.Microalga Spirulina can be a potentially more sustainable alternative to soybean meal,but comprehensive information about its use in growing pigs is still lacking.This study aimed to evaluate the effects of partial to full replacement of dietary soybean meal with Spirulina on the growth and carcass traits of growing pigs and on the chemical and physical attributes of the meat.Methods Eighty-eight pigs,gilts and barrows mixed together,with initial body weight of 52.4±4.2 kg,were allotted into 4 isoenergetic,isoproteic,and isoaminoacidic dietary treatments,which included a conventional control diet based on cereals and soybean meal and one of 3 diets formulated by replacing nearly 33%,66%or 100%soybean with Spirulina.Each treatment had 2 pens(11 pigs/pen),which were equipped with electronic feeders that were able to record individual feed intake.After 138 d on feed,at 174.9±6.4 kg body weight,the pigs were slaughtered,and the carcass traits and meat quality parameters from loin samples were assessed.Results The palatability of feeds was not depressed in pigs fed Spirulina,even when the soybean was completely replaced by the microalga.The incorporation of Spirulina in the diets in place of soybean did not impair the growth rate or feed efficiency,irrespective of the extent of replacement.The carcass traits and yield of commercial cuts were comparable for all Spirulina-included compared with those of the soybean-based groups,and the same was found for the chemical and physical attributes of loin meat.Conclusion The results obtained at the herd and slaughter levels revealed that the replacement of soybean meal with Spirulina did not negatively affect the growth or carcass traits of growing pigs or the main attributes of meat.Therefore,this study provides,for the first time,insights into the technical possibility of switching growing pig feeding systems toward more environmentally sustainable diets by including a microalga originating from landless feed production systems,which does not result in soil degradation or loss of biodiversity.展开更多
In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed： two-time centrifugation （C）...In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed： two-time centrifugation （C）, and one-time centrifugation and swim-up method （CS）. The results showed that the cleavage rate in the C treatment group was （75.6±4.5）%, which showed no difference compared with that （（76.4±1.9）%） in the CS treatment group （P〉0.05）; there was also no significant dif- ference in blastocyst rate between the two treatment groups （（35.7±4.1）% vs. （36.3± 2.7）%, P〉0.05）. However, the CS treatment significantly saved the capacitation time in vitro.展开更多
For studying the germplasm charactedsUcs and carcass traits of Changtai yak, 8 adult yaks （5 male, 3 female） were selected and tested. The results showed that the pre-slaughter weight of the adult male and female Ch...For studying the germplasm charactedsUcs and carcass traits of Changtai yak, 8 adult yaks （5 male, 3 female） were selected and tested. The results showed that the pre-slaughter weight of the adult male and female Changtai yak was 364.32 and 266.83 kg, respectively, which presented extremely significant difference （P〈0.01）. The carcass weight, net bone weight net meat weight, and the ratio of bone to meat also showed extremely significant difference （P〈O.01）, which were 186.60 and 125.67 kg, 39.74 and 25.00 kg, 147.84 and 100.83 kg, 1：3.73 and 1： 4.03, respectively. The dressing percentage had significant difference which was 51.15% and 49.34%, respectively （P〈0.05）. The neat meat percentage and carcass meat production rate showed no significant difference which were 40.54% and 37.66%, 79.29% and 80.24%, respectively （P〉0.05）. It indicated that Changtai yak has better growth performance and meat performance potential, and worth of further studying and breeding.展开更多
Quantitative trait loci(QTL)were detected for 8 internal organ traits,3 carcass length traits,and teat number trait in 214 pigs in a resource population that included 180 F2 individuals.A total of 39 microsatellite ma...Quantitative trait loci(QTL)were detected for 8 internal organ traits,3 carcass length traits,and teat number trait in 214 pigs in a resource population that included 180 F2 individuals.A total of 39 microsatellite markers were examined on SSC4,SSC6,SSC7,SSC8,and SSC13.The genetic traits included heart weight(HW),lung weight(LW),liver and gallbladder weight(LGW),spleen weight(SPW),stomach weight(STW),small intestine weight(S1W),large intestine weight(LIW),kidney weight(KW),carcass length to the first cervical vertebra(CL1),carcass length to the first thoracic vertebra(CL2),rib numbers(RNS),and teat numbers(TNS).Results indicated that,3 highly significant QTL(P≤0.01 at chromosome-wise level)for HW(at 30 cM on SSC6),RNS(at 115 cM on SSC7),TNS(at 110 cM on SSC7),and 6 significant QTL(P≤0.05 at chromosome-wise level)for LW(at 119 cM on SSC13),LGW(at 94 cM on SSC6),SPW(at 106 cM on SSC8),SIW(0 cM on SSC4),LIW(170 cM on SSC 4),and TNS(at 95 cM on SSC6)were detected.The phenotypic variances for which these QTL were accounted ranged from 0.04%to 14.06%.Most of these QTL had not been previously reported.展开更多
[Objective] This study aimed to explore the effects of IGFs system on the growth of goose skeletal muscles. [Method] Quantitative fluorescence PCR technique was adopted to study the variety- and gender-specificity in ...[Objective] This study aimed to explore the effects of IGFs system on the growth of goose skeletal muscles. [Method] Quantitative fluorescence PCR technique was adopted to study the variety- and gender-specificity in the expression of GHR, IGF-I, IGF-IR and IGFBP-3 genes in leg muscles of 70-day-old Taihu goose and Wanxi white goose, and the correlation between their expression and carcass traits was also investigated. [Resull] There was no variety difference in the expression of GHR, IGF-t, IGF-IR and IGFBP-3 genes in leg muscles of Taihu goose and Wanxi white goose, but there were significant variety differences in the body weight and leg muscle weight. There were no gender difference in the body weight, leg muscle weight and the rate of leg muscles; except IGF-I mRNA level that was significantly higher in male Taihu goose than in female ones（P=0.032）, there was no gender dif- ference in the expression of other three genes. Among the four tested genes, only IGFBP-3 mRNA exhibited an extremely significantly positively correlation with the rate of leg muscles, suggesting that IGFs may play a role in regulating the growth of leg muscles via IGFBP-3 system in 70-day-old goose. [Conclusion] This study provides theoretical basis for research in the skeletal growth and development.展开更多
China＇s animal husbandry industry has developed rapidly and the inventory of swine, poultry, and sheep has been in the first place in the world of late years. For several consecutive years, the annual slaughter swine...China＇s animal husbandry industry has developed rapidly and the inventory of swine, poultry, and sheep has been in the first place in the world of late years. For several consecutive years, the annual slaughter swine has reached to more than 700 million head, 70 million head of carcasses, about 2 million tons. The number will be even more if cattle, sheep and poultry had been considered. If handled improperly, the large number of carcasses of livestock and poultry will seriously pollute environment and even bring food safety issues and harm to public health security. More and more concern has been attracted on harmless disposal of dead animals. Of all the harmless disposal methods on carcasses of livestock and poultry, the application and research of alkalizalion hydrolysisar （ AH ） are less and only restricted in the higher-level security laboratory field in China. The method of alkalization hydrolysis has the advantages of completely inactivating pathogenic microorganisms （including prions）, no harmful gas, simple operation, low cost, etc, which has the value of research and application. This paper summarized the characteristics and the sterilization effect of alkaline hydrolysis, and discussed the processing and application of AH products of animal carcasses ,meanwhile, introduced the types, research and application state of AH in China, finally, briefly discussed the application prospect of AH in China.展开更多
Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor wa...Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spreeta biosensor kits were used to detect Salmonella Typhimurium on chicken carcass successfully. A taste sensor like electronic tongue or biosensors was used to basically ＂taste＂ the object and differentiated one object from the other with different taste sensor signatures. The surface plasmon resonance biosensor has potential for use in rapid, real-time detection and identification of bacteria, and to study the interaction of organisms with dif- ferent antisera or other molecular species. The selectivity of the SPR biosensor was assayed using a series of antibody con- centrations and dilution series of the organism. The SPR biosensor showed promising to detect the existence of Salmonella Typhimurium at 1 x 106 CFU/ml. Initial results show that the SPR biosensor has the potential for its application in pathogenic bacteria monitoring. However, more tests need to be done to confirm the detection limitation.展开更多
The unbonded flexible pipe of eight layers, in which all the layers except the carcass layer are assumed to have isotropic properties, has been analyzed. Specifically, the carcass layer shows the orthotropic character...The unbonded flexible pipe of eight layers, in which all the layers except the carcass layer are assumed to have isotropic properties, has been analyzed. Specifically, the carcass layer shows the orthotropic characteristics. The effective elastic moduli of the carcass layer have been developed in terms of the influence of deformation to stiffness. With consideration of the effective elastic moduli, the structure can be properly analyzed. Also the relative movements of tendons and relative displacements of wires in helical armour layer have been investigated. A three-dimensional nonlinear finite element model has been presented to predict the response of flexible pipes under axial force and torque. Further, the friction and contact of interlayer have been considered. Comparison between the finite element model and experimental results obtained in literature has been given and discussed, which might provide practical and technical support for the application of unbonded flexible pipes.展开更多
Background: Residual feed intake(RFI) describes an animal’s feed efficiency independent of growth performance.The objective of this study was to determine differences in growth performance, carcass traits, major bact...Background: Residual feed intake(RFI) describes an animal’s feed efficiency independent of growth performance.The objective of this study was to determine differences in growth performance, carcass traits, major bacteria attached to ruminal solids-fraction, and ruminal epithelium gene expression between the most-efficient and the least-efficient beef cattle. One-hundred and forty-nine Red Angus cattle were allocated to three contemporary groups according to sex and herd origin. Animals were fed a finishing diet in confinement for 70 d to determine the RFI category for each. Within each group, the two most-efficient(n = 6; RFI coefficient =-2.69 ± 0.58 kg dry matter intake(DMI)/d) and the two least-efficient animals(n = 6; RFI coefficient = 3.08 ± 0.55 kg DMI/d) were selected. Immediately after slaughter, ruminal solids-fraction and ruminal epithelium were collected for bacteria relative abundance and epithelial gene expression analyses, respectively, using real-time PCR.Results: The most-efficient animals consumed less feed(P = 0.01; 5.03 kg less DMI/d) compared with the leastefficient animals. No differences(P > 0.10) in initial body weight(BW), final BW, and average daily gain(ADG) were observed between the two RFI classes. There were no significant RFI × sex effects(P > 0.10) on growth performance.Compared with the least-efficient group, hot carcass weight(HCW), ribeye area(REA), and kidney, pelvic, and heart fat(KPH) were greater(P ≤ 0.05) in the most-efficient cattle. No RFI × sex effect(P > 0.10) for carcass traits was detected between RFI groups. Of the 10 bacterial species evaluated, the most-efficient compared with least efficient cattle had greater(P ≤ 0.05) relative abundance of Eubacterium ruminantium, Fibrobacter succinogenes, and Megasphaera elsdenii, and lower(P ≤ 0.05) Succinimonas amylolytica and total bacterial density. No RFI × sex effect on ruminal bacteria was detected between RFI groups. Of the 34 genes evaluated in ruminal epithelium, the mostefficient cattle had greater(P ≤ 0.05) abundance of genes involved in VFA absorption, metabolism, ketogenesis, and immune/inflammation-response. The RFI × sex interactions indicated that responses in gene expression between RFI groups were due to differences in sex. Steers in the most-efficient compared with least-efficient group had greater(P ≤ 0.05) expression of SLC9 A1, HIF1 A, and ACO2. The most-efficient compared with least-efficient heifers had greater(P ≤ 0.05) m RNA expression of BDH1 and lower expression(P ≤ 0.05) of SLC9 A2 and PDHA1.Conclusions: The present study revealed that greater feed efficiency in beef cattle is associated with differences in bacterial species and transcriptional adaptations in the ruminal epithelium that might enhance nutrient delivery and utilization by tissues. The lack of RFI × sex interaction for growth performance and carcass traits indicates that sex may not play a major role in improving these phenotypes in superior RFI beef cattle. However, it is important to note that this result should not be considered a solid biomarker of efficient beef cattle prior to further examination due to the limited number of heifers compared with steers used in the study.展开更多
Two 3×3 factorial design trials with 1 080 of Yorkshire×Landrace×Duroc barrows were conducted to investigate the effects of dietary net energy （NE） density and standardized ileal digestible （SID） ly...Two 3×3 factorial design trials with 1 080 of Yorkshire×Landrace×Duroc barrows were conducted to investigate the effects of dietary net energy （NE） density and standardized ileal digestible （SID） lysine：NE ratio on the performance of growing- finishing pigs and carcass characteristic of finishing pigs fed low crude protein （CP） supplemented with crystalline amino acids （CAA） diets. Low CP corn-soybean meal basal diets （14% for Exp. 1 and 11% for Exp. 2） supplemented with crystalline lysine, methionine, threonine, and tryptophan were formulated. Nine treatments with increasing NE density and SID lysine：NE ratio were used in each trial （Exp. 1： 9.66, 9.87, and 10.08 MJ kg-1 NE, 0.89, 0.96, and 1.03 g MJ-1 SID lysine： NE; Exp. 2： 9.83, 10.04, and 10.25 MJ kg-1 NE, 0.69, 0.76, and 0.83 g MJ-1 SID lysine：NE）. In Exp. 1, we observed that the average daily gain （ADG） for barrows that received the diet containing 9.87 MJ kg-1 NE was significantly higher than that of barrows fed a 9.66 MJ kg-1 NE diet （P0.05）, but no difference was observed when compared with barrows that received a diet containing 10.08 MJ kg-1 NE （P0.05）. The ADG was affected both linearly （P0.05） and quadratically （P0.05） as the SID lysine：NE ratio increased. The NE density or SID lysine：NE ratio and their interaction had no effect on the average daily feed intake （ADFI） and serum urea nitrogen （SUN） （P0.05）. The feed to gain ratio （F：G） decreased （linearly, P0.05; quadratically, P0.05） as the NE density or SID lysine：NE ratio increased, but no interaction of NE density and SID lysine： NE ratio on the F：G. In Exp. 2, the dietary NE density both linearly （P0.05） and quadratically （P0.05） affected the ADG and F：G. Barrows that received a diet containing 10.04 MJ kg-1 NE had a greater ADG （P0.05） than barrows that received a 9.83 MJ kg-1 diet, but there was no difference （P0.05） as compared with barrows that received a diet containing 10.25 MJ kg-1 NE. F：G was significantly higher （P0.05） for barrows that received a 9.83 MJ kg-1 diet when compared with barrows that received the other two diets. The ADG was significantly decreased （P0.05） for pigs that received a diet containing 0.69 g MJ-1 SID lysine：NE ratio when compared with pigs fed a diet containing 0.76 or 0.83 g MJ-1 SID lysine：NE ratio. The NE density or SID lysine：NE ratio and their interaction had no effect on the average daily feed intake, SUN, and carcass characteristic for finishing barrows （P0.05）. The overall results of the two experiments indicated that barrows that received the diet with the dietary CP level reduced 4 percentage units compared the NRC （1998） recommendations. Maximized the best performance with NE density and SID lysine：NE ratio were 9.87 MJ kg-1, 1.03 g MJ-1 NE for 20-50 kg pigs, and 10.04 MJ kg-1, 0.76 g MJ-1 NE for 60-100 kg pigs, respectively.展开更多
Two experiments were conducted to in- vestigate the effects of net energy （NE） level on the performance and carcass traits of finishing pigs fed low crude protein （CP） diets supplemented with crystalline amino aci...Two experiments were conducted to in- vestigate the effects of net energy （NE） level on the performance and carcass traits of finishing pigs fed low crude protein （CP） diets supplemented with crystalline amino acids （CAA）. A total of 216 （Exp. 1） and 360 （Exp. 2 ） barrows （ Yorkshire × Landrace× Duroc ） were allotted to one of six treatments （n =6）. The experimental diets were based on corn and soybean meal, and consisted of a high-CP diet that contained approximately 16% CP and 2.50 Mcal/kg of NE as well as five low-CP diets in which the CP level of the diet was reduced by approximately four percentage units but was supplemented with crystalline lysine, methionine, threonine, and tryptophan. The low CP diets provided 2.64, 2.58, 2.50, 2.42, or 2.36 Mcal/kg in Exp. 1 as well as 2.45, 2.40, 2.35, 2.30, or 2.25 Mcai/kg in Exp.2. In Exp. 1, a linear （P=0.03） increase in weight gain was observed with decreasing NE level while the ratio of gain to feed was unaffect- ed （P 〉 0.05） by NE level. There was a linear in-crease （P = 0.01 ） in the percentage of fat-free lean and a linear decrease （ P = 0.03 ） in the percentage of total fat with decreasing NE levels. In Exp. 2, a sig- nificant quadratic （ P = 0.03 ） effect of NE level was observed for weight gain. The ratio of gain to feed demonstrated a significant （P 〈0.01 ） quadratic effect with pigs fed 2.35 and 2.40 Mcal/kg of NE, Pigs fed the diet containing 2.40 Mcal/kg of NE had the lowest percentage of total fat （36. 95% ） and the highest percentage of fat-free lean （49.36%）. The overall results of these experiments indicate that feed- ing either a surplus or a deficiency of NE is detrimen- tal to both pig performance and carcass composition when low CP diets supplemented with CAA are fed. Our results indicate that when the CP content of the diet is reduced by four percentage units and the diet is properly supplemented with CAA, maximum per- formance and carcass quality will be obtained if the diet provides approximately 2.42 Mcal/kg of NE.展开更多
Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently re...Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently reported in choice white grease compared with soybean oil. Therefore, two experiments were conducted to determine whether practical responses confirm that difference between choice white grease and soybean oil, and to extend the observations to other fat sources.Results: In Exp. 1, pigs fed fats had lower(P < 0.05) average daily feed intake in phase II and overall period,greater(P < 0.05) gain:feed in phase I, phase II, and overall period than pigs fed the control diet. Pigs fed fats tended(P = 0.057) to have thicker backfat depth at the last rib than those fed control. Pigs fed 6% fats had greater(P < 0.01) gain:feed in phase II and overall period than pigs fed 3% fats. During phase I, pigs fed choice white grease grew faster(P < 0.05) than pigs fed soybean oil. In Exp. 2, pigs fed dietary fats(soybean oil, choice white grease, animal-vegetable blend, palm oil, or tallow) had greater(P < 0.01) gain:feed in each phase and overall period, greater(P < 0.01) average daily gain in phase I, but lower(P < 0.01) average daily feed intake in phase II an overall than pigs fed the control diets. The choice white grease also increased(P < 0.05) average daily gain during phase I compared with soybean oil. Pigs fed palm oil had thicker(P < 0.05) backfat depth at the 10 thrib than those fed soybean oil, animal-vegetable blend, or tallow.Conclusions: Inclusion of 6% dietary fat improved feed efficiency of finishing pigs, while different fats produced different practical results that may be consistent with their different energy values. Results from the early stage indicate that dietary fats with relatively more saturated fatty acids may provide greater energy than those with relatively more unsaturated fatty acids for growing pigs.展开更多
The selection of meat quality has received considerable focus in chicken breeding.This study was aimed at investigating the effect of CAPN1 gene on meat quality traits in chicken populations.Primer pairs for 3 UTR in ...The selection of meat quality has received considerable focus in chicken breeding.This study was aimed at investigating the effect of CAPN1 gene on meat quality traits in chicken populations.Primer pairs for 3 UTR in CAPN1 were designed from database of chicken genomic sequence.Polymorphisms were detected using PCR-SSCP and DNA sequencing.A mutation at position 9950 nt(G/A,locus A)was found among individuals in each population.The allele and genotype frequencies significantly differed among eight lines with higher frequencies of allele A2 and genotype AIA2(P〈0.01).The least square analysis showed that there was significant difference(P〈0.05)in muscle fiber density and some carcass traits among genotypes and that the breast muscle fiber density(BFD)of birds ofAIA1 genotype was significantly higher(P〈0.05)than that of birds ofA2A2 genotype.It was concluded that the CAPN1 gene was the major gene affecting the muscle fiber traits of chicken or was linked with the major gene.These results were useful for studying the molecular mechanism that influences meat traits and were used as the base of molecular-assisted selection to meat quality traits.So,this site may be a potential marker affecting the muscle traits of chickens.展开更多
文摘This paper introduced the difficulties in the handling of infected pig carcasses,such as difficulty in finding,difficulty in collection and transportation,difficulty in facility construction,and difficulty in monitoring and supervision,etc.The reasons for these difficulties are shortcomings in the top-level design of the policy to the specific measures at the grassroots level.In view of these shortcomings,the author came up with some pertinent recommendations,including improving relevant regulations and policy measures,establishing a sound system and network for the collection,transportation and processing of infected pig carcasses,reinforcing punishment and strengthening linkage and cooperation between departments.
文摘<strong>Objectives:</strong> This study aimed to conduct a comparative assessment of bacterial cross-contamination in commercial and non-commercial processing plants including associated risk factors for bacterial contamination. <strong>Study Design</strong><strong>:</strong> This was analytic cross sectional survey on bacterial contamination of broiler carcasses between different processing systems. <strong>Introduction:</strong> Zambia, like most African and Asian Countries, still practices “live-open non-commercial broiler carcass processing systems” besides the “closed abattoir based systems”. However, shelf life, spoilage and hygiene levels have been postulated to vary based on the type of processing system. Live-open non-commercial processing systems are popular among majority consumers owing to their perceived “freshness”, compared to commercially dressed chickens. In between, consumers have to balance freshness and quality assurance. Ultimately, this becomes inert, remotely but an important public health issue. However, lack of empirical evidence on safety levels to guide consumer product selection leaves them to speculation. It is this need to close this gap that created an impetus for us to undertake this study. <strong>Methods:</strong> Biological samples were collected before carcass wash and after carcass wash alongside a structured questionnaire that gathered risk-associated data. Standard microbiological enumeration methods were used to isolate bacteria and enumerate contamination. <strong>Results:</strong> Broiler carcasses processed from “open” non-commercial systems were more contaminated (45.6%) than “closed-abattoir” commercially processed systems (35%). <em>Escherichia coli</em> were major contaminants (71.3%) and few <em>Salmonella</em> spices (typhi or para-typhi) in 1.3%. Risk analysis indicates washing (method) of carcasses at commercial systems was significantly more risky for contamination than non-commercial ones. Major sources of contamination were “distance from water sources”. Increased volume of slaughters per day (>15,000 birds) for commercial systems accounted for increased cross-contamination, particularly, distance from water source was a ma-jor risk factor for contamination.
文摘The objective of the study was to determine the level of Bruising and Dark Firm Dry on Arsi, Boran and Harar cattle breeds in Ethiopia. A total of 39 beef bulls from three different breeds (14 Boran, 14 Harar, and 11 Arsi cattle breeds) were used in this study. Based on the present finding, from 39 slaughtered beef bulls 66.7% was bruised and 30.77% produced DFD meat. Harar breed had the highest (39.1%) overall level of bruising while Boran and Arsi had the lowest level. However, Harar breed had the lowest level of DFD (14.29%). Age groups 3 - 6 and 6 - 9 years had the highest level of a bruise (29.70% and 28.10%, respectively) compared to age groups 2 - 3 years. The mean number of bruises per carcass was 1.96 ± 0.25 while the bruise score per carcass was 3.58 ± 0.68. A linear bruise was the most observed (33.33%) shape of a bruise. It was concluded that the level of bruising and DFD was higher compared to some other abattoir studies in other countries which indicated the possible presence of poor handling practice of cattle from farm to abattoir gates. To minimize the incidence of DFD and bruising, it was recommended that proper handling of cattle during loading, transport, unloading, at lairriage and during slaughter need to be practiced.
基金financially supported by the National Natural Science Foundation of China(Grant No.52301339)the Natural Science Foundation of Fujian Province(Grant No.2021J05004)+1 种基金the State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation,Tianjin University(Grant No.HESS-2402)the Fundamental Research Funds for the Central Universities(Grant No.20720240038).
文摘A carcass is the innermost layer of a deep-sea unbonded flexible pipe,which is in direct contact with the gas/liquid-solid multi-phase flow.Considering that stress-accelerated erosion is common for carcasses,this study proposes a general model and simulation method for stress-accelerated erosion(SE)of carcasses under external water pressure.First,an SE model suitable for 316 stainless steel was developed,which was then used for stress-erosion simulation for an external pressurized carcass,and the solid domain,fluid domain and rough inner surface of the carcass were carefully considered.Moreover,a simplified model(equivalent smooth pipe)was also established on the basis of the main geometric characteristics of the carcass,and the stress-erosion characteristics under different operating conditions,including the effects of the elastic stress level,flow velocity,particle diameter and concentration,were carefully compared,and the key factors governing the elastic stress-erosion of the carcass were discussed.Finally,a modified geometry factor(GF)for carcasses was proposed considering the stress acceleration effect.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.U1906233 and 52201312)Dalian High-Level Talent Innovation Program(Grant No.2021RD16)the Natural Science Foundation of Liaoning Province of China(Grant No.2023-BSBA-052).
文摘The carcass layer is the innermost structure of flexible marine risers and is responsible for resisting external pressure.It has an“S”section with a spiral interlocking feature.After the multi-pass roll forming of a flat steel strip,a carcass layer is formed by lock forming.During roll forming,the steel strip undergoes significant plastic deformation,and its local area accumulates residual stress owing to multiple loading and unloading cycles.These phenomena complicate the design and analysis of the carcass layer multi-pass roll forming(CLMRF)process and cause issues in the carcass layer during manufacturing,such as strip fracture and low forming quality.Thus,herein,CLMRF was investigated to clarify the stress distribution,and a parameter analysis was performed.First,the CLMRF process was designed on the basis of classical roll-forming design theory.Second,a finite element model was established,and CLMRF was simulated.Third,the distributions of the forming stress and residual stress of the strip during CLMRF were investigated.Finally,the influences of the strip thickness,roll gap,roll distance,and angular increment were investigated.The conclusions of this study can be used to provide technical guidance in the manufacturing of flexible risers.
基金supported by the National Natural Science Foundation of China (No.42007026)the Medical Innovation and Development Project of Lanzhou University (lzuyxcx-2022-172)
文摘The degradation of animal carcasses can lead to rapid waste release(e.g.,pathogenic bacteria,viruses,prions,or parasites)and also result in nutrient accumulation in the surrounding environment.However,how viral profile responds and influences nutrient pool(carbon(C),nitrogen(N),phosphorus(P)and sulfur(S))in polluted water caused by animal carcass decomposition had not been explored.Here,we combined metagenomic analysis,16S rRNA gene sequencing and water physicochemical assessment to explore the response of viral communities under different temperatures(23℃,26℃,29℃,32℃,and 35℃)in water polluted by cadaver,as well as compare the contribution of viral/bacterial communities on water nutrient pool.We found that a total of 15,240 viral species were classified and mainly consisted of Siphoviridae.Both temperature and carrion reduced the viral diversity and abundance.Only a small portion of the viruses(∼8.8%)had significant negative correlations with temperature,while most were not sensitive.Our results revealed that the viruses had lager contribution on nutrient pool than bacteria.Besides,viral-related functional genes involved in C,N,P and S cycling.These functional genes declined during carcass decomposition and covered part of the central nutrient cycle metabolism(including carbon sugar transformation,denitrification,P mineralization and extracelluar sulfate transfer,etc.).Our result implies that human regulation of virus communities may be more important than bacterial communities in regulating and managing polluted water quality and nutrition.
基金Supported by Hainan Provincial Natural Science Foundation of China(322MS134)。
文摘This study aimed to investigate the effects of dietary guanidinoacetic acid on growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.Total 48042-day-old female ducks were randomly divided into four groups with six replicates and 20 ducks per replicate and fed the basal diet to the control group.The experimental groups were fed the basal diet with 400,600 and 800 mg·kg^(-1) guanidinoacetic acid,respectively.The trial lasted 48 days.Compared with the control group,(1)the body weight at 90 days and average daily gain were increased(P<0.05),the feed conservation ratio was decreased(P<0.05);(2)the dressing percentage and breast muscle percentage were increased(P<0.05);(3)the total amino acid content,polyunsaturated fatty acids to monounsaturated fatty acids ratio were increased(P<0.05)in breast and thigh muscles;(4)activities of superoxide dismutase,catalase and glutathione peroxidase enzyme were increased(P<0.05)in thigh muscles;(5)the relative expressions of superoxide dismutase 1,glutathione peroxidase 1,and catalase were significantly increased(P<0.05)in the liver.In this study,the optimum dosage of 600 mg·kg^(-1) guanidinoacetic acid improved the growth performance,meat quality,antioxidant activity,and antioxidant-related gene expression in ducks.
基金funding from the European Union Next Generation EU(PIANO NAZION-ALE DI RIPRESA E RESILIENZA—PNRR–MISSIONE 4 COMPONENTE 2,CUP C93C22002790001)from University of Padova(2024DAFNAE1SIDPRO-GETTI-00004)。
文摘Background The protein sources in pig diets strongly rely on soybean meal,but its production has been associated with soil degradation,deforestation and loss of biodiversity.Microalga Spirulina can be a potentially more sustainable alternative to soybean meal,but comprehensive information about its use in growing pigs is still lacking.This study aimed to evaluate the effects of partial to full replacement of dietary soybean meal with Spirulina on the growth and carcass traits of growing pigs and on the chemical and physical attributes of the meat.Methods Eighty-eight pigs,gilts and barrows mixed together,with initial body weight of 52.4±4.2 kg,were allotted into 4 isoenergetic,isoproteic,and isoaminoacidic dietary treatments,which included a conventional control diet based on cereals and soybean meal and one of 3 diets formulated by replacing nearly 33%,66%or 100%soybean with Spirulina.Each treatment had 2 pens(11 pigs/pen),which were equipped with electronic feeders that were able to record individual feed intake.After 138 d on feed,at 174.9±6.4 kg body weight,the pigs were slaughtered,and the carcass traits and meat quality parameters from loin samples were assessed.Results The palatability of feeds was not depressed in pigs fed Spirulina,even when the soybean was completely replaced by the microalga.The incorporation of Spirulina in the diets in place of soybean did not impair the growth rate or feed efficiency,irrespective of the extent of replacement.The carcass traits and yield of commercial cuts were comparable for all Spirulina-included compared with those of the soybean-based groups,and the same was found for the chemical and physical attributes of loin meat.Conclusion The results obtained at the herd and slaughter levels revealed that the replacement of soybean meal with Spirulina did not negatively affect the growth or carcass traits of growing pigs or the main attributes of meat.Therefore,this study provides,for the first time,insights into the technical possibility of switching growing pig feeding systems toward more environmentally sustainable diets by including a microalga originating from landless feed production systems,which does not result in soil degradation or loss of biodiversity.
基金Supported by Earmarked Fund for China Agriculture(Beef and Yak)Research System(NYCYTX-38)Key Agriculture Research and Development Program of Qiqihar(NYGG-201524)~~
文摘In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed： two-time centrifugation （C）, and one-time centrifugation and swim-up method （CS）. The results showed that the cleavage rate in the C treatment group was （75.6±4.5）%, which showed no difference compared with that （（76.4±1.9）%） in the CS treatment group （P〉0.05）; there was also no significant dif- ference in blastocyst rate between the two treatment groups （（35.7±4.1）% vs. （36.3± 2.7）%, P〉0.05）. However, the CS treatment significantly saved the capacitation time in vitro.
基金Supported by Functional Gene Screen and Tissues' Differential Expression Analysis of Yak Muscle Development in Growth StagesNational Beef Cattle Industrial Technology System(CARS-38)+1 种基金Sichuan Province Yak Germplasm Resource Information Sharing Platform Construction Program(14010121)Ganzi Community Key Grass-Livestock Transformation Technology in Hongyuan County(201203008)~~
文摘For studying the germplasm charactedsUcs and carcass traits of Changtai yak, 8 adult yaks （5 male, 3 female） were selected and tested. The results showed that the pre-slaughter weight of the adult male and female Changtai yak was 364.32 and 266.83 kg, respectively, which presented extremely significant difference （P〈0.01）. The carcass weight, net bone weight net meat weight, and the ratio of bone to meat also showed extremely significant difference （P〈O.01）, which were 186.60 and 125.67 kg, 39.74 and 25.00 kg, 147.84 and 100.83 kg, 1：3.73 and 1： 4.03, respectively. The dressing percentage had significant difference which was 51.15% and 49.34%, respectively （P〈0.05）. The neat meat percentage and carcass meat production rate showed no significant difference which were 40.54% and 37.66%, 79.29% and 80.24%, respectively （P〉0.05）. It indicated that Changtai yak has better growth performance and meat performance potential, and worth of further studying and breeding.
基金supported by the State Key Basic Research and Development Plan of China(No.2006CB102102)the National Natural Science Foundation of China(No.30500358).
文摘Quantitative trait loci(QTL)were detected for 8 internal organ traits,3 carcass length traits,and teat number trait in 214 pigs in a resource population that included 180 F2 individuals.A total of 39 microsatellite markers were examined on SSC4,SSC6,SSC7,SSC8,and SSC13.The genetic traits included heart weight(HW),lung weight(LW),liver and gallbladder weight(LGW),spleen weight(SPW),stomach weight(STW),small intestine weight(S1W),large intestine weight(LIW),kidney weight(KW),carcass length to the first cervical vertebra(CL1),carcass length to the first thoracic vertebra(CL2),rib numbers(RNS),and teat numbers(TNS).Results indicated that,3 highly significant QTL(P≤0.01 at chromosome-wise level)for HW(at 30 cM on SSC6),RNS(at 115 cM on SSC7),TNS(at 110 cM on SSC7),and 6 significant QTL(P≤0.05 at chromosome-wise level)for LW(at 119 cM on SSC13),LGW(at 94 cM on SSC6),SPW(at 106 cM on SSC8),SIW(0 cM on SSC4),LIW(170 cM on SSC 4),and TNS(at 95 cM on SSC6)were detected.The phenotypic variances for which these QTL were accounted ranged from 0.04%to 14.06%.Most of these QTL had not been previously reported.
基金Supported by the National Sci-tech Support Plan(2012BAD39B04)the Special Fund for Yangzhou Municipal Key Agricultural Science and Technology Projects(YZ2011067)Special Fund for the Industrial Technology System Construction of Modern Agriculture(nycytx-42-G1)~~
文摘[Objective] This study aimed to explore the effects of IGFs system on the growth of goose skeletal muscles. [Method] Quantitative fluorescence PCR technique was adopted to study the variety- and gender-specificity in the expression of GHR, IGF-I, IGF-IR and IGFBP-3 genes in leg muscles of 70-day-old Taihu goose and Wanxi white goose, and the correlation between their expression and carcass traits was also investigated. [Resull] There was no variety difference in the expression of GHR, IGF-t, IGF-IR and IGFBP-3 genes in leg muscles of Taihu goose and Wanxi white goose, but there were significant variety differences in the body weight and leg muscle weight. There were no gender difference in the body weight, leg muscle weight and the rate of leg muscles; except IGF-I mRNA level that was significantly higher in male Taihu goose than in female ones（P=0.032）, there was no gender dif- ference in the expression of other three genes. Among the four tested genes, only IGFBP-3 mRNA exhibited an extremely significantly positively correlation with the rate of leg muscles, suggesting that IGFs may play a role in regulating the growth of leg muscles via IGFBP-3 system in 70-day-old goose. [Conclusion] This study provides theoretical basis for research in the skeletal growth and development.
基金Surported by Jiangsu Vocational Colleges Young Teachers Enterprise Practice Training Funding Project(2016QYSJ058)Xuzhou Vocational College of Bioengineering 2017 Science and Technology Project-A Preliminary Study on Farm Animal Welfare(2017KY07)Xuzhou Vocational College of Bioengineering Animal Husbandry and Veterinary Brand Profession Construction Fund
文摘China＇s animal husbandry industry has developed rapidly and the inventory of swine, poultry, and sheep has been in the first place in the world of late years. For several consecutive years, the annual slaughter swine has reached to more than 700 million head, 70 million head of carcasses, about 2 million tons. The number will be even more if cattle, sheep and poultry had been considered. If handled improperly, the large number of carcasses of livestock and poultry will seriously pollute environment and even bring food safety issues and harm to public health security. More and more concern has been attracted on harmless disposal of dead animals. Of all the harmless disposal methods on carcasses of livestock and poultry, the application and research of alkalizalion hydrolysisar （ AH ） are less and only restricted in the higher-level security laboratory field in China. The method of alkalization hydrolysis has the advantages of completely inactivating pathogenic microorganisms （including prions）, no harmful gas, simple operation, low cost, etc, which has the value of research and application. This paper summarized the characteristics and the sterilization effect of alkaline hydrolysis, and discussed the processing and application of AH products of animal carcasses ,meanwhile, introduced the types, research and application state of AH in China, finally, briefly discussed the application prospect of AH in China.
文摘Chicken is one of the most popular meat products in the world. Salmonella Typhimurium is a common foodbome pathogens associated with the processing of poultry. An optical Surface Plasmon Resonance （SPR） biosensor was sensitive to the presence of Salmonella Typhimurium in chicken carcass. The Spreeta biosensor kits were used to detect Salmonella Typhimurium on chicken carcass successfully. A taste sensor like electronic tongue or biosensors was used to basically ＂taste＂ the object and differentiated one object from the other with different taste sensor signatures. The surface plasmon resonance biosensor has potential for use in rapid, real-time detection and identification of bacteria, and to study the interaction of organisms with dif- ferent antisera or other molecular species. The selectivity of the SPR biosensor was assayed using a series of antibody con- centrations and dilution series of the organism. The SPR biosensor showed promising to detect the existence of Salmonella Typhimurium at 1 x 106 CFU/ml. Initial results show that the SPR biosensor has the potential for its application in pathogenic bacteria monitoring. However, more tests need to be done to confirm the detection limitation.
基金supported by the "111" Project of China (Grant No. B07019)State Key Laboratory of Ocean Engineeringof Shanghai Jiao Tong University (Grant No. 1008)the Fundamental Research Funds for the Central University
文摘The unbonded flexible pipe of eight layers, in which all the layers except the carcass layer are assumed to have isotropic properties, has been analyzed. Specifically, the carcass layer shows the orthotropic characteristics. The effective elastic moduli of the carcass layer have been developed in terms of the influence of deformation to stiffness. With consideration of the effective elastic moduli, the structure can be properly analyzed. Also the relative movements of tendons and relative displacements of wires in helical armour layer have been investigated. A three-dimensional nonlinear finite element model has been presented to predict the response of flexible pipes under axial force and torque. Further, the friction and contact of interlayer have been considered. Comparison between the finite element model and experimental results obtained in literature has been given and discussed, which might provide practical and technical support for the application of unbonded flexible pipes.
文摘Background: Residual feed intake(RFI) describes an animal’s feed efficiency independent of growth performance.The objective of this study was to determine differences in growth performance, carcass traits, major bacteria attached to ruminal solids-fraction, and ruminal epithelium gene expression between the most-efficient and the least-efficient beef cattle. One-hundred and forty-nine Red Angus cattle were allocated to three contemporary groups according to sex and herd origin. Animals were fed a finishing diet in confinement for 70 d to determine the RFI category for each. Within each group, the two most-efficient(n = 6; RFI coefficient =-2.69 ± 0.58 kg dry matter intake(DMI)/d) and the two least-efficient animals(n = 6; RFI coefficient = 3.08 ± 0.55 kg DMI/d) were selected. Immediately after slaughter, ruminal solids-fraction and ruminal epithelium were collected for bacteria relative abundance and epithelial gene expression analyses, respectively, using real-time PCR.Results: The most-efficient animals consumed less feed(P = 0.01; 5.03 kg less DMI/d) compared with the leastefficient animals. No differences(P > 0.10) in initial body weight(BW), final BW, and average daily gain(ADG) were observed between the two RFI classes. There were no significant RFI × sex effects(P > 0.10) on growth performance.Compared with the least-efficient group, hot carcass weight(HCW), ribeye area(REA), and kidney, pelvic, and heart fat(KPH) were greater(P ≤ 0.05) in the most-efficient cattle. No RFI × sex effect(P > 0.10) for carcass traits was detected between RFI groups. Of the 10 bacterial species evaluated, the most-efficient compared with least efficient cattle had greater(P ≤ 0.05) relative abundance of Eubacterium ruminantium, Fibrobacter succinogenes, and Megasphaera elsdenii, and lower(P ≤ 0.05) Succinimonas amylolytica and total bacterial density. No RFI × sex effect on ruminal bacteria was detected between RFI groups. Of the 34 genes evaluated in ruminal epithelium, the mostefficient cattle had greater(P ≤ 0.05) abundance of genes involved in VFA absorption, metabolism, ketogenesis, and immune/inflammation-response. The RFI × sex interactions indicated that responses in gene expression between RFI groups were due to differences in sex. Steers in the most-efficient compared with least-efficient group had greater(P ≤ 0.05) expression of SLC9 A1, HIF1 A, and ACO2. The most-efficient compared with least-efficient heifers had greater(P ≤ 0.05) m RNA expression of BDH1 and lower expression(P ≤ 0.05) of SLC9 A2 and PDHA1.Conclusions: The present study revealed that greater feed efficiency in beef cattle is associated with differences in bacterial species and transcriptional adaptations in the ruminal epithelium that might enhance nutrient delivery and utilization by tissues. The lack of RFI × sex interaction for growth performance and carcass traits indicates that sex may not play a major role in improving these phenotypes in superior RFI beef cattle. However, it is important to note that this result should not be considered a solid biomarker of efficient beef cattle prior to further examination due to the limited number of heifers compared with steers used in the study.
基金supported by the National Key Tech-nology R&D Program of China (2006BAD12B02)
文摘Two 3×3 factorial design trials with 1 080 of Yorkshire×Landrace×Duroc barrows were conducted to investigate the effects of dietary net energy （NE） density and standardized ileal digestible （SID） lysine：NE ratio on the performance of growing- finishing pigs and carcass characteristic of finishing pigs fed low crude protein （CP） supplemented with crystalline amino acids （CAA） diets. Low CP corn-soybean meal basal diets （14% for Exp. 1 and 11% for Exp. 2） supplemented with crystalline lysine, methionine, threonine, and tryptophan were formulated. Nine treatments with increasing NE density and SID lysine：NE ratio were used in each trial （Exp. 1： 9.66, 9.87, and 10.08 MJ kg-1 NE, 0.89, 0.96, and 1.03 g MJ-1 SID lysine： NE; Exp. 2： 9.83, 10.04, and 10.25 MJ kg-1 NE, 0.69, 0.76, and 0.83 g MJ-1 SID lysine：NE）. In Exp. 1, we observed that the average daily gain （ADG） for barrows that received the diet containing 9.87 MJ kg-1 NE was significantly higher than that of barrows fed a 9.66 MJ kg-1 NE diet （P0.05）, but no difference was observed when compared with barrows that received a diet containing 10.08 MJ kg-1 NE （P0.05）. The ADG was affected both linearly （P0.05） and quadratically （P0.05） as the SID lysine：NE ratio increased. The NE density or SID lysine：NE ratio and their interaction had no effect on the average daily feed intake （ADFI） and serum urea nitrogen （SUN） （P0.05）. The feed to gain ratio （F：G） decreased （linearly, P0.05; quadratically, P0.05） as the NE density or SID lysine：NE ratio increased, but no interaction of NE density and SID lysine： NE ratio on the F：G. In Exp. 2, the dietary NE density both linearly （P0.05） and quadratically （P0.05） affected the ADG and F：G. Barrows that received a diet containing 10.04 MJ kg-1 NE had a greater ADG （P0.05） than barrows that received a 9.83 MJ kg-1 diet, but there was no difference （P0.05） as compared with barrows that received a diet containing 10.25 MJ kg-1 NE. F：G was significantly higher （P0.05） for barrows that received a 9.83 MJ kg-1 diet when compared with barrows that received the other two diets. The ADG was significantly decreased （P0.05） for pigs that received a diet containing 0.69 g MJ-1 SID lysine：NE ratio when compared with pigs fed a diet containing 0.76 or 0.83 g MJ-1 SID lysine：NE ratio. The NE density or SID lysine：NE ratio and their interaction had no effect on the average daily feed intake, SUN, and carcass characteristic for finishing barrows （P0.05）. The overall results of the two experiments indicated that barrows that received the diet with the dietary CP level reduced 4 percentage units compared the NRC （1998） recommendations. Maximized the best performance with NE density and SID lysine：NE ratio were 9.87 MJ kg-1, 1.03 g MJ-1 NE for 20-50 kg pigs, and 10.04 MJ kg-1, 0.76 g MJ-1 NE for 60-100 kg pigs, respectively.
基金supported by the National Natural Science Foundation of P.R.China (No.NSFC30525029)
文摘Two experiments were conducted to in- vestigate the effects of net energy （NE） level on the performance and carcass traits of finishing pigs fed low crude protein （CP） diets supplemented with crystalline amino acids （CAA）. A total of 216 （Exp. 1） and 360 （Exp. 2 ） barrows （ Yorkshire × Landrace× Duroc ） were allotted to one of six treatments （n =6）. The experimental diets were based on corn and soybean meal, and consisted of a high-CP diet that contained approximately 16% CP and 2.50 Mcal/kg of NE as well as five low-CP diets in which the CP level of the diet was reduced by approximately four percentage units but was supplemented with crystalline lysine, methionine, threonine, and tryptophan. The low CP diets provided 2.64, 2.58, 2.50, 2.42, or 2.36 Mcal/kg in Exp. 1 as well as 2.45, 2.40, 2.35, 2.30, or 2.25 Mcai/kg in Exp.2. In Exp. 1, a linear （P=0.03） increase in weight gain was observed with decreasing NE level while the ratio of gain to feed was unaffect- ed （P 〉 0.05） by NE level. There was a linear in-crease （P = 0.01 ） in the percentage of fat-free lean and a linear decrease （ P = 0.03 ） in the percentage of total fat with decreasing NE levels. In Exp. 2, a sig- nificant quadratic （ P = 0.03 ） effect of NE level was observed for weight gain. The ratio of gain to feed demonstrated a significant （P 〈0.01 ） quadratic effect with pigs fed 2.35 and 2.40 Mcal/kg of NE, Pigs fed the diet containing 2.40 Mcal/kg of NE had the lowest percentage of total fat （36. 95% ） and the highest percentage of fat-free lean （49.36%）. The overall results of these experiments indicate that feed- ing either a surplus or a deficiency of NE is detrimen- tal to both pig performance and carcass composition when low CP diets supplemented with CAA are fed. Our results indicate that when the CP content of the diet is reduced by four percentage units and the diet is properly supplemented with CAA, maximum per- formance and carcass quality will be obtained if the diet provides approximately 2.42 Mcal/kg of NE.
文摘Background: There are various fat sources with different energy values and fatty acid compositions that may affect growth performance and carcass composition of grow-finishing pigs. A higher net energy was recently reported in choice white grease compared with soybean oil. Therefore, two experiments were conducted to determine whether practical responses confirm that difference between choice white grease and soybean oil, and to extend the observations to other fat sources.Results: In Exp. 1, pigs fed fats had lower(P < 0.05) average daily feed intake in phase II and overall period,greater(P < 0.05) gain:feed in phase I, phase II, and overall period than pigs fed the control diet. Pigs fed fats tended(P = 0.057) to have thicker backfat depth at the last rib than those fed control. Pigs fed 6% fats had greater(P < 0.01) gain:feed in phase II and overall period than pigs fed 3% fats. During phase I, pigs fed choice white grease grew faster(P < 0.05) than pigs fed soybean oil. In Exp. 2, pigs fed dietary fats(soybean oil, choice white grease, animal-vegetable blend, palm oil, or tallow) had greater(P < 0.01) gain:feed in each phase and overall period, greater(P < 0.01) average daily gain in phase I, but lower(P < 0.01) average daily feed intake in phase II an overall than pigs fed the control diets. The choice white grease also increased(P < 0.05) average daily gain during phase I compared with soybean oil. Pigs fed palm oil had thicker(P < 0.05) backfat depth at the 10 thrib than those fed soybean oil, animal-vegetable blend, or tallow.Conclusions: Inclusion of 6% dietary fat improved feed efficiency of finishing pigs, while different fats produced different practical results that may be consistent with their different energy values. Results from the early stage indicate that dietary fats with relatively more saturated fatty acids may provide greater energy than those with relatively more unsaturated fatty acids for growing pigs.
基金financially sup-ported by Bio-Tech Programs of Sichuan Province,China(05NG002-017).
文摘The selection of meat quality has received considerable focus in chicken breeding.This study was aimed at investigating the effect of CAPN1 gene on meat quality traits in chicken populations.Primer pairs for 3 UTR in CAPN1 were designed from database of chicken genomic sequence.Polymorphisms were detected using PCR-SSCP and DNA sequencing.A mutation at position 9950 nt(G/A,locus A)was found among individuals in each population.The allele and genotype frequencies significantly differed among eight lines with higher frequencies of allele A2 and genotype AIA2(P〈0.01).The least square analysis showed that there was significant difference(P〈0.05)in muscle fiber density and some carcass traits among genotypes and that the breast muscle fiber density(BFD)of birds ofAIA1 genotype was significantly higher(P〈0.05)than that of birds ofA2A2 genotype.It was concluded that the CAPN1 gene was the major gene affecting the muscle fiber traits of chicken or was linked with the major gene.These results were useful for studying the molecular mechanism that influences meat traits and were used as the base of molecular-assisted selection to meat quality traits.So,this site may be a potential marker affecting the muscle traits of chickens.
