Protein glycation:a wolf in sweet sheep’s clothing behind neurodegeneration

At the beginning of the 16th century,Paracelsus coined the maxim:“the dose makes the poison”.This principle can be applied to all living organisms,including organs and cells.The brain and its glial and neuronal cells are no exception.Even small compounds that are essential for the life of brain cells can become truly toxic when overdosed.

Supplementation of Lycium barbarum residue increases the growth rate of Tan sheep by enhancing their feed intake and regulating their rumen microbiome and metabolome

Lycium barbarum residue(LBR),a by-product of L.barbarum processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal husbandry.However,the fundamental understanding of its effectiveness on livestock animals is still lacking,particularly in ruminants.To explore the effects of LBR on the growth performance,rumen fermentation parameters,ruminal microbes and metabolites of Tan sheep,sixteen fattening rams(aged 4 mon)were fed a basal diet(CON,n=8)or a basal diet supplemented with 5%LBR(LBR,n=8).The experiment lasted for 70 d,with 10 d adaptation period and 60 d treatment period.The results showed that the LBR enhanced the average daily feed intake,average daily gain(P<0.05),and ruminal total volatile fatty acids(P<0.01)while decreasing ammonia-nitrogen concentration and rumen pH value(P<0.05).Additionally,the LBR improved the relative abundances of Prevotella,Succiniclasticum,Ruminococcus,Coprococcus,Selenomonas,and Butyrivibrio(P<0.05)and reduced the relative abundances of Oscillospira and Succinivibrio(P<0.05).The LBR altered the ruminal metabolome(P<0.01)by increasing the abundances of ruminal metabolites involved in amino acids(e.g.,L-proline,L-phenylalanine,L-lysine,and L-tyrosine),pyrimidine metabolism(e.g.,uridine,uracil,and thymidine),and microbial protein synthesis(e.g.,xanthine and hypoxanthine).In conclusion,LBR had positive effects on the growth rate of Tan sheep as well as on rumen fermentation parameters,rumen microbiome and rumen metabolome.

Etiological Agent, Pathogenesis, Diagnosis, Treatment, Measures for Prevention and Control of Caseous Lymphadenitis Disease in the Small Ruminants with Special Reference to Sheep

Caseous lymphadenitis (CL) is a chronic infectious disease caused by Corynebacterium pseudotuberculosis (C. pseudotuberculosis) that is transmitted mainly by contact with contaminated exudate wounds. Caseous lymphadenitis affects different species of animals and is considered an occupational zoonotic disease. CL is responsible for important economic losses in the small ruminant industry, which include decreased production, damaged quality of milk and wool, reproductive disorders, total or partial confiscation of carcasses, and depreciation of the skin. Caseous lymphadenitis disease can present in two clinical pictures: a skin or superficial picture and a visceral or deep picture. The presumptive diagnosis of CL in the skin is based on the exploration of superficial lymph nodes. These have little value in diagnosing visceral CL, where the main sign is emaciation. The prevention and control of CL involve identifying the skin condition and debriding the abscesses. In addition to the treatment of superficial lesions, the animal facilities must be repaired and adapted. To avoid exposure of negative herds to CL, new animals must be subjected to observation to identify any of the clinical manifestations. Another form of control is vaccination, though only some countries have commercial vaccines. General information on the etiological agent and its characteristics can be used to improve the understanding of this disease.

Genomic signatures of selection,local adaptation and production type characterisation of East Adriatic sheep breeds

Background The importance of sheep breeding in the Mediterranean part of the eastern Adriatic has a long tradition since its arrival during the Neolithic migrations.Sheep production system is extensive and generally carried out in traditional systems without intensive systematic breeding programmes for high uniform trait production(carcass,wool and milk yield).Therefore,eight indigenous Croatian sheep breeds from eastern Adriatic treated here as metapopulation(EAS),are generally considered as multipurpose breeds(milk,meat and wool),not specialised for a particular type of production,but known for their robustness and resistance to certain environmental conditions.Our objective was to identify genomic regions and genes that exhibit patterns of positive selection signatures,decipher their biological and productive functionality,and provide a"genomic"characterization of EAS adaptation and determine its production type.Results We identified positive selection signatures in EAS using several methods based on reduced local variation,linkage disequilibrium and site frequency spectrum(eROHi,iHS,nSL and CLR).Our analyses identified numerous genomic regions and genes(e.g.,desmosomal cadherin and desmoglein gene families)associated with environmental adaptation and economically important traits.Most candidate genes were related to meat/production and health/immune response traits,while some of the candidate genes discovered were important for domestication and evolutionary processes(e.g.,HOXa gene family and FSIP2).These results were also confirmed by GO and QTL enrichment analysis.Conclusions Our results contribute to a better understanding of the unique adaptive genetic architecture of EAS and define its productive type,ultimately providing a new opportunity for future breeding programmes.At the same time,the numerous genes identified will improve our understanding of ruminant(sheep)robustness and resistance in the harsh and specific Mediterranean environment.

High-efficiency Embryo Cryopreservation Technology for Mutton Sheep

Embryo cryopreservation is an important part of embryo biotechnology.It plays a key role in the development of quality animal husbandry.However,the effect of in-vivo(in-vitro)embryo freezing of cattle and sheep in China has not reached an expected level,which limits the commercial application of embryo transfer technology.The technical bottleneck that needs to be broken through is that embryos are subject to mechanical damage and protective agent toxicity during freezing and thawing.This paper summarized the successful application of plant antifreeze protein in vitrification preservation of pig embryos,which makes this technology widely used in animal husbandry production,and is of great significance in accelerating the large-scale breeding of improved livestock and saving endangered animals.

A computational framework for improving genetic variants identification from 5,061 sheep sequencing data

Background Pan-genomics is a recently emerging strategy that can be utilized to provide a more comprehensive characterization of genetic variation.Joint calling is routinely used to combine identified variants across multiple related samples.However,the improvement of variants identification using the mutual support information from mul-tiple samples remains quite limited for population-scale genotyping.Results In this study,we developed a computational framework for joint calling genetic variants from 5,061 sheep by incorporating the sequencing error and optimizing mutual support information from multiple samples’data.The variants were accurately identified from multiple samples by using four steps:(1)Probabilities of variants from two widely used algorithms,GATK and Freebayes,were calculated by Poisson model incorporating base sequencing error potential;(2)The variants with high mapping quality or consistently identified from at least two samples by GATK and Freebayes were used to construct the raw high-confidence identification(rHID)variants database;(3)The high confidence variants identified in single sample were ordered by probability value and controlled by false discovery rate(FDR)using rHID database;(4)To avoid the elimination of potentially true variants from rHID database,the vari-ants that failed FDR were reexamined to rescued potential true variants and ensured high accurate identification variants.The results indicated that the percent of concordant SNPs and Indels from Freebayes and GATK after our new method were significantly improved 12%-32%compared with raw variants and advantageously found low frequency variants of individual sheep involved several traits including nipples number(GPC5),scrapie pathology(PAPSS2),sea-sonal reproduction and litter size(GRM1),coat color(RAB27A),and lentivirus susceptibility(TMEM154).Conclusion The new method used the computational strategy to reduce the number of false positives,and simulta-neously improve the identification of genetic variants.This strategy did not incur any extra cost by using any addi-tional samples or sequencing data information and advantageously identified rare variants which can be important for practical applications of animal breeding.

Phylogenetic Relationship and Molecular Divergence Dating Using SRY Gene Polymorphism about Four Ladoum Sheep Lineages in Senegal

Animal genetic resources are playing a vital role in livestock production and are essential to food security. The present study aims to contribute to a better understanding genetic local sheep breeds and to elucidate the phylogenetic relationships through the evolution of the SRY gene in four different lineages of Ladoum sheep raised in Senegal. After a brief analysis of genetic diversity, the phylogenetic relationships and molecular dating were inferred through haplotype networks and four phylogenetic reconstruction methods. The different haplotype networks are constructed with NETWORK ver. 5.0.0.0 using the Median-Joining method. Phylogenetic trees were reconstructed using neighbor-joining, maximum parsimony, maximum likelihood and Bayesian inference. The robustness of the nodes in phylogenetic trees of the three first methods was assessed by 1000 bootstraps. For Bayesian inference, the posterior probability distribution of the trees was estimated by 4 MCMC chains. 5,000,000 generations were performed for each of the chains by sampling the different parameters every 1000 generations. Results show a low polymorphism. Haplotypic diversity is much higher than the average nucleotide divergence between all pairs of haplotypes. The majority and central haplotype indicates a close relationship between “Batling” and “Tyson” individuals. “Birahim” lineage is very distinct from the rest. Phylogenetic trees confirm two genetically separate clades between “Birahim” and the other lineages. The period of divergence between “Birahim” lineage versus the common ancestor of the other three lineages was 2504 years ago. The polyphyly revealed in “Birahim” lindicates that this lineage does not contain the common ancestor of all individuals who compose it. It could therefore be derived from two or more sheep breeds with a common ancestor, Ovis aries. The monophyletic clade appears to be a group including a common ancestor and all of its genetic descendants. This group, bringing together the other three lineages, is in the process of being structured into sub-lineages. This study is the first to show that there are only two genetic lines within ladoum sheep in Senegal.

Study on Breeding Practices and Reproductive Performance of Black-Head Somali Sheep under Traditional Management System: The Case of Awbarre District, Eastern Ethiopia

The study was conducted in the Awbarre district of the Fafen zone of the Somali regional state of Ethiopia. The objective of the study was to assess the breeding practices and reproductive performance of Black-head Somali sheep under a traditional management system. Purposive and simple random sampling techniques were used to select targeted kebeles and households, respectively. A total of 120 households were selected from four kebeles, each of 30 households, based on the production system and sheep population. Semi-structured questionnaires, group discussions, key informants interviews and field observations were used to generate the required data. The primary purpose of keeping sheep was for income generation, followed by saving as a future asset. The majority (89.2%) of the respondents separated male and female animals during herding. The selection criteria for breeding rams were appearance, growth, pedigree, and color while for breeding ewes were appearance, adaptability, pedigree, color, and lamb growth. The overall weaning age of Black-head Somali sheep in the study area was 3.7 months for both males & females. The castration of male sheep was common for the purpose of fattening, fattening with breeding control and breeding control as well. The castration is mainly performed during the summer and autumn and the methods of castration were both traditional and modern methods, the traditional castration method being the most important one in pastoral areas. The age of sexual maturity was 7.64 months for rams and 8.97 months for ewe’s male and female lambs in the pastoral area and 8.42 & 8.38 for rams & ewes in agro-pastoral and overall lambing interval was 11 months. On average, the ewe of Black-head Somali sheep in pastoral & agro-pastoral could produce 9.49 & 9.57 lambs, respectively in their lifetime. As the pastoralists and agro-pastoralists indicated the source of the breeding ram was their own, so the exchange of breeding ram is recommended to minimize the risk of inbreeding and further studies of on-farm performance investigation would be necessary to be carried out so as to understand the uniqueness of the breed better.

Effects of LPA on the development of sheep in vitro fertilized embryos and attempt to establish sheep embryonic stem cells

Lysophosphatidic acid(LPA)is a small molecule glycerophospholipid,which regulates multiple downstream signalling pathways through G-protein-coupled receptors to achieve numerous functions on oocyte maturation and embryo development.In this study,sheep in vitro fertilized embryos were applied to investigate the effects of LPA on early embryos development and embryonic stem cell establishment.At first,the maturation medium containing estrus female sheep serum and synthetic oviduct fluid(SOF)were optimized for sheep IVF,and then the effects of LPA were investigated.From 0.1 to 10μmol L^(–1),LPA had no significant effect on the cleavage rate(P>0.05),but the maturation rate and blastocyst rate increased dependently with LPA concentration(P<0.05),and the blastocyst morphology was normal.When the LPA concentration was 15μmol L^(–1),the maturation rate,cleavage rate and blastocyst rate decreased significantly(P<0.05),and the blastocyst exhibited abnormal morphology and could not develop into highquality blastocyst.Besides,the exogenous LPA increases the expression of LPAR2,LPAR4,TE-related gene CDX-2and pluripotency-related gene OCT-4 in sheep early IVF embryos with the raise of LPA concentration from 0.1 to 10μmol L^(–1).The expression of LPAR2,LPAR4,CDX-2 and OCT-4 from the LPA-0.1μmol L^(–1)to LPA-10μmol L^(–1)groups in early embryos were extremely significant(P<0.05),while the expression of these genes significantly decreased in 15μmol L^(–1)LPA-treated embryos compared with LPA-10μmol L^(–1)group(P<0.05).The inner cell mass in 15μmol L^(–1)LPA-treated embryos was also disturbed,and the blastocysts formation was abnormal.Secondly,the sheep IVF blastocysts were applied to establish embryonic stem cells.The results showed that LPA made the blastocyst inoculated cells grow towards TSC-like cells.They enhanced the fluorescence intensity and mRNA abundance of OCT-4 and CDX-2 as the concentration increased from 0 to 10μmol L^(–1),while 15μmol L^(–1)LPA decreased OCT-4 and CDX-2 expression in the derived cells.The expression of CDX-2 and OCT-4 in the blastocyst inoculated cells of LPA-1μmol L^(–1)group and LPA-10μmol L^(–1)group extremely significantly increased(P<0.05),but there was significant decrease in LPA-15μmol L^(–1)group compared with LPA-10μmol L^(–1)group(P<0.05).Meanwhile,the protein expression of LPAR2 and LPAR4 remarkably increased after treatment of LPA at 10μmol L^(–1)concentration.This study references the IVF embryo production and embryonic stem cell research of domestic animals.

MicroRNA-370-5p inhibits pigmentation and cell proliferation by downregulating mitogen-activated protein kinase kinase kinase 8 expression in sheep melanocytes

In mammals,microRNAs(miRNAs)play key roles in multiple biological processes by regulating the expression of target genes.Studies have found that the levels of miR-370-5p expression differ significantly in the skins of sheep with different hair colors;however,its function remains unclear.In this study,we investigated the roles of miR-370-5p in sheep melanocytes and found that the overexpression of miR-370-5p significantly inhibited cell proliferation(P<0.01),tyrosinase activity(P=0.001)and significantly reduced(P<0.001)melanin production.Functional prediction revealed that the 3′-untranslated region(UTR)of MAP3K8 has a putative miR-370-5p binding site,and the interaction between these two molecules was confirmed using luciferase reporter assays.In situ hybridization assays revealed that MAP3K8 is expressed in the cytoplasm of melanocytes.The results of quantitative RT-PCR and Western blotting analyses revealed that overexpression of miR-370-5p in melanocytes significantly inhibits(P<0.01)MAP3K8 expression via direct targeting of its 3′UTR.Inhibition of MAP3K8 expression by siRNA-MAP3K8 transfection induced a significant inhibition(P<0.01)of melanocyte proliferation and significant reduction(P<0.001)in melanin production,which is consistent with our observations for miR-370-5p.Target gene rescue experiments indicated that the expression of MAP3K8 in melanocytes co-transfected with miR-370-5p and MAP3K8-cDNA(containing sites for the targeted binding to miR-370-5p)was significantly rescued(P≤0.001),which subsequently promoted significant increases in cell proliferation(P<0.001)and melanin production(P<0.01).Collectively,these findings indicate that miR-370-5p plays a functional role in inhibiting sheep melanocyte proliferation and melanogenesis by downregulating the expression of MAP3K8.

Gait analysis in swine,sheep,and goats after neurologic injury:a literature review

Medical research on neurologic ailments requires representative animal models to validate treatments before they are translated to human clinical trials.Rodents are the predominant animal model used in neurological research despite limited anatomic and physiologic similarities to humans.As a result,functional testing designed to assess locomotor recovery after neurologic impairment is well established in rodent models.Comparatively,large r,more clinically relevant models have not been as well studied.To achieve similar locomotor testing standardization in larger animals,the models must be accessible to a wide array of researchers.Non-human primates are the most relevant animal model fo r translational research,however ethical and financial barriers limit their accessibility.This review focuses on swine,sheep,and goats as large animal alternatives for transitional studies between rodents and non-human primates.The objective of this review is to compare motor testing and data collection methods used in swine,sheep,and goats to encourage testing standardization in these larger animal models.The PubMed database was analyzed by searching combinations of swine,sheep,and goats,neurologic injuries,and functional assessments.Findings were categorized by animal model,data collection method,and assessment design.Swine and sheep were used in the majority of the studies,while only two studies were found using goats.The functional assessments included open pen analysis,treadmill walking,and guided free walking.Data collection methods included subjective behavioral rating scales and objective tools such as pressure-sensitive mats and image-based analysis software.Overall,swine and sheep were well-suited for a variety of assessment designs,with treadmill walking and guided free walking offering the most consistency across multiple trials.Data collection methods varied,but image-based gait analysis software provided the most robust analysis.Future studies should be conducted to standardize functional testing methods after neurologic impairment in large animals.

Effects of Antimicrobial Peptides on Production,Slaughter Performance and Blood Routine of Tan Sheep

[Objectives]This study was conducted to analyze effects of antimicrobial peptides added to the diet of Tan sheep on their production, slaughter performance and blood composition. [Methods] Ninety two four-month-old Tan sheep were randomly divided into two treatment groups according to their body weight, 46 in each group. The control check group(CK) was feed with conventional diet, and the experimental group was fed with the addition of antimicrobial peptide on the basis of the conventional diet, with the added amount of 2.5 g/sheep per day. The experimental period was 60 d. [Results] The incidence rate was 75.06% lower in the experimental group than in the CK. The average daily weight gain per sheep was 11.27% higher in the experimental group than in the CK(P<0.05). The feed conversion ratio was 8.45% lower in the experimental group than in the CK(P<0.05). The average daily gross profit per sheep was 12.12% higher in the experimental group than in the CK. For slaughter performance, the data difference of each item was not significant. The PH at 45 min and 24 h after slaughter was within the normal range of fresh mutton. The cooked meat percentage and water loss rate showed no significant differences(P>0.05). The marbling ranged from 2.45 to 2.50, indicating that the fat content was moderate, and the difference between groups was not significant(P>0.05). The flesh color ranged from 3.00 to 3.15, between light red and bright red, belonging to the normal color of mutton, and the difference between groups was not significant(P>0.05). The shear force was between 2.50 and 2.65, without a significant difference between groups(P>0.05). The white blood cells, lymphocytes and platelets in the experimental group were lower than those in the CK(P<0.01). The erythrocytes and hemoglobin in the erythrocyte group were higher than those in the CK(P<0.05). The neutrophils and monocytes in the experimental group were lower than those in the CK(P<0.05). [Conclusions] This study provides a technical basis for the rational use of antimicrobial peptides and their application in ruminants.

发酵中药和油莎豆复合物对湖羊生长性能及血清抗氧化和免疫指标的影响

【目的】研究发酵中药和油莎豆复合物对湖羊生长性能、血清抗氧化及免疫指标的影响,为新型饲料添加剂的开发提供依据。【方法】选取体重相近、健康状况良好的育肥湖羊40只,随机分为2组:对照组和试验组,每组20只。对照组湖羊饲喂基础饲粮,试验组湖羊在基础饲粮中添加2%复合发酵物,预试期7 d,正试期42 d,在正试期第0、42天分别称重,计算平均日增重;记录日采食量,计算料重比;在试验第1、21和42天颈静脉采血并分离血清,测定湖羊血清中抗氧化指标和免疫指标。【结果】试验组湖羊的终末体重、平均日增重及平均日采食量均显著高于对照组(P<0.05)。与对照组相比,在试验第21天,试验组湖羊血清中过氧化氢酶(CAT)、总抗氧化能力(T-AOC)活性及免疫球蛋白G(IgG)、γ干扰素(INF-γ)含量分别提高了2.75%、3.46%、7.28%和4.55%(P<0.05),丙二醛(MDA)含量降低了12.72%(P<0.05);在试验第42天,CAT、T-AOC活性及IgG、INF-γ含量分别提高了3.17%、3.67%、9.77%和11.91%(P<0.05),MDA含量降低了15.10%(P<0.05)。【结论】在本试验条件下,饲粮中添加2%发酵中药和油莎豆复合物能有效改善湖羊的生长性能,提高抗氧化和免疫机能,可作为一种新型饲料添加剂应用到畜牧生产中。

新疆肉羊产业2023年度发展分析及2024年度发展趋势预测

【目的】本文在全国及新疆2023年肉羊产业形势分析的基础上,跟踪了解新疆17家高效肉羊品种选育推广体系重点示范企业生产经营等情况,并且对2024年肉羊产业进行了趋势分析。【方法】结合产业动态信息和市场行情,采取定性和定量相结合的方法。【结果】2023年新疆羊肉价格下跌趋势明显,羊肉产量、消费稳中有增,活羊调运量增长,示范企业肉羊年出栏数、出栏率增长,存栏量下降,羊繁殖率和羔羊成活率稳步提升,羊单位平均总成本与饲草料成本变动趋势大致一致,均呈现逐年攀升态势,企业平均收益和利润降至近五年最低。【结论】预计2024年饲草料价格上涨将导致羊单位总成本继续攀升,羊肉价格将继续震荡运行,但振幅区间有限,羊肉消费增加是大趋势,但增速可能会放缓,随着羊肉需求的增长,羊肉市场供应将会进入平稳增长阶段。

羊捻转血矛线虫病检测方法研究进展

羊捻转血矛线虫病是由捻转血矛线虫寄生于羊等小反刍动物皱胃内引起的一种危害严重的嗜血性寄生虫病。病羊临床表现为消瘦、贫血和衰弱等慢性消耗性症状,严重感染者可致死。该病在我国牧区普遍流行,目前暂无安全长效疫苗可用,加之耐药性严重,放牧羊群感染率和发病率居高不下,极大地降低了羊养殖业的经济效益。准确可靠的检测手段是诊断寄生虫感染、制定驱虫治疗方案、耐药监测及流行病学调查的关键环节。本文详细介绍了羊捻转血矛线虫病的检测技术研究现状,分析了病原学、免疫学及分子检测等方法的优缺点,并对未来检测技术发展趋势进行了展望,以期为该病新型检测方法的研发及综合防控策略提供参考。

补饲胆固醇对高温环境下湖羊母羊繁殖性能和血清生化指标的影响

【目的】研究饲粮中添加胆固醇对中国南方夏季湖羊发情率、受胎率和血清生化指标的影响。【方法】选择108只体重相近(33.60 kg±1.86 kg)的健康湖羊母羊,其中30只湖羊在非高温季节(4月份,平均最高温度20.9℃±3.2℃)饲粮添加不同剂量胆固醇(0.1%和0.5%),ELISA方法检测血清中胆固醇含量的动态变化,筛选合适的胆固醇添加量;另外78只湖羊随机分成2组(对照组和试验组),试验期63 d(从同期发情处理第1天到自然发情后配种的第30天),在夏季高温季节(7-9月份,平均最高温度31.3℃±2.6℃),对照组饲喂基础饲粮,试验组饲喂添加0.1%胆固醇的基础饲粮,ELISA方法检测血清中雌二醇(E2)和孕酮(P4)水平,研究饲粮添加胆固醇对湖羊发情率、受胎率和血清生化指标的影响。【结果】非高温季节湖羊基础饲粮中分别添加0.1%和0.5%胆固醇,48 h后两组湖羊血清中胆固醇含量趋于一致,据此选择0.1%作为高温季节补饲胆固醇的添加剂量。夏季高温季节在补饲0.1%胆固醇的第3、30和63天均能显著提高湖羊血清中胆固醇含量(P<0.05);且试验组湖羊自然发情率(89.7%)高于对照组(82.1%)(P>0.05),受胎率(60.0%)显著高于对照组(46.9%)(P<0.05)。试验组湖羊总蛋白、球蛋白、白细胞介素-1和甘油三酯含量均显著高于对照组(P<0.05),而尿素氮含量显著下降(P<0.05)。【结论】夏季高温环境下,在湖羊母羊饲粮中添加0.1%胆固醇可有效提高其发情率和受胎率。

青贮甘蔗梢替代玉米秸秆对湖羊生长性能、消化代谢及肉品质的影响

[目的]本试验旨在探索青贮甘蔗梢替代青贮玉米秸秆作为肉羊日粮的可行性,并确定最佳的替代比例。[方法]选取3月龄、体重相近[(20.15±2.18)kg]的健康湖羊公羔48只,随机分成4组,每组3个重复,分别用青贮甘蔗梢替代0%(对照组)、50%(A组)、75%(B组)、100%(C组)青贮玉米秸秆饲喂,预试期10 d,正试期为60 d。试验开始和结束时测定湖羊生产性能,并采集血液样品进行血清生化分析;饲喂试验结束后,从每组不同重复各选择1只湖羊屠宰,测定其屠宰性能及肉品质;从每组不同重复再挑选3只湖羊进行消化代谢试验,测定养分消化代谢参数。[结果]B组和C组平均日增重、胴体重和屠宰率显著高于A组和对照组(P<0.05);B组和C组氮沉积量显著高于A组和对照组,A组、B组和C组的表观消化能和能量转化率均显著高于对照组;各组间血液生化指标、肉品质及肉营养成分均无显著差异(P>0.05)。青贮甘蔗梢替代75%和100%青贮玉米秸秆可以显著提高湖羊生长性能和屠宰性能,而且对湖羊血清生化指标、组织器官发育和肉品质无不利影响。[结论]青贮甘蔗梢可替代青贮玉米秸秆饲喂肉羊,且最佳替代比例为75%~100%。

全株玉米青贮不同比例替代花生秧对肉羊生产性能及肉品质的影响

试验旨在研究全株玉米青贮不同比例替代花生秧对肉羊生长性能、屠宰性能、肉品质和营养物质消化率的影响。选取杜寒杂交育肥羊100只,随机分为4组,每组5个重复,每个重复5只羊。对照组饲喂含100%花生秧的基础饲粮,3个试验组分别饲喂利用全株玉米青贮替代50%(50%替代组)、75%(75%替代组)、100%(100%替代组)花生秧的试验饲粮,试验期30 d。结果表明:与对照组相比,75%替代组可以显著提高肉羊试验期末重和平均日增重(P<0.05),显著降低肉羊试验期料重比(P<0.05),且75%替代组肉羊试验期末重和平均日增重显著高于50%替代组和100%替代组(P<0.05),料重比显著低于100%替代组(P<0.05);75%替代组可以提高肉羊屠宰前活体重(P<0.05)、胴体重(P>0.05)和眼肌面积(P>0.05);3个替代组对肉羊肉品质各项指标均无显著影响(P>0.05);75%替代组可以显著提高肉羊干物质和有机物的表观消化率(P<0.05)。综上所述,肉羊养殖饲粮中应用全株玉米青贮替代75%的花生秧可以提高肉羊生长性能、屠宰性能及饲粮中干物质和有机物的表观消化率。

小尾寒羊不同部位风味物质与风味前体物的相关性分析

以6~7月龄、体质量为50 kg的小尾寒羊为实验对象,选取颈肉(NM)、里脊(LLDM)和腿肉(RG),对小尾寒羊挥发性风味物质、脂肪酸和氨基酸进行相关性分析。结果表明:在3个部位共检测到45种挥发性风味物质,其中醛类是最主要的挥发性风味物质,占总挥发性风味物质的50%左右。经主成分分析得知,庚醛、壬醛、苯甲醛等24种风味物质是导致不同部位间挥发性风味物质差异的主要影响因素。LLDM中对人体有益的单不饱和脂肪酸和多不饱和脂肪酸含量均为最高,脂肪酸比例更符合人体对羊肉脂肪酸营养价值的需求,对人体健康更有益。氨基酸中以谷氨酸(Glu)和赖氨酸(Lys)为主,约占总氨基酸的17%和10%,其中RG除蛋氨酸(Met)、酪氨酸(Tyr)、赖氨酸(Lys)外含量均为最高,且除谷氨酸(Glu)和脯氨酸(Pro)外与LLDM差异不显著,与NM差异均显著。相关性分析表明,多不饱和脂肪酸与大多数挥发性风味物质呈正相关,且与醛类、醇类和芳香类等挥发性风味物质呈显著正相关,这可能是因为多不饱和脂肪酸极易氧化,在氧化过程中生成醛类、醇类和芳香类等物质。氨基酸与大多数醛类和醇类都呈正相关,这可能是因为氨基酸通过转氨反应等一系列反应,最终生成醛类和醇类等物质。

花生秧青贮对肉羊生长性能、养分表观消化率及经济效益的影响

试验旨在研究花生秧青贮对肉羊生长性能、养分表观消化率及经济效益的影响。试验选择60只体重相近、体况良好的肉羊,随机分为4组,每组15个重复,每个重复1只羊。对照组肉羊饲喂全株玉米青贮饲粮,试验1组使用20%的花生秧青贮替代全株玉米青贮,试验2组使用40%的花生秧青贮替代全株玉米青贮,试验3组使用80%的花生秧青贮替代全株玉米青贮。试验期60 d。结果表明,各花生秧青贮组肉羊的料重比显著低于对照组(P<0.05),平均日增重显著高于对照组(P<0.05)。试验2组和试验3组肉羊对粗蛋白和中性洗涤纤维的表观消化率显著高于对照组(P<0.05)。试验2组和试验3组肉羊血清中总蛋白水平显著高于对照组(P<0.05),尿素氮和甘油三酯水平及谷丙转氨酶活性显著低于对照组(P<0.05)。各花生秧青贮组养殖的利润均高于对照组,且随着花生秧青贮用量的增大呈上升趋势。研究表明,花生秧青贮可以提高肉羊的生长性能及养分表观消化率,改善血清生化指标,提高养殖利润。综合考虑,肉羊养殖中使用40%~80%的花生秧青贮比较适宜。