Effect of Crossbreed on the Muscle Quality(Chemical Composition) in Yun-Ling Black Goats

Twenty castrated male goats, each of Yun-Ling Black goats （YLB goat）, N × YLB hybrid goats （Nubian ♂ ×Yun-Ling Black goats 9） and B × YLB hybrid goats （Boer ♂× Yun-Ling Black goats ♀）, were used to evaluate the effect of crossbreeding on the meat chemical composition in the YLB goats of China. After weaning of 90 days, all the experimental goats were reared on natural pasture when they were slaughtered at an age of 730 days. The longissimus dorsi （LD） and biceps femoris （BF） muscles were sampled from each carcass to determine chemical compositions. Both hybrid goats had higher protein content （P 〈 0.01） and lower fat content （P 〈 0.05） than the YLB goats in the two types of muscle. The inosinic acid contents of LD muscle for the YLB goats and the B × YLB hybrid goats were significantly higher （P 〈 0.05） than that for the N × YLB hybrid goats. The LD muscle from the YLB goats contained higher essential amino acid （P 〈 0.01）, total amino acid （P 〈 0.01）, and some individual amino acid （P 〈 0.05） than those from the hybrid goats. The concentration of unsaturated fatty acid （USFA） of LD muscle from the N × YLB hybrid goats was significantly higher than the other two goat breeds （P〈0.05） but did not differ between the other two goat breeds （P〉0.05）. The YLB goats had significantly higher （P〈0.05） concentrations of oleic acid （C18：1） and linolenic acid （C18：3） of LD muscle than the hybrid goats, had significantly higher （P 〈 0.05） proportion of mono-unsaturated （Sum for C 16：1 and C 18：1） than the B ×YLB hybrid goats, and tended to be higher than the N × YLB hybrid goats （P 〉 0.05）. In contrast, the proportion of poly-unsaturated in the YLB goats was significantly lower （P 〈 0.05） than that in the hybrid goats.

Cloning and Transcriptional Activity of Follicle-Stimulating Hormone Receptor Promoter in the Jintang Black Goat

[ Objective] To clone follicle-stimulating hormone receptor （FSHR） promoter in the Jintang black goat, study its transcriptional activity, and provide a basis for alternative splicing of FSHR gene. [Method] The total DNA were extracted from the womb of Jintang black goat, and one pair of primers were designed for amplification of FSHR promoter fragments, then the sequences and homology were analyzed. The FSHR promoter fragment was inserted into the pcFSHRB1 expression vector to substitute the CMV promoter and construct the pcFSHRB2 expression vector. The pcFSHRB1 and pcFSHRB2 expression vectors were transformed into HEK293 cells, respectively. Then these cells were collected after 24 and 48 h treatment with 2 mlU/ml follicle-stimulating hormone （FSH）, and the cAMP levels were detected. [Result] The FSHR promoter sequence of Jin- tang black goat had 34.2% homology to that of chicken and 41.6% to that of rat, respectively. The transcription initial site of FSHR was at -576 bp and its upstream sequences contained two TATA-boxes, four CAAT-boxes, one E-box and one Wl-box. After treating for 24 and 48 h, the cAMP levels of pcFSHRB2 were respectively 299.581 3 and 125.528 1 pmol/L; and that of pcFSHRB1 were respectively 120.057 1 and 109.940 7 pmoVL. [Conclusion] The FSHR promoter of Jintang black goat is a typical type 2 eukaryotic promoter, and it is also a strong promoter.

Research Progress of Gene Polymorphism of Guizhou Black Goat

Guizhou black goat is the second-largest breed of goat in Guizhou, an important part of ecosystem of karst region. Constructing cladogTam of black goat and Guizhou local goat with molecular biological technique, we found some functional genes related to reproduction and growth of black goat, such as FSHR, LHβ, GDF9, MSTN, POU1F1, GFI1B, etc. In view of the genetic relations between Guizhou black goat and other local goats, we reviewed the research status and progress of gene polymorphism of FSHR, LHβ,GDF9, MSTN, POU1F1, GFI1B, and prospected the research field of molecular properties of the breed resource.

Physicochemical Properties and Eating Quality of Lamp Meat of Dazu Black Goats

The routine nutrients, mineral content, amino acid content and fatty acid content as well as the physicochemical properties and the heavy metal and pesticide residues of Iongissimus dorsi muscles in confined Dazu black goats at the age of 6 months were determined. The results showed that the lamb meat of Dazu black goats was dch in nutrients, fresh, tender, palatable and fine in texture as well as non-hazardous in quality. Thus, the meat of Dazu black goat is a kind of healthy and nutritious food with rich nutrients, and it has better prospects of exploitation and utilization in the food industry.

Interrelation between Seasonal Grazing Behavior of Guizhou Black Goat and Grassland Productivity

In order to discover the relationship of the Guizhou black goat seasona grazing behavior traits and grassland productivity, the varieties of grazing behavior of Guizhou black goat and its relationship with the grassland productivity under different grazing intensity in all seasons on Guizhou karst artificial grassland were studied. Obvious differences for goat grazing behavior were found under differen grazing intensity in either the same season or different seasons. The grazing behav ior in the same season showed that it could significantly reduce the mouth eating grass within 5 minutes, each step number, feeding speed, each food intake, daily feed intake（P0.05） under high grazing intensity. In different seasons, it could in crease the feeding time within 5 min, marching step, standing time and intake（P0.05） in the spring; while in the summer, it could improve intake mouth number each mouth eating grass number and feeding rate（P0.05）. It had no obvious dif ference in ruminant behavior parameters in the same season under different grazing intensity, but in different seasons, it can obviously increase ruminant within 5 minutes, number of ruminant feed group（P0.05） in the spring, and it can obviously in crease the time and number of each food group chew（P0.05） in the summer. The correlation analysis of main goat grazing behavior parameter showed that it had good correlation among other parameters except within 5 min walk time, each feed intake and daily feed intake（P0.05）.The relationship between goat grazing behavio parameters and grassland productivity showed that, the foraging time and standing time within 5 min were lower in the medium level of grassland productivity, while number of food intake, every step to eat grass and daily feed intake were higher with increasing grassland productivity, goats feeding speed was reduced, but each intake was increased.

Genetic Diversity Analysis of Guizhou Black Goat Using Microsatellite DNA Markers

In this study, the genetic diversity of Guizhou black goat was analyzed by using eight microsatellite DNA markers, including MAF33, OarFCB48, OarF- CB3IM, BM1258, MAF70, OarFCB11, RM088 and AEIO1. According to the results, a total of 43 alleles were found at eight microsatellite loci in Guizhou black goat population. The average heterozygosity was 0. 679 2 in Guizhou black goat population. Microsatellite locus MAF70 had the highest hetemzygosity （0.780 7 ）, and locus AE101 exhibited the lowest heterozygosity （0.545 5 ）. The average polymorphism information content （PIC） was 0. 626 7 in Guizhou black goat popula- tion, which was higher than O. 5, indicating high levels of polymorphism.

Investigation on the Growth and Development of Muscle Fibers in Black Goat Lambs

[Objectives]This study was conducted to analyze and study the growth and development of muscle fibers at different stages,so as to provide a theoretical basis for subsequent research on developmental biology and nutritional regulation.[Methods]The body weights of black goat lambs in groups at different month age(0-6 months old)were recorded,and the diameter,area and number of muscle fibers were measured by tissue section and hematoxylin-eosin staining.The curves of body weight and muscle fiber growth and development of black goat lambs were drawn.[Results]The black goat lambs maintained a high absolute growth intensity of 2.95-4.35 kg/30 d throughout the rearing cycle,and the body weight continued to increase significantly,while the relative growth coefficient decreased from 93.05%at the age of 30 d to 13.83%at the age of 180 d.The diameter and area of muscle fibers in black goat lambs showed obvious"three-stage"growth and development characteristics,and showed different trends of gender advantages in different stages.[Conclusions]This study will help to further optimize the key supporting technologies for production and promote the diversified and comprehensive development of the mutton sheep industry in Sichuan Province.

Thinking on Breeding of Fecundity Genes in Guizhou Black Goats Through Cost-benefit Analysis of Mutton Sheep by SAS Multivariate Stepwise Regression

The total output value of mutton in Northwestern China has accounted for more than 60%of the total output value of animal husbandry over the years.It can be seen that the mutton industry in Northwest China not only plays a pivotal role in animal husbandry,but also plays an important role in Chinese agriculture.In this study,based on cost accounting theory,income-related theories and total factor productivity theory,using basic knowledge of statistics and economics,drawing on existing research results at home and abroad,and adopting a combination of qualitative analysis and quantitative analysis of SAS multiple stepwise regression,the changing trends of cost-benefit of mutton sheep breeding in Northwest agricultural and pastoral areas and influencing factors of production costs and production efficiency were investigated,aiming to provide reference for saving mutton sheep feeding material resources,reducing mutton sheep breeding costs,and improving mutton sheep breeding benefits.

Effect of Pelleted Total Mixed Ration on Production Performance and Serum Biochemical Index of Growing Hainan Black Goats

[Objective] The paper was to investigate effects of pelleted total mixed ration on production performance and serum biochemical index of growing Hainan black goats.[Method] Twenty-four growing Hainan black goats with the same genetic backgrounds and similar initial weight of(10.05±0.049) kg were randomly assigned into two treatments, and supplied with Juncao + concentrate(control group), pelleted total mixed ration(experimental group), respectively. The trial lasted 50 d.[Result] The final weight, daily gain and feed intake of experimental group were significantly higher than those of control group(P<0.05), but the feed/gain ratio of experimental group was markedly lower than that of control group(P<0.05). Compared with the control group, the gross profit of experimental group significantly increased( P <0.05).[Conclusion] Pelleted total mixed ration led to better production performance of growing Hainan black goat.

Slaughtering Performance and Meat Quality of Hainan Black Goat and Its Hybrid Offsprings with Nubian Black Goat

In order to compare the slaughter performance and meat quality of Hainan black goats and hybrid offsprings of Nubian Black Goat and Hainan Black Goat, six 7-month-old Hainan black goats and six hybrid offsprings were selected to determine slaughter performance and muscle quality. The results showed that hybridization of Nubian black goat and Hainan black goat significantly improved the production performance and slaughter performance of hybrid offsprings (P>0.05). The meat quality of F1 hybrid black goat had no significant difference with that of Hainan black goat except for the hardness and elasticity (P<0.05). Therefore, the crossbred progenies of Nubian black goat and Hainan black goat have advantages in meat yield and meat performance, and the main meat quality indexes are not significantly different, which meets the market requirements for high-yield and high-quality hybrid combinations, and can be used for cross promotion.

Effect of Pelleted Total Mixed Ration of Different Particle Sizes on Production Performance and Serum Biochemical Index of Fattening Hainan Black Goats

[Objective] The paper to investigate the effects of pelleted total mixed ration of different particle size on production performance and serum biochemical index of fattening Hainan black goats.[Method] Thirty-six fattening Hainan black goats with the same genetic backgrounds and similar initial weight of(19.02±0.22) kg were randomly divided into three treatments. Goats were fed with Juncao+concentrate(control group), pel-leted total mixed ration I(particle size 6 mm, experimental group I) and II(particle size 5 mm, experimental group II), respectively. The trial lasted 45 d.[Result](1) The final weight and daily gain of experimental group II were significantly higher than those of control group( P<0.05), and the daily gain of experimental group II was also higher than that of experimental group I(P<0.05);the feed intake of experimental group II was markedly higher than that of control group(P<0.05), but was significantly lower than that of experimental group I(P<0.05). The feed/gain ratio of experimental group II was significantly lower than those of control group and experimental group I(P<0.05).(2) The feed gain cost of experimental group II was markedly lower than that of control group(P<0.05), but the gross profit was significantly higher than those of control group and experimental group I(P<0.05).(3) Compared with the control group, the serum total protein content of experimental group II increased markedly( P<0.05) while the urea nitrogen level decreased(P>0.05).[Conclusion] The pelleted total mixed ration with the particle size of 5 mm obtained better fattening ef-fect, and obviously improved the serum total protein level.

Meat Quality Characteristics of Hainan Black Goat and Its Hybrid with Nubian Black Goat

[Objective] The paper was to understand the meat quality characteristics of Hainan black goat and its hybrid with Nubian black goat. [Method]Four 6-month-old Hainan black goats and Hainan black goat × Nubian black goat F1 were slaughtered respectively,and the contents of crude protein,total fat,moisture,amino acids,mineral elements( Se,Zn and Mn) and fatty acid were determined. [Result]There was no significant difference in total fat,crude fat and moisture content in muscle of Hainan black goat × Nubian black goat F1 and Hainan black goat( P > 0. 05). The Fe content in the muscle of Hainan black goat × Nubian black goat F1 was significantly higher than that in Hainan black goat( P < 0. 05). There was no significant difference in EAA,NEAA,TAA and FAA between Hainan black goat × Nubian black goat F1 and Hainan black goat( P > 0. 05). The C17∶ 0 methyl heptadecanoate content in the muscle of Hainan black goat × Nubian black goat F1 was extremely lower than that in Hainan black goat( P < 0. 01),but the saturated fatty acid content and total unsaturated fatty acid content in the muscle of Hainan black goat × Nubian black goat F1 was lower than that in Hainan black goat( P > 0. 05). [Conclusion]The meat quality characteristics of Hainan black goat × Nubian black goat F1 had little difference with its female parent,and the goal of breeding had been basically achieved.

Effect of Pelleted Total Mixed Ration with Different Concentrate-roughage Ratios on Production Performance and Serum Biochemical Parameters of Fattening Hainan Black Goats

[Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method] Thirty-six fattening Hainan black goats with the same genetic background and similar initial weight of(14.08±0.13) kg were randomly assigned into three treatments. Goats were fed with Juncao + concentrate(control group), pelleted total mixed ration I(concentrate: roughage 50 ∶50, group Ⅰ) and Ⅱ(concentrate: roughage 45∶55, group Ⅱ), respectively. The test lasted 45 d.[Result] The final weight, daily gain and feed intake of rams in experimental group Ⅰ were significantly higher than those of control group and experimental group Ⅱ(P<0.05);the final weight and daily gain of rams in experimental group Ⅰ were also markedly higher than those of experimental group Ⅱ(P<0.05);the feed/gain of rams in experimental group Ⅰ was significantly lower than those in control group and experimental group Ⅱ(P<0.05). The feed gain cost of rams in experimental group Ⅰ was markedly lower than that in experimental group Ⅱ( P<0.05), but was significantly higher than that in experimental group Ⅰ(P<0.05);the gross profit of rams in experimental group Ⅰ was significantly higher than those in control group and experimental group Ⅱ(P<0.05). Compared with control group and experimental group Ⅱ, the serum total protein and glucose lev-els in experimental group Ⅱ increased significantly(P<0.05), but the urea nitrogen content reduced(P>0.05).[Conclusion] When the concentrateroughage ratio of pelleted total mixed ration was 50∶50, the fattening effect of Hainan black goat was better, and the serum total protein and glucose levels were evidently improved.

基于GBS测序的湘东黑山羊的亲缘关系及近交系数

利用基因分型测序(GBS)对60只湘东黑山羊(9只公羊、51只母羊)进行基因组测序,获得湘东黑山羊染色体上的SNP数据和连续纯合子片段(ROH)数据。通过SNP数据进行基于G矩阵的基因组亲缘关系分析和NJ聚类分析,构建湘东黑山羊的群体家系结构,并通过ROH数据得到群体平均近交系数。结果表明,60只湘东黑山羊的平均测序深度为9.15X,与参考基因组比对率平均为99.59%;在SNP检测过程中,3只母羊不符合基因型数据质控标准,将其过滤后获得其他57只黑山羊29条染色体上153046个SNPs位点和1937个ROH片段;构建的湘东黑山羊8个家系,其中9只公羊和6只母羊被分为7个家系,另42只母羊被单独分类;基于ROH片段分析的湘东黑山羊群体中每个个体的近交系数均值为0.047,说明湘东黑山羊公羊在繁育过程中有较大的利用空间。

不同处理方法对海南黑山羊同期发情效果和繁殖性能的影响

为探讨不同处理方法对海南黑山羊同期发情效果和繁殖性能的影响。随机选取海南省某规模化养羊场的120头(35~50)kg海南黑山羊,分为2次注射氯前列烯醇(PG)法、孕酮阴道栓(CIDR)+孕马血清促性腺激素(PMSG)二联法、CIDR+PMSG+PG三联法3种不同的处理方法,诱导发情试验结束后,分别观察3组羊的发情情况和繁殖性能。结果显示,3组试验羊的同期发情率差异显著,且试验组C海南黑山羊同期发情率显著高于试验组A和试验组B(P<0.05);试验组A母羊发情时间主要集中在48~72 h,试验组B和试验组C母羊发情时间主要集中在24~48 h;试验组C母羊的受胎率和产羔率均显著高于试验组A和试验组B(P<0.05);待分娩后,3组试验母羊初生的羔羊平均初生重差异不显著(P>0.05)。结果表明,应用CIDR+PMSG+PG三联法处理方法能够显著提高海南黑山羊同期发情效果和繁殖性能,为今后提高海南黑山羊同期发情效果和繁殖性能提供了参考依据。

基于简化基因组测序(Super-GBS)的子午岭黑山羊保种群遗传结构评估

旨在分析子午岭黑山羊的群体遗传多样性和亲缘关系以及家系结构,为子午岭黑山羊的保护和利用提供依据。本研究通过简化基因组测序(super-genotyping by sequencing,Super-GBS)技术对99只(10公/89母)成年子午岭黑山羊进行全基因组SNP检测。利用Plink软件计算观测杂合度(Ho)、期望杂合度(He)、多态信息含量(PIC)、核苷酸多样性(Pi)、有效等位基因数(Ne)及次要等位基因频率(MAF)等6项遗传多样性指标;GCTA软件进行主成分分析及基因组亲缘关系G矩阵构建;Plink软件构建IBS遗传距离矩阵,R语言绘制热图;PHYLP构建系统发育树;detect RUNS工具检测ROH。结果表明,99只子午岭黑山羊个体共检测到996042个SNPs。子午岭黑山羊群体的PIC、Pi、Ne及MAF值分别是0.161、0.193、1.295、0.130,且Ho(0.167)低于He(0.192),说明子午岭黑山羊群体遗传多样性较低。G矩阵和IBS遗传距离结果均表明子午岭黑山羊群体间大部分个体间亲缘关系较远。主成分分析结果揭示子午岭黑山羊群体内部不存在明显分化,系统发育树结果说明子午岭黑山羊群体公羊可大致分为6个家系,所有家系公羊数量较少。子午岭黑山羊群体的近交系数FROH为0.0496,说明子午岭黑山羊群体内部近交程度相对较低。综上所述,子午岭黑山羊群体遗传多样性较低,大部分个体间亲缘关系较远,群体内近交程度较低,后期应注意后代的选育,避免血统流失。

菌糠替代紫花苜蓿对贵州黑山羊母羊生产性能、抗氧化能力和瘤胃微生物区系的影响

试验旨在研究饲粮中菌糠替代紫花苜蓿对贵州黑山羊母羊生产性能、抗氧化能力和瘤胃微生物区系的影响。选取18只体况相近的贵州黑山羊母羊,随机分为3组,每组6个重复,每个重复1只羊。对照组饲喂基础饲粮,试验组分别以金针菇和海鲜菇菌糠等量替代基础饲粮中的紫花苜蓿,依次记为对照组(CK组)、金针菇组(JZG组)、海鲜菇组(HXG组)。预试期14 d,正式试验期60 d。结果显示,JZG组和HXG组血清中超氧化物歧化酶(SOD)、谷胱甘肽过氧化酶(GSH-Px)活性和总抗氧化能力(T-AOC)均显著高于CK组(P<0.05),丙二醛(MDA)含量显著低于CK组(P<0.05)。JZG组和HXG组瘤胃液中乙酸(AA)含量显著低于CK组(P<0.05)。通过高通量测序分析发现,JZG组瘤胃微生物的物种多样性和丰度显著高于HXG组和CK组(P<0.05)。聚类分析发现:在门水平上,厚壁菌门和变形菌门相对丰度在CK组中较高,而拟杆菌门、疣微菌门、浮霉菌门和螺旋菌门相对丰度在JZG组和HXG组较高;在种和属水平上,奎因氏菌属、普雷沃氏菌属、溶糊精琥珀酸弧菌等相对丰度在CK组中较高,而毛螺科菌、理研菌科、支原体_girerdii等相对丰度在JZG组和HXG组较高。研究表明,以金针菇和海鲜菇菌糠替代紫花苜蓿调制全混合日粮对贵州黑山羊母羊的育肥效果无不良影响,其中金针菇菌糠效果优于海鲜菇菌糠。

饲喂青贮黄梁木代替青贮玉米川中黑山羊肝转录组的表达分析

旨在分析饲喂青贮黄梁木替代50%青贮玉米的川中黑山羊肝转录组测序中差异表达的mRNA、lncRNA及其靶基因,挖掘饲喂青贮黄梁木影响川中黑山羊肝代谢的关键基因,从而探究青贮黄粱木的饲喂效果。试验共选取6只雄性健康川中黑山羊[5月龄,平均体重(21.07±4.05)kg]并随机分为两组,试验组为青贮黄梁木替代50%青贮玉米组,对照组为青贮玉米组。试验期间采用全混合日粮(TMR)进行饲喂。于试验期的最后1 d对山羊进行屠宰并取其肝,提取肝组织的RNA,构建文库后使用高通量测序技术进行转录组测序,以P<0.05为阈值筛选出差异mRNA和lncRNA,进行生物学功能富集分析并构建靶向关系网络。再从差异表达lncRNA和mRNA中各随机选择3个基因,采用RT-qPCR进行验证分析。结果表明,共发现差异表达的mRNA有1696个,其中943个上调,753个下调;差异表达lncRNA共有33个,其中22个上调,11个下调。结合差异表达lncRNA的靶基因与差异表达mRNA的交集基因的富集分析发现,NDUFA10、NDUFB11、NDUFS 5参与肝功能相关的信号通路,如多糖代谢过程、葡聚糖分解代谢过程、纤维素分解代谢等。结合lncRNA靶基因预测发现,GSTA3、GSTA 4基因参与肝功能相关的信号通路如药物代谢-细胞色素P450及细胞色素P450对异源物质的代谢等代谢通路。本研究发现,在饲喂青贮黄梁木川中黑山羊的肝组织中,NDUFA10、NDUFB11、NDUFS 5以及GSTA3、GSTA 4等可能从营养物质代谢和毒素代谢等方面影响肝功能。

20~35kg川中黑山羊公羊能量需要量研究

本试验旨在研究20~35 kg川中黑山羊公羊的能量需要量,为川中黑山羊的科学饲养提供营养需要参数。采用比较屠宰试验法,选择2.5月龄、体重(19.97±5.47)kg的健康断奶川中黑山羊去势公羔22只,试验开始时屠宰4只,其余18只羔羊分为3个饲喂水平组(每组6只羊):自由采食组(AL组)、75%自由采食组(AL75组)、60%自由采食组(AL60组)。试验羊单笼单饲,试验期96 d。在饲养试验结束前4 d开展消化代谢试验,收集全粪全尿。当AL组试验羊平均体重达到35 kg时结束饲养试验,每组选取接近该组平均体重的4只羊(共12只)进行屠宰,屠体冷冻保存待测。结果表明:1)20~35 kg生长川中黑山羊维持净能需要量(NE m)为178.24 kJ/(kg BW 0.75·d),维持代谢能需要量(ME m)为263.74 kJ/(kg BW 0.75·d),代谢能维持利用效率(k m)为0.68。2)日增重100~300 g/d的川中黑山羊的生长净能需要量(NE g)为0.99~3.71 MJ/d,生长代谢能需要量(ME g)为3.15~11.78 MJ/d,代谢能生长利用效率(kg)为0.31。本研究可为我国地方品种肉羊饲养标准的健全提供数据参考。

20~35 kg川中黑山羊蛋白质需要量研究

旨在研究生长期川中黑山羊的蛋白质需要量,为川中黑山羊的科学饲养提供营养需要参数。选择2.5月龄(19.97±5.47)kg断奶川中黑山羊羯羊22只,试验开始时屠宰4只,其余18只羔羊分为3个饲喂水平组,分别为自由采食组(AL组)、75%自由采食组(AL75组)、60%自由采食组(AL60组),每组6只羊。试验羊单笼单饲,试验期96 d。在饲养试验结束前4 d开展消化代谢试验,收集全粪全尿。当AL组试验羊平均体重达到35 kg时结束饲养试验,每组选取接近该组平均体重的4只羊(共12只)进行屠宰,屠体冷冻保存待测。结果表明:1)川中黑山羊试验末期AL组公羊平均体重极显著高于AL60组(P<0.01);AL75和AL60组公羊净增重、平均日增重(ADG)、平均干物质采食量(DMI)极显著低于AL组(P<0.01);AL60组料重比显著高于AL和AL75组(P<0.05);2)AL组黑山羊宰前活重、空腹体重、胴体重、净肉重均极显著(P<0.01)高于AL75和AL60组,而屠宰率、净肉率、胴体净肉率、肉骨比3组间均无显著差异(P>0.05),AL组的骨重显著高于AL75和AL60组(P<0.05);3)AL、AL75和AL60组山羊的心脏、脾脏、肺脏器官指数和皮毛器官指数差异不显著(P>0.05),AL组肝脏器官指数极显著高于AL75和AL60组(P<0.01),肾脏器官指数随饲喂水平下降显著降低(P<0.01);4)20~35 kg川中黑山羊公羊的维持净蛋白质需要量为1.60 g·kg^(-1)·BW-0.75·d^(-1),日增重100~300 g·d^(-1)的川中黑山羊生长净蛋白质需要量Np_(g)=13.13~40.13 g·d^(-1),净蛋白质的总需要量Np_(r)=28.26~63.15 g·d^(-1)。本研究可为我国地方品种山羊饲养标准的优化提供数据参考。