This study aimed to observe the effects of varying dietary proportions of palm kernel meal (PKM) on fermentation parameters and the rumen microbiota in Tibetan sheep. At farrowing, lambs were identified as having low birth weights (LBWs, < 4.0 ± 0.35 kg) or normal birth weights (NBWs, > 5.50 ± 0.50 kg). NBW lambs were selected for further experiments. On day 60, lambs were weaned onto a common diet. A total of 120 NBW Tibetan male lambs (18.39 ± 1.25 kg) were randomly assigned to four groups. The control group (PKM control, PC) was fed a basal diet, while the three experimental groups were fed diets supplemented with 15

The calpastatin gene has been extensively studied as a candidate gene because of its regulatory function within muscle development of animals. However, little is known about the association between variation of the calpastatin gene and growth traits in Tibetan sheep. Using DNA sequencing, four single-nucleotide polymorphisms g.3844A>G, g.88874T>C, g.89126C>T, and g.89157A>C were identified in this study. An association analysis indicates that the g.3844A>G and g.89126C>T polymorphisms affected body weight (P < 0.05). The g.89157A>C polymorphism was significantly correlated with body weight and chest circumference (P < 0.05). The quantitative real-time polymerase chain reaction analysis revealed that the expression of calpastatin gene presented an increasing trend with an increase in age. Remarkably lower mRNA expression was detected at the fetal stage compared with adult ewes (P < 0.05). These findings indicated that the calpastatin gene polymorphisms were involved in growth-related traits in Tibetan sheep, which can be considered as genetic markers for improving the growth traits of Chinese Tibetan sheep.

Background Compared with corn, wheat contains higher crude protein, amino acids concentration. However, wheat contains a mass of anti-nutritional factors, resulting in increased of the digesta viscosity and impaired the intestinal function in ruminant. Objective This study aimed to investigate the effects of substitution of different amounts of wheat for corn on hepatic metabolism in the Tibetan lamb. Methods Ninety Tibetan lambs (Body weight = 12.37 ± 0.92 kg) were randomly assigned to three groups: 0% wheat diet (Control), 10% wheat diet (Low group), and 15% wheat diet (High group). The feeding trial lasted for 130 d, including a 10 d adaption period. Hepatic gene expression profiling was performed via RNA sequencing after the conclusion of the feeding trials. Results Results showed that greater level of glutathione peroxidase levels in L group compared with those of the C and H groups ( P < 0.05). The immune indexes, including interleukin-1β (IL-1β), immunoglobulin A (IgA), and IgM were also elevated in L group compared with the other groups ( P < 0.05). Compared with H group, the hepatocytes were arranged radially, and hepatic plates anastomosed with each other to form a labyrinth-like structure in L group. Transcriptomic analysis showed 872 differentially expressed genes (DEG) between H and L group, of which 755 were down-regulated and 117 were up-regulated. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, 32 pathways were significantly enriched (Q-value < 0.05), such as the cAMP signaling pathway, Th1 and Th2 cell differentiation, leukocyte transendothelial migration, platelet activation and adipocytokine signaling pathway. Additionally, the expression of comment DEGs were verified via quantitative reverse-transcription polymerase chain reaction. Conclusion In summary, our findings suggest that wheat can be supplemented up to 10% in Tibetan sheep, contributing to improve the hepatic oxidative stress, immune response and lipid metabolism through regulating the expression of related genes.

Palm kernel meal (PKM) is a by-product of oil palm kernel after oil extraction, which is widely used in animal feeds due to its high energy content. This study aimed to investigate the impact of supplementing Tibetan sheep with PKM on their hepatic phenotype, oxidative stress and immune response. A total of 120 Tibetan lambs (Initial weight = 12.37 ± 0.92 kg) were randomly assigned into four groups: control group (C group, 0

Xylanase is a heteropolysaccharide found in the plant cell wall, which aids in the absorption and utilisation of nutrients. When embedded in animal feed, it enhances nutrient availability, leading to improved animal performance. The aim of this study was to explore the effect of xylanase supplementation in wheat-based feeds on the hepatic development, antioxidant capacity, and immune response in Tibetan sheep. Sixty healthy, weaned, non-neutered male lambs (19.35 +/- 2.18 kg) were randomly assigned to two equal groups (n = 30 per group). Dietary treatments were: basal diet (H group), and basal diet with 0.2% xylanase supplementation (E group). After a 10-day adaptation period, the feeding trial was carried out for 90 days. The live weight, morphology, antioxidant capacity and immune response were measured. The differential genes in liver were identified by RNA-sequencing. Our results showed that the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were significantly higher in E group than in H group (p < 0.05). Enzyme-linked immunosorbent assay (ELISA) revealed that immunoglobulin A (IgA), IgM, and IgG were significantly higher in E group than in H group (p < 0.05). The hepatocytes of sheep fed xylanase diet showed arranged radially into hepatic plates cantered around the central vein, and the plates linked with each other to form a lost-like structure. A total of 4,509 differential genes (DEGs) were identified, among which 4,427 were up-regulated and 82 down-regulated. Additionally, the expression of antioxidant-related genes in cluding catalase (CAT), superoxide dismutase 1 (SOD1), oxidation resistance 1 (OXR1) and glutathione peroxidase 2 (GPX2), and immunity-related gene including mitogen-activated protein kinase 1 (MAPK1), signal transducer and activator of transcription 5B (STAT5B), janus kinase 3 (JAK3) and jun proto-oncogene (JUN) were verified using the quantitative reverse transcription polymerase chain reaction (qRT-PCR). Conclusion: In conclusion, dietary 0.2% xylanase supplementation promoted hepatic antioxidant capacity and immune response via modulating the expression of functional genes in Tibetan sheep.

The objective of this study was to evaluate the effect of the level of wheat substitution for corn on the fat metabolism of Tibetan lamb. A total of 90 Tibetan lambs [body weight (BW) of 19.78 +/- 2.45 kg] were arranged with three substitution levels of wheat: WC (100 % corn), WL (10 % wheat substitution for corn), and WH (15 % wheat substitution for corn) on a dry matter basis. After the experiment, cry section technology was used to scrutinize the subcutaneous adipose tissue morphology, and genes related to fat metabolism were excavated using high-throughput sequencing technology. According to the study results, fat diameter and fat biovolume of the WL and WH groups were less than the WC group. A total of 506 differentially expressed genes (DEGs) were identified by RNA sequencing (RNA-Seq) technology. Compared with the WC group, 66 DEGs were upregulated and 59 DEGs were downregulated in the WL group, and 179 DEGs were upregulated and 269 DEGs were downregulated in the WH group. The top 20 DEGs were analyzed by Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway, indicating significant differences in the fat metabolism pathway. Five DEGs were randomly screened for quantitative reverse transcription-polymerase chain reaction (qRT-PCR) verification, and the results were consistent with the RNA-Seq results, which proved the accuracy of sequencing. In summary, with the increase in the proportion of supplemental wheat, the fat cells became smaller, and the genes related to fat decomposition were significantly upregulated.

Class IV sirtuin (SIRT6 and SIRT7) played essential roles in biometabolism processes via deacetylating specific transcription factors. The present study was conducted to search for mutations in SIRT6/7 and determine their associations with growth traits in black Tibetan sheep. Via DNA sequencing methods, three single-nucleotide polymorphisms (SNPs) were identified in 427 ewes, including a mutation (g.3724C > T) in the intron 1 of SIRT6 and two mutations (g.3668G > T and g.4223C > G) in SIRT7 intron 6 and 8, respectively. Based on the χ2 test, both g.3724C > T and g.4223C > G loci fitted with Hardy-Weinberg equilibrium (p > 0.05). Compared with animals with genotype TT, the CC genotype at g.3724C > T locus (SIRT6) exhibited the highest mean for body weight (p < 0.05) and heart girth (p < 0.05). At g.3668G > T locus (SIRT7), individuals carrying the GG genotype tended to have heavier body weight than those of TT genotype (p < 0.05). With the exception of body weight, body measurement traits not affected by combinative genotype (p > 0.05). Our results could be used as genetic markers for marker-assisted selection and maybe guide sheep breeding in economic traits.

本实验旨在评估在精料补充料中用10％小麦粉替代玉米对高原型藏羊小肠形态发育、消化酶活性、抗氧化功能以及肌肉氨基酸含量的影响.选取60只体重相近且发育良好的2～3月龄高原型藏羊(♂),随机分为2组,每组5个重复,每个重复6只羊,分别饲喂玉米日粮(玉米组)和10％小麦粉替代玉米日粮(小麦组).实验分为预饲期10 d,正试期90 d.结果表明:玉米组空肠的绒毛宽度、黏膜厚度以及回肠的绒毛高度、绒毛高度/隐窝深度均显著小于小麦组(P＜0.05);两组间空肠的胰蛋白酶、糜蛋白酶、脂肪酶、纤维素酶及α-淀粉酶活性差异均不显著(P＞0.05);小麦组空肠的丙二醛含量显著低于玉米组(P＜0.05),而其他指标差异不显著(P＞0.05);两组间肌肉中鲜味氨基酸、甜味氨基酸及总氨基酸含量差异均不显著(P＞0.05).精料中用10％小麦粉替代玉米有利于藏羊小肠组织形态发育,并能够减轻空肠脂质氧化程度,但对空肠消化酶活性和肌肉氨基酸含量影响较小,可考虑在藏羊舍饲中开展推广.

This study was carried out to evaluate the effects of dietary concentrate: forage (C: F) ratio on fat deposition, fatty acid composition, oxidative stability and mRNA expression levels of sirtuins genes associated with adipose tissue metabolism of subcutaneous fat in Black Tibetan sheep. Three diets with different C: F (HC: 70:30, IC:50:50 and LC: 30:70) were fed to fifteen weaned male lambs (2-month-old, 10.05 & PLUSMN; 0.96 Kg). The experiment lasted for 120 d. Five lambs from each group were randomly selected and slaughtered at the end of the experiment. The subcutaneous fat thicknesses increased with increasing concentrate level (P < 0.05). The concentration of polyunsaturated fatty acid (PUFA), C15:1 and C18:2n decreased by feeding the HC diet (P < 0.05). Both glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities significantly increased as dietary concentration levels decreased (P < 0.05). Additionally, SIRT1 and SIRT2 expression level was downregulated (P < 0.05) with increasing concentration supplementation (P < 0.05 and P < 0.05, respectively). In conclusion, the addition of 70% concentration supplementation is not recommended in Black Tibetan sheep, considering that no benefits were observed for nutrient utilization, oxidative stability or economic returns, while the supplementation of C: F at 50:50 proved to be suitable for finishing lambs.

The objective of this study was to evaluate various wheat supplementation levels on rumen microbiota and fermentation parameter in Tibetan sheep. A total of ninety ram with an average 12.37 ± 0.92 kg at the age of 2 months were randomly allocated to three treatments: 0% wheat diet (CW, N = 30), 10% wheat diet (LW, N = 30), and 15% wheat diet (HW, N = 30) on a dry matter basis. The experiment was conducted over a period of 127 days, including 7 days of adaption to the diets. Our results showed that sheep fed 10% wheat exhibited optimal average daily gain and feed gain ratio compared with HW group (p < 0.05). The serum alkaline phosphatase concentration was the lowest when fed the 10% wheat diet (p < 0.05), whereas serum aspartate aminotransferase concentration was the highest (p < 0.05). Both acetate and propionate increased with increase in dietary wheat ratio (p < 0.05), while a greater decrease in concentrations of NH3 -N was observed (p < 0.05). In rumen fluid, 3413 OTUs were obtained with 97% consistency. Phylum Firmicutes was the predominant bacteria and accounted for 49.04%. The CW groups supported significantly increased the abundance of Bacteroidetes (p < 0.05), as compared with the HW group. The abundance of Bacteroidales_UCG-001, Ruminococcus, and Mitsuokella possessed a higher relative abundance in HW group (p < 0.05). No differences in the bacterial community and fermentation parameters were observed between the sheep fed 0% and 10% wheat (p > 0.05). Ruminal bacterial community structure was significantly correlated with isobutyrite (r2 = 0.4878, p = 0.035) and valerate (r2 = 0.4878, p = 0.013). In conclusion, supplementation of 10% wheat in diet promoted the average daily gain and never altered microbial community structure and fermentation pattern, which can be effectively replace partial corn in Chinese Tibetan Sheep.

This study was conducted to evaluate the effects of adding different proportions of palm kernel cake into the diet of plateau Tibetan sheep; the corresponding growth performance, apparent nutrient digestibility, and serum biochemical indices were assessed in these sheep. A total of 120 healthy Tibetan ewes with similar weights [(18.39 ± 1.25) kg] were randomly divided into 4 groups, with 30 replicates per group and 6 ewes per replicates; the ewes were then fed with a 0% (Group A), 15% (Group B), 18% (Group C), or 21% (Group C) palm kernel cake diet. The pre-feeding period spanned across 7 days and the formal evaluation period lasted for 90 days. The corresponding results showed that: 1) Compared with Group A, the final body weight and average daily weight gain of Group D was significantly lower (P < 0.05), whereas the ratio of feed to weight exhibited a contrasting trend (P < 0.05). Additionally, compared with Group A, the chest circumference of Group C was significantly higher (P < 0.05). 2) Regarding apparent digestibility of nutrients, the amount of dry matter, crude protein, crude ash, and neutral detergent fiber in Group C was significantly higher than those in group A (P < 0.05); however, there was no significant difference observed between Group C and D (P > 0.05). 3) For serum biochemistry analysis, the amount of albumin and total protein in groups A and C were significantly higher than those in Group B and D (P < 0.05); additionally, there was no significant difference observed between Group A and C (P > 0.05). Conclusion: Overall, it was determined that it is feasible to add 18% palm kernel cake as a dietary supplement for plateau Tibetan sheep under experimental conditions.

This study aims to evaluate the effects of dietary concentrate: forage ratio (C:F) on the development of the gastrointestinal tract in Tibetan lamb. A total of 60 healthy two-month-old weaned black Tibetan sheep (approximately 10.50 kg of initial body weight) were assigned to three treatments and fed C:F of 70:30 (HC group), 50:50 (MC group) and 30:70 (LC group). Using the haematoxylin-eosin (HE) staining, morphological results showed that the increase of dietary roughage level from 30 to 70% exerts a positive effect on the development of the forestomach including rumen, reticulum and omasum, especially in papillae and muscle layer. Both submucosa thickness and muscle layer of abomasum are significantly increased in the LC group when compared with the HC group. Moreover, the mucosal thickness of the small intestine is higher in the LC group than that in the HC group, whereas crypt depth is higher in HC compared to the LC group. These data suggest that increased dietary forage levels promote gastrointestinal tract growth in black Tibetan sheep by changing in papilla, muscle layer and mucosal thickness, and concentrate can be supplemented up to 30% to fulfil the nutrient requirements without restriction on the development of the gastrointestinal tract.

为了研究不同蛋白水平对育肥藏羊瘤胃细菌多样性的影响,选取健康且体况相近的3月龄早期断奶藏羊公羔15只,平均体重为((22.05±2.06)kg,随机分为3组,日粮粗蛋白水平分别为10.08％(Ⅰ组),12.84％(Ⅱ组)和14.97％(Ⅲ组).预试期7d,正试期112d.饲养实验结束后对试验羊进行屠宰并于不同位点采集瘤胃液样品,测定瘤胃细菌的相对丰度.结果表明:(1)Shannon指数和Simpson指数各组之间无显著性差异(P＞0.05),ACE指数和Chao Ⅰ指数 Ⅰ组显著高于Ⅱ组和Ⅲ组(P＜0.05).(2)门水平下,拟杆菌门(Bacteroidetes)和厚壁菌门(Firmicutes)为瘤胃细菌的优势菌门,且均随日粮蛋白水平提高而显著增加(P＜0.05);变形菌门(Proteobacteria)和放线菌门(Actinobacteria)相对丰度Ⅱ组显著较高(P＞0.05).(3)科水平下,毛螺菌科(Lachnospiraceae)相对丰度较高,但各组之间差异不显著(P＞0.05);瘤胃球菌科(Ruminococcaceae)相对丰度Ⅱ组和Ⅲ组显著高于 Ⅰ组(P＜0.05);韦荣氏菌科(Veillonellaceae)相对丰度Ⅲ组显著高于Ⅰ组(P＜0.05).(4)属水平下,Prevotella(普雷沃氏菌属)的相对丰度Ⅰ组显著高于Ⅰ组和Ⅱ组(P＜0.05),瘤胃球菌属(Ruminococcus)Ⅱ组相对丰度显著较高(P＜0.05).(5)PCA分析显示各组间瘤胃细菌结构差异不明显,但采食低蛋白水平日粮的藏羊瘤胃细菌相似度更高,能更好聚类在一起.综上可知,不同蛋白水平对育肥藏羊瘤胃细菌多样性无显著影响,但可影响其丰富度;同时随着日粮蛋白水平的提高,厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes)相对丰度显著增加,普雷沃氏菌属(Prevotella)在日粮蛋白水平为14.97％时更适宜生长,瘤胃球菌属(Ruminococcus)则在日粮蛋白水平为12.84％时活性更高.

This study evaluated the effects of different non-fibrous carbohydrate/neutral detergent fiber (NFC/NDF) ratios on the rumen fermentation parameters and bacterial community of black Tibetan sheep. Fifteen 2-month-old rams with an average body weight of 10.45 +/- 0.96 kg were randomly assigned to three treatments and fed NFC/NDF of 1.82 (H group), 1.16 (M group), and 0.71 (L group), respectively. This study was conducted for 127 d, including 7 d of adaption to the diets. The fermentation parameters and bacterial characteristics of rumen fluid were measured after the end of feeding trials. According to the results, the concentrations of propionate and total volatile fatty acids (TVFA) increased in the H group than those in the L group (P < 0.05), while the concentration of acetate was highly increased in the L group (P < 0.05). A total of 1463 OTUs were obtained with 97% consistency. Both phylum Bacteroidetes and Firmicutes were dominant bacterial phyla. Proteobacteria accounted for a significantly higher proportion of bacteria in the L group than in the H and M groups (P < 0.05). At the genus level, the main cellulose-degrading bacteria, such as Prevotella_1, Prevotellaceae UCG-003 and Ruminococcus_1 possessed a higher relative abundance in dietary NFC/NDF ratio of 0.71 (P < 0.05). Correlation analysis revealed that the abundance of Patesicbacteria was negatively associated with TVFA, whereas the abundance of Bacteroidetes was positively associated with TVFA. Using clusters of orthologous groups (COG), the functions of the rumen microbial community were mainly enrichment in amino acid metabolism and carbohydrate metabolism. In summary, ruminal bacterial community composition and fermentation characteristics were altered under different dietary NFC/NDF ratios in black Tibetan sheep.

[目的]旨在研究不同非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)对藏羊瘤胃发酵参数及微生物区系多样性的影响.[方法]选取2月龄健康、平均体重为(21.27±0.38)kg的断奶母羔15只,随机分为3组,每组5只.分别饲喂粗蛋白水平相似,NFC/NDF水平为2.20(Ⅰ组)、1.39(Ⅱ组)和0.92(Ⅲ组)的全混合饲粮.试验期持续119 d,其中预试期7 d,正试期112 d.试验结束后采集瘤胃液测定细菌多样性及各类细菌相对丰度.[结果]①随着NFC/NDF水平的降低,瘤胃液pH显著增加,瘤胃液中氨态氮浓度、丙酸和异丁酸占总挥酸含量的百分比以及总挥发酸含量逐渐降低,乙酸百分比及乙酸丙酸比逐渐增加(P<0.05).②3组共产生347种操作分类单元(OTU),其中共有OTU为269种,占总OTU的77.52％.③Ⅰ组的Shannon指数、ACE指数和Chao1指数均显著低于Ⅲ组(P<0.05).④门水平上,拟杆菌门(Bacteroidetes)相对丰度Ⅱ组显著高于其余两组(P<0.05),厚壁菌门随NFC/NDF降低而降低(P<0.05);⑤科水平上,毛螺菌科(Lachnospiraceae)Ⅰ组显著高于Ⅱ组(P<0.05),瘤胃球菌科(Ruminococcaceae)Ⅰ组和Ⅱ组显著高于Ⅲ组(P<0.05);韦荣氏菌科(Veillonellaceae)Ⅱ组显著高于Ⅰ组和Ⅲ组(P<0.05).⑥属水平上,丁酸弧菌属(Butyrivibrio)Ⅱ组显著高于Ⅰ组和Ⅲ组(P<0.05);瘤胃球菌属(Ruminococcus)相对丰度有降低趋势,且Ⅰ组和Ⅱ组显著高于Ⅲ组(P<0.05).⑦主坐标分析瘤胃细菌第一主成分和第二主成分贡献率分别为63.93％和57.63％,各组间瘤胃液细菌群落结构差异明显,Ⅰ组与Ⅱ组明显分隔.[结论]饲喂不同NFC/NDF水平饲粮,改变了瘤胃发酵模式,显著影响了育肥藏羊瘤胃中微生物的种类和丰富度,并影响门、科和属水平上细菌的组成.

为了研究冬季补饲对妊娠期藏母羊瘤胃挥发性脂肪酸（volatile fatty acid,VFA）、微生物区系及羔羊生长发育影响。采用单因子试验设计,随机选择健康藏母羊440只,分为2组。对照组（control check,CK）为放牧饲喂,处理组（test,T）在放牧基础上,每只母羊补饲0.1 kg·d-1精料补充料,试验期为45 d（配种后106～150 d）。试验结束后,从处理组和对照组中随机选择5只和6只母羊屠宰后分析瘤胃挥发性脂肪酸和细菌菌群组成。同时测定新生羔羊的生长发育指标。结果表明:（1）处理组羔羊的体重、体高和胸围显著高于对照组（P ＜0.05）;（2）处理组瘤胃液总挥发性脂肪酸（Total volatile fatty acids,TVFA）、丙酸和丁酸含量显著高于对照组（P＜0.05）,同时乙酸和异丁酸显著低于对照组（P＜0.05）;（3）两组母羊瘤胃微生物在门和属水平上组成相似,拟杆菌门（Bacteroidetes）、厚壁菌门（Firmicutes）以及疣微菌门（Verrucomicrobia）为优势菌门;而普雷沃菌属-1（Prevotella 1 ）、理研菌科RC9肠道群（Rikenellaceae-RC9-gut-group）、普雷沃氏菌科-UCG-001（Prevotellaceae-UCG-001）为优势菌属;（4）Alpha多样性指数中,对照组的Shannon指数显著高于处理组（P ＜0.05）,说明对照组瘤胃微生物多样性优于处理组;（5）瘤胃微生物功能预测发现,两组母羊瘤胃微生物主要富集于复制和修复（Replication and Repair）、碳水化合物代谢（Carbohydrate Metabolism）和信号转导（Signal Transduction）。综上,妊娠后期藏母羊的冬季补饲能够为胎儿的生长发育提供必要的营养需求,同时提高母羊瘤胃液中TVFA、丙酸和丁酸含量,但在一定程度上影响了瘤胃细菌的多样性。

旨在研究不同非纤维性碳水化合物(NFC)/中性洗涤纤维(NDF)饲粮对藏羊肉中营养成分、氨基酸和脂肪酸含量的影响.采用单因素随机设计,以高原型藏羊为研究对象,将30只体质量为(26.38±0.43) kg健康的藏羔羊,按性别分为3个公羊组和3个母羊组,每组5只,分别饲喂NFC/NDF为2.20(精粗比为70∶30)、1.39(精粗比为50∶50)和0.92(精粗比为30∶70)的试验饲粮.预试期为15d,正试期为90 d.试验结束后,每组选取3只试验羊进行屠宰,采集第12～13肋骨间背最长肌,测定其营养成分、氨基酸和脂肪酸含量.结果 显示,在营养成分方面,饲粮精粗比对羔羊肉中水分(moisture)与粗蛋白(CP)含量无显著影响(P＞0.05),但对粗脂肪(EE)与粗灰分(ash)影响显著(P＜0.05);在氨基酸组成和含量方面,饲粮精粗比对羔羊肉中氨基酸种类、氨基酸总量(TAA)、必需氨基酸(EAA)以及非必需氨基酸(NEAA)含量无显著影响(P＞0.05);在脂肪酸组成和含量方面,饲粮精粗比对羔羊肉中脂肪酸种类、多不饱和脂肪酸(PUFA)无显著影响(P＞0.05),但对饱和脂肪酸(SFA)与单不饱和脂肪酸(MUFA)含量影响显著(P＜0.05).说明不同NFC/NDF饲粮能够影响藏羊肌肉中营养成分、氨基酸和脂肪酸含量,其中公羊饲粮适宜的NFC/NDF为1.39,母羊NFC/NDF则为0.92.

试验研究不同精粗比日粮对育成期藏羊母羔肺脏抗氧化功能和形态发育的影响.选取健康、体重(22.00±0.38) kg的3月龄藏羊母羔90只,随机分为3组,每组5个重复,每个重复6只羊.各组母羔分别饲喂70％精料+30％粗料(C70组)、60％精料+40％粗料(C60组)、50％精料+50％粗料(C50组)的全混合日粮.预试期10 d,正式试验期90 d.结果 显示,C60组肺泡隔厚度显著高于C70组(P＜0.05);C50组和C60组单个肺泡面积显著低于C70组(P＜0.05);C60组单位面积肺泡数显著高于其他各组(P＜0.05).C60组血管数显著高于C70组(P＜0.05);C60组和C50组血管直径、中膜厚度显著低于C70组(P＜0.05).C60组和C50组肺组织总抗氧化能力(T-AOC)、过氧化氢酶(CAT)活性显著高于C70组(P＜0.05).研究表明,适宜精粗比的日粮能够加强藏羊母羔气体交换率,增强低氧适应性,有效提高抗氧化能力,其中精粗比为60:40的日粮效果较佳.

本试验旨在研究饲粮不同非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)对高原型育肥藏羊生长发育、瘤胃发酵及微生物多样性的影响.选取3月龄健康、体重[(22.14±0.02)kg]相近的高原型藏羊母羔210只,随机分为7组,每组30只.各组分别饲喂NFC/NDF为2.86(Ⅰ组)、2.69(Ⅱ组)、2.42(Ⅲ组)、2.06(Ⅳ组)、1.88(Ⅴ组)、1.63(Ⅵ组)和1.43(Ⅶ组)的试验饲粮.预试期10 d,正试期90 d.试验结束后,测定各组试验羊的终末体重、平均日增重和平均日采食量.此外,每组随机选择3只试验羊屠宰并采集瘤胃液,测定其挥发性脂肪酸含量以及微生物菌落组成.结果表明:1)Ⅰ、Ⅱ、Ⅲ、Ⅳ组终末体重显著高于Ⅴ、Ⅵ、Ⅶ组(P<0.05),Ⅰ、Ⅱ组平均日增重显著高于Ⅳ、Ⅴ、Ⅵ、Ⅶ组(P<0.05).2)Ⅰ、Ⅱ组瘤胃内氨态氮含量显著高于Ⅴ、Ⅵ、Ⅶ组(P<0.05),Ⅰ组瘤胃内乙酸含量显著低于Ⅴ、Ⅵ、Ⅶ组(P<0.05),Ⅰ、Ⅱ组瘤胃内丙酸含量显著高于Ⅶ组(P<0.05),Ⅲ组瘤胃内丁酸含量显著高于Ⅶ组(P<0.05),Ⅱ组瘤胃内总挥发性脂肪酸(TVFA)含量显著高于其他各组(P<0.05).3)真菌方面,Ⅳ、Ⅴ、Ⅵ和Ⅶ组瘤胃内丛赤壳科(Nectriaceae)、隔孢伏革菌科(Peniophoraceae)和毛球壳科(Lasiosphaeriaceae)相对丰度显著低于Ⅱ组(P<0.05),Ⅴ组瘤胃内曲霉科(Aspergillaceae)和黏毛菌科(Myx?otrichaceae)相对丰度显著高于Ⅱ、Ⅲ组(P<0.05),Ⅲ组瘤胃内蜡壳耳科(Sebacinaceae)相对丰度显著高于其余各组(P<0.05).4)细菌方面,Ⅴ、Ⅶ组瘤胃内奎因菌属(Quinella)相对丰度显著高于Ⅰ、Ⅱ组(P<0.05),Ⅵ组瘤胃内克里斯滕菌科_R?7_群(Christensenellaceae_R?7_group)相对丰度显著高于其他各组(P<0.05),Ⅴ、Ⅵ和Ⅶ组瘤胃内瘤胃球菌科_NK4A214_群(Ruminococ?caceae_NK4A214_group)相对丰度显著高于其他各组(P<0.05),Ⅲ组瘤胃内普雷沃菌属_1(Prevotella_1)相对丰度显著高于其他各组(P<0.05),Ⅶ组瘤胃内毛螺菌科_NK3A20_群(Lach?nospiraceae_NK3A20_group)相对丰度显著高于其他各组(P<0.05),Ⅴ、Ⅵ、Ⅶ组瘤胃内鞘氨醇单胞菌属(Sphingomonas)相对丰度显著低于Ⅰ、Ⅱ组(P<0.05).综上所述,饲粮NFC/NDF对高原型育肥藏羊生长发育、瘤胃挥发性脂肪酸含量以及微生物多样性有一定影响,当饲粮NFC/NDF为2.69时,不仅能够促进高原型育肥藏羊生长发育,同时也能够促进瘤胃发酵并提高微生物多样性.

For its role in the mediation of myoblast proliferation, fibroblast growth factor receptor 1 (FGFR1) was considered a functional candidate gene for growth performance in Tibetan sheep. Via the polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP) approach, four single nucleotide polymorphisms (SNPs) including g.14752C > T (intron 1), g.45361A > G (intron 7), g.49400A > G (3'UTR region) and g.49587A > T (3'UTR region), were identified in 422 ewes. The association analysis demonstrated that individuals carrying the AA genotype of g.49400A > G had significantly greater withers height, length than those with GG genotype (p < 0.05). Individuals with genotype AA of g.49587A > T had significantly greater weight and chest circumference than those with genotype TT (p < 0.01). Additionally, the individuals with Hap1/1 diplotypes (CAAA-CAAA) were highly significantly associated with weight and chest circumference than Hap1/2 diplotypes (CAAA-CAAT) (p < 0.05). The quantitative real-time polymerase chain reaction (qPCR) analysis revealed that the FGFR1 was detectable expressed in muscle tissues within three different age stage. Remarkably higher mRNA expression was detected at fetal lamb stage as compared with adult ewes (p < 0.01). The outcome of this research confirmed that both g.49400A > G and g.49587A > T of FGFR1 were involved in growth-related traits, which may be considered to be genetic markers for improving the growth traits of Tibetan sheep.