The objective of this study is to determine the effects of the dietary replacement of soybean oil (SO) with rubber seed oil (RSO) on the growth performance, carcass trait, and lipid metabolism in Pekin ducks. A total of 160 1-day-old Pekin ducks were randomly allocated to four experimental treatments and fed diets with different ratios of SO to RSO as follows: 3:0 (control), 2:1, 1:2, and 0:3. Dietary RSO supplementation had no effect on their growth performance; however, it significantly decreased the yield of abdominal fat (p < 0.05). As the dietary RSO increased, the plasma TG, CHO, LDL-C, and HDL-C contents of ducks decreased (p < 0.05). Additionally, the contents of total fat, triglycerides, and cholesterol in the liver and breast reduced in the ducks fed RSO diets (p < 0.05). Liver n-3 PUFA levels linearly increased (p < 0.05), while the n-6/n-3 PUFA ratios reduced with increasing RSO levels (p < 0.05). Moreover, dietary RSO supplementation resulted in decreased gene expressions of FABP1, ME1, SREBP1c, FASN, DGAT2, and HMGCR (p < 0.05), while there was an increased expression of the ABCA1 gene (p < 0.05) in the liver of the ducks. In conclusion, dietary RSO supplementation reduced fat deposition and enhanced n-3 PUFA levels without affecting the growth performance of Pekin ducks.

Black Tibetan sheep is a branch of Tibetan sheep on the Qinghai-Tibet Plateau (QTP). It is mainly distributed in Guinan County, Qinghai Province. In order to accurately identify the core regulatory genes in the process of muscle development of black Tibetan sheep, further explore the physiological processes of growth, development and myogenesis of black Tibetan sheep, and carry out molecular breeding of black Tibetan sheep, this experiment took the unique black Tibetan sheep on the Qinghai-Tibet Plateau as the experimental object, and selected three stages of 4-month-old embryo (embryonic stage, MF group), 10-month-old(breeding stage, ML group) and 36-month-old (adult, MA group). The longissimus dorsi tissues of 3 sheep were taken at each stage to quantify the expression of genes during muscle development at different developmental stages. Meanwhile, overexpression and interference techniques were used to detect the role of core genes in the proliferation of primary muscle cells of black Tibetan sheep. In the process from embryonic stage to mature stage and adulthood, more than 1000 genes were up-regulated and more than 4000 down-regulated in black Tibetan sheep, while from breeding to adulthood, there were only 51 up-regulated genes and 83 down-regulated genes. About 998 genes were newly identified in each group. During muscle development from embryonic stage to mature stage to adulthood, two significant differential trend gene sets of Profile1 and Profile 6 were screened and identified, in which there were 121 and 31 core regulatory genes identified, respectively. In the trend of first decreasing and then stable expression in the whole development stage, 121 genes are core regulatory transcripts, which are mainly related to axonal guidance, cell cycle and other functions. 31 genes are core regulatory transcripts in the first rising and then stable expression, which are mainly related to biological metabolic pathway, oxidative phosphorylation and other processes. In the MF-ML stage, 75 genes were selected as the core regulatory gene set, the core genes were PTEN, AKT3, etc., and there were 134 differentially expressed genes in the ML-MA stage, and the core regulatory genes were IL6, ABCA1 and so on. In the MF-ML stage, the core gene set widely plays a role in cell components, cell matrix and other biological processes, while in the ML-MA stage, the core gene set widely plays a role in cell migration, cell differentiation, tissue development and so on. Adenovirus vector overexpressed and interfered with the core gene PTEN in primary muscle satellite cells of black Tibetan sheep shown that, interference and overexpression of PTEN would correspondingly increase and decrease the expression of other core genes, like AKT3, CKD2, CCNB1, ERBB3, HDAC2, but the specific interaction mechanism of each gene still needs to be further explored.

[目的]本试验旨在研究填饲对北京鸭生长发育、胸肌生化指标和肉品质的影响.[方法]选用120只体重相近(2 529 g+40 g)的35日龄北京鸭,随机分为2组(正常饲喂组和填饲组),每组6个重复,每重复10只鸭.试验周期为7 d,正常饲喂组1～7 d每只饲喂260 g/d,填饲组第1和2天每只分别饲喂260和300 g/d,第3～7天每只饲喂420 g/d.于试验鸭42日龄时,空腹12 h,每重复选取2只鸭,翅静脉取血5 mL后进行屠宰,对屠体、胸肌和腿肌进行称重,计算屠体率、胸肌率和腿肌率,并测定其血浆和胸肌生化指标、胸肌肉品质以及脂肪酸含量.[结果]①填饲组北京鸭平均体重、平均日增重、屠体重、屠体率和胸肌重显著高于正常饲喂组(P＜0.05),腿肌重和腿肌率显著低于正常饲喂组(P＜0.05),料重比和胸肌率在两组间无显著差异(P＞0.05).②填饲组北京鸭血浆中的谷丙转氨酶(ALT)活力和谷丙转氨酶/谷草转氨酶(ALT/AST)显著高于正常饲喂组(P＜0.05),谷草转氨酶(AST)活力显著低于正常饲喂组(P＜0.05).填饲组北京鸭胸肌中的水分、粗蛋白质含量和苹果酸脱氢酶(MDH)活力显著低于正常饲喂组(P＜0.05),肌内脂肪和甘油三酯(TG)含量显著高于正常饲喂组(P＜0.05).③填饲组北京鸭胸肌亮度(L*)、黄度(b*)和蒸煮损失显著高于正常饲喂组(P＜0.05).④填饲组北京鸭胸肌中C22:5 n-6含量和多不饱和脂肪酸/饱和脂肪酸(PUFA/SFA)显著低于正常饲喂组(P＜0.05),C14:0,C16:1 n-7、C18:1 n-9、C20:2 n-6、C20:3 n-6、C22:0、总脂肪酸(FA)、不饱和脂肪酸(UFA)和单不饱和脂肪酸(MUFA)含量显著高于正常饲喂组(P＜0.05).[结论]填饲可促进北京鸭生长发育,增强北京鸭脂肪代谢,提高胸肌肌内脂肪、不饱和脂肪酸和总脂肪酸含量,降低胸肌水分和粗蛋白质含量,且填饲组北京鸭胸肌肉蒸煮损失更高.

Black Tibetan sheep (Ovis aries) is a unique branch of Tibetan sheep in Qinghai province, which was used for wool and meat. The third-generation transcriptome was sequenced and compared with the sheep genome to explore the new transcriptome and genes of black Tibetan sheep. PacBio Iso-seq mixed cell sequencing was performed on longissimus dorsi muscle tissues of black Tibetan sheep at different ages. There was a total of 96596073037 bp base data of Iso-seq, with N50 2822 bp. Iso-seq sequencing depth was about 34.5. There were 36191 isoforms mapped to 8665 reference genes and there were 1846 novel isoforms and 25,680 new isoforms in black Tibetan sheep compared with sheep database. Among these transcripts, there were 25,323 new coding RNA and 1065 novel coding RNA, 357 new long non-coding RNA, and 781 novel long non-coding RNA. Using hmmscan compared isoforms to the animal transcription factor (TF) database, there were 519 and 156 isoforms respectively associated with ZF-C2H2 and TF family including TF-bZIP. The next family of transcription factors enriched in isoforms was bHLH, Homeobox, MYB, and others. All these results would provide a valuable genetic resource that could be further used for future genetics and genomics studies.

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。

[目的]分析不同部位肌肉的肌纤维特性,为充分挖掘青海黑藏羊(♂)的肉用潜质提供参考.[方法]利用ATP酶(ATPase)组织化学染色法和实时荧光定量聚合酶链式反应(real-time qPCR)测定黑藏羊背最长肌(longissimus dorsi,LD)、臂三头肌(biceps femoris muscle,BF)和股二头肌(Triceps femoris muscle,TF)3个部位肌肉的肌纤维组织学特征以及与其相关的肌球蛋白重链(Myosin heavy chains,MyHCs)基因的表达量.[结果]①背最长肌与臂三头肌ⅡA型、ⅡB型肌纤维直径显著低于股二头肌(P<0.05);而股二头肌Ⅰ型、ⅡA型和ⅡB型肌纤维横截面积显著高于背最长肌(P<0.05);Ⅰ型、ⅡA型和ⅡB型肌纤维密度均表现为背最长肌>臂三头肌>股二头肌(P>0.05).②背最长肌ⅡA型肌纤维数量比例高于臂三头肌和股二头肌,其中背最长肌与股二头肌差异显著(P<0.05);背最长肌Ⅰ型肌纤维面积比例高于臂三头肌(P>0.05)和股二头肌(P<0.05).③背最长肌MyHCⅡA基因的表达量显著高于股二头肌(P<0.05),较臂三头肌差异不显著(P>0.05),各部位间MyHCⅠ、MyHCⅡB和MyHCⅡX基因的表达量差异均不显著(P>0.05).[结论]揭示了黑藏羊不同部位肌肉的肌纤维特性差异,为今后黑藏羊的分档加工提供了理论参考.