过瘤胃胆碱对黔北麻羊羔羊生长性能及血浆生化指标的影响

本试验旨在研究补饲过瘤胃胆碱(RPC)对黔北麻羊羔羊生长性能及血浆生化指标的影响.选取体况良好、体重相近的4月龄黔北麻羊羔羊20只随机分为对照组[(15.89±1.66) kg]和试验组[(15.30±1.86) kg],每组10只.对照组饲喂基础饲粮,试验组补饲10 g/d的RPC.试验期40 d,其中预试期10 d,正试期30 d.结果表明,补饲RPC:1)显著提高干物质采食量全期平均值(P＜0.05),显著降低料重比(P＜0.05);2)对干物质、粗蛋白质、粗脂肪、中性洗涤纤维的表观消化率无显著影响(P＞0.05),但可显著提高酸性洗涤纤维、粗灰分的表观消化率(P＜0.05);3)可显著提高食入氮、吸收氮和沉积氮(P＜0.05);4)对血浆超氧化物歧化酶活性以及丙二醛、葡萄糖、尿素氮、极低密度脂蛋白、甘油三酯、总胆固醇、肌酐浓度的全期平均值均无显著影响(P＞0.05).在本试验条件下,补饲10 g/d的RPC可提高黔北麻羊羔羊生长性能,但对血浆生化指标没有显著影响.     

口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响

分析探讨口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响。选取新生健康的双羔湖羊公羔42只,随机分为两组,分别饲喂颗粒化和口感化开食料,试验期42 d。两组羔羊21日龄之前的采食量、体重和绝对生长的变化趋势相似。21日龄以后,口感化开食料组羔羊的采食量、体重、绝对生长和相对生长均明显高于颗粒化开食料组,42日龄体重、后两周的采食量及15～21日龄的相对生长率在两组间有显著差异(P < 0.05)。口感化开食料还显著提高(P < 0.05)了羔羊42日龄时的育肥指数、体长指数、胸围指数、管围指数和断奶前的瘤胃质量和瘤胃/胴体。以上结果表明,与颗粒化开食料相比,口感化开食料更有利于羔羊早期断奶前后的瘤胃发育、采食量提高、体重和体尺的发育,但对其他胃室及肠道发育没有影响。     

Effects of a topical anaesthetic formulation and systemic carprofen, given singly or in combination, on the cortisol and behavioural responses of Merino lambs to castration

Objective   To determine the effectiveness of a topical anaesthetic formulation (Tri-Solfen) with or without the administration of a non-steroidal anti-inflammatory drug (carprofen) on the pain and distress response associated with ring or surgical castration of ram lambs.
Procedures   Merino ram lambs (n = 78) were allocated to 10 treatment groups: 4 groups of knife-castrated lambs and 4 groups of ring-castrated lambs received carprofen (4 mg/kg SC) and Tri-Solfen; 2 control groups (sham) received carprofen at 0 or 4 mg/kg SC. Measurements included plasma cortisol and haptoglobin concentrations, haematology, and behaviour, including posture.
Results   Knife-castrated lambs had higher peak cortisol and integrated cortisol responses for the first 6 h after treatment and greater concentration s of circulating acute phase proteins than ring-castrated lambs, both of which were significantly different from the sham controls. Tri-Solfen applied to the knife castration wound significantly reduced both the peak plasma cortisol concentration and the integrated cortisol response for the first 6 h and improved lying behaviour in the first 12 h. Carprofen reduced the cortisol response to knife castration at 30 min, but elevated the cortisol responses at 24 and 48 h. Carprofen nearly halved the number of acute pain behaviours associated with ring castration. There were no significant additive or synergistic effects from combining the analgesic treatments. Tri-Solfen applied to the tail wound provided no detectible benefits during ring castration + tail docking.
Conclusions   The physiological and behavioural responses suggest that ring castration has less impact on the lamb than knife castration. The specific analgesic treatments can provide modest amelioration of the pain and discomfort associated with castration. Alternative doses or application methods may enhance their efficacy.     

山区羊舍“圈中圈”设计及应用效果

为探索山区羔羊保育技术,提高羔羊成活率和增重效果,笔者通过改进圈舍设计,加强饲养管理,开展了"圈中圈"羔羊保育应用效果观察试验。结果表明,试验组羔羊的断奶(120d)成活率为97.78%,比对照组的断奶成活率(68.89%)提高了41.94%;试验组羔羊的日增重为96.2 g,比对照组(71g)提高了35.49%,效果显著。     

益康XP替代抗生素对早期断奶藏羔羊应激和免疫的影响

选取早期断奶([55±2)日龄,体重(7.91±0.83)kg]藏羔羊42只,随机分为3组(每组14只,公母各半),饲喂基础日粮为粗蛋白和能量水平分别为18.02%和12.95 MJ/kg开口料。试验Ⅰ组为基础日粮,试验Ⅱ组为基础日粮+1%益康XP,试验Ⅲ组为基础日粮+0.03%莫能菌素。对早期断奶藏羔羊血清中反应应激的酶类指标(Cor、CK、LDH、AST、ALP)和免疫指标(IgG、IgA、IgM)进行了测定。试验结果表明:各试验组的Cor、CK、AST和LDH差异不显著(P>0.05),但Cor、CK试验Ⅱ组小于其它两组,AST试验Ⅱ组小于试验Ⅲ组、LDH试验Ⅲ组小于其它两组;ALP试验Ⅱ组明显大于试验Ⅲ组(P>0.05);试验Ⅱ组IgG、IgA、IgM高于试验Ⅰ组和试验Ⅲ组(P>0.05);试验Ⅱ组藏羔羊的日增重明显高于试验Ⅰ组和试验Ⅲ组,差异显著(P<0.01);试验Ⅱ组藏羔羊的日采食量高于试验Ⅰ组和试验Ⅲ组,试验Ⅱ组对藏羔羊的腹泻率明显低于试验Ⅰ组和试验Ⅲ组(P<0.05)。综合评价表明基础日粮中添加益康XP能减小藏羔羊的早期断奶应激,提高早期断奶藏羔羊免疫机能,是抗生素的一种优良替代品。     

不同杂交组合育肥羔羊生长、屠宰性能和肉品质的研究

 通过饲养试验对3个不同杂交组合育肥羔羊生产性能、屠宰性能和肉品质进行了研究,为选育优质肉羊品种提供理论基础。选取杜寒14只,南本18只,寒本12只为研究对象,相同条件下,饲养到9月龄,选取部分试羊进行屠宰,比较其屠宰性能和肉品质。结果表明：杜寒F1羔羊全期平均日增重达252.81g,极显著高于寒本（P＜0.01）,显著高于南本（P＜0.05）,南本显著高于寒本（P＜0.05）;杜寒的屠宰率和净肉率极显著高于寒本（P＜0.01）,显著高于南本（P＜0.05）,南本与寒本差异不显著（P>0.05）;南本的大理石纹极显著高于杜寒与寒本（P＜0.01）。南本的熟肉率显著高于寒本（P﹤0.05）。杜寒杂交组合生产性能和屠宰性能优势明显。     

Regulation by gonadal steroids of estrogen and progesterone receptors along the reproductive tract in female lambs.

The regulation of estrogen and progesterone receptor (ER, PR) expression by estradiol (E2) and progesterone (P4) in the oviduct, uterus and cervix of female lambs was studied. The animals received three intramuscular injections of E2, P4 or vehicle with an interval of 24 h and they were slaugthered 24 h after the third injection. Determinations of ER and PR were performed by binding assays and mRNAs of ER alpha and PR by solution hybridization. High levels of ER and PR in both cervix and oviduct were found in the female lamb, differing from other mammalian species. No significant effects by either E2 or P4 treatment on ER and PR levels in the cervix and oviduct could be observed. E2 treatment increased the mRNA levels of ERa and PR more than 3-fold in the cervix, while P4 treatment increased the mRNA levels of ERa and PR in the uterus. The results show differential effects of gonadal steroids on sex steroid receptor expression along the reproductive tract in female lambs, suggesting that steroid target tissues can modulate responses to the same circulating levels of steroid hormones.     

Two single nucleotide polymorphisms in the promoter of the ovine myostatin gene (MSTN) and their effect on growth and carcass muscle traits in New Zealand Romney sheep

Myostatin is a negative regulator of muscle growth and development in mammals, and variation in ovine myostatin gene (MSTN) has been demonstrated to be associated with variation in the muscularity of sheep. Polymerase chain reaction–single‐stranded conformational polymorphism (PCR–SSCP) was used to look for single nucleotide polymorphisms (SNPs) in a 304‐bp amplicon from the promoter region of ovine MSTN. Sequence analyses revealed two previously identified SNPs (c.?2449G/C and c. ?2379T/C) that resulted in three haplotypes (H₁ (c.[?2449G; ?2379C]), H₂ (c.[?2449C; ?2379C]) and H₃ (c.[?2449G; ?2379T]). The effect of these SNPs on growth and carcass traits was investigated in 357 NZ Romney lambs. General linear mixed‐effect models revealed that sheep with the genotype c.?2449GC had a higher loin meat yield (p = 0.032) and proportion loin yield (p = 0.028), than those with the genotype c.?2449GG. The genotype c.?2379CC was associated with an increase in three weight traits: birthweight (p = 0.003), tailing weight (p = 0.009) and weaning weight (p = 0.028), when compared with the genotype c.?2379TC, but it was not found to have an association with growth rate. This suggests that c.?2379T/C has an effect that originates at, or before birth. Haplotype H₃ was associated with a decrease in birthweight (p = 0.002), tailing weight (p = 0.003) and weaning weight (p = 0.011). Haplotype H₂ was associated with increased loin yield (p = 0.012) and proportion loin yield (p = 0.002). The SNPs may have value as genetic markers for improved Romney breeding.     

沙蒿多糖组合制剂对滩羊羔羊瘤胃菌群多样性的影响

本试验旨在研究沙蒿多糖不同组合制剂对滩羊羔羊瘤胃菌群多样性的影响.选择健康、体重相近的断奶滩羊公羔60只,按体重随机分为4个组,每组15只羊.对照组饲喂基础饲粮,试验1组、试验2组和试验3组分别饲喂在基础饲粮中添加5.5 g/d沙蒿多糖+5.5 g/d包被丁酸钠、5.5 g/d沙蒿多糖+5.5 g/d丁酸甘油酯和5.5...     

干草对羔羊瘤胃发育影响及其机制的研究进展

羔羊刚出生时,瘤胃在生理和代谢方面发育不健全,主要依赖母乳满足维持和生长的需要。随着羔羊日龄的增长及固体饲粮的采食,瘤胃生理功能逐渐成熟。近年来研究发现,羔羊仅饲喂精料容易引起瘤胃pH降低、瘤胃乳头凝集和角化不全等症状,而在精料基础上添加干草可以提高瘤胃pH,增加瘤胃容积,减少瘤胃乳头凝集,维持瘤胃乳头正常形态。目前虽然已有关于干草对羔羊瘤胃发育影响及其作用机制的研究,但认识并不全面。本文对羔羊瘤胃发育过程和干草影响羔羊瘤胃发育及其作用机制的最新研究进展进行了综述。结果表明：1)羔羊断奶前补饲干草有助于纤维分解菌在瘤胃定植;2)羔羊断奶前补饲干草可以促进瘤胃上皮发育和挥发性脂肪酸代谢;3)干草促进断奶前羔羊瘤胃发育的机制与干草调节细胞内钙信号通路及氨基酸和脂肪酸的代谢网络,降低胰岛素样生长因子结合蛋白2(IGFBP2)和IGFBP4的基因表达量,抑制活化B细胞的核因子kappa-轻链增强子(NF-kB)信号通路,提高3-羟基-3-甲基-戊二酸单酰辅酶A裂解酶(HMGCL)、3-羟基-3-甲基戊二酰辅酶A合成酶Ⅱ(HMGCS2)、3-羟基丁酸脱氢酶1(BDH1)和单羧酸转运载体1(MCT...