营养对母羊繁殖性能影响的研究进展

母羊的营养状况直接影响着母羊发情、排卵数、受胎率、羔羊成活率及后代的繁殖性能.文章将不同阶段营养及各种营养因素对母羊繁殖性能的影响作一综述.     

中草药饲料添加剂对母羊繁殖性能的影响

试验设3个处理组（A组为中药组、B组为中草药＋激素组、C组为激素组）,于母羊配种开始时将中草药添加于饲料中,每只羊每天25克,连用20 d,C组不添加。结果表明：1）A组使阴道涂片上皮细胞变化明显,间质细胞最终转化成角化细胞;使母羊发情并排卵,但排卵作用较弱;使处于非繁殖季节母羊于用药9 d后进入发情前期,用药15 d后进入发情期,并且出现发情外观变化;可有效诱导非繁殖季节羊的发情,并且阴道细胞学变化明显;诱导非繁殖季节母羊发情时,发情率达到80%,受胎率仅有25%。2）B组可有效诱导非繁殖季节母羊发情,效果显著,发情率达87.5%,受胎率高到85.5%。     

不同营养水平对母羊繁殖性能的影响

为研究不同营养水平对母羊繁殖性能产生的影响,采用对比试验的方法,从新疆巴州和硕县浩牧养殖场选择300只健康的能繁母羊,按照随机原则将其划分为试验1组、试验2组和对照组,每组羊100只,对不同组别的养给予不同营养水平的饲料,保证其他饲养管理条件一致的情况下,观察3组母羊的繁殖情况。试验结果显示对照组母羊的营养水平最低,繁殖性能最差,试验2组母羊的繁殖性能最好,试验1组的繁殖性能一般,试验1组、试验2组和对照组的母羊受胎率分别为74.00%、66.00%、41.00%。改善母羊饲料营养水平,增加苜蓿和浓缩饲料投喂,有利于提高母羊的繁殖性能,在今后养殖中值得进一步推广应用。     

不同能量水平对母羊繁殖性能的影响

在高、中、低(18.99、14.48、8.81MJ/d)3个不同能量水平饲养条件下,对36只杂交母羊(萨福克♂×小尾寒羊♀)的体重变化,黄体数及激素FSH、LH分泌情况进行了研究分析。结果表明:高能量组的试验羊平均日增重比低能组和中等能量组分别提高235.5g(/(只·d)(P<0.05)、70.6g(/只·d)(P<0.05),黄体数分别增加81.3%(P<0.05)、43%(P>0.05)。同时,低能量组FSH、LH激素水平高于中等能量和高能量组,说明日粮能量水平影响母羊卵泡发育,排卵及黄体形成。     

舍饲因素对妊娠后期繁殖母羊生产性能影响研究

本项研究的目标是通过试验分析,找出舍饲条件中对繁殖母羊生产性能起主导作用的影响因素,并探索应对措施以指导生产。为此,笔者于2009年末开始在洮南市向阳乡开展了舍饲对母羊生产性能影响要素研究试验。结合我省西部的气候和饲料资源条件,总结试验结果,我们推荐在生产中使用代谢能8.50MJ/kg、粗蛋白9.50%、环境温度＋4℃、饲养密度0.8只/m2、环境湿度60%的参数,对妊娠后期繁殖母羊有较好的增产效果。     

养殖模式对母羊繁殖性能及初生羔羊成活率的影响

为了探讨两种养殖模式对母羊繁殖性能和初生羔羊成活率的影响,测定放牧（Ⅰ组）与舍饲（Ⅱ组）两组母羊配种前体重和产前体重、妊娠时间、难产率、流产率、平均产羔数、羔羊初生重和羔羊病死率等,并采集血液分析母羊和羔羊血常规和部分生化指标.结果表明：与Ⅰ组妊娠母羊相比,Ⅱ组母羊妊娠期平均日增重、平均产羔数和羔羊初生重极显著或显著提高（P＜0.01或P＜0.05）,RBC、HGB和PCV指标极显著提高（P＜0.01）,血液中GLOB含量显著提高（P＜0.05）;但WBC和UN水平下降（P＜0.01或P＜0.05）,平均妊娠时间延长（P＜0.05）,难产率提高,但流产率降低.与Ⅰ组羔羊相比,Ⅱ组羔羊的RBC、HGB、PCV和MCH指标以及血液中的TP、GLOB和ALP含量提高（P＜0.05或P＜0.01）,但UN水平和WBC降低（P＜0.01）,羔羊病死率下降.由此得出,受不同营养水平的影响,两种养殖模式下母羊繁殖性能差别较大,在科学合理的舍饲养殖模式下,母羊的繁殖性能得到提高,妊娠母羊对营养的需求得到满足,产羔率、初生重和羔羊成活率得到提高.     

营养水平对母羊繁殖性能的影响及精准营养调控的研究进展

繁殖性能是羊产业的重要经济性状之一,直接关系到养羊业生产成本和效率。羊的季节性繁殖特性导致其繁殖效率低,是羊产业高效养殖的主要瓶颈。在羊生产中,营养水平直接影响母羊的繁殖性能。综述了营养水平对发情、排卵、受孕等母羊繁殖过程和羊非繁殖季繁殖性能的影响,以及精准营养调控母羊繁殖性能的研究进展,以期为进一步研究营养水平对母羊繁殖性能的调控机制提供参考。     

补喂瓜氨酸对妊娠90 d湖羊母羊繁殖性能和泌乳性能的影响

本试验旨在研究补喂瓜氨酸对妊娠90 d湖羊母羊繁殖性能和泌乳性能的影响,为瓜氨酸在湖羊母羊中的应用提供科学依据。试验选取妊娠90 d的湖羊母羊50只,随机分成2组,每组25只。对照组饲喂基础饲粮,试验组在基础饲粮中添加瓜氨酸10 g/d进行补喂。试验一直进行到母羊产后45 d,记录羔羊初生重和45日龄体重。每组选取6只母羊,测定产后16～30 d泌乳量及乳成分变化,采集母羊产后第15、30、45天晨饲前颈静脉血样。结果表明：与对照组相比,试验组羔羊初生重极显著提高了19.6%(P <0.01);试验组羔羊45日龄体重显著提高了6%(P <0.05);试验组母羊产后第16～30天平均日泌乳量和总泌乳量分别极显著提高了19.6%(P <0.01);试验组母羊产后第1天乳蛋白率极显著提高了20%(P <0.01);试验组母羊产后第7～15天以及20～30天乳脂率分别极显著提高了21%和16.7%(P <0.01);试验组母羊产后第15天血浆中催乳素（PRL）含量极显著提高了167%(P <0.01),其血浆中孕酮（P4）含量显著降低207%(P <0...     

补饲矿物元素和维生素对多浪羊母羊繁殖性能影响的研究

2009年3月至10月,在新疆喀什地区麦盖提县多浪羊繁育基地,研究补饲矿物元素和维生素对多浪羊母羊繁殖性能的影响.将试验羊按年龄和体重配对分成3组:对照组(自然发情组),不做任何处理;试验Ⅰ组,在催情补饲阶段,每天每只羊补饲铜50 mg、碘50 mg、锌600 mg、硒2 mg,妊娠阶段每天每只羊补饲铜20 mg、碘2.5 mg、锌100 mg、硒0.5 mg;试验Ⅱ组,在催情补饲阶段,每天每只羊补饲维生素A 50万u、维生素E 800u,妊娠阶段每天每只羊补饲维生素A 5万u、维生素E 500 u.结果表明:①气温升高会降低多浪羊的发情率和受胎率;②补饲VA和VE或矿物元素铜、锌、硒、碘会提高多浪羊的产双羔率,特别是补饲VA和VE对提高双羔率效果明显.     

冷季补饲对放牧后备母羊生产性能和血液生化指标的影响

为研究放牧地区冷季后备母羊适宜的补饲配方,试验选取体重相近的8月龄阿勒泰后备母羊40只,随机分为4组,每组10只,在放牧条件下,补饲组每只羊每日补饲精料350 g,设置全价日粮瘤胃可降解氮（RDN）:可发酵有机物（FOM）分别为35、30和25共3组,记作R:F₃₅组、R:F₃₀组和R:F₂₅组,对照组不补饲,试验期45 d。结果表明：1)试验末期,R:F₃₅组、R:F₃₀组、R:F₂₅组的体重较对照组分别提高了20.48%、19.24%和17.90%,差异极显著（P <0.01）;日增重较对照组极显著提高（P <0.01）。2) R:F₃₅组、R:F₃₀组极显著提高了试验羊的血清葡萄糖（GLU）(P <0.01)。3) R:F₃₅组、R:F30组的血清尿素氮（SUN）含量显著高于对照组（P <0.05）,R:F₃₅组的谷丙转氨酶（ALT）显著高...     

Effects of trichostrongyle larval challenge on the reproductive performance of immune ewes

Ostertagia circumcincta larvae were administered to adult immune ewes either during the breeding period or around parturition to investigate whether reproductive performance was affected. Two groups of 25 ewes were given water or 12,000 ostertagia larvae three times weekly for five weeks before and five weeks after breeding to synchronised oestrus. Plasma pepsinogen levels were raised in the larval-challenged ewes during the treatment period but no significant effect of treatment was observed on ovulation rate or plasma progesterone concentration. Neither ewe live-weight nor body condition score differed between groups throughout gestation or for four weeks post partum and there was no effect from larval challenge during the breeding period on lambing rate, lamb birthweight or liveweight at four weeks old. A second experiment involved 20 twin-bearing immune ewes which were administered 17,000 ostertagia larvae three times weekly for three weeks before and three weeks after parturition. Plasma pepsinogen concentration was elevated during the larval challenge period and nematode eggs were detected in the faeces after parturition but there was no effect from treatment either on ewe liveweight and body condition score or on lamb birthweight and lamb liveweight at four weeks old. These results indicate that larval challenge with ostertagia larvae at dose rates comparable to larval intake from heavily contaminated pasture did not affect the general well being and reproductive performance of immune Greyface ewes.     

Effect of feed flushing during summer season on growth, reproductive performance and blood metabolites in Malpura ewes under semiarid tropical environment

Feed scarcity during hot summer months is one of the major predisposing factors for low reproductive efficiency of livestock reared in hot semiarid environment. A study was conducted to assess the effect of concentrate supplementation during summer months on growth, reproductive performance, and blood metabolites in Malpura ewes. Twenty adult Malpura ewes were used in the present study. The ewes were divided into two groups viz, group 1 (n?=?10; control) and group 2 (n?=?10; concentrate supplementation). The study was conducted for a period of 35 days covering two estrus cycles. In the first cycle, only PGF_2α was given to all ewes, while in second cycle, all ewes were synchronized for estrus using progesterone-impregnated intravaginal sponges and pregnant mare serum gonadotropin. The animals were allowed for grazing for 8–10 h per day. Apart from grazing, group 2 ewes were supplemented with concentrate mixture at 1.5 % of body weight. Concentrate supplementation had significant influence on body weight, ADG, estrus percentage, estrus duration, onset of estrus, ovulation response, plasma glucose, total protein, and urea. The present study reveals that ewes supplemented with concentrate mixture at 1.5 % of body weights during summer season significantly influenced the growth and reproductive performance of Malpura ewes. Further, the study signifies the importance of providing additional feed supplementation to ewes kept grazing under the conditions of a hot, semiarid environment to improve their reproductive efficiency.     

放牧率对绵羊体重及繁殖性能的影响

通过不同放牧率对内蒙古本地绵羊(母羊)连续2年(2008～2009)的体重和繁殖性能的影响的研究表明:(1)在试验期内,随着时间的推移,不同放牧率下的绵羊体重总体上都呈上升趋势;间隔1个放牧率或以上的处理间,存在不同程度的显著性差异;(2)绵羊的个体增重与放牧率之间存在负相关关系;而公顷增重与放牧率的关系符合二次曲线关系,在达到公顷最大增重前,随着放牧率的增大而增大,之后随着放牧率的增大减小;(3)单位家畜增重和单位面积增重的交点的生态学意义在于放牧率为1羊/hm2,公顷增重和家畜个体增重相同;单位家畜个体增重对应的畜产品最优放牧率为0.50羊/hm2,单位面积家畜最大增重对应的畜产品最优放牧率为2.38羊/hm2;(4)过高的放牧率导致绵羊出现空怀现象及产羔率下降;羔羊的初生重和个体增重均随着放牧率的增大而减小,但其显著性差异仅表现在较高的放牧率与较低的放牧率之间,而在相邻放牧率间差异不显著。     

日粮能量水平对母羊繁殖性能影响的研究进展

能量是影响母羊繁殖性能的重要因素之一.满足母羊不同时期的能量需求是提高母羊生产效益的重要措施,对保证母羊繁殖和羔羊健康生长有重要意义.能量主要通过下丘脑-垂体-肾上腺轴来影响母羊的繁殖性能.文章综述不同能量水平对母羊的发情、胚胎发育、泌乳和羔羊生长的影响,以期为母羊合理的日粮能量水平提供依据.     

Effects of feed supplementation on growth,blood parameters and reproductive performance in Sanga and Friesian-Sanga cows grazing natural pasture

This study determined the effects of feed supplementation during the postpartum period on the weight gain, milk yield, blood profiles and reproductive performance of Sanga and Friesian-Sanga cows grazing on natural pasture. 20 Sanga and 20 Friesian-Sanga cows were randomly allocated either to serve as a control on grazing only or to be supplemented with 2.5 kg of concentrate a day for 10 weeks during the dry season. Each week, all cows were weighed and scored for body condition. Partial milk yield of cows was determined daily. Plasma concentrations of blood metabolites were assessed fortnightly from weeks 1 to 10 postpartum. Resumption of postpartum ovarian activity was determined by measuring progesterone concentration in the plasma from weeks 1 to 10. Supplemented cows had a better body condition score (6.2 versus 5.8; P?<?0.05) and higher partial milk yield (1.94 versus 1.55 L/day; P?<?0.01) than non-supplemented cows. Sanga cows had a better body condition score (6.2 versus 5.8; P?<?0.05) but lower milk yield (1.58 versus 1.92 L/day; P?<?0.01) than the Friesian-Sanga crossbreds. Total protein (P?<?0.05) and albumin (P?<?0.01) concentrations were higher in the supplemented than in the non-supplemented cows. Sanga cows recorded higher globulin (P?<?0.05) and total cholesterol (P?<?0.01) but lower albumin (P?<?0.01) concentrations than Friesian-Sanga crossbred cows. Feed supplementation did not affect (P?<?0.05) the interval from calving to resumption of ovarian activity, and the days to resumption of ovarian activity in the Sanga and Friesian-Sanga cows were also similar (P?>?0.05). The results demonstrate the beneficial effects of feed supplementation in terms of improved body condition and metabolic status and increased milk yield.