复合添加剂对冬春季放牧母羊生产性能的影响

用中国农科院兰州畜牧与兽药研究所研制的牛羊复合饲料添加剂在甘肃天祝种羊场冬春季对羊进行了饲喂试验。将４０只甘肃细毛羊妊娠母羊分为对照组和试验组,试验组每日每只羊补饲５０ｇ添加剂。两组放牧条件、补饲草料完全一样。结果试验组妊娠母羊妊娠期少减重４２５％（Ｐ＜００５）,羔羊初生重提高１２％,哺乳期母羊体重提高３７４％,羊毛产量提高１６％（Ｐ＜００５）。     

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。     

冷季标准化暖棚对绵羊产羔成活率的影响

畜舍中建立必需的小气候是提高家畜生产性能和幼畜生长发育的重要条件。我国北方地区低温是影响绵羊产羔成活率的重要因素。在寒冷的冬季和春季,往往由于低温而造成初生羔羊大量死亡,从而影响养羊的经济效益。塑料暖棚的应用在很大程度上为冷季养羊的保暖提供了一条可行有效的途径。为此我们对冷季标准化养羊暖棚对绵羊产羔成活率的影响进行了研究。     

新疆牧区温性荒漠草原草群营养成分变化与放牧绵羊体重及产羔性能的关系

为了研究新疆牧区温性荒漠草原草群营养成分的变化对不同品种断奶母羊增重和繁殖性能的影响,试验以放牧的多胎萨福克羊、萨福克羊和中国美利奴羊(新疆军垦型)为研究对象,定期测量6—9月份断奶母羊的体重、牧草产量和草群营养成分(粗蛋白、粗纤维、粗脂肪、粗灰分、钙、磷、无氮浸出物等),记录母羊次年的窝产仔数及羔羊的初生窝重和断奶重,分析牧草产量、营养成分与母羊体重和繁殖情况之间的关系。结果表明：6—8月份,新疆牧区气温较高,降雨天数减少;进入9月份气温下降,降雨天数增多。6—9月份新疆牧区温性荒漠草原类沟羊茅、针茅和新疆绢蒿型草群牧草产量、干物质、粗灰分、粗脂肪和粗纤维含量均呈先下降后升高的趋势。多胎萨福克羊、萨福克羊和中国美利奴羊的体重从63.50 kg、91.33 kg、56.25 kg降至63.33 kg、86.00 kg、51.50 kg,分别下降0.27%、5.84%、8.44%。多胎萨福克羊的体重未恢复至初始体重与体重恢复至初始体重群体母羊的窝产仔数分别为1.83只、1.91只,萨福克羊为0.93只、 1.00只,中国美利奴羊为0.95只、1.00只,均差异不显著(P>0.05)...     

放牧与舍饲对滩羊生产性能的影响

滩羊是产于中国西北干旱半荒漠地区的一个独特的绵羊 品种,主要分布在东经105°～108°,北纬35°45′～39°40′的区 域内,以宁夏中、北部为中心产区。传统的生产方式为放牧,当 地特殊的自然和生产条件形成了滩羊特殊的品种特点。近年 来,随着西部大开发战略决策的实施,滩羊中心产区全面实行 了退牧还草和禁牧措施。从而改变了滩羊的传统生产方 式———由放牧转为舍饲,由采食荒漠及干旱草原牧草为主转向 以人工牧草和作物秸秆为主。为了了解舍饲对滩羊生产性能 的影响及程度,为今后科学组织生产提供依据,特以宁夏滩羊 保种基地盐池滩羊…     

左咪唑对冬季舍饲母羊产羔性能的影响

近年来,在气候恶劣的冬季对处于山地和低地的羊群在妊娠中期到产后进行舍饲有很明显的优越性。产羔时给母羊驱虫已经是一般的常规,其目的在于控制围产期寄生虫卵的上升,减少草场污染。Mackay等(1974,75,80)根据初生羔羊数和饲养到12周龄羔羊数的增加,对产前驱虫的优越性提供了证明。在妊娠中期到产后进行舍饲的母羊,不一定能受到园虫的严重感染,但在舍饲后不久即用驱虫药治疗,可能会使这种优越性更加显著。本试验对每年在妊娠中期     

塑膜暖棚对繁殖母兔生产性能的影响

本文研究了冬季塑膜暖棚饲养繁殖母兔对其生产性能的影响,试验用９￣１０月龄新西兰繁殖母兔５０只和公兔６只,均分为二组即试验组和对照组。试验组用塑膜暖棚饲养,对照组在普通兔舒饲养。试验表明：试验验和对照组相比,受胎率差异不显著（Ｐ〉０．０５）;窝产仔数,总产仔数,初生窝重差异显著（Ｐ〈０．０５）,４０日龄断乳窝重,仔兔成活率,经济效益受异极显著（Ｐ〈０．０１）。     

塑膜暖棚对繁殖母兔生产性能的影响

本试验将９～１０月龄新西兰繁殖母兔５０只和公兔６只,随机分为两组,试验组用塑膜暖棚饲养,对照组用普通兔舍饲养。试验结果表明,受胎率差异不显著（Ｐ＞００５）;窝产仔数、总产仔数、初生窝重差异显著（Ｐ＜００５）;４０日龄断奶窝重、仔兔成活率、经济效益差异极显著（Ｐ＜００１）。     

Body weight changes and subsequent lambing rates of western whiteface ewes grazing winter range

The objective was to describe body weight change (BWC) and subsequent lambing performance of Columbia, Polypay, Rambouillet, and Targhee ewes that grazed shrub-dominated range in winter of 1989, 1990, and 1991. In December (winter), after breeding each year (yr; October to December), ewes were moved to range. Depending upon severity of climatic conditions and vegetation accessibility, ewes grazed winter range for 30 to 60 days (d). Body weights were measured 2 d before grazing commenced (initial) and 2 to 7 d after ewes were transported off range (exit). Total BWC was calculated by subtracting finial BW from initial BW. All data were analyzed within each breed, as repeated measures using mixed models with age and year included in the model. For all breeds, 2-yr-old ewes were lightest going on to winter range and had the lowest lambing rate. Ewes lost weight while grazing winter range, but mature BW, once achieved, was restored annually with the exception of the 7-yr-old Columbia and Targhee ewes. Regardless of breed or age, ewes were able to achieve lambing rates > 1.5 lambs following early- and mid-pregnancy weight loss. Lambing rates were greater in older ewes, which generally experienced substantial negative BWC during winter grazing.     

呼伦贝尔短尾羊产前补饲精喂对家畜个体特征及生产效益的影响

在内蒙古草原牧区,冬季对绵羊补饲精喂的研究具有重要的意义。为研究产羔前对母畜舍饲精料后,呼伦贝尔短尾羊体重、体尺及经济效益的变化,本研究选取60对待产的呼伦贝尔短尾母绵羊作为试验对象,在母畜产羔前一个月,试验组母畜舍饲精料,对照组仅补饲干草,分析100日龄内家畜体重、体尺及经济效益变化。利用方差及偏最小二乘回归法,分析产前补饲对家畜个体、生产效益的影响及影响家畜体重的主要体尺权重,结果显示,100 d时间段内,母畜体重呈先减少后增加的趋势;仔畜出生后一个月左右的时间段,试验组仔畜的胸围、胸宽、体高、胸深、体长和体斜长显著高于对照组(P<0.05)。影响呼伦贝尔短尾羊体重的主要体尺指标为:胸围、胸宽、体高和胸深,影响权重达到50%以上。补饲使得仔畜的成活率、出售价格显著高于未进行补饲的对照组(P<0.05)。通过补饲母畜不仅可以影响仔畜体重和体尺指标,而且对提高仔畜成活率和经济效益具有重要的作用,这为今后后备母羊的选育、家畜的精准淘汰提供了理论基础。     

Comparison of performance of F1 Romanov crossbred ewes with wool and hair breeds during spring lambing under intensive and extensive production systems

The objective was to evaluate wool (Dorset and Rambouillet) and hair (Dorper, Katahdin, and White Dorper) breeds for their ability to complement Romanov germplasm in two distinct production systems by estimating direct sire and grandsire effects on lamb growth, survival, and ewe productivity traits. Rams of the five breeds (n = 75) were mated to Romanov ewes (n = 459) over a 3-yr period to produce five types of crossbred lambs (n = 2,739). Sire breed (P > 0.06) did not impact body weight or survival traits of the first-generation crossbred (F1) lambs. The productivity of retained crossbred ewes (n = 830) mated to Suffolk and Texel terminal sires was evaluated at 1, 2, and 3 yr of age in each production system. In the intensive production system, labor and harvested feed were provided for sheep that lambed in March in barns, and ewes were limited to rearing two lambs with additional lambs reared artificially. Ewes in the extensive production system lambed in May on pasture and were responsible for rearing all lambs born with no labor or supplemental feed provided before weaning. A total of 1,962 litters and 4,171 lambs from 2,229 exposures to two terminal sire breeds (Suffolk and Texel) were produced in the experiment. Crossbred ewes in the intensive production system were mated in October, resulting in larger litter sizes than crossbred ewes mated in December for the extensive production system. However, single- and twin-born lamb mortality was similar between the two systems that differed greatly in labor, feed, and facilities. Lambs produced in the intensive system received concentrate feed from an early age and were heavier at 24 wk of age than lambs produced in the extensive system. These outcomes resulted in greater 24-wk litter weight in the intensive than in the extensive system (P < 0.0001). Unexpectedly, the relative performance of crossbred types did not differ importantly between production systems. White Dorper × Romanov crossbred ewes had numerical advantages in productivity in each system; however, differences between ewe types were not significant. In the extensive system, without labor and shelter at lambing or supplemental feed until weaning, 3-yr-old crossbred ewes of all types averaged 1.78 lambs marketed per ewe lambing, and 40% of the ewes that gave birth to triplets weaned their entire litters. These results document that prolific sheep and extensive systems can be successfully combined if appropriate crossbred types are used.     

荒漠草原放牧与舍饲对滩羊屠宰性能与肉品质的影响

为探究荒漠草原放牧与舍饲对滩羊屠宰性能和肉品质的影响,本研究将39只3月龄滩羊公羔分为荒漠草原放牧组(GZ)、限时放牧4 h补饲组(TG)和舍饲组(SF)3组,测定滩羊的屠宰性能与肉品质指标.结果显示:SF组滩羊的宰前活重、胴体重、屠宰率、净肉率和肉骨比显著优于TG组,TG组滩羊除肉骨比和净肉率外,显著优于GZ组(P<...     

甘肃高山细毛羊枯草季放牧与暖棚舍饲饲养对比试验

枯草期选甘肃高山细毛羊成年母羊180只,后备母羊38只,羔羊40只,进行为期171 d的放牧与舍饲对比试验。结果表明:试验组(暖棚舍饲)平均每只成年母羊、后备母羊和羔羊体质量分别增加5.1、9.8和6.9 kg,增幅为:11.72%、30.81%和32.86%;对照组(放牧)每只成年母羊、后备母羊和羔羊体质量分别平均下降7.3、5.0和1.0 kg;试验末,试验组成年母羊和后备母羊体质量极显著高于对照组(P0.01),试验组羔羊体质量显著高于对照组(P0.05)。羊毛长度试验组成年母羊、后备母羊和羔羊羊毛每只分别平均增长3.9、3.8和2.7 cm,试验组成年母羊和后备母羊比对照组提高10.4%和16.0%,羔羊比对照组降低11.2%,试验组和对照组差异不显著(P0.05)。试验组各年龄段产羊毛量分别达5.24、4.56和3.79 kg,比对照组分别提高60.24%、73.38%和49.80%,差异极显著(P0.01)。试验组纯收入分别为成年母羊5.35元/只,后备母羊45.65元/只,羔羊59.57元/只,对照组由于掉膘损失严重,成年母羊和后备母羊分别损失28.32和13.05元/只,羔羊收益29.3元/只。     

母牦牛妊娠后期暖棚补饲对繁殖性能和后代犊牛育肥效果的影响

为了验证枯草期对母牦牛进行产前和产后7个月补饲对其来年繁殖性能和后代犊牛生长发育的影响,设计了枯草期妊娠母牦牛“产犊前5个月”+“产犊后2个月”暖棚补饲试验,方法是从2020年10月1日开始对试验组和对照组妊娠母牦牛白天放牧,夜间暖棚过夜,但试验组早上出牧前和黄昏归牧后精料补饲,对照组不补饲,试验于2021年4月30日结束,试验期共7个月。试验结果表明：试验组的妊娠母牦牛所产犊牛的繁殖成活率、公母犊牛平均初生重、母牦牛翌年发情时间、受胎率比对照组母牦牛分别高30%、2.94 kg和2.71 kg、40 d、45%,公母犊牛平均初生重差异极显著（P<0.01）。另对两组母牦牛所产后代犊牛进行短期集中育肥效果观测,结果表明：在相同的饲养条件下,试验期内试验组和对照组公、母牛的体重分别增长46.91 kg和41.74 kg、34.47 kg和30.35 kg,验期期内两组公母牛的日增重分别为52.12 g和46.38 g、38.30 g和33.72 g,试验组公母牛的日增重分别比对照组高13.82 g和12.22 g。通过本组试验得出如下结论：如果保证了母牦牛在妊娠期和哺乳前期的营养需要,不仅可以提高其来年繁殖性能,其后代犊牛的生长发育水平远高于不补饲母牦牛后代犊牛,进行育肥效果更明显。     

Effect of dietary Ulva and Spirulina on weight loss and body composition of rainbow trout, Oncorhynchus mykiss (Walbaum), during a starvation period

A study was conducted to determine the effect of dietary algal supplementation on weight loss and proximate composition in rainbow trout, Oncorhynchus mykiss, during starvation. An algae-free control diet (C) and four experimental diets, including varying levels of raw Ulva meal (5% = U5; 10% = U10) and Spirulina meal (5% = S5; 10% = S10) were formulated. Fish were fed to satiation for 12 weeks and then subjected to a 3-week starvation period. Body weight, viscerosomatic index (VSI, %), hepatosomatic index (HSI, %), dress-out (DO, %) and chemical composition of carcass were analysed at the end of each starvation week. The accumulated weight loss of the fish fed dietary algae was almost 50% less than the control group (p < 0.05) after 2 and 3 weeks starvation. No significant differences in weight loss were observed among the fish fed different algal diets during the starvation period. Total body protein and ash contents remained constant in all groups throughout the starvation period. Fish in all treatments lost a significant level of total lipids and changes of liver fatty acid profiles were also observed. Results indicate that low level inclusion of algae in aquafeeds may have economical advantages in terms of reducing weight loss in fish when subjected to a short-term fasting period, that sometimes is necessary after a heavy rainfall or when fish stocks are held back to meet market demand.     

饲养模式对绵羊冷季生产效益的影响

在肃南裕固族自治县选择草场类型一致,绵羊(Ovisaries sp.)体况相近的3个牧户分别采取暖棚全舍饲(试验组Ⅰ),放牧+补饲(试验组Ⅱ)以及全放牧(对照组)3种饲养方式,通过测定整个繁殖周期绵羊体质量变化、母羊繁殖率和羔羊成活率指标,比较不同饲养模式对绵羊生产效益的影响.结果表明,3种饲养模式下越冬母羊体质量损失...     

Effects of summer heat stress on physiological variables,ovulation and progesterone secretion in Pelibuey ewes under natural outdoor conditions in an arid region

Ten non‐lactating multiparous Pelibuey breed ewes were housed in a corral to evaluate the effects of summer thermal stress on physiologic variables, estrous behavior, ovulation and corpus luteum functionality under natural conditions of an arid region. In summer and autumn, daily estrous detection with a ram fitted with an apron and blood sample collections were performed during two natural estrous cycles. An environment of heat stress was detected in summer and thermoneutral in autumn. Rectal temperature and respiratory frequency were greater (P < 0.01) in summer than in autumn during the morning and afternoon. Season did not affect (P > 0.05) live weight, body condition, length of estrous cycle or percentage of ewes in estrous and ovulating. Compared with autumn, serum progesterone concentrations in summer decreased (P < 0.05) between days 8 and 14 of the estrous cycle. It is concluded that under outdoor conditions of arid regions, while estrous and ovulatory activities of Pelibuey ewes were not affected by summer thermal stress, the corpus luteum functionality was decreased.     

Effect of water restriction on milk yield and quality in Lacaune breed ewes

The effect of water restriction on body weight, body condition score, milk yield, and milk composition and rheological characteristics in intensively reared Lacaune ewes was evaluated. After 7 days of adaptation, the trial lasted 28 days. Thirty lactating ewes (48 ± 5 months of age; mean value ± standard deviation) at the beginning of third lactation month were divided into three groups (n = 10), corresponding to the following water restriction treatment: a group control received no drinking water restriction (W100), and two groups received water to the extent of 80% and 60% of W100 daily consumption (W80 and W60 group respectively). The effects of water restriction were assessed at the beginning of experiment (D0), at D14 and D28. The W60 group resulted in a significant decrease in body weight, body condition score, milk yield and feed consumption of hay due to the experimental treatment; whereas a marked increase in both W60 and W80 groups of milk lactose, urea, sodium, sodium chloride content and titratable acidity was observed. Rheological parameters of milk, rennet coagulation time and curd‐firming time were positively affected by water restriction treatments, with a decrease in both experimental groups of the time required for the formation of a stable and firm curd. Results highlight the importance of water consumption in dairy sheep. The scarce availability of water, significantly affecting ewes milk production, is worthy of particular attention in arid area where water stress‐resistant breeds should be considered. This study underlines that milk yield, being closely linked to the availability of water of the breeding habitat due to its high water content (about 81%), could be reached in area where water is not a limiting factor without reducing the genetic expression of the animals. Less severe water restrictions, such as 20% of daily voluntary water intake, produce no detrimental effect on milk yield.