对妊娠后期甘肃高山细毛羊补饲秸秆全价颗粒饲料效果的研究

试验采用放牧+补饲的方式,分别利用玉米秸秆和小麦秸秆全价颗粒饲料在冷季对妊娠后期甘肃高山细毛羊进行补饲,测定妊娠后期母羊体重、血清生化指标、瘤胃液发酵参数及羔羊初生重。试验选取体况相近且健康的妊娠后期母羊60只,随机分为3组,每组20只。试验组补饲营养量根据中国美利奴羊妊娠后期母羊的饲养标准确定(扣除放牧采食量),试验组Ⅰ补饲小麦秸秆全价颗粒饲料(1.19kg/(只·d)),试验组Ⅱ补饲玉米秸秆全价颗粒饲料(1.19kg/(只·d)),对照组按牧民传统方式(玉米0.05kg/(只·d)、燕麦草0.2kg/(只·d))补饲,正试期60d。结果表明,试验组妊娠母羊的平均日增重、羔羊初生重均显著高于对照组(P0.05),而两试验组间无显著差异(P0.05);试验组妊娠母羊血液总蛋白、白蛋白、葡萄糖、总胆固醇浓度及谷草转氨酶、谷丙转氨酶和乳酸脱氢酶活性均显著高于对照组(P0.05);试验组妊娠母羊瘤胃液中总氮、蛋白氮、挥发性脂肪酸浓度和丙酸摩尔比均显著高于对照组(P0.05),而乙酸摩尔比显著低于对照组(P0.05)。综上所述,补饲小麦秸秆或玉米秸秆全价颗粒饲料均可改善妊娠后期甘肃高山细毛羊营养状况,促进羔羊的生长发育。     

两种饲料补饲对妊娠后期青海半细毛羊羔羊初生重的影响

为了探讨牧户传统自配饲料与全价精料补饲对妊娠后期青海半细毛羊羔羊初生重的影响,选择体重、胎次、预产期基本相近的青海半细毛羊妊娠母羊60只,随机分成试验组和对照组,每组30只,在临近预产期42d开始进行补饲试验。结果表明,试验组羔羊平均初生重为3.41kg;对照组羔羊平均初生重为3.06kg;试验组羔羊比对照组羔羊高0.35kg,提高11.33%,差异显著(P<0.05)。     

湖羊妊娠后期补饲颗粒料的效果试验

本试验旨在探讨湖羊妊娠后期补饲颗粒料对母羊繁殖性能、羔羊初生重、断奶重以及经济效益的影响。试验采用随机分组设计,将30头妊娠后期湖羊随机分成对照组和试验组,每组15头,对照组补饲羊场自配粉料,试验组补饲研制的颗粒饲料,两组基础日粮饲喂一致。试验预饲期为10d,正式试验期120d,待羔羊出生后分别测定羔羊初生重和断奶重,统计母羊产羔率和羔羊成活率,并分析不同补饲方式下的经济效益。结果表明,与对照组相比,试验组母羊繁殖率和羔羊存活率分别提高了13%和6%;较对照组相比,补饲颗粒料对羔羊初生重无显著影响(P>0.05),但试验组羔羊平均断奶总重比对照组羔羊提高了2.17kg(P<0.05),试验组羔羊平均日增重(237g/d)比对照组(199g/d)提高了18.15%(P<0.05);补饲颗粒料的经济效益比补饲自配粉料提高了27.91%。试验表明,湖羊妊娠后期补饲颗粒料切实可行,能提升湖羊养殖效益。     

牧区极端条件下绵羊饲喂秸秆应急料的研究

为研究小麦(Triticum aestivum)秸秆型及玉米(Zea mays)秸秆型全价颗粒饲料作为家畜草料空缺期的应急料,在高寒牧区特殊气候条件下对甘肃高山细毛羊育成羊生长发育的影响,本研究选择体况相近的6月龄甘肃高山细毛羊育成母羊48只,随机分为试验组Ⅰ(18只,每只仅饲喂小麦秸秆型全价颗粒饲料1.2 kg·d~(–1))、试验组Ⅱ(17只,每只仅饲喂玉米秸秆型全价颗粒饲料1.2 kg·d~(–1))、对照组[13只,每只饲喂玉米0.05 kg·d~(–1)+燕麦草(Avena sativa) 0.2 kg·d~(–1)],在舍饲条件下进行为期16 d的饲喂试验。结果表明:试验组Ⅱ羊只平均日增重显著高于对照组(P 0.05);试验组Ⅱ羊只血清中总蛋白、球蛋白的浓度显著高于对照组(P 0.05);试验组Ⅰ羊只血清中谷草转氨酶、乳酸脱氢酶的活性及白蛋白的浓度显著高于对照组(P 0.05),试验组Ⅱ与对照组无显著差异(P 0.05)。由此可见,用玉米秸秆型全价颗粒饲料作为应急料优于传统的燕麦草与整粒玉米,能够充分满足甘肃高山细毛育成母羊在肃南高寒牧区饲草料空缺期和不足期生长发育中的营养需要。     

补饲颗粒料对哺乳期羔羊生长性能及经济效益的影响

本试验旨在探究哺乳期羔羊补饲颗粒料对湖羊羔羊生长性能和经济效益的影响。选取20只分娩日期和胎次相近,产两羔以上的母羊,分娩后每只母羊留两只羔羊随母羊哺乳,20只母羊和40只羔羊随机分为对照组和试验组。母羊饲喂相同的自配料,羔羊出生后10d,试验组补饲羔羊颗粒饲料,对照组不补饲。试验期50d。记录羔羊的初生重,试验始重,试验末重和颗粒料补饲量。结果表明,试验组羔羊末重显著高于对照组羔羊(P<0.01),试验组羔羊日增重达到214g/d,比对照组提高了57.9%(P<0.01);补饲颗粒料经济效益比对照组提高了50.2%。因此,补饲羔羊颗粒料能显著提高哺乳羔羊生长性能和经济效益。     

围产期补饲对放牧蒙古羊母羊泌乳性能及羔羊生长性能的影响

旨在研究围产期补饲精补料对戈壁地区妊娠期放牧蒙古羊母羊增重、血液生理生化指标、泌乳性能以及羔羊生长性能的影响。选取20只体况相近、平均体重为（60±5.54）kg的妊娠期蒙古羊母羊, 按平均体重分为试验组和对照组, 每组10只。对照组按照传统补饲方法补饲玉米300 g/（只·d）, 试验组补饲精补料300 g/（只·d）。补饲试验预饲期5 d, 正饲期60 d。测定试验母羊初始体重和补饲试验末体重, 计算总增重;补饲试验结束时, 采集试验母羊血液样本, 测定血液常规指标和血清生化指标;从产后第15天起使用差重法测定母羊泌乳量, 持续到产后第85天;测定羔羊的初生重、90日龄重, 计算羔羊在90日龄内的日增重。利用统计学方法对对照组和试验组的上述指标进行分析。结果表明, 在补饲试验期间, 试验组母羊与对照组母羊的总增重差异不显著（P>0.05）, 试验组母羊的体重减少幅度比对照组母羊低1.71%;试验组母羊的各项血液常规指标和血清生化指标与对照组母羊相比差异均不显著（P>0.05）;整个泌乳期试验组母羊的泌乳量都高于对照组母羊, 其中, 产羔后75 d和85 d, 试验组母羊的泌乳量显著（P<0.05）或极显著（P<0.01）高于对照组母羊;与对照组羔羊相比, 试验组羔羊的90日龄体重和90日龄内日增重有所提高（P>0.05）。综上提示, 围产期补饲精补料能够提高放牧蒙古羊母羊的产后泌乳量, 并且有助于提升羔羊日增重。     

放牧补饲精补料对妊娠后期和泌乳前期苏尼特母羊体重、血清生化指标和矿物质含量的影响

本试验旨在研究放牧补饲精补料对苏尼特母羊体重、血清生化指标和矿物质含量以及羔羊初生重的影响。试验采用单因子随机试验设计,选择体重、胎次接近、健康无病的苏尼特妊娠母羊66只,随机分为2组,每组33只。分娩前,对照组妊娠母羊补饲玉米和青干草,试验组则用等量的精补料代替对照组中的玉米;分娩后,对照组泌乳母羊补饲玉米、豆粕和青干草的混合料,试验组则用等量的精补料替代混合料中的玉米和豆粕。试验期120 d,分为妊娠后期与泌乳前期2个阶段。结果表明:试验组母羊补饲结束时体重以及羔羊初生重有高于对照组的趋势(0.05≤P≤0.10),羔羊2月龄体重显著高于对照组(P0.05),母羊产后2个月失重显著低于对照组(P0.05)。妊娠后期试验组血清碱性磷酸酶活性有高于对照组的趋势(0.05≤P≤0.10),血清磷、铜、锰、锌和硒含量显著高于对照组(P0.05)。泌乳前期试验组血清碱性磷酸酶活性以及尿素氮、钙、磷、镁、钾、铜、锌和铬含量显著高于对照组(P0.05),血清铁、钴和硒含量有高于对照组的趋势(0.05≤P≤0.10)。由此得出,放牧补饲精补料等量替代玉米或玉米与豆粕的混合料,促进了苏尼特母羊产后体重的恢复与羔羊的生长,提高了妊娠后期与泌乳前期母羊血清磷、镁、铜、锌、硒含量,以及泌乳前期母羊血清钙、钾、铁、钴和铬含量。     

冷季补饲对阿勒泰妊娠母羊及羔羊生长性能的影响

为了研究冷季补饲对阿勒泰妊娠母羊和羔羊生产性能的影响,2012年10月份—2013年8月份在阿勒泰市散德克库木种畜场选择年龄和胎次相同、体重接近的阿拉泰大尾母羊220只,随机分为对照组和试验组,试验组每只母羊每天补饲颗粒料600 g,对照组不补饲。试验羊分娩后测定母羊体重、羔羊初生重、初生体尺及每月体重、体尺指标。试验组母羊分娩的羔羊为试验组,断奶后补饲颗粒料;对照组母羊分娩的羔羊为对照组,不补饲颗粒饲料。结果表明:补饲颗粒料能显著增加母羊分娩体重,显著增加羔羊初生体高、体长和胸围(P0.05);羔羊断奶后补饲颗粒料可显著提高生产性能,120日龄时试验组羔羊体重极显著高于对照组羔羊(P0.01)。说明母羊和断奶羔羊补饲颗粒料可以提高羔羊体尺指标,促进前躯发育水平。     

不同水平饲料补饲泌乳期母羊对羔羊生长发育的效果对比

选择体重、胎次、预产期基本相近的青海高原毛肉兼用半细毛（以下简称青海半细毛羊）妊娠母羊120只,随机分成试验组和对照组,每组60只,在泌乳期内采用牧户传统自配饲料和全价精料补充饲料进行40d的补饲试验。试验表明：40日龄的羔羊只均增重试验组比对照组高0.98kg（P〈0.01）,增重幅度提高34.64%,平均日增重比对照组增加25.33g,提高39.12%（P〈0.0 1）。     

青海半细毛母羊补饲料中添加预混料的试验

通过妊娠后期青海半细毛羊母羊补饲精料中添加复合预混料的试验,研究复合预混料对母羊生产性能、羔羊初生质量、羔羊成活率及补饲精料利用率的影响.结果表明,试验组羔羊的初生质量比对照组增加0.51 kg(P＜0.05);1和2月龄羔羊体质量比对照组多增质量1.50和2.50 kg(P＜0.05);成活率比对照组提高4.5%;羊粪中粗蛋白、中性洗涤纤维和酸性洗涤纤维含量分别比对照组降低2.37%、5.87%和5.10%(P＜0.05);活质量产值幅度比对照组提高25.18%;扣除补饲料和预混料费用后,比对照组羊只均增加21.9元.     

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。     

膨化玉米秸秆发酵饲料对肉羊育肥效果的影响

为研究膨化玉米秸秆发酵饲料对肉羊育肥的效果,选取杂交绵羊(南非美利奴羊×东北细毛羊)16只,随机分为2组,每组8只,每只为一个重复。对照组以干玉米秸秆为粗饲料来源,试验组以膨化玉米秸秆发酵饲料为粗饲料来源,两组精料相同,每天每只1 000 g。日粮均以先精后粗的方式饲喂。试验共计90 d。试验结束后每组随机选择3只羊进行屠宰。结果表明:(1)试验组干物质采食量比对照组提高20%(P<0.05),净增重比对照组提高14.16%(P>0.05);(2)试验组羊血液中总蛋白含量显著高于对照组(P<0.05),而尿素氮含量显著低于对照组(P<0.05),其他血液指标两组间未见显著性差异(P>0.05);(3)试验组瘤胃食靡中的滤纸酶活性和果胶酶活性均显著高于对照组(P<0.05),木聚糖酶活性两组间未见显著性差异(P>0.05)。     

甘肃高山细毛羊母羊妊娠后期补饲效果研究

根据甘肃高山细毛羊母羊妊娠后期营养缺乏状况,配制出中等能量中等蛋白质补饲料 Ⅰ、低能量高蛋白质补饲料 Ⅱ和高能量低蛋白质补饲料 Ⅲ 3种补饲料。选择健康、体重相近的妊娠后期母羊60只,随机分为A、B、C、D 4组,每组15只,每个重复1只羊,A、B、C组为试验组,分别补饲饲料Ⅰ、Ⅱ和Ⅲ;D组为对照组,按牧民传统方式饲养,试验期共68 d。试验结果表明,A、B、C补饲组母羊平均日增重分别为102、109和114 g/d;A、B、C补饲组羔羊初生重分别为4.09、3.91和 4.40 kg,均显著高于对照组。补饲料Ⅲ对试验羊血清葡萄糖(glucose)、甘油三酯 (triglyceride)和尿素氮(blood urea nitrogen)浓度有显著影响(P<0.05);补饲料Ⅱ对试验羊血清总蛋白(total protein)、谷草转氨酶(aspartate transaminase)浓度有显著影响。补饲组试羊瘤胃液总氮、瘤胃液蛋白氮含量显著高于对照组(P<0.05)且A组显著高于其他各组,B组瘤胃液尿素氮浓度显著高于其他各组(P<0.05)。试验组瘤胃液挥发性脂肪酸(volatile fatty acid)浓度和丙酸摩尔比显著高于对照组(P<0.05);试验组瘤胃液中乙酸/丙酸显著低于对照组(P<0.05)。3种补饲料对试验羊瘤胃液pH和瘤胃液氨态氮影响均不显著(P>0.05)。     

不同粗饲料组合效应对育肥公羊生产性能及经济效益的影响

为研究不同粗饲料组合效应对育肥公羊采食量、日增重、料肉比及经济效益的影响,试验采用单因素完全随机试验设计,将体重相近的40只小尾寒羊后备种公羊随机分为8组,每组5只。基于等能等氮原则配制日增重350 g试验饲粮,其中A组日粮中粗饲料添加苜蓿,B组添加玉米秸秆,C组添加棉花秸秆,D组添加苜蓿和棉花秸秆,E组添加苜蓿和玉米秸秆,F、G、H组添加不同比例苜蓿、棉花秸秆和玉米秸秆。试验期40 d,其中预试期10 d,正式试验期30 d。结果表明:(1)G组干物质采食量极显著高于C组和D组(P<0.01),显著高于F组(P<0.05);A、B、E、H组干物质采食量极显著高于C组和D组(P<0.01);F组干物质采食量显著高于C组(P<0.05)。(2)A组日增重极显著高于C组(P<0.01),显著高于D组(P<0.05);G组日增重显著高于C组和D组(P<0.05)。(3)A组饲粮单价最高,C组单价最低,饲料单价如下趋势:A组>E组>G组>H组>F组>D组>B组>C组,饲料总成本趋势与饲料单价趋势基本相同。(4)增重收益中A组最高,C组最低,前者比后者高35.76%;经济效益G组最高,D组最低,前者比后者高34.46%。综上,在本试验条件下,以苜蓿:玉米秸秆:棉杆为12:24:13调配日粮时,经济效益最优,为265.43元/只。     

Effect of Bacillus licheniformis and Bacillus subtilis supplementation of ewe's feed on sheep milk production and young lamb mortality

The purpose of this pilot study was to evaluate under field conditions the effect of a probiotic containing Bacillus licheniformis and Bacillus subtilis on young lamb mortality and sheep milk production when administered in the late pregnancy and lactation feed of ewes. In a sheep farm, two groups of milking ewes with identical genetic material, management, nutrition, health status and similar production characteristics were formed. One group (46 ewes) served as control, while the other one (48 ewes) served as a probiotic-treated group. Both groups of ewes received a similar feeding regiment, but the ewes of the second group were additionally offered a probiotic product containing B. licheniformis and B. subtilis (BioPlus 2B, Chr. Hansen, Denmark) at the approximate dose of 2.56 x 10(9) viable spores per ewe per day. Lamb mortality during the 1.5 months suckling period, and milk yield during the 2 months of milk collection for commercial purposes have been recorded. In the non-treated control group, 13.1% mortality was observed versus 7.8% in the probiotic-treated group (P = 0.33), with mortality being mainly due to diarrhoea. Microbiological examination of diarrhoeic faeces from some of the dead lambs in both groups revealed the presence of Escherichia coli. The average daily milk yield per ewe was significantly lower in the control group (0.80 l) than that in the probiotic-treated group (0.93 l) (P < 0.05). Fat and protein content of milk in ewes that received probiotics was significantly (P < 0.05) increased compared with untreated ewes. It was concluded that supplementing ewe's feed with probiotics may have beneficial effect on subsequent milk yields, fat and protein content.     

复合秸秆颗粒饲料生产工艺优化

为了提高牧草类颗粒饲料的生产效率、产品质量和商品化水平,以玉米(Zea mays)秸秆和苜蓿(Medicago sativa)干草为原料(按照质量比1∶1),研究复合秸秆颗粒饲料的最优生产工艺。首先采用单因素试验设计,设置7个总水分含量,分别为8%、10%、13%、16%、19%、22%和25%。通过测定复合秸秆颗粒饲料的成型率筛选出较适宜的水分含量。结果表明,随着水分含量的提高,复合秸秆颗粒饲料的成型率呈下降趋势,总水分含量为8%的成型率显著高于其他处理组(P<0.05)。然后采用L9(34)设计正交试验,以总水分含量(8%、10%和13%)、原料粉碎粒度(4、6和8 mm)和模孔直径(6、7和9 mm)为影响因素,以成型率、硬度和密度为检测指标,筛选出复合秸秆颗粒饲料的最优生产工艺参数。影响复合秸秆颗粒饲料质量的主次因素为模孔直径>原料粉碎粒度>水分含量;复合秸秆颗粒饲料生产工艺的最优组合为模孔直径7 mm,粉碎粒度8 mm,总水分含量8%。     

Effects of Different Dietary Cotton by-products Levels on Production Performance,Nutrient Digestibility and Blood Biochemical Indexes of Sheep

The study was conducted to determine the effects of different dietary cotton by-products levels on production performance,nutrient digestibility and blood biochemical indexes of sheep.30 healthy sheep were chosen and randomly divided into 5 groups with 6 sheep per group. The feed of each group was that 50% formula concentrate feed was mixed with 50% wheat straw (control group),25% wheat straw and 25% cotton stalk (group Ⅰ),50% cotton stalk (group Ⅱ),45% cotton stalk and 5% cotton seed (group Ⅲ),and 40% cotton stalk and 10% cotton seed(group Ⅳ), respectively. The experiment lasted for 60 d. The result showed that:① The total weight gain and ADG of sheep showed a decreased with the increase of cotton stalk added proportion in the diets, and the total weight gain and ADG of group Ⅱ were significantly lower than group Ⅲ (P<0.05).② The concentration of NH₃-N was increased or decreased at different levels after adding different proportions of cotton by-products,and the TVFA and propionic acid concentration were not significantly affected (P>0.05).③ There was no significant difference of intake nitrogen, fecal nutrogen and uninary nitrogen among groups (P>0.05),but apparent digestibility of NDF and ADF showed a downward trend with the increase of cotton by-products added proportion in the diets,which were extremely significantly lower than control group (P<0.01).④ There were no significant differences among groups of the blood white cell count,red cell count,hemoglobin concentration,total protein,albumin,globulin,serum iron,sodium,chlorine and potassium content (P>0.05),but serum magnesium was significantly increased with increases of gossypol content in the diets (P<0.05). In conclusion,when the cotton by-products addition level in diets reaches 50% caused the free gossypol concentration in the feed more than 300 mg/kg, it would has certain negative effects on the production performance and health of sheep,and the cotton stalks add ratio in the diet should be controlled in the range of lower than 25%.     

妊娠后期限饲对母羊肝脏功能及抗氧化的影响

本研究旨在评估母羊妊娠后期限饲对其肝脏功能及抗氧化性能的影响。试验选择平均体重为(52.82±2.72)kg的妊娠后期母羊(2~3胎次)36只,随机分为3组,每组6个重复,每个重复2头羊。各组分别饲喂对照组日粮(代谢能:0.68 MJ/kg代谢体重/d)、处理1组日粮(代谢能:0.17 MJ/kg代谢体重/d)、处理2组日粮(代谢能:0.34 MJ/kg代谢体重/d),试验从妊娠90 d持续至140 d。结果:处理1组母羊肝脏脂肪含量较对照组和处理2组显著提高了288.03%和282.48%(P<0.05)。与对照组相比,处理1组肝脏水分、灰分和蛋白质占比显著降低19.28%、44.32%和45.83%(P<0.05),但处理1组肝脏脂肪占比较对照组显著提高210.19%(P<0.05)。处理1组和处理2组血清非酯化脂肪酸含量较对照组分别提高199.94%和185.51%(P<0.05)。与对照组相比,处理1组血清β-羟丁酸和肝脏甘油三酯含量显著提高392.45%和329.55%(P<0.05)。处理1组肝脏超氧化物歧化酶、过氧化氢酶和总抗氧化力活性较对照组显著提高103.32%、83.36%和75.85%(P<0.05),同时处理1组丙二醛含量较对照组和处理2组显著提高54.52%和67.31%(P<0.05)。结论:妊娠后期限制母羊采食量会导致肝脏重量和蛋白质含量下降,同时引起肝脏脂肪的积累,肝脏抗氧化功能失衡。     

Influence of body weight and number of inseminations on fertility of progestogen-treated ewe lambs raised in controlled environments

The influence of body weight at breeding on reproductive response to one and two artificial inseminations (AI) of fresh extended semen was assessed in 195 crossbred ewe lambs selected for early breeding and compared with 159 adult ewes, all housed indoors in a controlled environment. In six trials, ewe lambs and adult ewes in progestogen-induced estrus were inseminated 55 to 57 h after sponge removal. One-half of the lambs and one-fourth of the adults received a second insemination at 60 h. Resultant reproductive performance of both groups indicated no advantage in a double insemination. Overall fertility, litter size and fecundity after one and two inseminations were 33%, 1.7 and .6 for ewe lambs and 68%, 2.4 and 1.6 for adult ewes, respectively. Embryonic mortality after the first 2 wk of pregnancy was estimated at 24% for ewe lambs and 9% for adults. The influence of body weight was analyzed by grouping the ewe lambs according to body weight at breeding. The lambs in group 1 weighed 30 to 35 kg; group 2, 36 to 40 kg; group 3, 41 to 45 kg and group 4, 46 to 50 kg. The proportion of ewes lambing in groups 1, 2, 3 and 4 was 16, 34, 39 and 48%, respectively. Corresponding litter sizes were 1.4, 1.6, 1.8 and 2.0. Fecundity increased (P less than 01) from .2 in group 1 to 1.0 in group 4. The results indicate that even when ewe lambs are bred by AI (eliminating a ram behavioral problem), sheep with heavier body weights produce more lambs per ewe bred.