影响波尔山羊初生重的因素分析

作者分析了遗传因素、羔羊性别、母羊年龄、窝产羔数等因素对波尔山羊初生重的影响.结果表明,波尔山羊初生重的遗传力为0.22,公母羔的平均初生重分别为3.72和3.15 kg,性别之间存在显著差异(P＜0.05);母羊产羔年龄对羔羊初生重有显著差异影响(P＜0.05),其中母羊在3岁时所产羔羊的初生重最大,而母羊在1岁时所产羔羊的初生重最小;窝产羔数对羔羊初生重也存在着极显著影响(P＜0.01),其中窝产单羔数的羔羊初生重最大,而窝产3羔数的羔羊初生重最小.     

胎次对波尔山羊羔羊相关生长性状的影响

本文旨在研究不同胎次对波尔山羊羔羊初生重、体长、体高三个遗传性状指标的影响。选取了第1、2、3、4胎共301头波尔山羊羔羊,分别测定各胎次的三个生长性状指标,并对其进行统计分析。结果表明：羔羊初生重在前四胎之间没有显著的差异性（P〉0．05）;胎次对羔羊体长、体高均有显著的影响（P〈0．05）。     

湖羊胎产羔数对羔羊生长发育的影响

为了研究不同胎产羔数湖羊的泌乳量和羔羊的生长速度,以便进行科学饲养管理,该研究随机选择同期产双羔、三羔、四羔母羊各3只,对其产奶量、羔羊初生重及4月龄前日增重进行了测定,分析对生长发育的影响。结果表明:双羔羊初生重最大,平均为3.82 kg,显著高于三羔羊的3.21 kg和四羔羊的2.80 kg(P0.05);所有羔羊在2月龄前生长速度最快,双羔、三羔和四羔平均日增重分别为279.80 g、223.40 g和200.20 g,各组间差异显著(P0.05);虽然断奶应激对羔羊的生长速度有一定影响,但双羔羊2～4月龄日增重仍然最高,为228.50 g,显著高于四羔组(P0.05);另外,双羔羊的总吮乳量和日吮乳量为52.30 kg和0.88 kg,显著高于三羔组和四羔组(P0.05)。因此,湖羊同胞产羔数越多羔羊初生重越小,羔羊吮乳量越少,早期生长速度较慢。但在良好的饲养管理条件下,羔羊断奶后的代偿性生长可在一定程度上弥补初生重小所造成的影响。研究结果为不同胎产羔数湖羊及其羔羊的饲养管理提供科学依据,即多胎湖羊应分群饲养管理,羔羊早期锻炼采食。     

波尔山羊2号和8号染色体微卫星标记与产羔性状的关联研究

根据山羊2号和8号染色体遗传连锁图谱,选取8个微卫星标记INRA040、LSCV22、LSCV37、IDVGA64、FCB011、INRA129、SRCRSP10和CSSM47,分析它们与波尔山羊产羔性状的关联。结果表明：所研究的8个波尔山羊微卫星基因座均为高度多态性基因座（PIC〉0．5）。与波尔山羊产羔性状有显著效应的等位基因10个。其中与波尔山羊第1胎产羔数有显著正效应的等位基因1个：LSCV22的189bp;与波尔山羊第1胎产羔数有显著负效应的等位基因4个：LSCV22的179和191bp,SRCRSP10的273和303bp;与波尔山羊第2胎产羔数有显著正效应的等位基因6个：LSCV22的189bp、IDVGA64的281、283和245bp、FCB011的143和165bp。     

免疫时机对山羊产羔数及羔羊育成率的影响

山羊羔的成活率对山羊生产的发展影响很大,天峨县在实施《羔羊生产配套增产技术项目》过程中,为促进羔羊生长发育,增强抗病力,减少死亡率,曾采用补精料、补舔砖等办法,虽收到一定效果,但不太理想。笔者从１９９６年１０月至１９９８年１０月,先后进行四次重复试验...     

波尔山羊杂交后代体尺、体重与肉用性能的相关性研究

本文利用 SPSS数据处理软件 (10 .0版 )统计分析了 2 3只 (约 8～ 9月龄 )波尔山羊与唐山奶山羊杂交后代公羊的体尺、体重和肉用性能。结果表明 :(1)波尔山羊与唐山奶山羊杂交 F1 代体尺、体重与肉用性能指标的变异程度大于 F2 代 ,其中宰前重、胴体重、净肉重和胸宽四项指标变异程度在 F1 和 F2 代中都很大 ;(2 )杂交 F1 代、F2 代各项指标 t检验结果 ,除胸宽外其余指标差异显著或极显著 ;(3 )波尔山羊杂交后代中胸宽与各项指标间相关不显著 ,宰前重、胴体重、净肉重与体尺指标相关显著或不显著。     

波尔山羊随机扩增多态DNA标记与体重和体尺的关系

应用 19个波尔山羊个体间多态性较强、重复性好的随机引物对 2 0只 5～ 6月龄波尔山羊公羊组织样DNA进行扩增 ,共得到 15 6个标记 ,其中可变标记 4 7个。t检验表明 ,OPE 15 1阳性组腰角宽显著高于阴性组 ,OPH 15 8、OPE 15 4阳性组臀端宽显著高于阴性组 ;而OPH 13 6、OPH13 8等标记阴性组多个体尺、体重性状显著高于阳性组。这说明这些标记与特定性状可能存在相关 ,其遗传基础可能是该标记与控制性状的QTL或主基因连锁。     

麦盖提羊羔羊初生体重、体尺及其相关性的研究

对麦盖提羊羔羊体尺指数和初生体重与体尺指标的参数进行研究分析 ,并对羔羊初生体重与体高、体长、胸围、胸宽、胸深、管围、耳长、尾长、尾宽和尾厚等指标的相关性进行研究分析 ,认为麦盖提羊初生重与体高、胸围和耳长有相关关系而且差异显著 (P <0 .0 1) ,可作为麦盖提羊早期选种的依据     

皮山红羊产羔情况及影响羔羊初生重的因素分析

本研究旨在探析皮山红羊夏秋季产羔情况及影响羔羊初生重的因素。研究收集了503只皮山红羊母羊2022年7—10月的产羔数据,运用SAS 9.2软件进行最小二乘方差分析,分析性别、产羔类型、出生月份及母羊年龄对皮山红羊羔羊初生重的影响。结果表明：该场这段时期总产羔率为145%;公羔与母羔之比为1:0.96;产羔类型上单羔至四羔的比例分别为：43%、44%、11%、2%;性别效应、产羔类型效应、出生月份及母羊年龄效应均对羔羊初生重有极显著影响。本研究通过对影响皮山红羊初生重的4个非遗传因素进行科学合理分析,以期为今后估计皮山红羊的遗传参数和育种值时划分固定效应和选育提供一定的依据。     

影响绒山羊初生重和断奶重的固定效应分析

影响绒山羊初生重和断奶重的固定效应分析张文生，方展欢（北京市农林科学院畜牧兽医研究所１０００８１）前言我国绒山羊大都在草场较差，气候条件严酷的环＊境中放牧生产，幼龄羔羊的生长发育不仅关系到其未＊来的生产性能，而且决定着其是否能渡过第一个冬春＊枯草期。...     

Genetic determination of individual birth weight, litter weight and litter size in Mukota pigs

Genetic parameters for individual birth weight (IBWT), total number of pigs born (NBT), number of pigs born alive (NBA), number of pigs born dead (NBD) and litter weight at birth (LBWT) were estimated using 1961 Mukota pigs kept at the University of Zimbabwe Farm, Harare, Zimbabwe. Variance components were estimated for IBWT based on a direct-maternal genetic effects model. The genetic relationships among NBT, NBA, NBD and LBWT were assessed using a multi-trait direct effects model. For LBWT, the direct, maternal and common environmental litter proportions on the phenotypic variance were 0.090, 0.033 and 0.009, respectively. After adjustment of IBWT for NBA, phenotypic fractions were 0.091, 0.034 and 0.011 for direct, maternal and litter effects. The correlation between the direct and maternal genetic effects of IBWT was − 0.354 and − 0.295, with and without adjustment for NBT. Heritabilities for NBT, NBA, NBD and LBWT were 0.020, 0.030, 0.088 and 0.196, respectively. Differences in the maternal heritability and the heritability for LBWT, a trait of the dam, are different due to accumulation of observations per litter. Maternal genetic effects are, therefore, of less importance than in highly selected European breeds.     

Maintenance of body temperature in the neonatal lamb: effects of breed, birth weight, and litter size

To survive, the newborn lamb must be able to maintain body temperature and to stand and move to the udder to suck colostrum to fuel heat production. The objective of this study was to investigate whether neonatal lambs showing slow behavioral progress to standing and sucking also have an impaired ability to maintain body temperature. The time taken to stand and suck after birth, rectal temperatures, and blood samples were collected from 115 newborn single, twin, and triplet lambs of 2 breeds, Scottish Blackface and Suffolk, which are known to show variations in their neonatal behavioral progress. Blood samples were assayed for thyroid hormones, known to be involved in heat production, and cortisol, which plays a role in tissue maturation before birth. In addition, colostrum samples were collected from the 56 ewes that gave birth to the lambs, and assayed for protein, fat, and vitamin contents. Heavy lambs (more than 1 SD above the breed mean), Blackface lambs, and singleton or twin lambs were quicker to stand and suck from their mothers than lightweight (more than 1 SD below the breed mean), Suffolk, or triplet lambs. Low birth weight lambs also had lower rectal temperatures than heavier lambs (P < 0.01), as did Suffolk compared with Blackface lambs (P < 0.001). Lambs that were slow to suck after birth had lower rectal temperatures than quick lambs, and this difference persisted for at least 3 d after birth. Within breed, heavy lambs had greater plasma triiodothyronine and thyroxine immediately after birth than light lambs. Blackface lambs had greater plasma triiodothyronine and thyroxine than Suffolk lambs but tended to have less cortisol. Colostrum produced by Blackface ewes had a greater fat content than that of Suffolk ewes (P < 0.001). Thus, lambs that are behaviorally slow at birth are also less able to maintain their body temperature after birth. Although part of their lower body temperature might be attributable to behavioral influences on thermoregulation, the data also suggest that physiological differences exist between these animals. These differences may be related to different degrees of maturity at birth.     

大米草对肉兔血液生化指标的影响

选用30日龄的福建黄兔与太行山兔杂交后代幼兔100只,平均分成5组,每组20只。试验组日粮中分别添加大米草草粉5%、10%、15%和20%,试验期50 d。研究大米草对肉兔血液生化指标的影响。结果表明：随着大米草添加量的增加,血清总蛋白和白蛋白均呈上升趋势,其中以添加大米草草粉15%为最高,但各组之间差异不显著（P〉0.05）;甘油三酯和胆固醇含量均呈下降趋势,与对照组相比添加大米草草粉15%和20%的处理组甘油三酯含量分别下降10.13%和11.39%,差异显著（P〈0.05）;胆固醇含量分别下降8.48%和10.30%,差异显著（P〈0.05）。4种血清酶含量各处理组之间差异不显著（P〉0.05）。结论：适量添加大米草对肉兔肝脏、肾脏、心脏等器官无不良影响;添加15%-20%的大米草可以起到调整血脂作用。     

Effects of selecting for litter size and body weight on the components of litter size in mice

Divergent selection for the total number of young born in the first three litters (TNY-3) and for 6-week body weight in mice resulted in different changes in the components of first litter size.Selection for large TNY-3 increased the number of ova shed while pre-natal losses were not modified. Selection for small TNY-3 caused both a decrease in ovulation rate and an increase in post-implantation mortality. Divergent selection for body weight modified ovulation rate in the same direction as body weight. Embryo survival declined in both lines selected for body weight. That decline was caused by an increase in pre-implantation mortality in the case of the high line, and by an increase in post-implantation mortality in the low line.     

Relationship between litter birth weight and litter size in six breeds of sheep

Metabolizable energy requirements of the ewe increase during pregnancy due to increases in fetal and maternal metabolism. Fetal metabolism is related to total weight of the fetuses. Fetal number is a primary contributor to fetal weight. Litter birth weight represents the culminated fetal growth of the litter and can be used to estimate the effect of fetal metabolism on energy requirements of the ewe. We hypothesized that litter weight in sheep would increase at a decreasing rate with increasing litter size. Birth weights of lambs born to yearling (11 to 15 mo) and mature ewes (> 34 mo) were collected on litters born to Dorset, Rambouillet, Suffolk, Finnsheep, Romanov, and Composite III ewes mated to produce straightbred lambs. Litter birth weight expressed as a function of litter size increased at a decreasing rate and the quadratic term differed from zero for mature Rambouillet, Suffolk, Finnsheep, Romanov, and Composite III litters (P < 0.042). The quadratic coefficient differed among breeds. In yearlings, litter weight increased at a decreasing rate for Suffolk ewes (P = 0.002). The quadratic term for the relationship between litter weight and litter size did not differ from zero for Finnsheep (P = 0.39) or Romanov litters (P = 0.07). The hypothesis that litter weight increases at a decreasing rate with increased litter size is supported by experimental results.     

波尔山羊生长模型及体尺体重相关分析

用Gompertz、Bertalanffy及Logistic模型拟合4～39月龄的澳洲波尔山羊生长模型.结果表明:Logistic模型拟合效果最好(R2>O.98),公母羊生长模型分别为:w=51.59X(1十6.15×e-1.82)-1和W=52.56×(1+7.15×e2.08)-1.波尔山羊的体重与胸围呈极显著相关(P0.05).利用胸围和体高,估算体重的回归方程为:y=0.279Bug+0.893Bxw-19.28.     

Passive immunization in neonatal piglets in natural rearing--effects of birth order, birth weight, litter size and parity

603 neonatal piglets (German Landrace) were investigated for passive immunization affected by birth order, birth weight, litter size and parity. Concentrations of immunoglobulins in the blood serum of piglets on the first day of life served as measure for passive immunization. Blood samples were drawn at 12, 18 and 24 hours post partum. Quantitative measurements of immunoglobulin classes were carried out by radial immunodiffusion. There was a significant effect of birth order, because of the rapid changes in colostrum composition between onset of birth and the last piglet of each litter. The effect of birth weight was only partly significant and different for the immunoglobulin classes. There was no significant effect of litter size on passive immunization. Parity had a significant positive effect on IgG- and IgA-concentrations in sow's colostrum with litter two to six, parity 1 and 2 lead to highest IgM concentrations in the blood serum of piglets.     

Effect pf genotype, age of dams, litter size, birth weight and rams on morphological parameters of the placenta in sheep

It is well established that especially in prolific ewes the mortality rates are high in lambs with low birth weights and that after birth the absolute growth rates are lower in the surviving light lambs than in the heavier lambs. Differences in the prenatal placental development as the feto-maternal connection could be one of the reasons for this effect. The aim of the present study was to ascertain primary data for the placenta characteristics. Therefore three different genotypes which varied in litter size and weight of all born lambs were studied. In 197 placentas the weight, the number of cotyledones, the diameter of the cotyledones and the weight of ten cotyledones were determined. The total weight of all cotyledones and surface area of the cotyledones (the feto-maternal contact area) were calculated. The effects of the breed, the age of the dams (1.5-7.5 years), the litter size (1-4), the weight of all born lambs (5 classes between 3 and 15 kg) and the ram were tested with the ANOVA/MANOVA procedure (co-variable = weight of the dams before mating). Litter size and weight of all born lambs influenced significantly the morphologicaly parameters of the placenta. In the examined genotypes the placenta weight increased from a minimum of 500 g to 1100 g and the surface of the cotyledones grew from 200 cm2 to 350 cm2 with increasing litter size and increasing weight of all born lambs. This seems to be a maternal compensation mechanism for the raising fetal requirements. With the increase of the litter size the surface area of the cotyledones for each lamb decreases because the possible placental compensation mechanism collapses. This could be a reason for low birth weights and increasing deaths of lambs. A possible influence of the genotype on the characteristics of the placentas is discussed by considering the litter size and the condition of the ewe. Paternal effects were not found.     

Effect of selection for litter size and body weight on hormone-induced ovulation rate in mice.

Genetic differences in natural vs hormone-induced ovulation rates were compared in immature female mice from five lines that had undergone long-term single-trait and antagonistic index selection for litter size and(or) 6-wk BW. Lines used were control (K); high litter size (L+); high BW (W+); low litter size and high BW (L-W+); and high litter size and low BW (L+W-). Natural ovulation rate at a mean age of 34.3 d and hormone-induced (5 IU of pregnant mare's serum gonadotropin followed 2 d later by 5 IU of human chorionic gonadotropin) superovulation rate at a fixed age of 31 d were obtained. Total number of eggs ovulated was affected by line (P less than .001), treatment (P less than .001), and line x treatment interaction (P less than .001). Line differences were subsequently tested within treatment because of the significant line x treatment interaction. Line differences were important (P less than .001) for natural ovulation, hormone-induced ovulation, and response to hormones. Mean natural ovulation rates for K, L+, W+, L-W+, and L+W- were 14.1, 19.8, 15.1, 13.6, and 16.4, respectively. Selection changed ovulation rate by 40, 16, 7, and -4% in the L+, L+W-, W+ and L-W+ lines, respectively (P less than .01). Hormone-induced ovulation rates in K, L+, W+, L-W+, and L+W- were 32.3, 24.6, 19.6, 20.9, and 22.1, respectively. Exogenous hormones increased ovulation by 18.2, 4.8, 4.6, 7.3, and 5.7 ova for K, L+, W+, L-W+, and L+W-, respectively (P less than .001). Lines with lower natural ovulation rates had higher responses to superovulation. Increased ovulation rate due to treatment ranged from 24.3% in L+ to 129% in K. These results indicate significant differences among lines in ovarian response to exogenous hormones.     

Genetic parameters for birth weight,growth, and litter size in Nordic sheep breeds

Abstract

In this study, genetic parameters were estimated for the Danish populations of Danish Marsk, Finnish Landrace, Gotland Pelt and Spel for birth weight (BW), average daily gain until two months (DG2) and litter size (LS). A multivariate animal model was used for estimation of genetic parameters, including fixed effects, both direct and maternal additive genetic effects, common litter effects and permanent environmental effects. Mean birth weight and DG2 ranged from, respectively, 3.39 kg and 262 g to 4.61kg and 286 g. Litter size ranged from 1.60 to 2.07. Direct heritability for BW ranged from 0.12 to 0.24, and maternal heritability for BW was about 0.23 for all breeds. Direct heritability of DG2 ranged from 0.19 to 0.33. The heritability for LS was between 0.08 and 0.13. The significant genetic correlations between the direct and maternal effect on both BW and DG2 were negative. The genetic correlations between the growth traits and LS were not uniform.