不同胎次对齐卡新西兰兔产仔性能的影响

为探讨胎次对母兔产仔性能的影响,研究利用2010~2013年度665只齐卡新西兰母兔前3胎共计1 649窝次的生产性能记录,对不同胎次的产仔性能进行了比较和相关分析。结果表明:胎次极显著地影响母兔的产仔数、产活仔数、初生窝重以及初生个体重(P<0.01);随着胎次的增加,产仔性能逐步上升。进一步的相关分析结果显示,各胎次的产仔性状与前3胎平均值均呈极显著正相关(P<0.01),第3胎的产仔数、产活仔数、死胎数以及初生窝重的相关系数最高;第2胎的产仔数、产活仔数和初生个体重与第3胎呈极显著(P<0.01)或显著(P<0.05)正相关,而第2、3胎间的产仔数和产活仔数差异不显著(P>0.05),表明齐卡新西兰母兔第2胎的产仔性能可以作为总体繁殖性能的评价指标。     

季节因素对新西兰白兔繁殖性能的影响

本试验期1年,以月为单位,共分12个组,每月选择200窝空怀母兔、40窝产仔母兔研究不同季节因素对新西兰白兔繁殖性能的影响,统计测定受胎率、窝产仔数、窝产活仔数、产活仔率、初生个体重、初生窝重等指标。试验结果显示,春季总体繁殖性能优于其他季节,其中5月份为最好,其平均受胎率85.00%、平均窝产仔数7.33只、平均初生个体重73.08 g,平均初生窝重526.19 g;夏季高温对繁殖性能影响最大,其8月份的平均窝产仔数5.68只、平均产活仔率94.42%、平均初生个体重60.87 g、平均初生窝重326.44 g,基本处于最低水平;秋季繁殖性能总体呈恢复上升趋势,但由于高温的持续,繁殖性能低于平均水平;冬季除低温对受胎率影响较大外,其余指标相对稳定。试验表明,季节对新西兰白兔繁殖性能有一定影响,春季最宜配种、随后为冬季和秋季,最不宜配种季节为夏季,其中高温比低温的影响程度更大。     

胎次与配种季节对丹系大白母猪繁殖性能的影响研究

通过对广西扬翔某猪场1 314头丹系大白母猪的生产数据进行统计,并从不同配种胎次和不同配种季节对繁殖性能数据进行分析。结果表明:丹系大白母猪的总产仔数、产活仔数、初生窝重、初生个体重随着胎次的增加逐渐增加到一个最大值后减小。总产仔数和产活仔数在第4胎达到高峰,总仔为17.98头,活仔为16.06头,之后随着胎次增加繁殖性能逐步下降。初生窝重和初生个体重在第3胎达到高峰,初生窝重为20.95 kg,初生个体重为1.37 kg。冬季配种的母猪产活仔数最多,初生窝重最重;夏季配种的母猪产活仔数最少,初生窝重最轻。     

杜洛克猪繁殖性状遗传参数估计及非遗传因素影响分析

为了对杜洛克猪繁殖性状进行遗传参数估计，并分析非遗传因素分娩季节及胎次对繁殖性状的影响，试验整理了陕西省某核心育种场2009—2020年杜洛克母猪繁殖性状数据，利用DMU软件估计各繁殖性状的遗传参数，结合R软件中aov函数对非遗传因素季节和胎次进行方差分析，研究遗传参数和非遗传因素对繁殖性状的影响。结果表明：杜洛克猪除妊娠周期为中等遗传力性状外，其余繁殖性状遗传力均在0.01～0.05之间，且总产仔数与产活仔数、健仔数、弱仔数、初生窝重之间为遗传正相关，妊娠周期与总产仔数、产活仔数、健仔数、死仔数、弱仔数、初生窝重之间呈遗传负相关。分娩胎次对杜洛克猪的总产仔数、产活仔数、健仔数、初生窝重、妊娠周期的影响达到极显著水平(P<0.01);而季节仅对死胎数、死仔数、妊娠周期3个性状具有极显著影响(P<0.01)。冬季损失的仔猪数最少，死仔数和死胎数显著低于春季、夏季、秋季(P<0.05),春季总产仔数、产活仔数、健仔数和初生窝重显著高于夏季、秋季、冬季(P<0.05),冬季妊娠周期显著长于春季、夏季、秋季(P<0.05)。分娩胎次为2胎次时的死胎数、死仔数、弱仔...     

配种季节对法系獭兔繁殖性能的影响

为研究配种季节对法系獭兔繁殖性能的影响,对四川省獭兔原种场法系獭兔不同季节繁殖性能测定数据进行了统计学分析。结果表明:不同配种季节,法系獭兔产仔数、产活仔数、初生窝重、初生个体重、21日龄窝重、断奶仔兔数、断奶窝重等差异极显著(P<0. 01),断奶成活率差异不显著(P>0. 05),繁殖性能秋季最高,夏季最低。     

不同产箱类型对母獭兔繁殖行为及仔兔生长发育的影响

选择年龄相近的经产健康妊娠母獭兔120只,随机分为2组,使用平口式和暗箱式产箱进行接产试验,通过母兔的产前拉毛、箱内外产仔和产后哺乳情况判断产箱环境对母兔母性行为的影响,通过仔兔断奶前死亡率、断奶窝重、断奶个体重及断奶窝仔数,判断产箱类型对仔兔健康及生长的影响。结果表明:使用暗箱式产仔的母兔,在产前拉毛、箱内产仔和产后哺乳性能方面均优于平口式产箱的母兔。仔兔的初生窝重、初生个体重和产仔数不受产箱类型的影响(P0.05),但断奶时窝重、个体重和成活率,暗箱式均优于平口式(P0.05)。     

胎次及配种季节对加系大约克种猪产仔性能的影响研究

试验选用浙江某种猪场2010-2013年出生的加系大约克种猪共4382窝的繁殖性能数据,统计分析不同胎次和配种季节对总产仔数、产活仔数、总死产数、畸形胎数、木乃伊胎数、死胎数和初生窝重的影响。结果表明:胎次对种猪产仔性能有极显著影响(P0.01),母猪1~6胎总产仔数、产活仔数、初生窝重随胎次增加而增加,第6胎达到最高峰,且显著(P0.05)或极显著(P0.01)高于其他胎次;总死产数及死胎数则7~8胎极显著高于其他胎次(P0.01);但胎次对产畸形胎和木乃伊胎数影响不显著(P0.05)。配种季节对种猪产仔性能影响极显著(P0.01),冬季配种的总产仔数,产活仔数,初生窝重显著高于其他配种季节(P0.05);总死产数及死胎数极显著低于其他配种季节(P0.01);但冬季配种产木乃伊胎数极显著高于夏、秋两季(P0.01),显著高于春季(P0.05)。研究表明,加系大约克种猪的最佳产仔胎次为3~6胎,冬季配种的产仔性能明显高于其他配种季节。     

胎次、产仔季节和产仔年份对深县猪繁殖性能的影响

为了分析不同产仔季节、胎次和产仔年份对深县母猪繁殖性能的影响,试验根据河北正农牧业有限公司2013—2016年间的深县母猪繁殖记录,采用最小二乘法进行了数据分析。结果表明:产仔季节对深县猪的初生重影响极显著(P0.01),但对其他性状都无显著影响(P0.05);胎次对初生重影响极显著(P0.01),对总产仔数、活仔数、断奶窝重的影响显著(P0.05),总产仔数、活仔数、初生窝重和断奶窝重等均随着胎次的增加而增加;产仔年份对总产仔数、活仔数的影响极显著(P0.01)。     

分娩胎次及季节对台系杜洛克母猪繁殖性能影响研究

统计分析了不同胎次及产仔季节对台系杜洛克母猪繁殖性能的影响。结果表明,分娩胎次对台系杜洛克母猪的怀孕天数、健仔数、产活仔数、总产仔数、初生窝重、21日龄断奶总仔猪数、21日龄断奶窝重影响显著或极显著,对配种情期、死胎数、死仔数、寄入仔猪数、寄出仔猪数、21日龄断奶公仔数、21日龄断奶母仔数、哺乳成活率影响不显著。产仔季节对杜洛克母猪的产仔胎次、怀孕天数、健仔数、死胎数、产活仔数、死仔数、总产仔数、寄入仔猪数、初生窝重、21日龄断奶公仔数、21日龄断奶母仔数、21日龄断奶总仔猪数、21日龄断奶窝重影响显著或极显著,对配种情期、木乃伊数、寄出仔猪数、哺乳成活率影响不显著。     

长大、PIC、混血母猪繁殖性状研究

对红河州某猪场长大母猪311窝、PIC母猪138窝及当地农村饲养混血母猪753窝的繁殖性状进行测定,探讨品种、胎次和分娩季节对母猪繁殖性状的影响。结果表明,品种因素对母猪产仔性能有显著影响,长大母猪和混血母猪的总产仔数、产活仔数、初生窝重、28 d校正断奶窝重均极显著高于PIC母猪（P〈0.01）,长大母猪和混血母猪间除初生窝重、初生个体重和28 d校正断奶成活率有极显著差异（P〈0.01）外,其它指标差异均不显著（P〉0.05）。胎次因素对母猪产仔性能产生显著影响,经产母猪显著高于初产母猪（P〈0.05）,长大、PIC母猪2~8胎、混血母猪3胎以上产仔性能较好,其中长大、PIC母猪以第4胎最佳。分娩季节对PIC、混血母猪的繁殖性状无显著影响（P〉0.05）,而对长大母猪的产活仔数有显著影响（P〈0.05）。     

Genetic parameters for ewe productivity traits in the Columbia, Suffolk and Targhee breeds

Estimates of repeatability and heritability were obtained for the following productivity traits of ewes: litter weight at birth (LWB) and weaning (LWW), litter size at birth (LSB), litter size alive at birth (NBA), litter size at weaning (LSW), neonatal survival rate (SRB) and preweaning survival rate (SRW). Phenotypic and genetic correlations were estimated for litter traits. The data set contained 6,394 ewe breeding records from three state stations over 10 yr on 1,731 ewes that were the progeny of 488 sires among three breeds (Columbia, Suffolk and Targhee). Pooled intra-station estimates of repeatability ranged from .11 to .22 for LWB and LWW among the three breeds. For litter size at birth, number born alive and litter size at weaning these estimates varied from .09 to .17 and for the survival traits (SRB and SRW) the variation was from .11 to .20. Intra-station estimates of heritability for the three breeds varied from .12 to .28 for LWB and LWW, and for LSB, NBA and LSW estimates varied from .05 to .35. Heritability estimates for survival traits (SRB and SRW) were low, ranging from .00 to .14. Phenotypic correlations among LWB, LWW, NBA and LSW ranged from .35 to .92 among the breed-station subclasses, with higher correlations occurring where a part-whole relationship existed. The study suggests that selection of ewes with high litter size at birth or at weaning and(or) litter weight at birth or at weaning will genetically improve total litter weight at weaning per ewe lambing.     

Estimation of genetic parameters for farrowing traits in purebred Landrace and Large White pigs

Genetic parameters were estimated for six reproductive traits related to farrowing events in Landrace and Large White pigs; total number born (TNB), number born alive (NBA), number stillborn (NSB), total litter weight at birth (LWB), mean litter weight at birth (MWB), and gestation length (GL). We analyzed 62,534 farrowing records for 10,637 Landrace dams and 49,817 farrowing records for 8,649 Large White dams. Estimated heritabilities of TNB, NBA, NSB, LWB, MWB, and GL by single‐trait repeatability model analyses were 0.12, 0.12, 0.08, 0.18, 0.19, and 0.29, respectively, in Landrace, and 0.12, 0.10, 0.08, 0.18, 0.16, and 0.34, respectively, in Large White. Genetic correlation between NBA and NSB was unfavorable: 0.20 in Landrace and 0.33 in Large White. Genetic correlations of GL with the other five traits were weak: from ?0.18 with NSB to ?0.03 with NBA in Landrace, and from ?0.22 with NSB to ?0.07 with NBA in Large White. LWB had a highly favorable genetic correlation with NBA (0.74 in both breeds), indicating the possibility of using LWB for the genetic improvement of NBA.     

Genetic relationship of litter traits between farrowing and weaning in Landrace and Large White pigs

We estimated genetic parameters in Landrace and Large White pig populations for litter traits at farrowing (total number born, number born alive, number stillborn, total litter weight at birth (LWB), and mean litter weight at birth) and those at weaning (litter size at weaning (LSW), total litter weight at weaning (LWW), mean litter weight at weaning (MWW), and survival rate from farrowing to weaning). We analyzed 65,579 records at farrowing and 6,306 at weaning for Landrace, and 52,557 and 5,360, respectively, for Large White. Single‐trait and two‐trait repeatability animal models were exploited to estimate heritability and genetic correlation respectively. Heritability estimates of LSW were 0.09 for Landrace and 0.08 for Large White. Genetic correlations of LSW with MWW were –0.43 for Landrace and –0.24 for Large White. Genetic correlations of LSW with LWW and LWB ranged from 0.5 to 0.6. The genetic correlation of MWW with LWW was positive, but that with LWB was negligible. The results indicate that utilizing LWW or LWB could improve LSW efficiently, despite the antagonistic genetic correlation between LSW and MWW.     

荣昌猪初产繁殖性状的全基因组关联研究

旨在鉴定荣昌猪初产繁殖性状的重要变异位点和基因,为荣昌猪繁殖性状的遗传改良提供重要的分子标记和基因资源。本研究选取429头荣昌母猪进行猪50K芯片基因分型,经过质量控制和基因型填充后,保留35 046个SNPs用于分析。采用主成分分析法研究群体结构,利用混合线性模型(mixed-linear model, MLM)将出生年、出生月作为固定效应,将主成分值作为协变量对总产仔数、活产仔数、死胎数和初生窝重性状进行全基因组关联分析(GWAS)。结果显示,在全基因组显著水平上鉴定出2个影响荣昌猪初生窝重的SNPs和1个影响荣昌猪死胎数的SNP;在潜在显著水平上鉴定到5个影响荣昌猪总产仔数的SNPs, 3个影响荣昌猪活产仔数的SNPs和10个影响荣昌猪死胎数的SNPs。通过全基因组关联分析筛选到1个显著的SNP(SSC17:57 315 180 bp)同时影响荣昌猪总产仔数、活产仔数和初生窝重,1个显著的SNP(SSC1:279 214 647 bp)同时影响荣昌猪活产仔数和总产仔数,暗示基因在不同性状间具有一因多效性。本研究根据候选基因的相关分子生物学功能,确定BMP7基因为影响荣昌猪总产仔数...     

Correlated responses for litter traits to six generations of selection for ovulation rate or prenatal survival in French Large White pigs

Effects of selection for reproductive traits were estimated using data from 3 pig lines derived from the same Large White population base. Two lines were selected for 6 generations on high ovulation rate at puberty (OR line) or high prenatal survival corrected for ovulation rate in the first 2 parities (PS line). The third line was an unselected control line. Genetic parameters for age and BW at puberty (AP and WP); number of piglets born alive, weaned, and nurtured (NBA, NW, and NN, respectively); proportions of stillbirth (PSB) and survival from birth to weaning (PSW); litter and average piglet BW at birth (LWB and AWB), at 21 d (LW21 and AW21), and at weaning (LWW and AWW) were estimated using REML methodology. Heritability estimates were 0.38 +/- 0.03, 0.46 +/- 0.03, 0.16 +/- 0.01, 0.08 +/- 0.01, 0.09 +/- 0.01, 0.04 +/- 0.01, 0.04 +/- 0.02, 0.19 +/- 0.02, 0.10 +/- 0.02, 0.10 +/- 0.02, 0.36 +/- 0.02, 0.27 +/- 0.01, and 0.24 +/- 0.01 for AP, WP, NBA, PSB, NW, NN, PSW, LWB, LW21, LWW, AWB, AW21, and AWW, respectively. The measures of litter size showed strong genetic correlations (r(a) >/= 0.95) and had antagonistic relations with PSB (r(a) = -0.59 to -0.75) and average piglet BW (r(a) = -0.19 to -0.46). They also had strong positive genetic correlations with prenatal survival (r(a) = 0.67 to 0.78) and moderate ones with ovulation rate (r(a) = 0.36 to 0.42). Correlations of litter size with PSW were negative at birth but positive at weaning. The OR and PS lines were negatively related to PSW and average piglet BW. Puberty traits had positive genetic correlations with OR and negative ones with PS. Genetic trends were estimated by computing differences between OR or PS and control lines at each generation using least squares and mixed model methodologies. Average genetic trends were computed by regressing line differences on generation number. Significant (P < 0.05) average genetic trends were obtained in OR and PS lines for AP (respectively, 2.1 +/- 0.9 and 3.2 +/- 1.0 d/generation) and WP (respectively, 2.0 +/- 0.5 and 1.8 +/- 0.5 d/generation) and in the PS line for NBA (0.22 +/- 0.10 piglet/generation). Tendencies (P < 0.10) were also observed for LWB (0.21 +/- 0.12 kg/generation) and AWW (-0.25 +/- 0.14 kg/generation) in the PS line. Selection on components of litter size can be used to improve litter size at birth, but result in undesirable trends for preweaning survival.     

Evaluation of candidate genes related to litter traits in Indian pig breeds

Improvement in litter traits is the key to profitable pig farming that directly enhances the economic standing of the farmers in developing countries. The present study aimed to explore oestrogen receptor (ESR), epidermal growth factor (EGF), follicle-stimulating hormone beta subunit (FSHβ), prolactin receptor (PRLR) and retinol-binding protein 4 (RBP4) genes as possible candidate genetic markers for litter traits in indigenous pigs of India. The breeds included in the study were Ghungroo, Mali, Niang Megha and Tenyi Vo, and the reproductive traits considered were litter size at birth (LSB), number born alive (NBA), litter weight at birth (LWB), litter size at weaning (LSW) and litter weight at weaning (LWW) at their first parity. PCR-RFLP and primer-based mutation detection methods were used to identify polymorphism, and associations between the genotypes and the traits were analysed using a general linear model. The Ghungroo pigs recorded the best litter performances among the breeds (p < .05, LWB p < .01). Different alleles and genotypes of the genes under study were detected. Short interspersed nuclear element (SINE) −/− genotype of FSHβ revealed significantly higher litter traits (p < .05, LSB p < .01). The LWW was also found to be significantly influenced by ESR BB and AB, EGF AB and BB, and PRLR CC genotypes (p < .05). Although we did not find statistically significant and consistently superior litter traits with respect to different genotypes of other studied genes than genotype SINE −/− of the FSHβ, PRLR CC genotype demonstrated superior performances for all the litter traits. Our study revealed the FSHβ as a potential candidate genetic marker for litter traits in indigenous pig breeds of India.     

撒坝猪专门化母系繁殖性状的相关与通径分析

利用撒坝猪专门化母系 7个世代共 576头母猪的繁殖性能数据 ,对总产仔数 (x1 )、活产仔数 (x2 )、初生窝重 (x3)、 2 0日龄窝重 (x4 )、断奶窝重 (x5)、育成率 (x6 )和断奶仔数 (y) 7个繁殖性状进行了相关和通径分析 ,并在此基础上建立了估计断奶仔数的最优回归方程。结果表明 ,撒坝猪专门化母系的繁殖性能在经过 7个世代的选育后 ,获得了明显提高。各繁殖性状间在表型值上都存在不同程度的相关 ,其中以总产仔数与活产仔数的相关程度最高 (r=0 92 0 1 ) ,其次为 2 0日龄窝重与断奶仔数 (r=0 82 88) ,而初生窝重与育成率间的相关系数最低 (r=0 0 381 )。在所分析的 7个性状中 ,除了总产仔数和活产仔数与育成率间为负相关外 ,其余性状间均为正相关。所建立的估计断奶仔数的多元回归方程为 :y=- 6 1 1 90 +0 6986x2 +0 0 33 7x4 +0 0 0 4 8x5+0 0 71 8x6 。     

莆田黑猪繁殖性状的通径分析

本文对莆田黑猪206头初产母猪的繁殖性状进行了相关和通径分析,并分析了各繁殖性状对断乳窝重的直接影响和间接影响以及决定程度的大小.结果表明,莆田黑猪繁殖性状间在表犁值上都存在不同程度的相关,其中以产活仔数与初生窝重的表犁相关系数最高(0.943);影响断乳窝重的主要因素大小依次是20日龄窝重、产活仔数、20日龄个体重、初生窝重、初生重、乳头数和产仔数.揭示了莆田黑猪各繁殖性状问的真实关系.     

Genetic parameter estimates for growth traits and prolificacy in Raeini Cashmere goats

The main objectives of this study were to estimate genetic and phenotypic parameters for growth traits and prolificacy in the Raeini Cashmere goat. Traits included, birth weight (BWT), weaning weight (WWT), 6-month weight (6WT), 9-month weight (9WT), 12-month weight (12WT), average daily gain from birth to weaning (ADG1), average daily gain from weaning to 6WT (ADG2), average daily gain from 6WT to 12WT (ADG3), survival rate (SR), litter size at birth (LSB) and litter size at weaning (LSW) and total litter weight at birth (LWB). Data were collected over a period of 28 years (1982-2009) at the experimental breeding station of Raeini goat, southeast of Iran. Genetic parameters were estimated with univariate models using restricted maximum likelihood (REML) procedures. In addition to an animal model, sire and threshold models, using a logit link function, were used for analyses of SR. Age of dam, birth of type, sex and of kidding had significant influence (p < 0.05 or 0.01) all the traits. Direct heritability estimates were low for prolificacy traits (0.04 ± 0.01 for LSB, 0.09 ± 0.02 for LSW, 0.16 ± 0.02 for LWB and 0.05 ± 0.02 for SR) and average daily gain (0.12 ± 0.03 for ADG1, 0.08 ± 0.02 for ADG2, and 0.07 ± 0.03 for ADG3) to moderate for production traits (0.22 ± 0.02 for BWT, 0.25 ± 0.02 for WWT, 0.29 ± 0.04 for 6WT, 0.30 ± 0.02 for 9WT, 0.32 ± 0.05 for 12WT). The estimates for the maternal additive genetic variance ratios were lower than direct heritability for BWT (0.17 ± 0.03) and WWT (0.07 ± 0.02).