不同品种、胎次、断配间隔和输精次数对母猪繁殖性能的影响

为了探究不同品种、胎次、断配间隔和输精次数对母猪繁殖性能的影响,试验以健康、体况相近的长白猪、大白猪、长白猪和大白猪的二元杂交猪为研究对象,采用单次输精和传统深部人工授精配种试验猪,记录每窝产仔总数、产活仔数、产健仔数和初生窝重繁殖信息,研究不同品种、胎次、断配间隔和输精次数对母猪繁殖性能的影响。结果表明：长白猪和二元杂交猪母猪的窝均产仔总数、窝均产活仔数、窝均产健仔数及平均初生窝重差异不显著(P>0.05),且均显著优于大白猪母猪(P<0.05)。不同胎次母猪繁殖性能差异较大,母猪在第1胎或第2胎时繁殖性能最佳,窝均产仔总数、窝均产活仔数、窝均产健仔数和平均初生窝重分别为13.01头、12.96头、12.28头和19.85 kg;第3胎和第4胎时繁殖性能趋于稳定,第5胎后明显下降;第6～8胎繁殖性能最差,窝均产仔总数、窝均产活仔数、窝均产健仔数和平均初生窝重分别为11.54头、11.45头、10.89头、17.46 kg,除窝均产健仔数与第5胎差异不显著外(P>0.05),其他指标均显著低于其他胎次(P<0.05)。断配间隔为1 d或2 d的母猪繁殖性能最佳,...     

企业采风之——清凉山原种猪场

附　表1　　　瑞系长白猪繁殖性能　　　　　　　　　　头,kg年代　　　　　　　　胎次　　　　　　　　样本　　　　　　　　　窝产仔　　　　　　　　　　　　　　窝活仔　　　　　　　　　　　　　　初生窝重　　　　　　　　　　　断奶数　　　　　　　　　　　　　断奶窝重　　　　　　　　　　　断奶个体重　　　　　　　断奶前日增重(g/d)2002　　　　　　　平均　　　　　　　　　68　　　　　　　11.50±2.95　　　　　10.89±1.95　　　　　　15.66±4.07　　　　　8.71±2.29　　　　　　73.20±19.60　　…     

二元杂种母猪胎次、断奶至配种间隔与繁殖性能的关系

此研究以广东省某猪场长大和大长二元杂种母猪1461条完整的发情配种记录和产仔记录为材料,对母猪胎次、断奶至配种间隔与窝产活仔数、初生窝重的关系进行了分析。结果显示,第1胎母猪断奶至配种间隔最长为12.12d,随着胎次增加逐渐缩短;第3胎母猪窝产活仔数最多为10.50头,初生窝重最大为14.72kg,2～5胎都维持较高水平,且差异不显著;在排除繁殖障碍等疾病的前提下,断奶至配种间隔较长的母猪繁殖性能相对较好。     

太湖猪高产综合技术研究试验

本文系对103头360窝太湖猪的繁殖性能进行系统研究。结果是60头母猪在6个繁殖周期中共繁殖360窝,平均繁殖周期158.33天,年产仔2.31胎。窝产仔16.35头,活仔15.10头,35日龄断奶育成14.44头,窝重83.48公斤。每头母猪年产仔37.69头,年产活仔34.81头,年提供断奶仔猪33.29头。其中窝产仔达到18头以上,出现1胎或连续4胎高产的母猪69头,占试验母猪群66.99％。     

瑞典长白猪繁殖性能的研究

本文统计分析了1088窝瑞典长白猪的繁殖性能,产仔数、产活仔数、初生个体重、断奶头数、28日龄断奶窝重和断奶个体重分别达到了12.10头、11.40头、1.55千克、10.64头、85.07千克和8.4千克,产活仔率91.32%,第4和第5胎繁殖性能达到了最佳,最佳繁殖利用期为6胎次,是理想的母系种猪。     

山西白猪高产仔母系繁殖性能测定

以马身猪、太湖猪（二花脸类群）和长白猪为育种素材,采用标记辅助选择技术结合群体继代选育法,经7年6个世代育成山西白猪高产仔母系。对7个世代母猪繁殖性能分析结果表明,4世代母猪的繁殖性能最好,母猪初产窝产仔10.64头,产活仔数9.85头,断奶头数9.36头,哺育率达95.03%,初生个体均重1.42 kg,28日龄断奶窝重62.36 kg。除产活仔数外,均极显著高于0世代（P<0.01）。初生和断奶时仔猪均匀度随选育逐代提高,一致性增强。该品系已具有良好的繁殖性能,是一个优良的母本品系。     

胎次对杂交母猪繁殖性能的影响研究

通过整理沈阳农业大学科研种猪场595窝长大二元杂交母猪的繁殖记录,研究了母猪胎次对繁殖性能的影响,并回归拟合了胎次和繁殖性能之间的关系。结果表明:母猪胎次对总产仔数、产活仔数、初生窝重、断奶窝重和断奶存活率都有显著影响。第4胎总产仔数和产活仔数最多(10.92头和9.92头),第1胎总产仔数最少(9.12头),第1胎和第8胎产活仔数最低(8.46头和8.63头)。第1胎初生窝重最低,只有12.98kg,以后随胎次增加而提高,至第4胎达到峰值(15.73kg),以后又随胎次下降。在断奶窝重方面,第1胎最少(42.27kg),以后随胎次增加,至第5胎最多(69.53kg),然后又随胎次减少。另外第3胎的仔猪断奶存活率最低,只有78.48%,第5胎最高(93.95%),第1胎较低(78.88%)。这些结果表明3～5胎次为母猪的最佳繁殖胎次,第1和第8胎繁殖成绩显著降低,但第8胎尚优于第1胎。因此,应采取措施增加第2～6胎次的母猪数量。     

胎次对丹系大白猪繁殖性能的影响分析

对江苏省某国家生猪核心育种场丹系大白母猪各胎次的产仔数、产活仔数、断奶仔猪数及初生窝重、断奶窝重等繁殖性状进行了比较和相关性分析,旨在进一步了解丹系大白猪的繁殖性能,为后备母猪的选种选育提供参考。结果表明,丹系大白母猪第1、2胎产仔数较少,至第3胎达到最高为10.39头,后趋于稳定。不同胎次对产活仔数与断奶仔猪数的影响与产仔数的变化趋势基本一致。不同胎次的仔猪初生窝重基本持平,并以第3胎最高为14.81 kg。各胎次断奶窝重基本稳定。相关性分析表明,丹系大白母猪第3胎与第4胎产仔数、产活仔数、初生窝重呈显著正相关,第2胎与第5胎的产仔数、产活仔数、初生窝重间均呈显著负相关。第4胎与第5胎断奶仔猪数有显著负相关。第4胎和第5胎的断奶窝重有显著正相关。第3胎繁殖性能相对稳定,可以反映母猪繁殖性能,因此丹系大白母猪第3胎次的繁殖性能可作为选育后备母猪的重要依据。     

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。     

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)。     

杂谈猪的遗传改良——冻精与批次分娩对大白猪繁殖性状遗传参数估计或繁殖性能的影响

本研究旨在分析影响大白猪繁殖性能因素(批次管理体系和精液类型)与遗传参数估计,为目标群体的遗传评估及生产管理奠定理论基础。利用DMU和ASREML软件分析2 026头大白母猪共4 512窝繁殖记录,涉及4个繁殖性状(总产仔数、产活仔数、21日龄窝重和断奶仔猪数)。结果表明:大白猪4个繁殖性状的遗传力估计值均在0.10左右,各性状间均成强正遗传相关(0.54以上)。精液类型(鲜精和冻精)效应对断奶仔猪数和21日龄窝重影响不显著(P>0.05),对总产仔数和产活仔数影响显著(P<0.05),其中冻精在总产仔数和产活仔数上较鲜精均少1头左右(P<0.05)。批次管理体系研究表明,由单周批次管理体系转变为4周批次管理体系后,母猪繁殖性能有所下降,产活仔数、断奶仔数猪和21日龄窝重分别下降0.51头、0.61头和10.13 kg。     

Responses to 19 generations of litter size selection in the Nebraska Index line. I. Reproductive responses estimated in pure line and crossbred litters

Our objective was to estimate responses in reproductive traits in the Nebraska Index line (I) after 19 generations of selection for increased litter size. Responses were estimated in dams producing pure line, F1, and three-way cross litters. A total of 850 litters were produced over six year-seasons, including 224 pure line litters, 393 F1 litters produced from I and C females mated with Danbred NA Landrace (L) or Duroc-Hampshire (T) boars, and 233 litters by F1 L x I and L x C females mated with T boars. Contrasts of means were used to estimate the genetic difference between I and C and interactions of line differences with mating type. Farrowing rates of lines I (u = 91.0%) and C (u = 92.8%) did not differ. Averaged across all genetic groups, mean number born alive per litter was 10.1 pigs, and number and weight of pigs weaned per litter, both adjusted for number nursed and weaning age of 12 d, were 9.7 pigs and 34.4 kg, respectively. Averaged across mating types, direct genetic effects of I were greater than C (P < 0.05) for total born (3.53 pigs), number born alive (2.53 pigs), number of mummified pigs (0.22 pig), and litter birth weight (2.14 kg). The direct genetic effect of line I was less than C (P < 0.05) for litter weaning weight (-1.88 kg). Interactions of line effects with crossing system were significant (P < 0.05) for total number born, number of stillborn pigs, number weaned, and litter weaning weight. In pure line litters, I exceeded C by 4.18 total pigs and 1.76 stillborn pigs per litter, whereas the estimate of I-C in F1 litters was 2.74 total pigs and 0.78 stillborn pig per litter. The contrast between I and C for number weaned and litter weaning weight in pure litters was 0.32 pig and -0.28 kg, respectively, compared with 0.25 pig and -2.14 kg in F1 litters. Crossbreeding is an effective way to use the enhanced reproductive efficiency of the Index line.     

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 。     

辽宁绒山羊繁殖性状遗传参数的研究

本文应用EXCEL2004软件和SAS6.12软件对辽宁绒山羊繁殖性状进行统计和分析,结果为：辽宁绒山羊的产羔数、产活羔数、断奶只数、断奶窝重、初生窝重、初生个体重、断奶个体重等主要繁殖性状的遗传力分别为0．147、0．126、0．182、0．250、0．318、0．384、0．369,说明除产羔数、产活羔数、断奶只数外,其他性状均属中等遗传力;繁殖性状中,产羔数、产活羔数、断奶只数、初生窝重、断奶窝重等性状的表型相关和遗传相关均为强正相关,窝性状与个体性状呈负遗传相关;初生个体重、断奶个体重与其他5个性状间呈弱正相关或弱负相关。     

Genetic effects on ewe productivity of crossing D'man and Sardi breeds of sheep

Data from 364 ewes of Sardi (S), D'man (D), S x DS, DS x S, S x D, D x S (F1), F2, D x DS and DS x D breed groups mated to F1 rams were analyzed for fertility, number of lambs born alive, litter size at weaning, litter weight at weaning per ewe joined and mean lamb weight at 60 d. Each ewe was exposed in two seasons and had one or two lambings. Effects of breed group were significant for all traits. The highest number of lambs born alive and litter size at weaning were recorded in D'man (1.84 and 1.45, respectively) and D x DS (1.81 and 1.43, respectively). F1 ewes (S x D and D x S) had the highest fertility (.94) and litter weight at weaning per ewe exposed (13.8 kg). Mean lamb weight at 60 d was highest for S x DS and Sardi ewes (13.4 kg and 13.2 kg). D'man additive effects were positive and significant for number of lambs born alive, litter size at weaning and litter weight at weaning per ewe joined; were significant but negative for mean lamb weight at 60 d; and were not significant, although positive, for fertility. Significant individual heterosis was found for fertility, litter weight weaned and mean lamb weight at 60 d. Maternal heterosis and direct epistatic recombination effects were small for all traits.     

封闭群五指山小型猪主要繁殖性状的多重回归与通径分析

试验选取45头普通级封闭群五指山小型猪初产母猪,测定总产仔数(X1)、初生活仔数(X2)、初生窝重(X3)、初生个体重(X4)、21 d活仔数(X5)、21 d窝重(X6)、21 d个体重(X7)、断奶活仔数(X8)、断奶个体重(X9)和断奶窝重(Y)等10个繁殖性状表型值,并对各繁殖性状表型值进行相关、回归及通径分析,以揭示母猪繁殖性状间的真实关系。结果显示,封闭群五指山小型猪的绝大多数繁殖性状的表型值间存在显著正相关,有3对性状间存在较弱负相关。通过多重回归分析建立的估计断奶窝重的多元回归方程为:Y=－4.98690－2.61933X5+1.13628X6－7.55296X7+3.33048X8+6.74545X9,并且形成了三因素水平的性状间因果关系层次。通径分析剖析了相关性状间的直接效应和间接效应,显示X5~X9对断奶窝重有显著性直接影响,表明母猪的泌乳力和营养水平对其繁殖性能有显著影响,先天性繁殖性状对繁殖性能影响较小。     

Genetic correlations between lean growth and litter traits in U.S. Yorkshire,Duroc, Hampshire,and Landrace pigs

The objective of this study was to estimate breed-specific genetic correlations between lean growth and litter traits for four U.S. swine breeds. Records for lean growth and litter traits on Yorkshire, Duroc, Hampshire, and Landrace pigs collected between 1990 and April 2000 in herds on the National Swine Registry Swine Testing and Genetic Evaluation System were analyzed. A bivariate animal model and restricted maximum likelihood procedures were used to estimate genetic and environmental correlations between lean growth rate, days to 113.5 kg, backfat, and loin muscle area with litter traits of number born alive, litter weight at 21 d, and number weaned. Most genetic correlation estimates between lean growth and litter traits were small in magnitude and consistent across breeds. Backfat had the largest within-breed genetic correlations with number born alive (0.18 to 0.20) and litter weight at 21 d (-0.27 to -0.30). Estimates of genetic correlations between lean growth traits and number weaned were very small. Estimates of the environmental correlations between lean growth and litter traits also were very small for all traits and for all four breeds. Results indicate that selection for lean growth traits could have a long-term effect on litter traits. Including lean growth traits in a maternal-line evaluation using a multiple-trait model could increase the accuracy of the genetic evaluation for litter traits.     

黑白花兔繁殖性状的相关及通径分析

为研究黑白花兔的繁殖性能,对黑白花兔母兔产仔数、产活仔数、初生窝重、21日龄只数、21日龄窝重、28日龄断奶只数和28日龄断奶窝重7个性状进行相关分析和通径分析。结果表明:各繁殖性状在表型上存在极显著正相关关系,其中21日龄只数与28日龄断奶只数的相关系数最大(0.876 9);对28日龄断奶窝重直接影响最大的是28日龄断奶只数(通径系数为0.548 5),其次是21日龄窝重(通径系数为0.373 0);通过决定系数计算结果,也认为影响黑白花兔28日龄断奶窝重的主要因素是断奶只数和21日龄窝重。因此,在兔生产实际中,除了通过选育提高母兔的繁殖力外,还要健全仔兔保健措施以提高窝成活数,同时还要加强母兔的饲养管理以提高泌乳量,从而从整体上提高黑白花兔的繁殖性能。     

松辽黑猪繁殖性的相关及通径分析

对松辽黑猪总产仔数（X1）、产活仔数（X2）、出生均重（X3）、出生窝重（X4）、20日龄窝重（X5）、断奶仔猪数（X6）、35日龄断奶窝重（y）7个繁殖性状进行了通径分析和回归分析。结果表明各个繁殖性状在表型值上都存在不同程度的相关,其中对断奶窝重影响最大的为断奶仔猪数,其次为20日龄窝重、产活仔数及总产仔数。建立最优回归方程为y=20．031—1．958x1O．405x5＋8．201x6     

Hormonal therapy for sows weaned during fall and winter

Sows from five commercial herds were weaned in the fall and winter and used to ascertain the potential application of hormonal therapy to stimulate subsequent litter size born. At weaning sows within parity (1, 2, and 3 through 6) and lactation length classification (early weaned, < or = 14 d; conventionally weaned, > 14 d) were randomly assigned to treatment. Treatments were injection with P.G. 600 (400 IU PMSG with 200 IU hCG) at weaning or no treatment. Sows were individually observed for estrus and mated following protocol for each herd. Breeding, culling, and farrowing data were collected. Treatment with P.G. 600 did not change subsequent rebreeding performance for sows at parity 1 or parities 3 through 6. However, conventionally weaned parity-2 sows treated with P.G. 600 were more likely (P < .05) to return to estrus than conventionally weaned controls (99.0 vs 93.6%, respectively). For parity-1 and parity-2 sows, treatment did not significantly change the likelihood for farrow percentage. However, the likelihood to farrow a litter was greater (P < .05) among P.G. 600-treated sows at parities 3 to 6 that were conventionally weaned (84.4 vs 71.3%, respectively). Subsequent litter birth weight for parity-1 sows treated with P.G. 600 was lower (P < .02) than for controls (15.6 vs 16.6 kg, respectively). Subsequent litter size at birth was not affected by treatment for parity-1 or parity-2 sows compared with controls. However, early-weaned sows at parities 3 through 6 treated with P.G. 600 had more (P < .06) total number born than controls (12.4 vs 10.6, respectively). Treatment with P.G. 600 improved reproductive function within specific parity and lactation length classification for sows weaned in the fall and winter.