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1.
妊娠期背膘厚对母猪产程及繁殖性能的影响 总被引：1，自引：0，他引：1
为优化母猪繁殖效率,探究妊娠期不同背膘厚对母猪繁殖性能和分娩产程的影响,本研究以广西某公司2 969头大白母猪和1 787头长白母猪为试验群体,收集2017年1月至2017年10月妊娠期3个阶段(妊娠30、80和107 d)背膘厚与分娩接产记录数据,分析背膘厚与分娩产程、总产仔数、产活仔数和初生窝重等性状的关系。研究结果表明,大白母猪分娩产程时间显著短于长白母猪(P0.05),大白母猪总产仔数、产活仔数和初生窝重显著优于长白母猪(P0.05)。在妊娠30 d时,背膘厚在18～20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大;背膘厚在18～20 mm组的长白母猪总产仔数和产活仔数最高。在妊娠80 d时,背膘厚≥20 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大、产程最短;背膘厚在16～18 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较高、母猪产程较短。在妊娠107 d时,背膘厚在14～16 mm组的大白母猪总产仔数和产活仔数最高,且初生窝重最大,但母猪产程与其他组差异不显著(P0.05);背膘厚≥20 mm组的长白母猪总产仔数和产活仔数最高,且初生窝重较大。妊娠期背膘厚减少1～2 mm的大白母猪,其总产仔数和产活仔数最高,初生窝重较小,产程较长。而背膘厚减少2 mm的长白母猪,其总产仔数和产活仔数最高,初生窝重较大,产程较短。上述试验结果说明,在母猪妊娠期间,合适的背膘厚可有效提高母猪繁殖性能和母猪分娩期间的福利水平。养殖场可以根据营养配方和猪群品种建立背膘数据库,通过精准饲喂将母猪背膘厚调整至最佳范围,同时合理控制妊娠期背膘变化。 相似文献
2.
母猪不同时期背膘厚度与繁殖性能关系的研究 总被引：5，自引：0，他引：5
试验以198头纯种大白母猪为对象,研究分析了大白母猪在配种前和分娩时背膘厚度与产活仔数、初生窝重的关系,哺乳期背膘厚度变化与断奶至发情时间间隔、下一胎产活仔数、初生窝重的关系。结果表明：大白母猪配种前背膘厚度为15.5-20．0mm时的产活仔数最高,初生窝重也最重;初产大白母猪分娩时背膘厚度为15．5—20．5mm时的产活仔数最高;哺乳期间大白母猪背膘没有损失或者损失较少（〈0．5mm）时的断奶至发情时间间隔最短,下一胎产活仔数最高,下一胎初生窝重也最重。 相似文献
3.
《中国畜牧杂志》2019,(12)
为了探讨初产母猪不同妊娠期背膘厚度对其窝产仔数、死胎数和初生窝重的影响,本实验对加系长白和大白母猪第1胎妊娠开始(配种当天,74头)和结束(妊娠110 d,217头)时的背膘厚度进行测定,记录母猪总产仔数、产活仔数、死胎数和初生窝重等繁殖指标。结果表明:配种时背膘厚为14.0～18.0 mm的后备母猪总产仔数13.62头、活产仔数12.32头,显著高于配种时背膘厚为<14.0 mm和>18.0 mm的母猪;后备母猪妊娠110 d的背膘厚度为12.6～15.5 mm时,其总产仔数(13.14头)、初生窝重(14.93 kg)及初生个体重(1.37 kg),均高于其他3个组(P>0.05);哺乳期背膘损失随妊娠110 d后备母猪背膘厚的增大而不断增加,当母猪妊娠110 d的背膘厚>18.0 mm时,其哺乳期背膘损失达4.11 mm,且9.0～12.5 mm组和12.6～15.5 mm组的背膘损失与极显著低于其他各组。 相似文献
4.
为了研究不同胎次及分娩P2背膘厚度对母猪繁殖性能的影响,对辽宁省某种猪场2018年10月份1～4胎次145窝母猪的生产数据报表进行资料统计分析。结果显示:不同胎次之间,第3胎次母猪繁殖性能最佳,产程最长,分娩至配种日数最长;第4胎产公活仔猪数最高,产母活仔数最低。不同分娩时P2点背膘厚度之间,背膘厚19 mm母猪产弱仔数最高;背膘厚16 mm母猪死胎数最高;背膘厚14～16 mm母猪产公仔猪数较多,17～19 mm母猪产母仔猪数较多;背膘厚17 mm母猪所产仔数的平均初生重最高;背膘厚18 mm和19 mm母猪产程最长。 相似文献
5.
为探讨大白母猪在不同妊娠阶段的背膘厚对繁殖性能的影响，在妊娠前期、中期、后期对怀孕母猪进行背膘测定，根据测定的背膘厚将每个阶段的母猪分为3组，同时记录母猪窝总产仔数、窝产活仔数、产死胎数、初生窝重和仔猪平均初生重。结果表明，在妊娠前期，1组(背膘厚<14mm)、2组(背膘厚介于14～19mm)的窝总产仔数分别为13.54头、13.35头，显著高于3组(背膘厚> 19mm)的12头(P <0.05);1组、2组的窝产活仔数分别为12.95头、12.86头，显著高于3组的11.35头(P <0.05);1组的初生窝重为20.31kg，极显著高于3组的17.18kg(P <0.01)，显著高于2组的19.46kg(P <0.05);1组的平均初生重为1.58kg，显著高于2组的1.53kg(P <0.05)。在妊娠中期，在母猪的窝总产仔数、窝产活仔数、死胎数和平均初生重上3个组均无显著差异；1组的初生窝重为19.71kg，显著高于3组的18.20kg(P <0.05)。妊娠后期母猪在窝总产仔数、窝产活仔数和死胎数上3个组均无显著差异；1组的初生... 相似文献
6.
《黑龙江畜牧兽医》2017,(12)
为了分析不同胎次、配种季节对母猪繁殖性能的影响,笔者对江西省赣州市某猪场2015年长白母猪、大白母猪的繁殖记录进行统计分析,并按胎次及配种季节进行分组,分析其在不同胎次、配种季节条件下的繁殖性能差异。结果表明:长白母猪和大白母猪3~5胎繁殖性能较好,第1胎的初生均重、断奶均重最低;长白母猪第3胎窝产活仔数最高,显著高于1,2,6,7,8胎(P0.05);大白母猪第4胎窝产活仔数最高,显著高于第1,2胎(P0.05);长白母猪夏季配种窝产仔数、窝产活仔数最高,初生均重、断奶均重春季配种最高;大白母猪不同季节配种窝产仔数差异不显著(P0.05),夏季、秋季配种产活仔数显著高于冬季(P0.05)。说明不同胎次、配种季节对长白、大白母猪繁殖性能有较大影响。 相似文献
7.
母猪背膘厚是母猪体况的一个重要指标,与母猪的繁殖性能密切相关。本研究所用数据来源于扬翔公司2017年5月—2018年6月份期间的扬翔1号猪配套系,母本为纯种美系长白、美系大白、丹系长白和丹系大白的背膘测定和繁殖记录。利用超声波对母猪妊娠107 d背膘厚及断奶背膘厚进行测定,分析其对产活仔数、断奶至再配间隔及7 d内发情率的影响。结果表明:丹系长白、丹系大白在107 d时背膘厚度为14.0～16.0mm母猪产活仔数高,其中丹系长白的初生窝重最重;美系长白、美系大白在107d背膘厚度17.0～19.0mm时母猪产活仔数高,初生窝重最重。丹系长白、丹系大白同样在断奶时背膘厚度维持在为11.0～16.0mm之间时,断奶至再配间隔天数显著低于其他组(P0.05),且断奶7d内的发情率也明显高于其他组;断奶背膘厚度美系大白维持在14～16mm,美系长白维持在17～19mm之间时,断奶至再配间隔天数显著低于其他组(P0.05),且断奶7 d内的发情率也明显高于其他组。该研究说明母猪膘情管理在品系和品种间有差异,应针对不同品系或者品种合理进行膘情管理和饲喂管理,促使遗传潜力的最大化。 相似文献
8.
为了探讨妊娠母猪不同背膘厚度对其窝产仔数、死胎数和初生窝重的影响,对120头3胎次的约克夏母猪在分娩前进行背膘测定,根据背膘厚度分为薄组(16mm)、适中组(16~22mm)和厚组(22mm)3组,同时记录母猪产仔数、产活仔数、死胎数、死胎率和初生窝重。结果表明,背膘厚度适中组的产仔数11.62头,显著高于背膘厚度薄组产仔数9.83头和厚组9.61头(P0.05);背膘厚度适中组的窝产活仔数为11.62头,显著高于背膘厚度薄组窝产活仔数8.82头和厚组8.00头(P0.05);背膘厚度适中组初生窝重为17.71kg,极显著高于背膘厚度薄组初生窝重14.36kg和厚组12.54kg(P0.01);背膘厚度适中组的死胎数和死胎率分别为0.10头和0.01%均极显著低于背膘厚度薄组和厚组(P0.01)。研究结果表明,妊娠母猪膘情适中对于提高窝产仔数、窝产活仔数和初生窝重以及降低死胎数和死胎率有积极作用,在生产中应积极加强对妊娠母猪的饲养管理,确保妊娠母猪膘情使用,从而提高经济效益。 相似文献
9.
10.
为研究母猪分娩前背膘厚与繁殖性能及体况的关系,试验测定了分娩前3天进入产房的经产待产母猪的背膘厚,根据背膘测定结果选取其中24头母猪,再根据背膘厚度不同将其分为试验Ⅰ组(背膘厚13～≤17 mm)、试验Ⅱ组(背膘厚17～≤21 mm)和试验Ⅲ组(背膘厚21～≤24 mm),每组8头猪,即8个重复,后续对试验母猪的繁殖性能、体况进行测定,应用灰色关联分析法对母猪分娩前背膘厚与其繁殖性能及体况进行关联度分析。结果表明:母猪分娩前背膘厚对母猪总产仔数、仔猪初生重、仔猪21日龄窝重、仔猪28日龄断奶重及母猪发情间隔均有显著影响(P0. 05),但对母猪产活仔数没有显著影响(P0. 05)。母猪分娩前背膘厚与母猪断奶时背膘厚关联度最大,其次与母猪总产仔数关联度较大;母猪分娩前背膘厚13～≤17 mm时,其与仔猪初生重关联度最大,其次与仔猪21日龄窝重关联度较大;母猪分娩前背膘厚17～≤21 mm时,其与母猪断奶体重关联度最大,其次与仔猪初生重关联度较大;母猪分娩前背膘厚21～≤24 mm时,其与28日龄仔猪断奶重关联度最大,其次与仔猪初生重关联度较大。说明母猪分娩前背膘厚与一些繁殖性能关联度较大,可以通过营养手段调控母猪背膘厚来改善母猪繁殖性能。 相似文献
11.
《The Professional Animal Scientist》1999,15(1):7-13
The primary objective of this study was to determine the effects of supplemental dietary fat during lactation on sow BW, sow backfat thickness, sow feed consumption, litter size, and pig growth rate. Dietary treatments included 0, 3, 6, and 9% supplemental low acid yellow fat in a traditional corn-soybean meal basal lactation diet. A total of 160 Landrace and crossbred sows (approximately 40 per treatment) were included in the study. Sows fed 3 and 6% supplemental fat had greater (P<0.10) average backfat thickness at weaning. Sow weight change and feed consumption were inconsistent among dietary fat levels. Dietary fat level during lactation did not affect number of pigs born alive or number of stillborns. However, the 9% fat level was associated with more mummified pigs at birth. Number of pigs weaned was greater for the 0% supplemental fat than for the 9% fat level. The largest average pig weights at 21 (5.8±0.29 kg) and 28 (7.48±0.38) d of age were those from sows fed the 3% added fat diet. Sows with ≤25.4 mm backfat at farrowing had more pigs born alive (P<0.05), had less backfat at 21 and 28 d of lactation (P<0.05), and consumed more feed during wk 2 and 3 of lactation. Of all sows fed the control diet, sows with >25.4 mm backfat at farrowing consistently had heavier pigs throughout the lactation phase (P<0.05). Backfat loss during lactation was lower (P<0.05) for sows with ≤25.4 mm at farrowing within all dietary treatments. Consistent significant differences were not observed in sow weight loss or feed consumption between low and high backfat sows for each dietary treatment. Sow backfat loss during lactation is dependent on body condition at farrowing, in that, fatter sows at farrowing have greater backfat loss during lactation. Sows with ≤25.4 mm of backfat at farrowing responded to added dietary fat treatments and produced heavier pigs throughout the lactation period. 相似文献
12.
Veum TL Crenshaw JD Crenshaw TD Cromwell GL Easter RA Ewan RC Nelssen JL Miller ER Pettigrew JE Ellersieck MR;North Central Region- Committee On Swine Nutrition 《Journal of animal science》2009,87(3):1003-1012
A regional experiment was conducted at 8 experiment stations, with a total of 320 sows initially, to evaluate the efficacy of adding 13.35% ground wheat straw to a corn-soybean meal gestation diet for 3 successive gestation-lactation (reproductive) cycles compared with sows fed a control diet without straw. A total of 708 litters were farrowed over 3 reproductive cycles. The basal gestation diet intake averaged 1.95 kg daily for both treatments, plus 0.30 kg of straw daily for sows fed the diet containing ground wheat straw (total intake of 2.25 kg/d). During lactation, all sows on both gestation treatments were fed ad libitum the standard lactation diet used at each station. Response criteria were sow farrowing and rebreeding percentages, culling factors and culling rate, weaning-to-estrus interval, sow BW and backfat measurements at several time points, and litter size and total litter weight at birth and weaning. Averaged over 3 reproductive cycles, sows fed the diet containing wheat straw farrowed and weaned 0.51 more pigs per litter (P 相似文献
13.
The purpose of this study was to detect the genetic variation of the porcine developmental piuripotency associated 5 (Dppa5) gene and its association with reproductive performance in sow.PCR-RFLP and sequencing methods were used to detect SNPs and analyze its association with reproductive performance in Large White and Landrace sows.The results showed that two missense mutations g.363 T> C and g.844 G> T were detectd in exon of porcine Dppa5.SNP g.363 T> C affected total number born highly significantly in primiparous Large White sow (P< 0.01) and affected litter size and number born alive significantly in Large White and Landrace sows (P< 0.05).SNP g.844 G> T showed a significant impact on total number born in multiparous Landrace and Large White sows (P< 0.05).The results suggested that the SNPs of Dppa5 gene impacted reproductive performance of sows and could be genetic markers. 相似文献
14.
试验旨在研究猪多潜能性维持因子5(developmental piuripotency associated 5,Dppa5)基因的遗传多态性及其与母猪繁殖性状的遗传效应。以长白猪和大白猪为试验群体,采用PCR-RFLP、克隆测序等方法分析检测猪Dppa5基因的多态性并对其与母猪产仔性能进行关联分析。结果表明,猪Dppa5基因外显子上存在2个错义突变位点:g.363 T> C和g.844 G> T;猪Dppa5基因g.363 T> C 位点对初产大白猪的总产仔数有极显著影响(P< 0.01),对经产大白猪、长白猪的产活仔数有显著影响(P< 0.05);g.844 G> T位点对经产长白猪和大白猪的总产仔数有显著影响(P< 0.05)。综合结果分析,Dppa5多态位点对猪的繁殖性能存在影响,可作为潜在的遗传标记,为猪的分子育种提供参考。 相似文献
15.
Southern LL LeMieux FM Matthews JO Bidner TD Knowles TA 《Journal of animal science》2000,78(1):120-123
An experiment was conducted to evaluate feather meal as a source of Val in lactating sow diets. Sows (five farrowing groups; mean parity = 2.34) were allotted to one of two dietary treatments on the basis of ancestry, parity, and weight and date of d 110 of gestation. The treatment diets included 1) corn-soybean meal lactation diet (n = 40) or 2) corn-soybean meal lactation diet with 2.5% feather meal (n = 39). The diets were formulated on an equal Lys basis. All litters were adjusted to 10 pigs within 24 h after farrowing, and all sows weaned at least nine pigs. Sows were bled at 110 d of gestation and at weaning, and serum urea N was determined. Backfat thickness was determined ultrasonically at 110 d of gestation and at weaning. Serum urea N and backfat thickness at d 110 of gestation were used as covariates for serum urea N and backfat thickness at weaning, respectively. The litter response criteria (weaning weight, litter weight gain, and percentage survival) were not affected (P > .10) by feather meal. The sow response criteria (weaning weight, weight loss per day, weaning backfat thickness, change in backfat thickness, ADFI, and days to estrus) were not affected (P > .10) by feather meal. Sows fed feather meal had increased (P < .01) serum urea N and tended (P = .15) to have decreased sow weaning weight. Following the initial analysis of the data, the data set was split into two groups: 1) sows with litters gaining less than 2.17 kg/d (n = 19 and 20 for control and feather meal diets, respectively) and 2) sows with litters gaining more than 2.17 kg/d (n = 21 and 19 for control and feather meal diets, respectively). These two groups were analyzed separately. In sows with litters gaining less than 2.17 kg/d, the litter and sow criteria were not affected (P > .10) by treatment. In sows with litters gaining more than 2.17 kg/d, sow weaning weight was decreased (P < .04) and sow weight loss (P < .02) and serum urea N (P < .01) were increased in sows fed feather meal. Feather meal (as a source of Val) did not improve litter weight gain, but it increased serum urea N. 相似文献
16.
A total of 124 Duroc and 99 Landrace primiparous and multiparous sows were assigned, within breed and contemporary group, to control (N) or 10% added fat (F) diets on d 105 of gestation based on parity and genetic line (control or selected for improved sow productivity), to determine the effects of genetic line and fat addition to the lactation diet on sow and litter performance. Weekly feed intake was not affected (P greater than .10) by genetic line for Duroc and Landrace sows but feed intake was reduced (P = .08) during wk 1 to 4 for Duroc sows and during wk 1 and 4 for Landrace sows (P less than .05) when they were fed diet F compared with diet N. Select (S)-line Duroc and Landrace sows lost more weight during lactation (P less than .01) than did control (C)-line sows. Select-line Landrace sows lost more backfat during lactation (P less than .05) than did C-line sows. Landrace sows lost less weight during lactation (P less than .05) when fed diet F than when fed diet N. The total number of pigs born, born alive, and alive at 21 d and at weaning were higher (P less than .01) for S-line Duroc sows, and litter size at 21 d and at weaning was higher (P less than .01) for S-line Landrace sows than for C-line litters within each breed. Pig survival from birth to weaning was increased (P = .07) for Duroc sows fed diet F but not for Landrace sows.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
17.
Genetic relationship of litter traits between farrowing and weaning in Landrace and Large White pigs
Shinichiro Ogawa Ayane Konta Makoto Kimata Kazuo Ishii Yoshinobu Uemoto Masahiro Satoh 《Animal Science Journal》2019,90(12):1510-1516
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. 相似文献
18.
母猪妊娠末期背膘厚度对产仔性能和胎盘脂质氧化代谢的影响 总被引：1，自引：0，他引：1
本试验旨在探讨母猪妊娠末期背膘厚度对产仔性能和胎盘脂质氧化代谢的影响,以探索母猪妊娠期脂肪沉积与繁殖性能的关系。本试验度量了846头经产大白母猪妊娠第109天时的背膘厚度,并分为3组,背膘厚度≤18 mm的为第1组(母猪192头),背膘厚度为19~22 mm的为第2组(母猪265头),背膘厚度≥23 mm的为第3组(母猪389头)。记录母猪分娩后的产仔性能,测定胎盘组织中脂质、氧化产物水平及抗氧化酶活性。结果表明:1)尽管母猪妊娠末期背膘厚度对总产仔数、产活仔数及木乃伊数无显著影响(P0.05),但显著影响了死胎数、初生窝重、初生头重和胎盘效率(P0.05)。其中,第2组的初生头重、初生窝重及胎盘效率显著高于其他2组(P0.05);第2组的死胎数显著低于第1组(P0.05),与第3组差异不显著(P0.05)。值得注意的是,母猪妊娠末期背膘厚度显著影响每窝初生重≤0.9 kg的仔猪数和每窝初生重≤1.0 kg的仔猪数(P0.05),第3组的每窝初生重≤0.9 kg的仔猪数和每窝初生重≤1.0 kg的仔猪数均显著高于其他2组(P0.05)。2)在第3组的胎盘组织中,不仅甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)及游离脂肪酸(FFA)的水平显著高于其他2组(P0.05),而且丙二醛(MDA)和活性氧(ROS)水平也显著高于其他2组(P0.05),同时超氧化物歧化酶(SOD)活性显著低于其他2组(P0.05)。3)妊娠末期母猪胎盘组织中ROS水平与总产仔数、初生窝重及胎盘效率呈显著负相关(P0.05),而MDA水平与总产仔数呈显著负相关(P0.05)。由此可知,母猪妊娠末期背膘厚度与产仔性能密切相关。妊娠末期维持背膘厚度在19~22 mm,母猪可获得较高的产仔性能;背膘厚度≤18 mm时,会增加死胎数;而背膘厚度≥23 mm时,会引起胎盘组织中脂质过度沉积,从而加剧胎盘氧化应激的发生。 相似文献
19.
Between-breed variability of stillbirth and its relationship with sow and piglet characteristics 总被引：1，自引：0，他引：1
Canario L Cantoni E Le Bihan E Caritez JC Billon Y Bidanel JP Foulley JL 《Journal of animal science》2006,84(12):3185-3196
Litter characteristics at birth were recorded in 4 genetic types of sows with differing maternal abilities. Eighty-two litters from F(1) Duroc x Large White sows, 651 litters from Large White sows, 63 litters from Meishan sows, and 173 litters from Laconie sows were considered. Statistical models included random effects of sow, litter, or both; fixed effects of sow genetic type, parity, birth assistance, and piglet sex, as well as gestation length, farrowing duration, piglet birth weight, and litter size as linear covariates. The quadratic components of the last 2 factors were also considered. For statistical analyses, GLM were first considered, assuming a binomial distribution of stillbirth. Hierarchical models were also fitted to the data to take into account correlations among piglets from the same litter. Model selection was performed based on deviance and deviance information criterion. Finally, standard and robust generalized estimating equations (GEE) procedures were applied to quantify the importance of each effect on a piglet's probability of stillbirth. The 5 most important factors involved were, in decreasing order (contribution of each effect to variance reduction): difference between piglet birth weight and the litter mean (2.36%), individual birth weight (2.25%), piglet sex (1.01%), farrowing duration (0.99%), and sow genetic type (0.94%). Probability of stillbirth was greater for lighter piglets, for male piglets, and for piglets from small or very large litters. Probability of stillbirth increased with sow parity number and with farrowing duration. Piglets born from Meishan sows had a lower risk of stillbirth (P < 0.0001) and were little affected by the sources of variation mentioned above compared with the 3 other sow genetic types. Standard and robust GEE approaches gave similar results despite some disequilibrium in the data set structure highlighted with the robust GEE approach. 相似文献
20.
Sow longevity influences farm economy and can be considered an important indicator of animal welfare. Body features such as leg conformation can play a key role in sow longevity, although little is known about its effect on culling decisions. Within this context, longevity data from 587 Duroc, 239 Landrace, and 217 Large White sows were analyzed with special emphasis on the effect of leg conformation. Sow longevity was analyzed twice for each breed, testing the effect of a subjective overall score for leg conformation, or the presence or absence of 6 specific leg conformation defects. Each preliminary model also included a teat conformation score with 3 levels, farm or origin, backfat thickness at 6 mo of age, and 2 continuous sources of variation, namely the age at the first farrowing and the number of piglets born alive at each farrowing. Overall leg conformation score influenced (P < 0.01) sow longevity in Duroc, Landrace, and Large White sows, with a greater hazard ratio (HR) for poorly conformed sows (1.56, 2.16, and 1.79, respectively) than for well-conformed sows (0.32, 0.66, and 0.68, respectively). Abnormal hoof growth reduced survivability in Duroc (HR = 2.78; P < 0.001) and Landrace sows (HR = 1.88; P < 0.01); the presence of splayed feet (P < 0.05) or bumps and injuries (P < 0.001) increased the risk of culling in Duroc sows (HR = 2.08 and 3.57, respectively), whereas the incidence of straight pastern increased the HR in Large White sows (HR = 2.49; P < 0.01). In all 3 breeds, longevity decreased for plantigrade sows, with a greater HR in Duroc (HR = 3.38; P < 0.001) than in Landrace (HR = 1.53; P < 0.10) and Large White sows (HR = 1.73; P < 0.05). Teat conformation did not influence sow longevity (P > 0.10). Estimates of heritability for longevity in Duroc sows ranged from 0.05 to 0.07 depending on the algorithm applied. Leg conformation had a substantial effect on sow longevity, where an accurate removal of poorly leg-conformed candidate gilts before first mating could improve sow survival and reduce culling costs. These moderate estimates of heritability indicated that survivability of Duroc sows could be genetically improved by direct selection for leg conformation. 相似文献