Wageningen University, Department of Animal Sciences, Adaptation Physiology Group, PO Box 338, 6700AH, Wageningen, The Netherlands.
J Anim Sci. 2013 May;91(5):2099-107. doi: 10.2527/jas.2012-5659. Epub 2013 Mar 5.
Piglet birth weight and litter uniformity were studied in sows of different parities and crossbred lines in relation to: 1) weaning-to-pregnancy interval (WPI) and 2) sow body condition changes (in BW and backfat thickness) during lactation and gestation in sows with a short WPI (≤7d). At the Institute for Pig Genetics (IPG) research farm, individual piglet birth weights and sow body condition (BW and backfat thickness at farrowing and weaning) were measured for 949 TOPIGS20 and 889 TOPIGS40 sows with >4 total born piglets, inseminated between 2003 and 2011. In all analyses, mean piglet birth weight and birth weight SD and CV were corrected for total number born. Total number born was greater in sows with a WPI of 8 to 21 d (+1.2 piglets; n = 72) and >21 d (+0.7 piglets; n = 182), compared with sows with a WPI ≤7 d (P < 0.01; n = 1,584). Mean piglet birth weight was not affected by WPI. Birth weight SD (-23 g) and CV (-1.7%) were lower in sows with a WPI >21 d, compared with sows with a WPI ≤7 d (P < 0.01). Effects of WPI were independent of sow parity. Effects of body condition changes in sows with a WPI ≤7 d were studied separately in TOPIGS20 sows inseminated between 2006 and 2011 (n = 808), and in TOPIGS40 sows inseminated between 2003 and 2008 (n = 747). Sow body condition loss during lactation was not related with subsequent total number born or mean piglet birth weight. Only in TOPIGS20 sows, more BW loss during lactation was related with greater subsequent birth weight SD (β = 0.83 g/kg, P < 0.01; β = 1.62 g/%, P < 0.01). Additionally, more backfat loss during lactation was related with greater subsequent birth weight SD (β = 5.11 g/mm, P < 0.01) and CV (β = 0.36%/mm, P < 0.01), independent of sow parity. Sow BW increase during gestation was negatively related with total number born [TOPIGS20: β = -0.06 and -0.05 piglet/kg BW increase for parity 2 (P < 0.01), and 3 and 4 (P < 0.01), respectively; TOPIGS40: β = -0.04 piglet/kg BW increase (P < 0.01), independent of sow parity]. Sow BW increase during gestation was positively related with birth weight SD [TOPIGS20: β = 0.63 g/kg BW increase (P = 0.01), independent of sow parity]. Sow body condition increase during gestation was not related with mean piglet birth weight. To conclude, this study shows that litter uniformity is compromised by severe sow body condition loss during lactation and improved in sows with a prolonged WPI. These effects are likely related with (insufficient) restoration of follicle development.
研究了不同胎次和杂交系母猪的断奶至配种间隔（WPI）和哺乳期和妊娠期母猪体况变化（BW 和背脂厚度）与：1）断奶至配种间隔（WPI）和 2）哺乳期和妊娠期母猪体况变化（BW 和背脂厚度）与：1）断奶至配种间隔（WPI）和 2）哺乳期和妊娠期母猪体况变化（BW 和背脂厚度）之间的关系。在猪遗传研究所（IPG）研究农场，对 949 头 TOPIGS20 和 889 头 TOPIGS40 母猪进行了个体仔猪初生重和母猪体况（产仔时和断奶时的 BW 和背脂厚度）测量，这些母猪的总产仔数超过 4 头，于 2003 年至 2011 年之间配种。在所有分析中，总产仔数校正为总产仔数。WPI 为 8-21 天的母猪（n = 72）和 WPI >21 天的母猪（n = 182）比 WPI ≤7 天的母猪（n = 1,584）的总产仔数多（分别增加 1.2 头和 0.7 头；P < 0.01）。WPI 对仔猪初生重没有影响。WPI >21 天的母猪的仔猪初生重标准差（-23 g）和变异系数（-1.7%）比 WPI ≤7 天的母猪低（P < 0.01）。WPI 的影响独立于母猪胎次。在 WPI ≤7 天的母猪中研究了母猪体况变化的影响，这些母猪分别于 2006 年至 2011 年（n = 808）和 2003 年至 2008 年（n = 747）配种。哺乳期母猪体况损失与随后的总产仔数或仔猪初生重无关。只有在 TOPIGS20 母猪中，哺乳期 BW 损失越多，随后的初生重标准差越大（β = 0.83 g/kg，P < 0.01；β = 1.62 g/%，P < 0.01）。此外，哺乳期背脂损失越多，随后的初生重标准差越大（β = 5.11 g/mm，P < 0.01）和变异系数（β = 0.36%/mm，P < 0.01），与母猪胎次无关。妊娠期母猪 BW 增加与总产仔数呈负相关[TOPIGS20：母猪胎次 2（P < 0.01）和 3 和 4（P < 0.01）时，BW 增加 0.06 和 0.05 头/千克；TOPIGS40：BW 增加 0.04 头/千克（P < 0.01），与母猪胎次无关]。妊娠期母猪 BW 增加与仔猪初生重标准差呈正相关[TOPIGS20：BW 增加 0.63 g/千克（P = 0.01），与母猪胎次无关]。妊娠期母猪体况增加与仔猪初生重无关。综上所述，本研究表明，哺乳期母猪体况严重损失会导致仔猪均匀度变差，而 WPI 延长则会改善仔猪均匀度。这些影响可能与（不足的）卵泡发育恢复有关。
