Newton E A, Mahan D C
Department of Animal Science, Ohio State University, Columbus.
J Anim Sci. 1993 May;71(5):1177-86. doi: 10.2527/1993.7151177x.
A study was conducted with sows of a high-producing genotype to evaluate their reproductive performance using three breeding weights over a three-parity period in two management systems. A total of 114 F1 gilts (Landrace x Yorkshire) were used in a split-plot, randomized, complete block experiment conducted as a 3 x 2 factorial arrangement of treatments in two replicates. Three gilt breeding weights of 120, 135, and 150 kg were achieved by feeding 1.8, 2.3, or 3.2 kg/d of a .73% lysine corn-soybean meal (C-SBM) diet, respectively, from 5 to 8 mo of age. Two locations, each with different management systems, were considered the main plot and consisted of 1) outside, concrete-floored gestation lots and indoor farrowing pens or 2) indoor gestation pens and farrowing crates. All sows were fed 1.8 (Parity 1) or 2.1 (Parity 2 and 3) kg/d of a .73% lysine C-SBM diet during the breeding and gestation periods, whereas a .82% lysine C-SBM diet with 5% added fat was available ad libitum during lactation. All sows lost weight during the first lactation; larger weight losses occurred as breeding weight increased (P < .01). During the second and third lactations the 135- and 150-kg sow breeding groups had less lactation weight change, whereas the 120-kg group lost more weight, resulting in a breeding weight x parity interaction (P < .01). The 120-kg breeding weight group consumed less feed (P < .05) for the three lactation periods than did the heavier weight groups. Initial breeding weight had no effect on number of pigs born (total, live) or pig and litter weights at birth. Pig mortality increased with increasing breeding weight (P < .01) and parity (P < .05), a response that was exacerbated when sows farrowed in pens vs crates. Postweaning breeding intervals and sow removal from the experiment were not significantly affected by initial breeding weight, but a numerically higher percentage of sows in the 120-kg group were anestrous or failed to conceive than the percentage of such sows in the heavier weight groups. These data suggest that an initial breeding weight of approximately 135 kg at 8 mo of age may be best when sows farrow in crates, whereas when sows farrow in pens a lower breeding weight may be more desirable.
对高产基因型母猪进行了一项研究，在两个管理系统下，于三个胎次期使用三种配种体重来评估其繁殖性能。在一项裂区随机完全区组试验中，共使用了114头F1代后备母猪（长白猪×约克夏猪），试验采用3×2析因处理安排，重复两次。通过在5至8月龄时分别饲喂1.8、2.3或3.2千克/天的含0.73%赖氨酸的玉米-豆粕（C-SBM）日粮，使后备母猪达到120、135和150千克这三种配种体重。两个地点，每个地点有不同的管理系统，被视为主区，包括1）室外水泥地面妊娠栏和室内产仔栏，或2）室内妊娠栏和产仔箱。所有母猪在配种和妊娠期饲喂1.8（第1胎）或2.1（第2胎和第3胎）千克/天的含0.73%赖氨酸的C-SBM日粮，而在哺乳期可自由采食含5%添加脂肪的含0.82%赖氨酸的C-SBM日粮。所有母猪在第一个哺乳期体重都下降；随着配种体重增加，体重下降幅度更大（P < 0.01）。在第二个和第三个哺乳期，135千克和150千克配种体重的母猪组泌乳期体重变化较小，而120千克组体重下降更多，导致配种体重×胎次存在交互作用（P < 0.01）。120千克配种体重组在三个泌乳期的采食量比体重较重的组少（P < 0.05）。初始配种体重对出生仔猪数（总数、活仔数）或出生时仔猪和窝重没有影响。仔猪死亡率随着配种体重增加（P < 0.01）和胎次增加（P < 0.05）而升高，当母猪在产仔栏而不是产仔箱中产仔时，这种反应会加剧。断奶后配种间隔和母猪退出试验情况未受到初始配种体重的显著影响，但120千克组中不发情或未受孕的母猪百分比在数值上高于体重较重组中的此类母猪百分比。这些数据表明，当母猪在产仔箱中产仔时，8月龄时初始配种体重约为135千克可能最佳，而当母猪在产仔栏中产仔时，较低的配种体重可能更合适。
