交叉饲养通常用于商业猪生产中,以平衡产仔数和/或调整产仔数内的仔猪出生体重。然而,关于最佳交叉培养程序的公开信息有限。这项研究评估了交叉饲养(使用14只仔猪的产仔数)后产仔数内出生体重变化对仔猪断奶前死亡率(PWM)和断奶体重(WW)的影响。使用了RCBD(阻断因素是分娩日和母猪产次,身体状况评分,和功能性乳头数),具有以下两种处理方式的不完整阶乘排列:1)出生体重类别(BWC):轻(<1.0kg),中等(1.0至1.5公斤),或重(1.5至2.0公斤);2)垫料成分:均匀,同一BWC产仔中的所有仔猪[均匀轻(14只轻仔猪);均匀中等(14只中等仔猪);均匀重(14只重仔猪)];混合,两个或两个以上BWC[L+M(七个轻和七个中等仔猪);M+H(七个中和七个重仔猪);L+M+H(三个轻,六个中等,和五只重小猪)]。仔猪在出生后24小时称重,并随机分配给BWC内的垫料组合物处理;所有仔猪都是交叉饲养的。共有47个块,共6窝(共282窝和3,948只仔猪)。在18.7±0.64d年龄时收集断奶重量;记录所有PWM。使用SAS的PROCMIXED和PROCGLIMMIX分析了单个仔猪的WW和PWM数据,模型分别包括BWC的固定效应,垫料成分,和互动,和块内母猪的随机效应。WW和PWM的BWC相互作用存在凋落物组成(P≤0.05)。在每个《生物武器公约》中,随着垃圾重量的减少,WW通常增加,PWM通常减少。例如,WW最大(P≤0.05)的轻仔猪在均匀的轻窝中,对于L+M窝的中等仔猪,和重仔猪在L+M+H窝。L+M窝中仔猪断奶前死亡率最低(P≤0.05),对于L+M+H窝中的重仔猪;然而,产仔成分对轻型仔猪的PWM没有影响(P>0.05)。总之,交叉饲养后同窝平均出生体重的增加通常会降低WW,并增加所有出生体重类别的仔猪的PWM。这意味着最大限度地提高仔猪断奶前生长和存活的最佳交叉饲养方法可能会根据人口的出生体重分布而有所不同。
Cross-fostering is commonly used in commercial swine production to equalize litter sizes and/or adjust piglet birth weights within litters. However, there is limited published information on optimum cross-fostering procedures. This study evaluated the effects of within-litter birth weight variation after cross-fostering (using litters of 14 piglets) on piglet preweaning mortality (PWM) and weaning weight (WW). An RCBD was used (blocking factors were day of farrowing and sow parity, body condition score, and functional teat number) with an incomplete factorial arrangement of the following two treatments: 1) birth weight category (BWC): light (<1.0 kg), medium (1.0 to 1.5 kg), or heavy (1.5 to 2.0 kg); 2) litter composition: uniform, all piglets in the litter of the same BWC [uniform light (14 light piglets); uniform medium (14 medium piglets); uniform heavy (14 heavy piglets)]; mixed, piglets in the litter of two or more BWC [L+M (seven light and seven medium piglets); M+H (seven medium and seven heavy piglets); L+M+H (three light, six medium, and five heavy piglets)]. Piglets were weighed at 24 h after birth and randomly allotted to litter composition treatment from within BWC; all piglets were cross-fostered. There were 47 blocks of six litters (total 282 litters and 3,948 piglets). Weaning weights were collected at 18.7 ± 0.64 d of age; all PWM was recorded. Individual piglet WW and PWM data were analyzed using PROC MIXED and PROC GLIMMIX of SAS, respectively; models included fixed effects of BWC, litter composition, and the interaction, and random effects of sow within the block. There was litter composition by BWC interactions (P ≤ 0.05) for WW and PWM. Within each BWC, WW generally increased and PWM generally decreased as littermate weight decreased. For example, WW was greatest (P ≤ 0.05) for light piglets in uniform light litters, for medium piglets in L+M litters, and for heavy piglets in L+M+H litters. Preweaning mortality was lowest (P ≤ 0.05) for medium piglets in L+M litters, and for heavy piglets in L+M+H litters; however, litter composition had no effect (P > 0.05) on PWM of light piglets. In conclusion, increasing the average birth weight of littermates after cross-fostering generally decreased WW and increased PWM for piglets of all birth weight categories. This implies that the optimum approach to cross-fostering that maximizes piglet preweaning growth and survival is likely to vary depending on the birth weight distribution of the population.