Does split-suckling influence pre- and postweaning pig growth performance and mortality?

A total of 1,513 sows and litters, approximately 505 litters per treatment, were used to determine the effects of two split-suckling protocols on litter growth performance and mortality pre- and postweaning compared to no split-suckling. Sows were blocked by parity and allotted to one of three treatments: no split-suckling (control), or one of two split-suckle protocols. The first split-suckle protocol was based on birth order, where the first 8 pigs born were marked at birth, and at the completion of farrowing, were removed from the sow for 45 min. After 45 min, the first 8 born pigs were returned to the sow and the unmarked pigs born later in the birth order were removed from the sow for 45 min. Then, all pigs were returned to the sow. The second split-suckling protocol was based on body weight (BW.) After farrowing was completed, the 8 heaviest pigs in the litter were removed from the sow for 90 min and then returned to the sow, completing the split-suckle treatment. Litters on either split-suckle treatment were split-suckled within 18 h of birth, after the completion of farrowing if litters were born during the day or the following morning for litters born overnight. Cross-fostering occurred after split-suckling within treatment by 24 h after the completion of farrowing. No differences were observed in litter size or pig weights at the time of split-suckling (d 1) or at weaning, and preweaning mortality did not differ between treatments. Preweaning mortality from split-suckle to weaning was also analyzed by birth weight category within treatment, light (≤1.2 kg), medium (1.2 < × ≤ 1.5 kg), and heavy (≥1.5 kg) pigs, and was not affected by treatment. When litters were evaluated by sow parity, timing of split-suckling (day of birth vs. the following morning), or functional teat count, no differences in preweaning mortality were observed among treatments. A subset of pigs was monitored through the nursery and finishing phases. No treatment differences were observed in average daily gain, average daily feed intake, gain-to-feed ratio, or mortality in either phase. Overall, the split-suckling protocols evaluated in this study did not influence pig growth performance or mortality during the pre- or postweaning periods compared to no split-suckling.