Impacts of high nursing intensity on sow performance during a subsequent lactation

Abstract Text: One hundred-fifty gilts were used to determine the effects of nursing intensity on performance of sows during the subsequent lactation. The experiment was based on a 2 x 2 factorial arrangement with varied litter sizes (10 and 13 piglets: L10 and L13) and durations of lactation (21 and 27 d: D21 and D27) in parity 1. Sows rebred successfully were used in parity 2, during which litter size was set to 10 piglets, and all piglets were weaned at d 21 of lactation. Sow and litter weights were recorded at farrowing and weaning for both parities. Colostrum (within 24 h of parturition) and milk (at d 17 of lactation) samples were collected. Data were analyzed with General Linear Model procedure in SAS software (SAS Inst. Inc., Cary, NC). In parity 1, litter weight gain of L10 was less (P < 0.05) than L13, and sows in L10 tended (P = 0.095) to have less BW loss than sows in L13; correspondingly due to difference in litter size. Duration of lactation did not affect (P > 0.10) sow weight loss. The ADFI of sows did not differ (P > 0.10) among treatments for both parities. In parity 2, sow culling rate increased in D21 (35.7%) than D27 (24.4%), also in L13 (38.9%) than L10 (25.9%) due to conception, heat intolerance, and lameness. Sow weight loss during subsequent lactation was the lowest (P < 0.05) in L13 and D27 (0.69 kg) comparing to the other three treatments (7.27, 7.27, and 10.74 kg). Sows in L13 had less (P < 0.05) backfat loss than L10 in parity 2 (0.5 vs. 2.7 mm). Litter weight gain as well as pig weight gain did not differ (P > 0.10) among treatments in parity 2. Litter size and the duration of lactation during parity 1 did not affect (P > 0.10) the composition of colostrum and milk in parity 2. Collectively, the performance of sows and litters were not negatively affected by nursing intensity of a previous parity. Interestingly, sows with a high nursing intensity in parity 1 maintained their body condition better than sows with a lower nursing intensity during the subsequent parity.

Keywords: duration of lactation, litter size, nursing intensity, sows