Effects of suckling history of mammary glands on teat order and growth of nursing piglets during a subsequent lactation

Abstract Text: The suckling history of a mammary gland, suckled or not suckled, has a significant impact on that gland’s subsequent lactation performance. Litters of fifty-seven first parity sows were used to determine the effects of suckling history on teat order and piglet growth during a subsequent lactation. In parity 1, sows nursed either 10 or 13 piglets. Sows successfully rebred were used in parity 2, during which litter size was set to 10 piglets, and all piglets were weaned at d 21 of lactation. In both parities, teat order of all sows was observed lively at least 3 times during wk 2 and 3 of lactation. Piglet weights were measured at birth and weaning (d 21) in both parities. Results showed piglet weight gain was greater (P < 0.05) from sows in parity 2 (258 g/d) than in parity 1 (205 g/d), indicating that milk production of sows increased from parity 1 to 2. Teat order and teat preference were not affected by litter sizes (10 vs. 13) in parity 1. Piglets that suckled the anterior 5 pairs of mammary glands were more (P < 0.05) than others (85.1% vs. 61.6% in parity 1; 88.4% vs. 35.4% in parity 2) showing their preference of mammary glands by location. In addition, piglets that suckled the anterior 5 pairs of mammary glands had greater (P < 0.05) ADG than those that suckled posterior 3 pairs of mammary glands (263 vs. 229 g/d in parity 1; and 208 vs. 196 g/d in parity 2). The utilization rate of mammary glands in parity 2 with suckling history in parity 1 was more (P < 0.05) than those without suckling history in parity 1 (86% vs 14.0%), indicating that piglets preferred mammary glands with previous suckling history. However, ADG of piglets in parity 2 was not affected by suckling history during parity 1. Collectively, this study indicates that piglets preferred mammary glands with previous suckling history even though milk production was not affected by suckling history. Piglets also preferred the anterior 5 pairs of mammary glands which produced more milk than others.

Keywords: litter size, mammary glands, pigs, suckling history, teat order