Dietary ractopamine supplementation during the first lactation affects milk composition, piglet growth and sow reproductive performance

作者：van Wettere W H E J^*; Pain S J; Hughes P E

来源：Animal Reproduction Science, 2016, 174: 87-92.

DOI：10.1016/j.anireprosci.2016.09.009

• Lactation
• Piglet
• Reproduction
• Ractopamine
• Sow

Excessive mobilization of body reserves during lactation delays the return to reproductive function in weaned primiparous sows. This study tested the hypothesis that supplementing the lactation diets of first-parity sows with ractopamine hydrochloride would reduce maternal weight loss and improve subsequent reproductive performance. Gestating gilts were allocated to one of two treatment groups (n = 30 sows/treatment), with one group fed a standard lactation diet (2.5 g/Mcal LYS: DE) throughout lactation (CTRL), whereas the treatment group received the standard lactation diet supplemented with 10 mg/kg ractopamine hydrochloride (RAC) from d 1 to 13 of lactation and 20 mg/kg RAC from d 14 of lactation until artificial insemination (AI). Weaning occurred on d 21 of lactation, with AI occurring at the first post-weaning estrus. Compared to CTRL, RAC supplementation decreased (P < 0.05) liveweight loss between d 13 and 20 of lactation (4.3 +/- 0.90 versus 13 +/- 0.96 kg), and tended to increase (P=0.06) the number of second litter piglets born alive (9.5 +/- 0.52 versus 8.1 +/- 0.74). Treatment (RAC versus CTRL) reduced milk protein levels on d 13 and 20 of lactation (P<0.05), and piglet weight gain between d 13 and 20 of lactation (260 +/- 0.01 versus 310 +/- 0.01 g/day, P< 0.01). In conclusion, it is evident that dietary RAC altered milk composition and stimulated conservation of maternal body reserves during the third week of lactation, resulting in a beneficial effect on subsequent reproductive performance.

• 出版日期2016-11