Agriculture and Agri-Food Canada, Dairy and Swine R & D Centre, 2000 College St., Sherbrooke, Québec J1M 0C8, Canada.
J Anim Sci. 2012 Nov;90(11):3743-51. doi: 10.2527/jas.2012-5127. Epub 2012 Jun 4.
The impacts of a teat being suckled or not in first parity on its development, gene expression, and milk yield in the next parity were studied. Forty-seven first-parity sows (Sus scrofa) were divided into 2 groups: i) the same teats suckled in 2 subsequent lactations (controls, CTL; n = 22); and ii) different teats suckled in 2 subsequent lactations (treated, TRT; n = 25). In the first lactation, over half of the teats (Teats 1, 2, 5, 6, and 7 from 1 side of the udder, and Teats 3, 4, and 7 from the other side) were sealed with tape so that they were nonfunctional. During the next lactation, the CTL group had the same teats sealed as in the first lactation, whereas the opposite teats were sealed for the TRT group. In both parities, litters were standardized to 7 piglets around birth and to 6 piglets (1 piglet per available teat) at 48 h postpartum. During the second lactation, piglets were weighed at birth and on d 2, 4, 7, 14, 21, 35, and 56 postpartum. Weaning was at 17 ± 1 d of age. Behavioral measures were obtained (using 24-h video recording) on d 3 and d 10 of lactation on 15 sows per treatment to evaluate satiety of piglets, using aggressiveness and nursing behavior as indicators. At weaning in the second lactation, 16 sows per treatment were slaughtered and 4 functional mammary glands were collected for compositional analyses and parenchyma from 2 nonfunctional glands was collected to measure mRNA abundance for selected genes. Piglets from CTL sows weighed 1.12 kg more than piglets from TRT sows (P < 0.05) on d 56, and functional mammary glands from CTL sows contained more parenchymal tissue, more DNA, and more RNA (P < 0.01) than those from TRT sows. The relative mRNA abundance of prolactin in parenchymal tissue tended to be greater in CTL than TRT sows (P < 0.10). Behavioral measures indicated a greater hunger level for piglets using teats that were not previously suckled. Current findings clearly show that teats that were suckled in first lactation produce more milk and have a greater development in the second lactation than nonsuckled teats.
研究了第一胎中是否让奶头被吮吸对下一胎的发育、基因表达和产奶量的影响。将 47 头第一胎母猪（Sus scrofa）分为 2 组：i）在随后的两次泌乳中使用相同的奶头（对照组，CTL；n = 22）；ii）在随后的两次泌乳中使用不同的奶头（处理组，TRT；n = 25）。在第一次泌乳中，超过一半的奶头（一侧乳房的奶头 1、2、5、6 和 7，以及另一侧乳房的奶头 3、4 和 7）用胶带密封，使其无法使用。在下一次泌乳中，CTL 组的奶头与第一次泌乳时相同，而 TRT 组的奶头则相反。在这两个泌乳期，仔猪在出生时标准化为 7 头，在产后 48 小时标准化为 6 头（每一个可用的奶头 1 头）。在第二次泌乳期间，仔猪在出生时和产后 2、4、7、14、21、35 和 56 天称重。断奶时间为 17 ± 1 日龄。在处理组的 15 头母猪上，在泌乳的第 3 天和第 10 天进行了 24 小时视频记录，以评估仔猪的饱腹感，用攻击性和哺乳行为作为指标。在第二次泌乳的断奶时，每组 16 头母猪被屠宰，4 个功能性乳腺被收集用于组成分析，从 2 个非功能性乳腺中收集的组织用于测量选定基因的 mRNA 丰度。CTL 组的仔猪在第 56 天比 TRT 组的仔猪重 1.12 公斤（P < 0.05），CTL 组的功能性乳腺组织含有更多的实质组织、更多的 DNA 和更多的 RNA（P < 0.01）。组织中催乳素的相对 mRNA 丰度在 CTL 组中比 TRT 组中更倾向于增加（P < 0.10）。行为措施表明，使用以前未被吮吸过的奶头的仔猪饥饿程度更高。目前的研究结果清楚地表明，在第一胎中被吮吸过的奶头在第二胎中产生的乳汁更多，发育得更好。
