INRA, UMR1079 Systèmes d'Elevage Nutrition Animale et Humaine, F-35590 Saint-Gilles, France.
J Anim Sci. 2011 Oct;89(10):3048-59. doi: 10.2527/jas.2010-3507. Epub 2011 Apr 29.
Hormonal changes involved in the farrowing process partly control the initiation of lactation. Inducing farrowing by injection of PG may alter the normal prepartum hormonal cascade. The aim of the study was to investigate the consequences of farrowing induction on colostrum yield and composition, as well as newborn piglet growth. Gilts were treated with 2 mg of alfaprostol on d 113 of gestation (induced farrowing, IF, n = 9) or were injected with 1 mL of a saline solution (natural farrowing, NF, n = 11). Colostrum production was estimated during 24 h, starting at the onset of parturition, based on piglet BW gains. Colostrum samples were collected during the 36 h after the onset of parturition. Blood samples were collected from sows as of d 112 of pregnancy until d 2 postpartum (d 0 being the day of parturition). Piglet blood samples were obtained at birth, on d 1, and on d 21. Litter size and litter weight at birth did not differ between groups (P > 0.10). Farrowing induction did not influence (P > 0.10) colostrum yield (3.96 ± 0.20 kg) or piglet BW gain during d 1 postpartum (116 ± 8 g). At the onset of farrowing (T0), lactose content in colostrum was greater in IF sows than in NF sows (P < 0.05), whereas colostrum ash and protein contents were less (P < 0.05) in IF sows. Concentrations of IgG in colostrum were similar in both groups of sows, whereas concentrations of IgA at T0 were less in IF than in NF sows (P < 0.01). Overall, endocrine changes in blood from d -2 until d 2 (cortisol, prolactin, progesterone, and estradiol-17β) were not altered by farrowing induction (P > 0.10), but 1 h after the injection of alfaprostol, IF sows had greater circulating concentrations of prolactin (P < 0.01) and cortisol (P < 0.10) than NF sows. The greater concentration of lactose in colostrum from IF sows could be attributed to this transient increase in prolactin and cortisol. At birth, concentrations of white blood cells were less in piglets born from IF sows (P < 0.01). On d 1 and 21, piglets from IF sows had similar IgG concentrations in plasma to piglets from NF sows (P > 0.1). In conclusion, farrowing induction at 113 d of pregnancy induced transient hormonal changes in sows and alterations in colostrum composition, without significantly affecting colostrum yield. It also modified some hematological variables of piglets at birth.
分娩过程中的激素变化部分控制着泌乳的开始。通过注射 PG 诱导分娩可能会改变正常的产前激素级联。本研究的目的是研究诱导分娩对初乳产量和成分以及新生仔猪生长的影响。妊娠第 113 天，母猪分别接受 2 毫克 alfaprostol（诱导分娩，IF，n=9）或 1 毫升生理盐水（自然分娩，NF，n=11）处理。根据仔猪 BW 增重，从分娩开始后 24 小时内估计初乳产量。分娩后 36 小时内收集初乳样本。从妊娠第 112 天开始到产后第 2 天（分娩当天为 d0）采集母猪血液样本。仔猪在出生时、第 1 天和第 21 天采集血液样本。两组的产仔数和产仔重无差异（P＞0.10）。诱导分娩并未影响（P＞0.10）初乳产量（3.96±0.20kg）或产后第 1 天仔猪 BW 增重（116±8g）。在分娩开始时（T0），IF 母猪的初乳中乳糖含量高于 NF 母猪（P＜0.05），而 IF 母猪的初乳灰分和蛋白质含量较低（P＜0.05）。两组母猪的初乳 IgG 浓度相似，而 IF 母猪在 T0 时的 IgA 浓度较低（P＜0.01）。总的来说，从 d-2 到 d2（皮质醇、催乳素、孕酮和雌二醇-17β）的血液内分泌变化不受分娩诱导的影响（P＞0.10），但在 alfaprostol 注射后 1 小时，IF 母猪的催乳素（P＜0.01）和皮质醇（P＜0.10）循环浓度高于 NF 母猪。IF 母猪初乳中乳糖浓度的增加可能归因于催乳素和皮质醇的短暂增加。在出生时，IF 母猪所产仔猪的白细胞浓度较低（P＜0.01）。在第 1 天和第 21 天，IF 母猪所产仔猪的血浆 IgG 浓度与 NF 母猪所产仔猪相似（P＞0.1）。总之，妊娠第 113 天诱导分娩会引起母猪的短暂激素变化，并改变初乳成分，而不会显著影响初乳产量。它还改变了出生仔猪的一些血液学变量。
