INRA, UMR1079 Systèmes d'Elevage Nutrition Animale et Humaine, F-35590 Saint-Gilles, France.
J Anim Sci. 2010 May;88(5):1672-83. doi: 10.2527/jas.2009-2562. Epub 2010 Jan 29.
Relationships between hormonal and metabolic changes around parturition and colostrum yield and composition were investigated in 16 Landrace x Large White primiparous sows. Blood samples were taken daily from d 105 of pregnancy to d 2 postpartum (with d 0 being the day of parturition). Colostrum samples were taken at the onset of parturition (T0), and then 3, 6, and 24 h later (T3, T6, and T24, respectively). Colostrum yield was calculated from the beginning of parturition until 24 h later by adding colostrum intake of individual piglets, which was estimated from their BW gain. Colostrum yield averaged 3.22 +/- 0.34 kg. Four sows had very low colostrum production (1.10 +/- 0.12 kg; n = 4), whereas the others produced between 2.83 and 4.64 kg of colostrum (3.93 +/- 0.16 kg; n = 12). Compared with the high-colostrum-producing sows, the low-colostrum-producing sows tended (P < 0.1) to have greater plasma concentrations of progesterone during the 20-h prepartum and tended (P < 0.1) to have smaller plasma concentrations of prolactin 40 and 30 h before parturition. Sows with a low colostrum yield had greater plasma concentrations of glucose than sows with a high colostrum yield from d -9 to -2 (P < 0.05). At the onset of parturition, colostrum from low-producing sows had greater percentages (P < 0.01) of DM, lipids, and GE, but less (P < 0.05) lactose, than that from high-producing sows. The Na:K ratio in colostrum during the 6 h postpartum was greater (P < 0.01) in low-producing sows than in high-producing sows, indicating that cellular junctions between epithelial mammary cells were less tightly closed. Concentrations of IgG in colostrum varied greatly between sows and decreased by approximately 80% between T0 and T24. Within high-producing sows, concentrations of IgG in colostrum at T0, T3, and T6 were negatively correlated (P < 0.05) with lactose concentrations in colostrum at the same times and were positively correlated (P < 0.05) with plasma concentrations of IGF-I measured from d -9 to 0. In contrast, no correlation (P > 0.1) was found between IgG concentrations in colostrum at any time and prolactin, estradiol-17beta, progesterone, or cortisol. In conclusion, sows that produced a low yield of colostrum were characterized by a leaky mammary epithelium and reduced synthesis of lactose, related to delayed hormonal changes before parturition.
在 16 头长白 x 大约克初产母猪中研究了分娩前后激素和代谢变化与初乳产量和成分之间的关系。从妊娠第 105 天（d105）到产后第 2 天（d0 为分娩当天），每天采集血液样本。在分娩开始时（T0）采集初乳样本，然后在 3、6 和 24 小时后（分别为 T3、T6 和 T24）采集。通过添加个体仔猪的初乳摄入量来计算从分娩开始到 24 小时后的初乳产量，初乳摄入量估计来自仔猪的 BW 增加。初乳产量平均为 3.22 +/- 0.34 公斤。有 4 头母猪的初乳产量非常低（1.10 +/- 0.12 公斤；n = 4），而其他母猪的初乳产量在 2.83 到 4.64 公斤之间（3.93 +/- 0.16 公斤；n = 12）。与高初乳生产母猪相比，低初乳生产母猪在分娩前 20 小时有更高的孕酮浓度（P < 0.1），并且在分娩前 40 和 30 小时有更小的催乳素浓度（P < 0.1）。从 d-9 到 -2 时，低初乳产量的母猪的血糖浓度高于高初乳产量的母猪（P < 0.05）。在分娩开始时，低产母猪的初乳具有更高的 DM（P < 0.01）、脂质和 GE 百分比，但乳糖含量较少（P < 0.05），高于高产母猪。产后 6 小时初乳中的 Na:K 比值在低产母猪中高于高产母猪（P < 0.01），表明上皮乳腺细胞之间的细胞连接不那么紧密。初乳中 IgG 的浓度在母猪之间差异很大，并且在 T0 和 T24 之间减少了约 80%。在高产母猪中，T0、T3 和 T6 时初乳中 IgG 的浓度与同一时间初乳中乳糖的浓度呈负相关（P < 0.05），与从 d-9 到 0 测量的 IGF-I 的血浆浓度呈正相关（P < 0.05）。相比之下，在任何时间的初乳中 IgG 的浓度与催乳素、雌二醇-17β、孕酮或皮质醇之间没有相关性（P > 0.1）。总之，初乳产量低的母猪的特点是乳腺上皮通透性增加，乳糖合成减少，这与分娩前激素变化延迟有关。
