Kielland C, Rootwelt V, Reksen O, Framstad T
J Anim Sci. 2015 Sep;93(9):4453-62. doi: 10.2527/jas.2014-8713.
Colostrum provides newborn piglets with energy and passive immunity and is essential for survival of the piglets. The plasma concentration of immunoglobulin G (IgG) in piglets is dependent on several factors, most importantly the concentration of IgG in sow colostrum (colostrum IgG). The main aims of this study were to investigate the variation in concentration of colostrum IgG between herds and the individual sows within herd and to investigate factors associated with plasma IgG concentrations in piglets (piglet IgG). From 4 herds (A to D), 876 piglets from 62 sows were included in the study. Colostrum was sampled from sows immediately after expulsion of the first piglet and before the first suckling (t1), midway through farrowing (just after the sixth piglet was born; t2), and after the last piglet was born (t3). At d 1, 0.5 mL blood from piglets was collected in tubes containing EDTA, and IgG concentrations were analyzed. Mean colostrum IgG concentration across all herds was 53.9 g/L. Herd A had mean colostrum IgG of 38.3 g/L, whereas the other 3 herds (B,C, and D) had mean colostrum IgG of 47.4, 60.4, and 67.8 g/L, respectively. Colostrum IgG at t1, t2, and t3 across all herds was 56.2, 53.7, and 42.5 g/L, respectively. Mean concentration of piglet IgG across all samplings was 21.7 g/L. Multilevel linear regression analysis was performed with piglet IgG (g/L) as outcome. In this model, the herd effect accounted for 9% of the total variance and 34% of the variance resided at sow level. Piglet IgG was associated with herd, birth order (), body mass index (BMI) > 17 (kg/m), and colostrum IgG at t1 (g/L) with an overall -value < 0.01. Herd D had the highest predicted mean level of piglet IgG. The main model predicted that piglet IgG decreased linearly by 0.4 g/L with each piglet born ( < 0.01). The model also predicted an increase by 0.1 g/L for each gram per liter extra colostrum IgG in colostrum ( = 0.03). Piglets with a BMI above 17 kg/m had a greater piglet IgG (+4.5 g/L) than those with a BMI at 17 kg/m or below ( < 0.01). Concentrations of colostrum IgG varied largely between herds and between sows. The largest variation of piglet IgG was mainly on the piglet level, supporting the complex nature of IgG production and uptake. However, the strong association between colostrum IgG and piglet IgG shows that increased IgG level in colostrum will improve the levels of IgG in piglets and potentially increase survival of the piglets.
初乳为新生仔猪提供能量和被动免疫，对仔猪存活至关重要。仔猪血浆中免疫球蛋白G（IgG）的浓度取决于多个因素，其中最重要的是母猪初乳中IgG的浓度（初乳IgG）。本研究的主要目的是调查不同猪群之间以及同一猪群内个体母猪初乳IgG浓度的差异，并研究与仔猪血浆IgG浓度（仔猪IgG）相关的因素。本研究纳入了来自4个猪群（A至D）的62头母猪所产的876头仔猪。在第一头仔猪产出后且第一次哺乳前（t1）、产仔中期（第六头仔猪出生后；t2）以及最后一头仔猪出生后（t3）立即从母猪采集初乳样本。在第1天，从仔猪采集0.5 mL置于含有乙二胺四乙酸（EDTA）的试管中的血液，并分析IgG浓度。所有猪群的初乳IgG平均浓度为53.9 g/L。猪群A的初乳IgG平均浓度为38.3 g/L，而其他3个猪群（B、C和D）的初乳IgG平均浓度分别为47.4、60.4和67.8 g/L。所有猪群在t1、t2和t3时的初乳IgG分别为56.2、53.7和42.5 g/L。所有采样中仔猪IgG的平均浓度为21.7 g/L。以仔猪IgG（g/L）为结果进行多水平线性回归分析。在该模型中，猪群效应占总方差的9%，34%的方差存在于母猪水平。仔猪IgG与猪群、出生顺序、体重指数（BMI）>17（kg/m）以及t1时的初乳IgG（g/L）相关，总体P值<0.01。猪群D的仔猪IgG预测平均水平最高。主要模型预测，每出生一头仔猪，仔猪IgG线性下降0.4 g/L（P<0.01）。该模型还预测，初乳中每额外增加1 g/L初乳IgG，仔猪IgG增加0.1 g/L（P = 0.03）。BMI高于17 kg/m的仔猪比BMI为17 kg/m或更低的仔猪具有更高的仔猪IgG（高4.5 g/L）（P<0.01）。初乳IgG浓度在不同猪群和不同母猪之间差异很大。仔猪IgG的最大变异主要在仔猪水平，这支持了IgG产生和摄取的复杂性。然而，初乳IgG与仔猪IgG之间的强关联表明，初乳中IgG水平的提高将改善仔猪的IgG水平，并可能提高仔猪的存活率。
