Moretti D B, Kindlein L, Pauletti P, Machado-Neto R
1Departament of Animal Science, University of São Paulo, USP/ESALQ, Avenue Pádua Dias, 11, Piracicaba, São Paulo, Brazil.
Animal. 2010 Jun;4(6):933-7. doi: 10.1017/S1751731110000157.
The objective of this study was to evaluate the immunoglobulin G (IgG) absorption by Santa Ines lambs under two colostrum management systems usually used by producers. Twenty-seven Santa Ines newborn lambs received two meals of 250 ml of bovine colostrum from Holstein cows (BC group) or ovine colostrum from Santa Ines ewes (OC group) at 0 and 6 h of life. Pools of BC and OC were analyzed by radial immunodiffusion to quantify IgG. Results are expressed as least-square means and standard errors of mean (means ± s.e.m.). The concentration of IgG in bovine and ovine pools averaged 115.7 ± 20.5 and 48.1 ± 5.0 mg/ml, respectively, levels of concentration found in similar regular colostrum managements. The efficiency of IgG absorption was evaluated under two aspects, maximum apparent efficiency of absorption and total apparent efficiency of absorption (AEAmax and AEAtotal, respectively). The AEAmax was calculated taking into account the mass of IgG ingested just in the first meal of colostrum at birth and the serum IgG concentration at 6 h while the AEAtotal took into account the serum IgG concentration at 24 h of life that reflects the first colostrum offered at birth and the second meal at 6 h. The IgG and apparent efficiency of absorption results were transformed into the square root and log base 10, respectively, and were presented as geometric least-square means. In BC, lower (P < 0.05) AEAmax and AEAtotal were verified (14.2% and 15.6%, respectively), in relation to OC (23.6% and 24.4%, respectively). Serum IgG concentrations at 24 h were significantly higher (P < 0.05) in BC (31.4 mg/ml, respectively) compared with OC (22.2 mg/ml, respectively). The results in this study confirm that there is a limitation to the process of IgG absorption by the enterocytes of newborn lambs, which determined a nonlinear behavior of passive immunity acquisition. Similar values of AEAmax and AEAtotal for the two sources of colostrum reveal that the process of IgG absorption from the first and second meals during the first 6 h of life did not change and indicates that the ingestion of a second feeding of quality colostrum can enhance the acquisition of immune protection of newborn lambs.
本研究的目的是评估在生产者通常使用的两种初乳管理系统下，圣伊内斯羔羊对免疫球蛋白G（IgG）的吸收情况。27只新生的圣伊内斯羔羊在出生后0小时和6小时分别喂食两餐250毫升来自荷斯坦奶牛的牛初乳（BC组）或来自圣伊内斯母羊的羊初乳（OC组）。通过放射免疫扩散分析BC和OC的混合样本以定量IgG。结果以最小二乘均值和均值标准误表示（均值±标准误）。牛初乳和羊初乳混合样本中IgG的浓度平均分别为115.7±20.5毫克/毫升和48.1±5.0毫克/毫升，这是在类似常规初乳管理中发现的浓度水平。从两个方面评估IgG的吸收效率，即最大表观吸收效率和总表观吸收效率（分别为AEAmax和AEAtotal）。计算AEAmax时考虑出生时初乳第一餐摄入的IgG量和6小时时的血清IgG浓度，而AEAtotal考虑出生后24小时的血清IgG浓度，该浓度反映出生时提供的第一餐初乳和6小时时的第二餐初乳。IgG和表观吸收效率结果分别转换为平方根和以10为底的对数，并以几何最小二乘均值表示。与OC组（分别为23.6%和24.4%）相比，BC组的AEAmax和AEAtotal较低（分别为14.2%和15.6%，P<0.05）。24小时时BC组的血清IgG浓度（分别为31.4毫克/毫升）显著高于OC组（分别为22.2毫克/毫升，P<0.05）。本研究结果证实，新生羔羊肠细胞吸收IgG的过程存在局限性，这决定了被动免疫获得的非线性行为。两种初乳来源的AEAmax和AEAtotal相似值表明，出生后前6小时内第一餐和第二餐初乳中IgG的吸收过程没有变化，这表明摄入第二次优质初乳喂养可以增强新生羔羊的免疫保护获得。
