该实验的动机是需要了解延迟第一次初乳喂养对被动免疫(FTPI)转移失败的患病率的影响。根据出生后初乳喂养延迟,将216名儿童的队列分为几组:0-4小时,4-8小时,8-12小时,和12-16小时。所有孩子都接受了300毫升的一次初乳,喂食后约36小时收集血样。血清免疫球蛋白G(SIgG)采用ELISA法检测,使用Bradford方法和折光法(STPb和STPr)评估血清总蛋白(STP)。像皮尔逊相关性这样的统计方法,Bland-Altman阴谋,和Lin的一致性系数被用来评估SigG之间的关联和协议,STPb和STPr。采用接收器操作员特征分析来确定预测FTPI(SigG<12g/L)的最佳STPb和STPr阈值。随后,曲线下的区域,灵敏度,并检查特异性以评估这些阈值的准确性.我们的结果表明,从出生到初乳摄入每一个小时的延迟(长达16小时),IgG表观吸收效率(AEA)以每小时约2.0%的速率降低,和SigG以大约每小时1.0g/L的速率降低。然而,这种下降并不是随着时间的推移而恒定的,而是随着进食延迟的增加而逐渐加剧。具体来说,IgGAEA每小时减少1.3、2.9和5.9%,在0-4到4-8小时的时间间隔内,SigG的每小时减少0.2、0.3和0.7g,4-8到8-12小时,和8-12到12-16小时,分别。此外,每kgBW的IgG摄入量增加每克,SigG增加1.2g/dL,但IgGAEA减少1.9%.SigG与STPr和STPb的相关性分别为0.62和0.36。预测FTPI的最佳STPr和STPb阈值确定为4.6和6.2g/dL。FTPI的流行,根据SigG,STPr,STPb阈值分别为63%、62%和45%。总的来说,STPr显示出更高的关键性能指标值(即,灵敏度,阳性测试的似然比,整体精度,和Youden\的索引),表明预测能力优于STPb。我们的发现证实了快速初乳管理的关键重要性,理想情况下发生不晚于出生后12小时。此外,我们的研究验证了白利糖度折射计的有效性,评估山羊幼童FTPI的农场方法。
This experiment was motivated by the need to understand the impacts of delaying the first
colostrum feeding on the prevalence of failed transfer of passive immunity (FTPI). A cohort of 216 kids was stratified into groups based on the
colostrum feeding delay postbirth: 0-4 h, 4-8 h, 8-12 h, and 12-16 h. All kids received a single
colostrum meal of 300 mL, and blood samples were collected approximately 36 h after feeding. Serum immunoglobulin G (SIgG) was measured using ELISA, and serum total protein (STP) was assessed using the Bradford method and refractometry (STPb and STPr). Statistical methods like Pearson correlations, Bland-Altman plots, and Lin\'s concordance coefficient were employed to assess associations and agreements between SIgG, STPb and STPr. Receiver operator characteristic analysis was employed to determine optimal STPb and STPr thresholds for predicting FTPI (SIgG < 12 g/L). Subsequently, areas under the curve, sensitivity, and specificity were examined to assess the accuracy of these thresholds. Our results showed that for each hour\'s delay from birth to
colostrum intake (up to 16 h), IgG apparent efficiency of absorption (AEA) decreases at an approximate rate of 2.0% per hour, and SIgG decreases at an approximate rate of 1.0 g/L per hour. However, this decline is not constant over time but intensifies progressively with increased feeding delay. Specifically, reductions in IgG AEA were 1.3, 2.9, and 5.9% per hour, and decreases in SIgG were 0.2, 0.3, and 0.7 g per hour for SIgG across the time intervals of 0-4 to 4-8 h, 4-8 to 8-12 h, and 8-12 to 12-16 h, respectively. Additionally, there was an increase in SIgG of 1.2 g/dL but a decrease in IgG AEA of 1.9% for each gram per kg of BW increase in IgG intake. The correlations between SIgG and STPr and STPb were 0.62, and 0.36, respectively. Optimal STPr and STPb thresholds predicting FTPI were determined to be 4.6 and 6.2 g/dL. The prevalence of FTPI, according to SIgG, STPr, and STPb thresholds were 63, 62, and 45%. Overall, STPr showed higher values for key performance metrics (i.e., sensitivity, likelihood ratio of positive tests, overall accuracy, and Youden\'s index), indicating better prediction ability than STPb. Our findings corroborate the critical importance of swift
colostrum administration, ideally occurring no later than 12 h postbirth. Moreover, our research validates the effectiveness of Brix refractometry as a practical, on-farm method for assessing FTPI in goat kids.