Akköse Mehmet, Özbeyaz Ceyhan, Buczinski Sebastien, Gündoğar Umutcan, Ünal Necmettin
Department of Livestock, Dalaman Agricultural Enterprise, General Directorate of Agricultural Enterprises, Muğla, Türkiye.
Department of Animal Science, Faculty of Veterinary Medicine, Ankara University, Ankara, Türkiye.
Vet Med Sci. 2025 Jul;11(4):e70433. doi: 10.1002/vms3.70433.
This study was aimed at the assessment of the reliability and performance of the Brix refractometer for the determination of colostral IgG concentrations in sheep. A total of 190 colostrum samples were collected from 150 ewes of various breeds. Out of the colostrum samples, 101 were taken at parturition, 10 at 6 h postpartum, 6 at 8 h postpartum, 2 at 10 h postpartum, 65 at 12 h postpartum and 6 at 24 h postpartum. The Brix percentages of the colostrum samples were determined using a Brix refractometer, and the colostral IgG concentrations were measured with the radial immunodiffusion (RID) technique. Correlation coefficients were calculated between the Brix percentages and RID-IgG values. Receiver operating characteristics (ROC) analyses were performed to determine the optimal Brix thresholds for the prediction of colostral IgG concentrations using <20, <50, <75 and <100 g/L thresholds. The misclassification cost term (MCT) analyses were performed to test the robustness of the Brix thresholds based on the relative costs of misclassifications. The mean IgG concentration and Brix percentage of the ewe colostrum samples were determined as 62.7 g/L and 27.2%, respectively. A high correlation was detected between the colostral RID-IgG concentrations and Brix percentages (r = 0.83). Brix percentages of ≤25.0%, ≤25.9%, ≤27.5% and ≤31.9% indicated IgG concentrations of <20, <50, <75 and <100 g/L, respectively. The Brix refractometer was demonstrated to be a low-cost, practical and reliable tool for the determination of colostrum quality in sheep. It is recommended that the four Brix thresholds determined in this study be used strategically in feeding lambs in need of colostral supplementation due to inadequate or poor-quality colostrum production by their dams.
本研究旨在评估用于测定绵羊初乳中免疫球蛋白G（IgG）浓度的糖度折射仪的可靠性和性能。从150只不同品种的母羊中总共采集了190份初乳样本。在这些初乳样本中，101份在分娩时采集，10份在产后6小时采集，6份在产后8小时采集，2份在产后10小时采集，65份在产后12小时采集，6份在产后24小时采集。使用糖度折射仪测定初乳样本的糖度百分比，并采用放射免疫扩散（RID）技术测量初乳中的IgG浓度。计算糖度百分比与RID-IgG值之间的相关系数。进行受试者工作特征（ROC）分析，以确定使用<20、<50、<75和<100 g/L阈值预测初乳IgG浓度时的最佳糖度阈值。进行误分类成本项（MCT）分析，以根据误分类的相对成本测试糖度阈值的稳健性。母羊初乳样本的平均IgG浓度和糖度百分比分别确定为62.7 g/L和27.2%。初乳中RID-IgG浓度与糖度百分比之间检测到高度相关性（r = 0.83）。糖度百分比≤25.0%、≤25.9%、≤27.5%和≤31.9%分别表明IgG浓度<20、<50、<75和<100 g/L。糖度折射仪被证明是一种低成本、实用且可靠的工具，可用于测定绵羊初乳质量。建议将本研究中确定的四个糖度阈值策略性地用于喂养因母羊初乳产量不足或质量不佳而需要初乳补充的羔羊。
