Santillo Antonella, d'Angelo Francesca, Lamberti Cristina, Giuffrida Maria Gabriella, Romaniello Francesco, Albenzio Marzia
Department of Agricultural Sciences, Food, Natural Resources and Engineering, University of Foggia, 71122 Foggia FG, Italy.
Department of Agricultural Sciences, Food, Natural Resources and Engineering, University of Foggia, 71122 Foggia FG, Italy.
J Dairy Sci. 2025 Jun;108(6):5570-5579. doi: 10.3168/jds.2025-26317. Epub 2025 Mar 24.
The aim of the study was to evaluate β-CN variants and their effects on milk nutritional composition and protein profile in Podolian cattle breeds reared in Gargano Promontory (Southern Italy). Individual milk samples of Podolian and Holstein Friesian (HF) cattle were analyzed for β-CN allele and genotype frequencies, chemical composition, and protein fractions of milk. In both populations, the most common allelic variant was A2, followed by A1, whereas alleles B and I had frequencies lower than 10% in both populations. A total of 6 genotypes in Podolian population (A1A2, A1B, A2B, A1I, A2I, A2A2), and 7 genotypes (A1A1, A1A2, A1B, A2B, A1I, A2I, A2A2) in HF were detected. Milk protein, lactose, and casein percentages were affected by β-CN allele in both breeds. In particular, alleles A1 and A2 resulted in higher levels of both protein and casein in HF, whereas in Podolian, allele I showed the highest, alleles A1 and A2 intermediate, and B the lowest levels of the mentioned parameters. Protein fractions were influenced by β-CN alleles, and the most abundant protein fractions were β- and α-CN in both breeds, although with different percentage distribution. In Podolian milk, regardless of the detected allele, a similar behavior was observed for β- and κ-CN, and opposite to that observed for α-CN. The study of the genetic variability of milk proteins offers the opportunity to valorize the nutritional, technological, and functional features of Podolian cattle dairy productions as a strategy to sustain the economic value of this ancient breed which is well adapted to the farming systems in marginal areas.
本研究的目的是评估在意大利南部加尔加诺岬饲养的波多利牛品种中β-酪蛋白（β-CN）变体及其对牛奶营养成分和蛋白质谱的影响。对波多利牛和荷斯坦弗里生牛（HF）的个体牛奶样本进行了β-CN等位基因和基因型频率、化学成分以及牛奶蛋白质组分的分析。在这两个群体中，最常见的等位基因变体是A2，其次是A1，而等位基因B和I在两个群体中的频率均低于10%。在波多利牛群体中总共检测到6种基因型（A1A2、A1B、A2B、A1I、A2I、A2A2），在HF群体中检测到7种基因型（A1A1、A1A2、A1B、A2B、A1I、A2I、A2A2）。两个品种的牛奶蛋白质、乳糖和酪蛋白百分比均受β-CN等位基因影响。具体而言，等位基因A1和A2导致HF的蛋白质和酪蛋白水平较高，而在波多利牛中，等位基因I显示出最高水平，等位基因A1和A2为中等水平，B为上述参数的最低水平。蛋白质组分受β-CN等位基因影响，两个品种中最丰富的蛋白质组分均为β-酪蛋白和α-酪蛋白，尽管百分比分布不同。在波多利牛奶中，无论检测到何种等位基因，β-酪蛋白和κ-酪蛋白的行为相似，与α-酪蛋白相反。对牛奶蛋白质遗传变异性的研究为提升波多利牛乳制品的营养、技术和功能特性提供了机会，以此作为维持这个适应边缘地区养殖系统的古老品种经济价值的策略。
