Abstract In a scenario of climate change and risk of losing biodiversity, the safeguard of locally adapted breeds and their genetic reservoirs assumes a key role. Furthermore, these breeds are linked to their rearing territory maintenance also through the nutritional, economic or social value of their products. This study focussed on the analysis of milk protein genetic variability of the Piedmontese, the most abundant beef Italian breed, and the Barà-Pustertaler breed, through the testing of individual milk samples by isoelectrofocusing. Allelic and haplotypes frequencies were analysed and the presence of rare variants (CSN1S1*G, 0.7%, and CSN2*C, 0.7%, in Barà and Piedmontese breeds, respectively) was detected. The analysed breeds showed allelic frequencies close to the one found in breeds with good cheesemaking aptitude, like the Italian Brown and Reggiana breeds (e.g. CSN2*B, 20.7% and 16.4%, and CSN3*B, 41,1% and 35%, in Piedmontese and Barà breeds, respectively), and are a good reservoir of alleles that are decreasing (e.g. CSN2*B) in Italian Holstein. Moreover, they have higher frequencies of interesting haplotypes (e.g. BA1B, 8% and 11.2%, and BA2B, 20.8 and 13.1% in Piedmontese and Barà breeds, respectively) that could positively influence composition, nutritional, and technological properties of milk. These breeds could be used to further investigate the effects of variants and haplotypes that could help support the evolution and the changing demands of the dairy sector. Highlights In order to address the problem of climate change effects on animal biodiversity, local breeds should be safeguarded and valorised. The analysed breeds have discrete frequencies of milk protein variants and casein haplotypes associated with good technological properties. Knowing the genetic background of non-dairy commercial breeds is the first step to preserve potentially useful genetic variability.

中文翻译：

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皮埃蒙特地区两个牛品种牛奶蛋白质的遗传变异及其对牛奶质量的潜在影响

摘要 在气候变化和生物多样性丧失风险的情况下，保护当地适应品种及其遗传库发挥着关键作用。此外，这些品种还通过其产品的营养、经济或社会价值与其饲养领土的维护相关联。本研究的重点是通过等电聚焦测试单个牛奶样品，分析皮埃蒙特牛（最丰富的意大利牛肉品种）和 Barà-Pustertaler 品种的牛奶蛋白遗传变异性。分析了等位基因和单倍型频率，并检测到稀有变异的存在（在 Barà 和 Piedmontese 品种中，分别为 CSN1S1*G，0.7% 和 CSN2*C，0.7%）。分析的品种显示等位基因频率接近具有良好奶酪制作能力的品种中发现的频率，像意大利的 Brown 和 Reggiana 品种（例如 CSN2*B，20.7% 和 16.4%，以及 CSN3*B，分别为 41.1% 和 35%，在 Piedmontese 和 Barà 品种中），并且是良好的等位基因库在意大利荷斯坦中减少（例如 CSN2*B）。此外，它们具有更高频率的有趣单倍型（例如 BA1B，8% 和 11.2%，以及 BA2B，分别在 Piedmontese 和 Barà 品种中为 20.8 和 13.1%），可以对牛奶的成分、营养和技术特性产生积极影响。这些品种可用于进一步研究变异和单倍型的影响，这有助于支持乳制品行业的进化和不断变化的需求。要点 为了解决气候变化对动物生物多样性的影响问题，应保护和保护当地品种。分析的品种具有与良好技术特性相关的乳蛋白变体和酪蛋白单倍型的离散频率。了解非乳制品商业品种的遗传背景是保留潜在有用遗传变异性的第一步。