Departamento de Ciencias Agroforestales, E.U.I.T.A., Universidad de Sevilla, 41013 Sevilla, Spain.
J Dairy Res. 2011 Feb;78(1):32-7. doi: 10.1017/S002202991000083X.
The effects of the caprine α s1-casein (CSN1S1) polymorphisms on milk quality and cheese yield have been widely studied in French and Italian goat breeds. Much less is known about the consequences of κ-casein (CSN3) genotype on the technological and coagulation properties of goat milk. In the current study, we have performed an association analysis between polymorphisms at the goat CSN1S1 and CSN3 genes and milk coagulation (rennet coagulation time, curdling rate and curd firmness) and technological (time to cutting of curd and cheese yield) properties. In this analysis, we have included 193 records from 74 Murciano-Granadina goats (with genotypes constituted by different combinations of alleles B, E and F of the gene CSN1S1 and alleles A and B of the gene CSN3) distributed in three herds, which were collected bimonthly during a whole lactation. Data analysis, using a linear mixed model for repeated observations, revealed significant associations between CSN1S1 genotypes and the rate of the curdling process. In this way, milk from EE goats had a significantly higher curdling rate than milk from BB individuals (P<0·05). Contrary to previous experiments performed in French breeds, cheese yield was not significantly different in BB, EE and EF goats. Moreover, we have shown that CSN3 genotype has a significant effect on the rennet coagulation time (BB>AB, P<0·05) but not on cheese yield. No interaction between the CSN1S1 and CSN3 genotypes was observed.
αs1-酪蛋白（CSN1S1）多态性对法国和意大利山羊品种的牛奶质量和奶酪产量的影响已得到广泛研究。κ-酪蛋白（CSN3）基因型对山羊奶的技术和凝固特性的影响则知之甚少。在本研究中，我们对山羊 CSN1S1 和 CSN3 基因的多态性与牛奶凝固（凝乳酶凝固时间、凝乳速率和凝乳硬度）和技术（凝乳切割时间和奶酪产量）特性之间的关联进行了分析。在该分析中，我们包括了 74 只穆尔西亚-格拉纳迪纳山羊（基因型由 CSN1S1 基因的等位基因 B、E 和 F 和 CSN3 基因的等位基因 A 和 B 的不同组合构成）的 193 个记录，这些记录分布在三个牧场中，在整个泌乳期内每两个月收集一次。使用重复观测的线性混合模型进行数据分析，发现 CSN1S1 基因型与凝乳过程的速率之间存在显著关联。因此，EE 山羊的牛奶凝乳速率明显高于 BB 个体（P<0·05）。与在法国品种中进行的先前实验相反，BB、EE 和 EF 山羊的奶酪产量没有显著差异。此外，我们表明 CSN3 基因型对凝乳酶凝固时间有显著影响（BB>AB，P<0·05），但对奶酪产量没有影响。CSN1S1 和 CSN3 基因型之间没有观察到相互作用。
