Milk traits and polymorphism of alfa S1 casein in Balkan breed of goats
2003
Markovic, B.
Milk traits (duration of lactation, milk yield and chemical composition of milk) of Balkan goat in Montenegro (Serbia&Montenegro) were investigated during two-year period. Total number of 419 doers distributed in four flock, every of them is from different regions, was included into investigation. In order to estimate the effect of non genetic parameters on variation of these traits, the mixed model methodology was applied. Based on 529 completed lactations, which duration was 204 days in average, average milk yield was 140.54 litres. Variation of average milk yield was affected significantly (P0.01) by fixed effects such as flock and subsequent lactation, but not by strains of goats. Average daily milk yield was 0.638 litres, and it was determined on 3221 individual measurements during regular milk recording procedure. Based on the same number of the samples (3221) of milk fat percentage was 3.38%, protein 3.30% and solids non fat 8.38%. These traits were significantly (P0.01) affected by fixed effect of flock and lactation (daily milk yield and solids non fat only), as well as the random regression effect of animal, test day and interaction of flock x test day. By applying sequencing method of particular regions of DNA of 97 goat samples, genotypes of alfa S1 casein were determined. Two gene alleles (A and F), with frequency of 0.66 and 0.34, respectively, and three genotypes (AA, AF and FF) with frequency 0.39; 0.47 and 0.14, respectively were obtained. Genotype of alfa S1 casein significantly (P0.01) affected protein content and solids non fat in milk, as well as the fat content (P0.05), but not average daily gain of milk, Doers with AA genotype of alfa S1 casein had the highest protein content, then AF and FF genotypes followed. In case of fat content and solids non fat a rank was the following: AAFFAF, while rank for the average daily milk yield was AAAFFF.
显示更多 [+] 显示较少 [-]