Joint effects of breed, parity, month of lactation, and cow individuality on the milk fatty acids composition

Abstract

The aim of the study was to explain the effects of four animal factors - breed, parity, cow individuality (within breed phenotypic variation) and month of lactation on the composition of bovine milk fatty acids (FA) in a local dual-purpose Czech Fleckvieh breed as compared to the worldwide dairy Holstein breed. In total, 357 milk samples were analysed from 25 dairy cows of each breed during year-round testing. The variation in the individual FA was affected mainly by cows´ individuality (16-48) and month of lactation (3-18 %). The effects of breed and parity were limited (each about 2%). The animal related factors appeared significant also for FA groups. Greater differences in the explained variation of all factors were observed in the groups classified by the number of FA carbons (35.8, 54.4 and 44.8 % for C4 to C14, C16 and C18 to C24, respectively) and by the number of double bounds (45.4 % and 39.2 % for monounsaturated and polyunsaturated FA, respectively) as well. No differences in the explained variation were observed between the groups of saturated and unsaturated FA (46.8% and 45.9 %, respectively). In conclusion, from the viewpoint of nutrition it would be more convenient to classify FA by the number of carbons than by the usual grouping to saturated/unsaturated FA.