Milk production of imported Holstein cows over different environment

Indonesia is importing genetically superior Friesian Holstein (FH) cows as breeding stocks for domestic dairy cattle population. The milk production of these imported cows, however, are very much affected by temporary environmental effect due to the habitat changes and transportation. This study aimed to observe the consistency of milk production of imported cows viewed from the repeatability estimates. In total, milk yield records on lactation one (L1), two (L2) and three (L3) of 70 imported FH cattle were obtained from Baturaden Dairy Cattle Breeding Centre. The repeatability values were estimated with intraclass correlation method utilizing information from three lactation periods. Milk yield decreased over lactation periods which were 6077.55 +/- 1239; 4821.79 +/- 888 and 4374.6 +/- 1012 kg for L1, L2, and L3 respectively. The repeatability of milk yield trait in this population was 0.41. It indicates 59% of the variation in milk yield is controlled by the unknown error term, including temporary environmental effects. Imported cows undergone extreme adaptation processes to be able to live optimally in a new environment which would modify their physiology. We suspect environmental changes and resource differences between tropical and subtropical climates triggers different trait expression as the explanation of the phenomenon.