Studies on large herds management of high genetic merit dairy cattle: Present problems and methods for settlement
2009
Yokoyama, M.(Fukuoka-ken. Agricultural Research Center, Chikushino (Japan))
(1) Genetic trends of milk production on Holstein cows. To investigate the milk production abilities of Holstein cows in Fukuoka, estimated breeding value (EBV) trends in Fukuoka were compared with averages of those in Hokkaido and all other prefectures. To analyze breeding programs, the EBV of Holstein cows in Fukuoka was classified into six classes by Japanese EBV percentile. (1) EBV of milk yield (kg) and milk composition (kg) in Fukuoka tended to be equal to those in Hokkaido, but higher than the averages in other prefectures. However, EBV of milk composition (%) in Fukuoka tended to be lower than that in Hokkaido. (2) Holstein cows in Fukuoka by EBV of milk yield (kg) and solids-not-fat (%) tended to increase in the top three classes but were less in the sixth class by Japanese EBV percentile; however, Holstein cows in Fukuoka on EBV of milk fat (kg) and milk protein (kg) tended to decrease in the first class by Japanese EBV percentile. The results suggested that the present breeding program in Fukuoka stresses milk yield (kg) rather than milk composition (%). However, from the viewpoint of an effective breeding program in Fukuoka, we propose inseminating semen from sires with high EBV of milk composition (%) characteristics.
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