Long-term evaluation of milk production and reproductive performance of dairy cattle at Alemaya
1998
Moges Dereje (Alemaya University of Agriculture, Dire Dawa (Ethiopia))Robert Baars (Alemaya University of Agriculture, Dire Dawa (Ethiopia))
Milk records (987 completed lactations) were analyzed to compare the performance of pure Holstein-Friesian (HF) with HF x Boran crossbred dairy cattle (50% of Boran crosses with higher level of HF). The effects of lactation number, season of calving on milk production and reproductive parameters as well as year differences were assessed. The milk production of 7/8 and pure HF was significantly higher than that of 1/2 and 3/4 HF crossbreds. Average daily milk yields of the breed groups ranged from 9 to 12 kg, whereas the average yield per lactation ranged from 2314 to 3876 kg. Cows in the 3rd and 4th lactations showed the highest milk production. Season of calving had no effect on milk production. A general tendency of decline in daily and lactation yield per cow was observed over the years. The age at first calving increased by 11 months during the study period from 31 to 42 months. No differences in reproductive parameters were observed among HF and their crosses, lactation numbers and season of calving. It was concluded that a change in forage and nutrition management is required to increase milk production levels.
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