Milk Production and Reproductive Efficiency in Friesian and Friesian X Sharabi Cows

Abstract

The reproductive efficiency was estimated from records of 104 Friesian and 48 crossbreed [Friesian X Sharabi (native breed)] cows. Functional traits interm of reproductive efficiency as well as age at first calving were studied with relation with milk production in both breeds. The trends of the average milk production and reproductive efficiency at different age groups at first calving were estimated. Likewise, the average reproductive efficiency and age at first calving at different groups of milk production were determined. With increase in milk production there were decrease in reproductive efficiency and age at first calving. When the average milk production was related with age at first calving in both Friesian and crossbreed there are an increase in reproductive efficiency with increase age at first calving while milk production decreased. There were significant difference (P<0.05) in average milk production and age at first calving between Friesian and crossbreed, while the difference was not significant for average reproductive efficiency, they were 84.04% and 83.17% respectively for Friesian and crossbreed.The Pearson correlation coefficient as well as partial correlation coefficient between milk production and age at first calving was negative and significant in both breeds. Likewise, between milk production and reproductive efficiency was negative in both breeds and significant in Friesian only. On other hand, Pearson correlation and partial correlation coefficients between reproductive efficiency and age at first calving were positive and significant in both breeds.It can be concluded that for improving efficiency in Friesian and crossbreed cattle, it is necessary that functional traits interims of reproductive efficiency and age at first calving deserve primary consideration beside milk production into national breeding programmers.