PRODUCTIVE PERFORMANCE OF PURE BREEDS, F₁, F₂ AND F₃ GENERATIONS COWS RAISED IN CENTRAL CATTLE BREEDING AND DAIRY FARM OF BANGLADESH

The data on milk yield of 1837 healthy dairy cows of different genetic groups raised in Central Cattle Breeding and Dairy farms, Savar, Dhaka for the period from 1978 to 1992 were analyzed from first to 6th lactation. The mean (SE) milk yields of 100 days, 305 days, total lactation and total life time ($928{\pm}48.6kg$, $2,188{\pm}201.81kg$, $2,661{\pm}385.46kg$ and $11,134{\pm}2,916kg$) respectively, were in pure bred Friesian found to be highest among all genetic groups. The corresponding means in indigenous cows, $334{\pm}12.92kg$, $946{\pm}64.44kg$, $635{\pm}16.31kg$ and $3,934{\pm}402.21kg$ were the lowest. Among the $F_1$, $F_2$ and $F_3$ cross-breds, the $F_1$ half bred Friesian showed the highest performance in milk yield. The half bred Friesian in successive generations yielded low milk. Similar trend was obtained incase of cross-bred with other breeds such as Jersey, Sindhi and Sahiwal. From the over all results, it can be concluded that the performance in respect to milk yield of pure bred Friesian and their $F_1$ half bred with indigenous and Sahiwal were superior over the $F_2$ or $F_3$ cross-breds between Fresian and any other breed irrespective of proportion of blood. The performance in respect to production of indigenous local cow was found to be almost similar with that of Sahiwal breed.