Milk yield and reproductive performance of Borana cows and growth rate of their calves under partial suckling method

The experiment was conducted to study the effects of partial suckling and non-suckling system for cows previously recorded to produce high or low milk yield under non suckling system on their subsequent milk yield, reproductive performance, pre-weaning growth rate and survival of their calves. A total of 39 cows, (23 in second and 13 in third parity) were used for the study in 2 x 2 factorial design based on their milk production (high or low) and calf suckling method (partial suckling or non-suckling). Level of milk production and suckling method markedly (p0.001) affected average daily and total milk yields, growth rate of calves, postpartum anostrus interval (PPAI) and days open (DO). The interaction effect between the yield group and the suckling method was significantly high (p0.001). Daily and total milk yield of low yielding suckling (LYS) was 117%) and 102% respectively higher than that of low yielding non-suckling (LYNS). Daily and total milk yield of high yielding suckling (HYS) was 34.6% and 45.6% respectively higher than that of low yielding non-suckling (HYNS). Partial suckling resulted in increase of 82.5% of the daily milk yield and 56.7% of total milk yield of low yielding cows over the non-suckling once. Weaning weight and average daily weight gains of calves to 90, 120 and 150 days of age were significantly (p0.001) different among treatments. The overall least squares mean weaning weight (90 days), average daily weight gains up to 90, 120 and 150 days of age were 79.4 plus or minus 2.7 kg 585.2 plus or minus 25.5, 612.9 plus or minus 22.3, and 639.3 plus or minus 20.9 respectively. Partial suckled calves grew at a faster (p0.001) rate than the non-suckled calves. Suckling significantly (p0.05) affected PPAI and Do. PPAI and DO were prolonged (156 days for both) for cows under HYS and the shorter (81 and 104 days) for cows in HYNS, respectively. From the results of this study it can be concluded that milk production potentials of Borana cows could be estimated more than the previous reports as cows previously reported to be low yielder had produced high milk yield when partial-suckling system is applied. Partial suckling improved milk production and calf growth rate. Borana cows are used as dam breed in the cross breeding program to improve milk production. The practice therefore, could be used to rear F1 crossbred calves, as an option to accelerate heifer-rearing methods. The compromise between its impact on reproduction, its advantage on production traits, and economic implications could be the objectives of further study.