Tanzania Journal of Agricultural Sciences 2002, Vol. 5(2) : 81·90
The effect of urea-molasses-multinutrient blocks (UMMB) as an energy and protein supplement on reproductive performance and milk yield of dairy cows was investigated in 18 crossbred cows from eight smallholder farms. In treatment 1 nine, cows were fed a maximum of 1 kg (UMMB per cow per day in addition to the routine feeds forage and maize bran) and in treatment 2 (control) nine cows were fed routine feeds only. The experiment started 4 weeks pre-partum and lasted for 120 days postpartum. Onset of ovarian activity was monitored through progesterone in 612 sequentially collected milk samples and rectal palpation. In treatment 1. the intervals between calving to completion of uterine involution, first rise of milk progesterone, occurrence of first oestrus and conception were (mean ±se) 24±7. 65.3±8. 99.7±12.8 and 120.2±10 days. respectively. In treatment 2. the intervals were 29.6±5. 77. 6±9. 115,9±l5 and 133. 7±14 days. respectively. The treatment differences were not significant (P> 0. 05). Milk production in treatment 1 increased significantly by 1.21 (P<0.001) while in treatment 2 it decreased by 0. 21. Body condition score (BCS) improved significantly by 0.15 (P<0.05) in treatment 1 compared to treatment 2 cows. Use of UMMB gave an overall profit of US$ 0. 34 per day of lactation from sale of milk that resulted from increased yield and milk due to shortened days open. It was concluded that dry season improvement of reproductive and productive performance of dairy cows under smallholder farms could be cost effectively achieved through supplementation with urea-molasses-multinutrient blocks.