Abstract:
Sixty-four dairy cows (B taums x B indicus crosses) belonging to 40 peri-urban smallholder farms were investigated for relationship of their blood metabolites, body condition score (BCS) and body weight to milk yield and reproductive performance. Feed availability and quality were monitored monthly. Plasma concentrations of selected metabolites [albumin globulin beta-hydroxybutyrate (BHB) inorganic phosphorus urea] and packed cell volume (PCV) were measured at one month before calving at 30 days and 60-90 days postpartum (DPP). Milk yield BCS and body weight were taken once a month. The reproductive status was monitored by measuring milk progesterone (P4) concentrations and rectal palpation. Average daily food intake was 98=0.3 kg DM/day. Cows calved in good BCS (4-6) had mean milk yield between 6. 4±0. 44 and 7.3±0.66 L day in the first 90 days of lactation and delayed calving to conception interval (126.1 ± 6. 3 days) There was no relationship between apparent feeding level and therefore change in body weight and BCS with milk yield and reproductive performance (P>0.0.5). The mean body weight and BCS dropped within one month after calving which gradually recovered within the second month postpartum. A large proportion of cows (22-38%) had low PCV values (<27%) before calving to 60-90. DPP an indication of anaemia possibly due to low feed intake and probably diseases. Blood metabolite values remained more or less constant before calving and during the first 60-90. DPP 24% of cows had high BHB values (1 nmol L) before calving indicating a negative energy balance in late gestation. Globulin levels were high (50. g L) in 20% of the cows during the 60-90 DPP period suggesting probably an inflammatory reaction within the body. The differences between metabolite concentration among animals were small and they were not significantly related to productive and reproductive performance (P<.0.5). The use or metabolic profile testing identified under-nutrition as the potential constraint to productivity in dairy cows in smallholder farms in Morogoro.
