BLOOD PROTEIN CONCENTRATIONS IN SMALLHOLDER JERSEY COWS.

Smallholder production systems often lack feed sources with sufficient nutrients to support milk production. Of particular significance is the level of protein in the diets during early lactation. The authors referenced below therefore investigated a scenario of this kind by measuring serum protein concentration of pre-calving and early lactation Jersey cows kept under semi-intensive management on smallholder farms.

They selected 20 each late pregnant Jersey heifers reared under semi-intensive feeding systems in the semi-arid districts of Vhembe and Sekhukhune in Limpopo. They were fed a standard pre-calving dry cow pelleted supplement of 4kg per head per day and after calving 6kg per head per day of a standard dairy meal plus ad lib access to Eragrostis curvula hay and fresh water. The pelleted supplement contained 12.2% crude protein (CP) and 60% neutral detergent fibre (NDF) in the dry matter and the dairy meal 13.6% CP and 46% NDF. Blood samples were collected at 21 days pre-calving and 32 and 75 days post-calving from all 40 cows.

The Vhembe cows had higher pre-calving serum total protein (78.4g per litre), albumin (39.1g per litre) and blood urea nitrogen (5.9mmol per litre) than Sekhukhune cows (respectively, 72.6g per litre, 41.5g per litre and 4.8mmol per litre). Pre-calving serum creatinine , total globulin and the albumin to globulin ratio did not differ between cows of the two districts and also not the total serum globulin and the albumin to globulin ratio post-calving. However, the 32 day post-calving creatinine levels were lower for Vhembe district cows. Usually one associates low total blood protein and creatinine post-calving with a negative energy balance, but although lower in Sekhukhune cows, the values were still within the reference acceptable range. Total blood protein was low reflecting the lower than requirement CP of the total diet (supplement plus hay). Creatinine was also relatively low. It normally reflects kidney functionality, therefore it appears that functionality was compromised because of lower overall nutrient intake and management stress, resulting in sub-optimal milk yield.

Reference:

T.W. Kekana, F.V. Nherera-Chokuda, K.C. Lehloenya, C.M. Muya and K.M. Manyama, 2016. Serum protein concentrations in peri-partum and early lactation primiparous Jersey cows on smallholder farms in Limpopo Province. In: Proc. 49^th Annual Conf. SASAS, Stellenbosch, 4-7 July 2016.