Influence of different levels of dietary protein on serum biochemical parameters of dairy cows during the transition period

Abstract

A study was carried out to find the influence of different dietary protein levels on serum biochemical parameters of dairy cows during the transition period. Twenty cross bred cows, three weeks prior to their expected date of calving were selected from University Livestock Farm and Fodder Research and Development Scheme (ULF&FRDS), College of Veterinary and Animal Sciences, Mannuthy as experimental animals. The cows were randomly allotted to two dietary treatments – T1 (12 per cent CP (crude protein) TMR (Total Mixed Ration)) and T2 (14 per cent CP TMR). After calving, half of the animals in T1 were allotted to T3 (16 per cent CP TMR) and remaining half to T4 (18 per cent CP TMR). Similarly half of the animals in T2 were allotted to T3 and remaining half to T4. All these rations were iso-caloric. The feeding trial was carried out for a period of 3 weeks prepartum and 45 days postpartum. The serum biochemical parameters such as serum glucose levels were significantly higher (p<0.05) for groups receiving treatments T2 & T4 (84.87±2.64 mg/dL) and total protein levels were significantly lower for groups receiving treatments T1 and T3and the levels of all other biochemical parameters under observation remained unaffected in all treatment combinations, but the values of NEFA (non-esterified fatty acids) were below the normal range. Furthermore, there was no occurrence of metabolic diseases in any of the treatment groups, indicating that dietary treatments were sufficient to meet the requirement of the animals. Dietary protein levels did not have any significant effect on serum metabolites studied in the present work.