Evaluation of pea protein concentrate as a source of protein in milk replacers for Holstein calves

Abstract

Thirty pre-ruminant Holstein calves (six males + four females per treatment) were fed three milk replacer diets during the pre-weaning period of 45 days. The control diet (1) was based on skim milk powder as the major source of protein. The test diets (2 and 3) were formulated to contain, on a dry matter (DM) basis, 8.25 and 16.5% pea protein concentrate (PPC) which supplied 30 and 60% of total dietary protein, respectively. These diets were also supplemented with dl-methionine at ∼ 2% of the PPC. Calves were weighed at birth, Day 4 and once a week throughout the experimental period. Average daily gains during 0–45 days of age were significantly higher for calves receiving the control milk replacer diet than those given the diet containing 60% protein from PPC and slightly, but insignificantly ( P > 0.05), higher than those fed the lower level of PPC diet. The apparent digestibility of DM, crude protein (CP) and energy were significantly lower for the milk replacer diet containing 60% protein from PPC than the all-milk protein diet (control) and were similar to that of Diet 2 containing 30% protein from PPC. The digestion coefficient of ether extract (fat) was not significantly different among the three dietary treatments; however, there was a trend for lower fat digestion by the calves receiving the milk replacer containing the highest level of PPC. The data from the present studies indicate that PPC (80% CP) could supply 30% of the protein in milk replacer diets for Holstein calves without markedly affecting the utilization of nutrients and growth performance of pre-ruminant calves. PPC at 60% of the dietary protein appeared to depress the nutrient digestibility and growth of young calves.