[Protein utilization of mixed feed rations in the lactating pig with reference to the essential amino acid content of the feed proteins. 1. Report. Description of the study methods for protein utilization in the use of peanut extraction residues and dry skim milk in the ration].

A method is discussed which has been used to investigate protein utilization in lactating sows. Two N balance trials were carried out to establish the degree of protein utilization of mixed feed rations. The rations contained barley, oats and flaked potatoes. Extracted pea nut meal or, for comparison, dried skim milk, were added as protein sources. The average biological value achieved was 42% if extracted pea nut meal was fed and 59% if dried skim milk was added. The corresponding PPV data were 33% for the rations containing extracted pea nut meal and 49% for the dried skim milk rations. Balances made for the rate of dietary amino acid intake and amino acid excretion in the milk showed that lysine deficiency occurred when rations were fed containing the extracted pea nut meal.