The overall goal of this research project is to introduce soybean protein (meal and processed meal to increase rumen stability of protein) into diets of growing beef calves. The approach used is to show that using soybean protein to balance for amino acid requirements results in lower cost of gains than diets using competing protein feed ingredients balancing for protein levels in the diet. This study focused on determining the effect of balancing a diet to meet amino acid requirements on growth performance and the effect of metabolic efficiency phenotype on amino acid requirements. It was inferred from the data that the model used to estimate amino acid requirements, with calves fed 80% of predicted limiting amino acid requirement having growth performance less than calves fed a diet providing 100% of amino acid requirement. Likewise, calves fed a diet providing 120% of amino acid requirement did not have increased growth performance. Cattle have also been shown to vary in metabolic efficiency, which determines the amount of energy (feed) required for gain. This is a genetic trait seedstock breeders are focusing upon. This research showed that meeting amino acid requirements had an additive effect on growth performance of calves that were more metabolically efficient.

Soybean protein is unique in complementing corn protein to balance growing calf diets to meet amino acid requirements. The potential benefit to using soybean meal compared to other protein feeds is reduced cost of gain, typically $0.05 per Lbs or greater. The fed beef cattle market is estimated at 29 million head and the fed dairy calf market is estimated at 5 million head. The inclusion of soybean protein in beef diets will range depending on growth stage of the calf, but an average would be 8% of the diet. The consumption potential for soybean protein is substantial. Additionally, the use of rumen protected soybean meal is needed which creates a value-added opportunity. The benefit to US Soybean Farmers is the increased demand for soybean protein, which creates value in soybean meal and increased tonnage use. This in turn benefits soybean price and demand.