Optimal Heifer Growth Rates Based on Forage and Concentrate Price Relationships

Abstract

Concentrate price, interest rate, labor and housing costs, and heifer value were considered in determining maximum hay price for economic justification of increase less than .82 kg/d in BW of heifers. Feed intakes at seven different growth rates were determined by balancing rations consisting of orchardgrass hay, corn grain, and soybean meal for nutrient requirements of heifers at 181 to 363 kg of BW. Hay price solution was determined for equal present value between feed costs, labor and housing costs, and 363-kg heifer value at .82 kg/d and each of six slower growth rates. These prices were used as independent variables in an equation predicting maximum hay price for economic justification of reduced concentrate feeding for BW increase less than .82 kg/d based on interest rate, daily labor and housing cost, concentrate price, and rate of growth. When 363-kg heifers were equal in value regardless of age, maximum hay price ranged from 0 to $28/907 kg with examined scenarios, indicating few circumstances for economic feasibility of slower growth rates. When slower increase in BW resulted in additional heifer value at 363 kg of BW because of market conditions or more desirable timing of replacements, new parameter estimates indicated a variety of price and cost combinations in which reduced concentrate feeding was a profit maximizing strategy. © 1992, American Dairy Science Association. All rights reserved.