Economics of Recombinant Bovine Somatotropin Use in Individual Dairy Herds

Abstract

DairyORACLE, a computer simulation model of a dairy enterprise, was used to simulate the productivity of nine commercial herds following the hypothetical adoption of routine use of recombinant bovine somatotropin. Data, including performance indicators, management goals, and demographic information were collected from each herd, and simulation exercises performed to assess the likely economic impact of somatotropin use in each case.Existing mathematical expressions for lactation and DM intake used in the model were adjusted to reflect production characteristics of cows treated with somatotropin. Comparison of model output for each herd with and without somatotropin use provided a means for quantifying changes in milk production and feed utilization attributable to somatotropin.Point estimates for percentage increase in annual herd milk sales varied between 8.5 and 17.6% (10.3mg/d) and 17.0 and 32.0% (20.6mg/d). Corresponding point estimates for increase in whole farm forage consumption were .6 to 10.5% (10.3mg/ d), and 3.1 to 20.8% (20.6mg/d). Depending on parity, production, and dose, grain requirements were estimated to increase by 10.2 to 39.0%. Using a net price of $23.10/100kg for milk sold, estimates for the break-even cost per dose ranged between $.27 and $.64 (10.3mg/d) and $.61 and $1.12 (20.6mg/d). A sensitivity analysis was performed to provide estimates of break-even cost per dose for net milk prices ranging between $16.50 and $27.50/100kg.