|Van vleck, Lloyd|
|Van tassell, Curtis - Curt|
Submitted to: Veterinaria Mexico
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/31/2002
Publication Date: 4/1/2003
Citation: Economic evaluation of Holstein sire selection strategies for herds in Italy, Mexico, The Netherlands and the United States using stochastic simulation. Veterinaria - Mexico. 2003. v. 34(2). p. 179-201. Interpretive Summary: Semen for U.S. dairy bulls is used worldwide through artificial insemination. Management and economic conditions, however, are different in different countries. What might be the best purchase of semen for one country might not be best for another country. With criteria of maximizing profit, profit with high risk aversion, and lower confidence limit of profit, this paper compared purchases of semen from one or a group of bull that were progeny tested, pedigree evaluated or randomly chosen which had different semen costs and genetic values. Two planning horizons (10 or 20 yr) were also compared as were use in small or large herds. Conditions compared were based on situations in Italy, United States, the Netherlands, and Mexico. Following are general results of a simulation study based on purchase of semen of sires from the United States. Effect of herd size would be negligible. Use of one sire per year would give more profit than use of many sires. Use of progeny and pedigree evaluated sires would be superior to use of randomly chosen pedigree bulls for profit and lower confidence limit of profit but would be inferior for profit with high risk aversion. The study shows that criteria for purchase of semen depends on economic conditions where the semen would be used.
Technical Abstract: Stochastically simulated dairy herds with genetic, economic and managerial parameters for milk, fat and protein production in Italy, The Netherlands and the United States, and for milk yield in Mexico to planning horizons of 10 and 20 years were used to evaluate sire selection strategies. One to twenty progeny and pedigree evaluated sires that were commercially available from US AI units in January of 1996, were selected on expected profit indices. The use of 20 randomly selected young sires at low semen cost was also evaluated. Profit, lower 95% confidence limit of profit (LCL95) and utility (profit -.06 variance of profit) were obtained. Using one sire per year gave always the maximum profit. Number of sires for maximum response for LCL95 was smaller in countries with higher responses and using a longer planning horizon. Use of progeny and pedigree evaluated selected sires was superior to the use of randomly chosen pedigree sires for profit and lower LCL95 in all countries and herd sizes studied, but were generally inferior for utility at year 10. The effect of herd size on optimum decisions was small.