|KEOWN JEFFREY F|
|VAN VLECK L DALE|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/10/1995
Publication Date: N/A
Technical Abstract: Overlapping generation, semi-stochastic modelling of dairy herds, was utilized to estimate expected values and variances of cumulative milk response and profit from use of US Holstein sires, under five international scenarios; Italy (ITA), Mexico (MEX), Netherlands (NEH), Tropical Countries (TRO) and United States (US). Parameters in simulation models were age structure, calving interval, initial difference between US bull and cow populations, correlation and regression of EBV's between milk yield of daughters of sires in two countries, genetic standard deviation, selection intensity, genetic trend, reliability, sires used/year, herd size, semen units/replacement heifer, semen price, milk price, discount rate and ratio of net/gross profit to feeding costs. Sensitivity analysis was conducted for each scenario on factors associated with risk. Herd sizes studied were 500 cows, 100 cows, and 20 cows. Number of sires was 5 or 20. Five hundred replicates for each scenario x number of sires x herd size combination wer generated. Profit for risk neutral dairymen and utility with a risk coeffi- cient of -.06 for risk adverse dairymen, were estimated. Profits/cow at yr 10 were, respectively, 548, 78, 305, 18 and 244 US dollars and at yr 20 were, respectively, 1657, 475, 1017, 316 and 875 US dollars. Estimated utility was affected by time horizon, number of sires and herd size. Ranges for estimated utility/cow at yr 10 were -598 to 456, -232 to 45, -348 to 239, -107 to 7 and -318 to 197 and at yr 20 were -116 to 1525, -10 to 429, -14 to 917, 122 to 300 and -3 to 808 for ITA, MEX, NEH, TRO and US scenarios< respectively. At yr 20, the utility/profit ratio (%) for 20 sires and 100 cow herds were 76, 89, 78, 86 and 80 for ITA, MEX, NEH, TRO and US scenarios, respectively.