Ranking of ecuadorian sires by best linear unbiased prediction

Description: First and second lactation records from 785 Ecuadorian Holsteins distributed in four altitude areas, three "year" groups and six "season” groups were analyzed with the objective of ranking sires. BLUP approach was used to rank sires from three models and computer programs from Genstat were used to assist the analysis. Results show that sires did not rank the same in first and second lactation records.R^2 statistics were obtained for each model; the highest value, 0.50, was obtained with a model (iii) which includes herd, year group, season group, and sire as sources of variation in first lactation milk yield.