ESTIMATES USING AN ANIMAL-MODEL OF (CO)VARIANCES FOR YIELDS OF MILK, FAT, AND PROTEIN FOR THE FIRST LACTATION OF HOLSTEIN COWS IN CALIFORNIA AND NEW-YORK

First lactation yields of milk, fat, and protein from Holstein cows in New York and California were used to obtain REML estimates of (co)var iances for yield traits using a multitrait animal model. Data from eac h state were split randomly into 10 samples, averaging 5504 cows per s ample from California and 5078 from New York. Mean heritability estima tes for milk, fat, and protein yields were .30 +/- .02, .31 +/- .01, a nd .29 +/- .01 for California data and .33 +/- .01, .35 +/- .01 and .3 0 +/- .01 for New York data. Averages of genetic correlation estimates for California and New York were .63 +/- .01 and .52 +/- .02 between milk and fat, .84 +/- .01 and .83 +/- .01 between milk and protein, an d .73 +/- .01 and .68 +/- .01 between fat and protein. Estimates of en vironmental correlations were larger than estimates of genetic correla tions. Mean estimates of phenotypic correlations for California and Ne w York were .75 +/- .01 and .72 +/- .01 between milk and fat, .92 +/- .01 and .91 +/- .01 between milk and protein, and .81 +/- .01 and .79 +/- .01 between fat and protein yields. On average, these estimates ag ree with those obtained from animal models with limited rounds of iter ation for small data files.