CHROMOSOME AND SPERM SIZE OF HOLSTEINS WITH AND WITHOUT BOVINE LEUKOCYTE ADHESION DEFICIENCY

The objective was to evaluate bull differences in chromosomal and sper matozoal areas related to the occurrence of the bovine leukocyte adhes ion deficiency syndrome. Lymphocyte chromosomes from 30 Holstein bulls and 2 Holstein heifers were measured using image analysis and compute r-enhanced video-microscopy. Spermatozoal head areas from 29 of the 30 bulls were measured. Autosomal rank was based on decreasing area. Ave rage total autosomal areas were not the same across bulls. One group o f bulls had significantly smaller average chromosomal areas than the o thers; this group carried bovine leukocyte adhesion deficiency syndrom e. Area measures of spermatozoal heads showed that bulls with bovine l eukocyte adhesion deficiency syndrome had significantly larger head ar eas than normal bulls. Lymphocyte chromosomes from 3 cattle that were homozygous for bovine leukocyte adhesion deficiency syndrome were sign ificantly smaller than chromosomes from syndrome heterozygotes. Carrie r identification was improved by the use of autosomal and sperm area m easurements in addition to pedigree evaluation.