Bacteriological Studies of Bovine Semen. I. Numbers of Bacteria and the Relation to Fertility

Abstract

Bacterial plate counts for undiluted semen from bulls used for artificial breeding were detd. using veal infusion 4% blood agar. Wide variations were found not only between bulls but also in plate counts on semen samples from the same bull collected at different times. The avg. plate count on 202 ejaculates of semen from 36 bulls was 200,000 bacteria per ml., with a range of from 50 to 3,300,000 per ml. No significant differences were found in avg. plate counts of 1st and 2d ejaculates collected in succession from the same bull. Plate counts for 91 paired ejaculates showed 220,000 bacteria per ml. for 1st ejaculates and 130,000 per ml. for 2d ejaculates. There was no apparent relationship between the avg. plate count of semen and either general fertility level or age of bulls.