Bloat in cattle

Abstract
Procaine penicillin was given every third day to one cow of each of three monozygous twin pairs. The rates were 100,000 units per dose over a period of 15 days, 500,000 units per dose over a period of 12 days, and 200,000 units per dose over a period of 5 months. There was no evidence of transfer of penicillin to the milk. There was no adverse effect on the weights of the cows, on the yields of milk and butterfat, on fat and solids-not-fat contents of the milk, or on the iodine value, saponification value, softening point, Reichert value, carotene content, and vitamin A content of the butterfat. On this evidence it appears that penicillin may safely be used under New Zealand conditions for treatment and control of bloat at dose rates up to 500,000 units every third day.