Abstract
The relationship between space allowance and feeding antibiotics to pigs weaned at 3 to 6 wk of age was investigated in a cooperative study that involved nine experiment stations in the North Central Region of the United States. Treatments, arranged factorially, were control vs antibiotics (110 mg chlortetracycline, 110 mg sulfamethazine and 55 mg penicillin/kg of diet) and .14 vs .23 m2 of floor space/pig. Treatments were replicated 45 times, utilizing 1,724 pigs. Pigs allowed .23 m2, compared with .14 m2, had 10.6% greater (P<.01) rate of gain and 3.6% improved (P<.05) feed/gain. Pigs fed antibiotics had 13.2% faster (P<.01) rate of gain and 4.7% improved (P<.01) feed/gain in the 4-wk experimental period. There were no interactions between antibiotic and space allowance for performance measurements, except for average daily gain (P<.05) in the 0 to 3 wk period. In this period the antibiotic response was greater among pigs allowed .23 m2, as compared with those allowed .14 m2. Copyright © 1984. American Society of Animal Science . Copyright 1984 by American Society of Animal Science