The Effect of Arsanilic Acid and Low Levels of Antibiotics on Laying Chickens During Hot Weather

Abstract

DIFFERENT workers disagree about the effect of antibiotics on healthy laying chickens in a temperate climate. The data of Heywang (1956 Heywang (1957b), however, are apparently the only published ones showing that chlortetracycline at the levels of 50 and 100 grams per ton of diet improved egg production during the hot summer months in an area with a subtropical, semiarid climate, and that the lower level was as effective as the higher. An increase in egg production also occurred during cool and moderate weather in two of the three experiments in which such data were obtained.The results of experiments at the same station with growing chickens (Heywang, 1957a) showed that a combination of low levels of two antibiotics increased their growth and efficiency of diet utilization as much during hot weather as did much higher levels of only one antibiotic. Hence, it was considered desirable to determine what effect rather …