INFLUENCE OF SULFANILAMIDE ON INTESTINAL CALCIUM-ABSORPTION, UTERINE CONTRACTILE ACTIVITY AND EGG-SHELL THICKNESS IN THE DOMESTIC-FOWL

Experiments were conducted to investigate the effects of sulfanilamide on intestinal calcium absorption, uterine cotractile activity and egg shell thickness in order to help to elucidate the mechanism(s) of action of this drug as a shell-thinning agent. The study included 75 adult layers of each of White Leghorn (W. L.) and New Hampshire (N. H.). Sulfanilamide was given in drinking water for 21 days at the levels of 125 mg and 250 mg/litre. Effects of the drug on intestinal calcium absorption was studied in vivo, while it's effect on uterine activity was studied in vitro. Oral administration of sulfanilamide significantly inhibited intestinal calcium absorption, stimulated uterine contractile activity and resulted in thin-shelled eggs. Using the drug in vitro was found to be more potent than when given orally. The effect of the drug was also found to be dose dependent. The two breeds responded to the drug in the same manner with slight variations in the degree of response. It is suggested that a part of the effect of sulfanilamide as a shell-thinning agent could be attributed to; 1-reducing intestinal calcium absorption and hence decreasing the availability of an essential material for shell formation, and 2-altering the normal deposition of egg-shell components through continuous increased uterine contractility.