Purdue University-Agricultural Experiment Station Lafayette, Indiana
Mimeo. A.S. 242 January, 1959 (Final Report)
EFFECTS OF HYGROMYCIN AMD A COMBINATION
OF ANTIBIOTICS ON GROWING-FINISHING SWINE*
J. H. Conrad and W. M. Beeson Department of Animal Science
Hygromycin, an antibiotic, is being fed to swine because of its unique capacity to control certain internal swine parasites (roundworms, nodular worms and whipworms). Other antibiotics and feed additives are included in swine rations to stimulate gains and improve feed efficiency.
In a preliminary trial (A. H. Mimeo. 214), hygromycin fed pigs gained 8.8 percent faster and had no roundworms at the end of the experiment compared to control pigs which had an average of 14*5 roundworms. A second experiment (A. H. Mimeo. 233) indicated that hygromycin effectively controlled roundworms, nodular worms and whipworms, as shown by three ova counts and by worm counts obtained at slaughter, but hygromycin feeding failed to improve gains or feed efficiency. Furthermore, hygromycin depressed gains 8% and reduced feed intake 5$ when fed to non-wormed pigs. Feeding hygromycin to wormed pigs had no effect on gains and reduced feed intake 2.3$. A mixture of growth stimulating antibiotics (aureomycin, penicillin, terramycin and zinc bacitracin) increased gains 14 to 18$ compared to hygromycin.
In view of the above conflicting results, another experiment was conducted on pasture to determines
(1) the effects of hygromycin when fed to wormed and non-wormed pigs, and
(2) the effects of hygromycin when fed in addition to a combination of growth stimulating antibiotics to both wormed and non-wormed pigs.
EXPERIMENTAL PLAN
Eighty pigs seven weeks of age which averaged 30 pounds initially were allotted to 8 lots of 10 pigs each. Each group of 10 pigs was confined to a one-acre lot of ladino clover. Pigs had been pastured on these lots the previous summer. The experimental treatments were as follows:
*The authors wish to acknowledge Dr. T. M. Means and associates of Eli Lilly and Co., for their assistance in obtaining the information on the helminth infestation. Also to Darren Nelson and associates for feeding and caring for the experimental animals. Aureomycin was furnished by the American Cyanamid Co., Pearl River, New York; Zinc-Bacitracin-Penicillin by Commercial Solvents, Terre Haute, Indiana; Hygromycin by Eli Lilly and Company, Indianapolis, Indiana; and Terramycin by Chas. Pfizer and Company, Terre Haute, Indiana.