Purdue University Agricultural Experiment Station Lafayette, Indiana
Mimeo AS-287 April, 1961 Final Report
THE EFFECT OF ARSANILIC ACID ON THE PROTEIN REQUIREMENT OF THE GROWING PIG 1/
J. H. Conrad, D. M. Whitaker and W. M. Beeson Department of Animal Science
Summary
Different levels of protein had a very marked effect on the performance of pigs in this experiment (Table 4). Pigs fed the 14-11 percent ration (lots 3 and 4) gained 56 percent faster (1.42 vs. 0,86) than pigs fed the 12-9 percent protein ration (lots 1 and 2). The pigs fed the 16-13 percent protein ration (lots 5 and 6) gained 80 percent faster (1.55 vs. 0.86) than pigs fed the 12-9 percent protein ration. There were no significant differences in the gains of the pigs fed the 16-13 or the 14-11 percent protein rations but the gains of these groups were significantly greater (P-r" . 01) than the gains of pigs fed the 12-9 percent protein ration.
Twenty-seven percent more of the 12-9 percent protein ration and 6 percent more of the 14-11 percent protein ration was required to produce 100 pounds of gain than when the 16-13 percent protein ration was fed. Most economical gains were made by pigs fed the highest protein ration. Feed costs were $10.34, $8.34 and $8.04, respectively, for pigs fed the 12-9, 14-11 and 16-13 percent protein rations.
Since the vitamin and trace mineral fortifications were constant and the calcium and phosphorus levels were equalized, the above responses are due to different protein levels formulated by using different proportions of corn and soybean meal.
Data in Table 3 for the complete experimental period show that arsanilic acid stimulated gains 10 percent and improved feed efficiency 9 percent when added to the 14-11 percent protein ration (lot 3 vs. lot 4). At the higher level of protein (16-13), arsanilic acid had little effect on gains but resulted in a 4.4 percent improvement in feed efficiency (lot 5 vs. lot 6). For the complete experimental period, arsanilic acid had no effect on gains or feed efficiency when added to the low protein ration (lot 1 vs. lot 2).
There was no significant difference in average backfat thickness, loin-eye area or percent of four lean cuts between any of the three protein treatments.
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Protein
Proteins are a class of nutrients vitally important to the pig. Nutritionally, it is more correct to say that the pig has certain amino acid requirements (the component parts of protein); yet as long as protein sources are used to supply these amino acids, the term "percent of protein" will probably continue to be used as one measure of a ration's nutritional value.
Extensive research has been conducted at Purdue for more than 10 years on the amino acid requirements of the growing pig. However, no recent experiments have been conducted at this station to study the protein
1/ The research reported in this mimeograph was supported in part by grants-in-aid from Abbott Laboratories, North Chicago, Illinois.