At the beginning of this experiment the mean weight of the chicks in both groups was identical. Throughout the experiment the chicks fed Meat Builder feed with added amprolium outweighed the chicks fed Meat Builder feed with no added medication. The chicks fed amprolium also had a higher rate of weight gain than the non-med group until Days 17-21. During those four days, the non-medicated chicks grew slightly more on average. On Day 21 the chicks fed medicated feed weighed about 11% more than the non-medicated.
There could be several reasons why the medicated chicks grew to be heavier than the non-medicated chicks. Possibly the chicks contracted a mild case of coccidiosis and the medicated group was not affected and therefore gain more weight. Another reason might be that amprolium stimulates the appetites of chicks which makes them eat more and gain weight faster than non-medicated chicks. Perhaps the amprolium stimulated a hormone in the chicks, which promoted weight gain. The results of this experiment could be a chance variation, but this possibility seems unlikely.
The chicks’ weight gain appeared to plateau between Days 17-21. There could be several reasons for this. It could be that the chicks preferred the texture of the medicated feed in the first weeks of life. It could also be that the medicated birds were too crowded and could not continue to maintain a higher rate of weight gain than the non-medicated group. The reason could also be that amprolium only gives weight gain a boost when the birds are very young, and the non-medicated group caught up. This could also be a random variation.
For further study, this experiment could be modified in several ways. A study could be designed that involved monitoring the amount of feed consumed as well as the weight of the chicks. This might answer the question about the effect of amprolium on appetite stimulation. Testing for the presence of coccidian during a similar experiment would help measure this effect or eliminate coccidia infection as a variable.
If the results of this experiment can be reproduced and they are typical of the effect of amprolium on weight gain in healthy birds, then it may be tempting to use this drug not only as a coccidiostat but for increasing the efficiency of producing meat. This may have good and bad consequences.