Growth performance of pigs (6-25 kg) fed diets supplemented with DL-methionine or liquid MHA-FA under commercial conditions in Mexico

Dr. John, I understand the difficulties inherent to the fieldwork. I have some doubts about your study regarding: - to experiment with piglets, due to individual variation, I think the number of repetitions (six, 6) was low, although five (5) animals were used per experimental unit. : - I think the phases should be defined only by age, that is; 1-8,9-17; 18-37. It includes a confusing weight range, after all, it is weight or period: - it did not seem coherent to use the fully visualized experimental design if in the text it seems that the animals were blocked by weight .: it did not define the average test that was used: - how weaning influences the performance of piglets after weaning, they should have used the initial weight of the animals as a covariate .: - PHASE 2 - Based on the data presented in the table, it does not seem coherent to consider the improvement in weight gain as a trend if the conversion of the food is considered significant. This is because the two variables have variations of similar values. PHASE 3: - the first sentence does not correspond to the period of this phase, but to the total period.

In my opinion, at the end of the article, it does not seem appropriate to associate the homogeneity of the weight gain data, such as the variation that occurred between the phases. I understand that in this case study, homogeneity refers to the deviation of the mean data of each variable within each treatment group. My considerations are to better understand the work of Dr. John, whom I admire without knowing him personally.