OH-Methionine and DL-Methionine are similar in sustaining laying performance and egg quality of Babcock layers
Published:January 17, 2020
Summary
The objective of this trial was to compare the effects of OH-Methionine compared to DL-Methionine on laying performance and egg quality of Babcock laying hens on a 14-week period under tropical climate. The work was presented in a poster at 22nd ESPN (European Symposium in Poultry Nutrition) in Gdansk (Poland) and in an oral communication by Dolores Batonon-Alavo at PSA (Poultry Science Associati...
Hello
Without data on feed composition it is impossible to draw any conclusions from this report. Please can you post the FULL composition of the diets, ie % inclusion of each and every raw material. Then at least we can determine if another nutrient is actually the limiting factor in performance. MPS
Thank you for the detail, it helps a great deal. Evaluating the diet against Babcock recommendations, we find the diet deficient in energy ( - 100 kcal), threonine (4%), isoleucine (12%) and valine (6%). This is further exacerbated by the fact that feed intake is about 10% reduced against breed expectation, no doubt due to high ambient temperature. Of course, animals need a certain amount of each nutrient per day, not % in feed; so clearly a number of nutrients were limiting performance.
From this analysis, it is clear that to draw the conclusion that replacing DL Methionine with a similar amount of "OH-Methionine" is NOT correct. You should consider repeating the trial with diets correctly formulated and manufactured. I would also recommend the addition of a non-supplemented negative control. I am sure that, had this been used in THIS trial, there would have no sig. dif between control and either M+C source, as other nutrients were, in fact, limiting performance. MPS
Dr Martin, I would like to make a suggestion regarding the proposal of studies to evaluate the bioequivalence of products, in the case of two sources of Methionine. I think that in these studies at least three treatments should be used, Exemplifying: T1 basal diet with DL Methionine in the requirement of the animal: T2 diet with sub optimal level of methionine (90%) using DL Methionine: T3 diet T2 replacing DL Methionine with OH -Methionine in the proportion of bioequivalence. The need for T1 is to prove that in T2 methionine is deficient. This proposal is based on the fact that this type of diet seems more appropriate and would provide more confidence in the results of studies of this nature. I also made some other considerations in the work conducted by RAMA RAO
Juarez Donzele - While I agree that a true Negative Control is the halmark of good experimental desing, this study appears to have been more of a practical field trial, wherein multiple diets can be very hard to accomodate without introducing other problems. I think Martin's comments about other nutrients being first limiting is a more significant concern in this case.
From the broiler literature, there is evidence that bioequivalence of DL-methionine and the hydroxy-analog can be manipulated by where on the dose response curve the comparison is made. Using common intercept methods (Similar to the 3 point design you propose), DL-methionine is pretty consistently shown to be superior on a molar basis to the analog. However, comparisons closer to practical application levels (ie arround requirement) tend to show no difference or occasionally supperior performance from the analog as compared with DL-methionine. This is most clearly presented in the work of Kratzer and Littell (2006)
Kratzer, D. D., and R. C. Littell. 2006. Apropriate statistical methods to compare dose response of methionine sources. Poult. Sci. 85:947-954.
Dr Joshua, I agree with your considerations, but I would like to clarify that, in my considerations about this work, I mentioned in my report, that I had already made some considerations in the work previously published in ENGORMIX, which is a part of this study, which contains the composition of the experimental feed. that was used in this research. At that time I made considerations, that,. from my point of view, the results of our work team added to some others available in the literature that the relationship Met + Cist dig .: Lisina dig. it was below the value we found 100: 100. So we concluded that the level of lysine in the feed was overestimated. Thus, it would not be up to us to consider other amino acids.
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