The Schothorst Feed Research Institute, in the Netherlands, has just achieved a trial comparing the two main sources of methionine, DL-Methionine (DLM) and DL-Hydroxy-Methionine (HMTBA).
Ross 308 broilers were fed with 4 diets, formulated around the Aviagen 2010 recommendations: -20%; -10%, adequate and +10% (grower diet) and using DLM or HMTBA. Birds reached similar good performances for body weight gain and feed conversion ratio, whatever the methionine level used (Table 1).
|Product||BWG, g/bird||Feed Intake, g/bird||Feed conversion|
|DLM||1 557||2 146||1.378|
|HMTBA||1 560||2 148||1.377|
(lower value indicate better methionine efficiency)
The calculation of methionine efficiency giving the mg of methionine needed to gain 1 gram of body weight showed that HMTBA had a similar efficacy compared with DL-Met at low methionine levels, but a higher efficacy at high levels in the grower phase and in the overall period (0-28 days) (Figure 1). Taking DL-Methionine efficacy as the reference, the biological value of HMTBA in the grower phase ranged from 98.6 % (-10 % methionine than usual) to 102.8 % (10 % methionine than usual). This trial provides evidence that both HMTBA and DLM, when supplemented on an equimolar basis and at practical Total Sulfur Amino Acids levels, are equally effective in improving performances of broilers up to 28 days.
It confirms the results of two recent trials achieved in Bangkok Animal Research Center (BARC) in Thailand. The first one, ran on Ross 308 broilers up to 35 days, proved that both methionine sources could sustain similarly body weight gain, feed intake and feed conversion over the entire period, whatever the amino acid recommendation profile used (Lemme et al. 2010 or Rhodimet Nutrition Guide, 2013).
The second one compared the two methionine sources in diets with different nutrient densities, using the same amino acid/energy ratio. As expected, the nutritional specifications significantly affected broilers performances but no differences were observed between DLM and HMTBA on bird performances, irrespective of the nutrient density.
Together, these three trials, achieved in two independent and renowned research institutes, confirm that when used in practical diets even in different situations, DLM and HMTBA are equivalent methionine sources on a biological point of view. These trials and other scientific results on absorption and conversion answer and close the question which has been debated around the world for nearly three decades.
References of the 2 BARC trials.
M. K. Nonis, S. Srinongkote, R. Maillard, and Y. Mercier. Effects of dietary methionine sources on broiler performance. 2013, PSA Annual meeting, San Diego, California, July 22-25. P317.
Y.G. Liu and J. Hayat. Broiler Study shows full efficacy of methionine hydroxyl analogue. 25th Australian Poultry Science Symposium, Sydney, Australia, February 2014