Evidence for 2-hydroxy-4(methylthio) butanoic acid and DL-methionine having different dose responses in growing...

Area of Science:

• Animal Science
• Nutritional Biochemistry
• Poultry Science

Background:

• Methionine is an essential amino acid crucial for poultry growth and performance.
• Dietary supplementation with methionine sources is common practice in poultry nutrition.
• Understanding the dose-response relationship of different methionine sources is vital for optimizing feed formulations.

Purpose of the Study:

• To compare the gain-response curves of 2-hydroxy-4(methylthio) butanoic acid (HMTBA) and DL-methionine (DLM) across various dietary levels and trials.
• To evaluate the efficacy of HMTBA versus DLM in poultry under different nutritional conditions.
• To determine if the dose-response forms differ between HMTBA and DLM.

Main Methods:

• Four floor pen trials were conducted using a 2x3 factorial arrangement with HMTBA and DLM at three equimolar levels.
• Control diets were supplemented to be deficient in total sulfur amino acids (TSAA).
• Gain responses were analyzed using linear, quadratic, and exponential regressions to compare dose-response curves.

Main Results:

• Both HMTBA and DLM supplementation improved bird performance across trials.
• No significant differences between HMTBA and DLM were observed overall, except in one trial where HMTBA showed better performance.
• The shape of the gain-response curve differed between HMTBA and DLM in three trials, with HMTBA excelling at commercial levels and DLM at deficient levels.

Conclusions:

• HMTBA and DLM exhibit distinct dose-response curve forms in poultry.
• HMTBA may offer superior performance benefits compared to DLM when supplemented at commercial dietary levels.
• DLM demonstrated better efficacy than HMTBA under severely deficient dietary methionine conditions.