Use of Alimet® Feed Supplement (2-Hydroxy-4-(Methylthio) Butanoic Acid, HMTBA) for Broiler Production

Controversy about the efficacy of Alimet as a source of methionine arises from the fact that when it is ingested, it is fundamentally different from methionine. Thus, broiler performance studies comparing efficacy of Alimet and DL-methionine (DL-met) continue to be of interest. This report will cover two studies using Alimet Feed Supplement (an 88% aqueous solution of 2-hydroxy-4-(methylthio)butanoic acid, HMTBA). The objective of the first was to compare Alimet with DL-met as sources of supplemental L-methionine (L-met) for broiler production. The sources were fed on an equal dry-matter basis at a level approximating 85% of that used in commercial practice in the UK, where the study was run. A basal diet was used to confirm sensitivity to methionine source addition. No antibiotics were fed. Results confirmed a significant response to supplemental methionine over the 0-42 day study for gain and feed conversion efficiency with no significant difference between Alimet and DL-met. The objective of the second study was to compare performance of Alimet with DL-met when birds were fed high inclusion levels. In this experiment, conducted at Novus International, performance in a basal diet was compared to five supplemental levels of Alimet or DL-met (0.2, 0.5, 1.0, 1.5 and 2.0%). The first level of supplementation was designed to represent an adequate diet with subsequent levels representing excessive addition. Results confirmed that the performance and feed intake of birds fed DL-met was more negatively affected than those fed Alimet, with differences becoming significant above the 0.5% level. Data presented here confirm full molar equivalency of HMTBA to DL-met in broilers fed commercial diets and illustrate the relatively greater safety of Alimet when fed at higher inclusion levels.