The Thai Journal of Veterinary Medicine


This study was conducted to evaluate the effects of adding liquid DL-methionine hydroxyl analog free acid (LMA) to drinking water on the growth performance and gastrointestinal tract in broiler chicks during 1-42 days of age. The chicks were divided into 5 groups as follows, Group 1 (negative control); chicks received a methionine (Met) deficient diet without LMA supplementation in drinking water. Group 2, 3, 4 and 5 were diets supplemented with DL-methionine (DLM) that meet total sulfur amino acids (TSAA) requirement, then each group was graded level with LMA in drinking water at 0%, 0.025%, 0.05% and 0.1%, respectively. Average daily gain (ADG) and feed conversion ratio (FCR) were significantly improved by DLM supplementation in diet. Furthermore, adding LMA at 0.025% and 0.050% to drinking water showed better growth performance than that of DLM supplementation group (p<0.01). Met deficient significantly induce low consumption of feed and water (p<0.05). The pH of drinking water was significantly reduced by LMA supplementation (p<0.001), consequently water consumption of 0.1% LMA in drinking water group was significantly lower than that of the Met sufficient diet group (0.0% LMA). However, the acidity of drinking water did not affect to acid-base value in the gastrointestinal tract, and population of E. coli or Lactobasillus spp in the ceacum. Adding LMA 0.05% in drinking water significantly increased villous height, villous surface area and crypth depth in the duodenum and jejunum (p<0.01). Concentration of propionic acid and total volatile fatty acid (total VFAs) were increased (p<0.001). The result indicate that adding LMA in drinking water 0.05% can be used as Met source and an acidifier to achieve maximal growth performance of broiler chicks via the improvement of gut morphology.


Faculty of Veterinary Science, Chulalongkorn University

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