Effect of Methionine Supplementation on Lipogenesis and Lipolysis in Broiler Chicks

Abstract

The experiment was conducted to determine if marginal excess or deficiency of methionine (Met) in diet affects lipogenesis and lipolysis in broilers under ad libitum or pairfeeding conditions. A practicaltype diet (CS) containing 0.93% sulfur amino acids (SAA) as a control, mainly consisted of cornsoybean meal and an experimental diet (CSG) containing 0.56% SAA, based on corn, soybean meal and glutamic acid, were formulated to be isonitrogenous (23% crude protein, CP) and isoenergetic (3.2 Mcal metabolizable energy/kg). Glutamic acid in the experimental diet was replaced with Met at levels of 0.56, 0.93 or 1.15% of SAA to equalize the CP and metabolizable energy content with the control diet. Broilers (9 days of age) were fed these four diets for 17 days. The activity of malic enzyme (ME) in the liver was the highest at the level of 0.56% SAA among the chicks fed the CSG diets under both feeding regimen. The CS diet was more efficient in reducing the activity of ME as compared to the CSG diet. The lowest fatty acid synthetase (FAS) activity was observed in chicks fed the CSG diet containing 0.93% SAA under the ad libitum feeding condition, whereas FAS activity did not differ among the dietary groups in the pairfeeding condition. The activity of hormone sensitive lipase in the adipose tissue was the highest in chicks fed the CSG diet containing 1.15% SAA in the both feeding groups. The results suggested that dietary Met per se has a potential to alter lipogenesis and lipolysis in broiler chicks.