SONGKLANAKARIN JOURNAL OF SCIENCE & TECHNOLOGY

Volume 41, No. 06, Month NOVEMBER, Year 2019, Pages 1211 - 1218

Effect of low-protein diets supplemented with methionine on growth performance, carcass characteristics, and expression of ant and ucp genes in the breast muscle of betong chickens (ku line)

Jiraporn Marayat, Somruthai Lertpimonpan, Choawit Rakangthong, Panwadee Sopannarath, Chaiyapoom Bunchasak, Wiriya Loongyai

Abstract Download PDF

We investigated the effects of low-protein diets supplemented with methionine on the growth performance of Betong chickens (KU-Line) from 4 to 18 weeks. A total of 192 four-week-old male Betong chickens were divided into three groups: high-protein diet group (high crude protein [CP]), low protein diet group (low CP), and low-protein diet group supplemented with methionine (low CP+Met). We found no significant effect of protein levels on the body weight gain and average daily gain. Betong chickens fed a low-CP diet showed the highest feed intake (P<0.01) and protein intake (P<0.05), while birds fed the low CP+Met diet had the highest methionine intake (P<0.05). The addition of methionine to the low CP diet resulted in a significantly improved feed conversion ratio compared to the low CP and the high CP diet groups (P<0.01). Moreover, the feed cost was reduced in the low CP+Met diet compared to the high CP diet (P>0.05). At the end of the experiment, two birds per replicate were randomly selected and slaughtered. The carcass weights were not significantly different between the treatments. The abdominal fat yield decreased in the treatment with methionine supplementation (P<0.05) at 12 weeks. Breast muscle samples were collected for total RNA extraction. The cDNA was amplified using primers specific for ANT and UCP gene expression and analyzed using real-time PCR. At 12 weeks, mRNA ANT expression was significantly higher in the muscle of birds fed diets supplemented with methionine. The highest UCP expression was obtained from the low CP diet group, which also resulted in the worst feed conversion ratio at 18 weeks. Our results indicated that methionine supplementation in low CP diets improved growth performance, reduced feed costs, and influenced the expression of ANT and UCP in the muscle.

Keywords

adenine nucleotide translocase protein, uncoupling protein, Betong Chicken (KU line), low protein diets, methionine supplementation

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