Effects Of L-carnitine Supplementation On Growth Performance, Carcass Traits, Meat Quality And Lipogensis Of Sheep

This research was conducted to study the effect of L-carnitine and the effects of differentenergy levels supplemented with L-carnitine on weight gain, carcass characteristics, meatquality, and the genes of lipogenesis in sheep.Exp.1Effects of supplemented with L-carnitine on performance, carcass characteristics,meat quality and lipogenesis of growing sheepSixty-four healthy disease-free Tan sheep with similar weight were selected, andrandomly divided into two treatments. Every treatment had four replicates, and each replicatecontaining eight sheep. The experimental group was feed the basal diet that contained of200ppm L-carnitine. After60days feeding, one sheep from each replicate was randomly selectedand slaughtered. The blood was collected before slaughter. Slaughter live weight, carcassweight, dressing percentage and GR value were measured. Longissimus muscle were obtainedfor the measurements of pH, loin muscle area, color, shear force, cooked meat percentage,drip loss, the proximate composition of and amino acids compositions. Liver, fat in tail andsubcutaneous adipose tissue samples were taken immediately into liquid nitrogen forextraction of total RNA. By optimizing the reaction conditions, real time quantitative PCRmethod was used to detect the expression of FAS, HSL, LPL and SCD genes in liver, fat intail and subcutaneous adipose tissues.The results showed that supplemented with L-carnitine had no significant effect on thegrowth performance of Tan sheep, but it tended to reduce the live weight pre-slaughter,carcass weight, dressing percentage and fat deposits (P>0.05). Supplementation withL-carnitine could improve the meat quality, however, the amino acid compositions inlongissimus muscle were not affected (P>0.05). Supplementation with L-carnitine increasedon the concentrations of BUN and decreased on the concentrations of TG (P<0.01), however,the concentrations of TC and GLU were not affected (P>0.05). According to the results ofthe real time quantitative PCR, the expressions of FAS, HSL, LPL and SCD in liver, fat in tailand subcutaneous fat were significant affected by the supplementation with L-carnitine. The results indicated that the supplementation of L-carnitine could affect the growth performance,carcass traits, meat quality and lipogensis of sheep.Exp.2Effects of different energy levels supplemented with L-carnitine on performance,meat quality and lipogenesis of lambA total of144healthy disease-free Tan sheep with similar weight were randomly dividedinto six treatments by a3×2factorial arrangement. Treatments consisted of three energyintakes (low, medium, high) and two L-carnitine supplementations (0,200ppm). Eachtreatment had four replicates, and each replicate comprised six sheep. After60days feeding,one sheep from each replicate was randomly selected and slaughtered. The blood wascollected before slaughter. Slaughter live weight, carcass weight, dressing percentage and GRvalue were measured. Longissimus muscle were obtained for the measurements of pH, loinmuscle area, color, shear force, cooked meat percentage, drip loss, the proximate compositionof and amino acids compositions. Liver, fat in tail and subcutaneous adipose tissue sampleswere taken immediately into liquid nitrogen for extraction of total RNA. By optimizing thereaction conditions, real time quantitative PCR method was used to detect the expression ofFAS, HSL, LPL and SCD genes in liver, fat in tail and subcutaneous adipose tissues.The results showed that the growth performance of Tan sheep was increased with theincreasing of energy intake (P<0.01). Supplementation with L-carnitine could reduce the fatdeposits. Different of energy intakes had significant effect on carcass traits and meat qualityof lamb. The interaction effect between energy and L-carnitine on ether extract was observed(P <0.05). The effects of L-carnitine or energy levels had not significant effect (P>0.05) onthe amino acid compositions in longissimus muscle, however, the interaction effect ofL-carnitine and energy levels on Glu, Ala, Cys, Val, Lys and His was noted (P<0.05).Supplementation with L-carnitine could increase the concentrations of BUN (P<0.05) andGLU. Higher energy intake resulted in higher BUN concentrations (P<0.01). The interactioneffects between energy and L-carnitine on TG, GLU and TC were noted (P <0.05). Theexpressions of FAS, HSL, LPL and SCD in liver, fat in tail and subcutaneous fat weresignificant affected by both energy intake and supplementation with L-carnitine. However, theinteraction effects were not observed. It could be concluded that different of energy intakescould affect the growth performance, carcass traits, meat quality and lipogensis of sheep. Thelipogenesis of sheep was significant affected by the supplementation with L-carnitine.