The effects of dietary L-carnitine supplementation on the performance, organ weights and circulating hormone and metabolite concentrations of broiler chickens reared under a normal or low temperature schedule.
1. The present study examined the effects of the addition of 100 mg/kg L-carnitine to the basal starter (containing 17.8 mg/kg L-carnitine) and finisher (containing 22.9 mg/kg L-carnitine) diets on performance, organ weights and plasma hormone and metabolite concentrations of male and female broiler chickens. The broiler chickens were reared either in a room with a normal temperature (NT) program or with a low temperature (LT) program (rapid decrease from 28 degrees C to 20 degrees C at 14 d of age). 2. Broiler chickens reared under the LT schedule consumed more food and attained a greater body weight at 42 d of age than their counterparts reared under NT schedule, without any difference in food efficiency or abdominal fat content. Dietary L-carnitine supplementation had no significant effects on any of these production parameters, except for a reduction in the abdominal fat content of female NT chickens. However, the LT schedule and dietary L-carnitine supplementation greatly increased absolute and proportional heart weights. The elevated heart weights were not due to right ventricle hypertrophy. 3. Both the LT program and L-carnitine supplementation increased circulating plasma triiodothyronine concentrations. There were also some transient effects of both experimental variables on plasma growth hormone, glucose and triglyceride concentrations. 4. L-carnitine did not improve broiler performance. However, this result does not mean that L-carnitine supplementation cannot have beneficial effects in other circumstances. In view of the elevated proportional heart weights, it can also be argued that L-carnitine is a potential agent for reducing the incidence of metabolic diseases in broiler chickens.
Buyse
J
J
Catholic University of Leuven, Faculty of Agricultural and Applied biological Sciences, Belgium. johan.buyse@agr.kuleuven.ac.be
Janssens
G P
GP
Decuypere
E
E
D000273:Adipose Tissue / Q000187:drug effects / Q000254:growth & development; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D001823:Body Composition; D001835:Body Weight / Q000187:drug effects; D002331:Carnitine / Q000008:administration & dosage*; D002645:Chickens / Q000097:blood / Q000254:growth & development*; D018592:Cross-Over Studies; D002149:Energy Intake / Q000187:drug effects; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006321:Heart / Q000187:drug effects / Q000254:growth & development; D008099:Liver / Q000187:drug effects / Q000254:growth & development; D008297:Male; D008460:Meat / Q000032:analysis; D009929:Organ Size / Q000187:drug effects; D011897:Random Allocation; D012737:Sex Factors; D013696:Temperature; D014280:Triglycerides / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D001786:Blood Glucose; D014280:Triglycerides; D014284:Triiodothyronine; D013006:Growth Hormone; D002331:Carnitine