Effect of L-Carnitine Supplementation on Utilisation of Energy and Protein in Broiler Chicken Fed Different Dietary Fat Levels

Abstract

Effects of a supplementation of 80 mg L-carnitine per kg diet were studied in broiler chicken at two dietary levels of fat (4 and 8%) and different feeding levels (ad libitum in a growth trial, 95 and 85% of ad libitum in a balance trial). A low-carnitine basal diet adequate in amino acid concentration was used. In the growth trial, each diet was fed to 9 groups of 10 birds each for 16 days from day 5 of live onwards. Growth and feed intake were determined. At the end of the trial, birds were killed and homogenised for subsequent empty body analysis. Accretion of protein and energy was determined using a representative blank group killed at the beginning of the trial. In the balance trial, 8 individual birds were used per treatment. Birds were offered the feed at approximately 85 and 95% of ad libitum intake, which was determined with separate birds for both fat levels. Excreta were quantitatively collected three times daily for 8 consecutive days beginning on day 17 individually for each bird. Supplemented L-carnitine did not significantly affect any response criterion. However, growth and feed conversion tended to be improved by about 5% in the carnitine supplemented diets when fed ad libitum. An interaction between carnitine and fat level occurred with regard to feed conversion, indicating that carnitine had a positive effect at the high fat level, but not at the low fat level. L-carnitine did not positively affect the metabolisability of energy (ME/GE) and the efficiency of energy utilisation (RE/GE or RE/ME). Similarly, no significant carnitine effect was determined with regard to N accretion and the efficiency of utilisation of dietary protein in both trials. It is concluded that endogenous carnitine synthesis is not the limiting factor for energy utilisation in broiler chicken, even at high dietary fat concentration. Occasionally reported positive effects of supplemental carnitine were likewise caused by reasons other than improved energy or protein utilisation. Further studies on amino acid utilisation and catabolism should consider marginal amino acid supply.

The Effects of Dietary L-Carnitine and Gemfibrozil on Performance, Carcass Characteristics, Cholesterol and Triglycerides in Broiler Chicks

“…This level significantly improved the FCR and is similar to reports by (Rabie et al, 1997) and (Rodehutscord et al, 2002). Other studies reported finding no effect of L-carnitine on FCR (Barker and Sell, 1994;Buyse et al, 2001;Lien and Horng, 2001).…”

Effects of dietary L-carnitine and coenzyme Q10at different supplemental ages on growth performance and some immune response in ascites-susceptible broilers

“…Some reports showed that L-carnitine supplementation improved BWG (Rabie et al 1997;Rabie & Szilagyi 1998), but some others showed that there were no positive effects of L-carnitine supplementation on broiler's growth performance (Buyse et al 2001;Rodehutscord et al 2002). Ç elik and Ö ztü rkcan (2003) even indicated that L-carnitine or L-carnitine þ ascorbic acid supplementation reduced BWG of broiler chicks under thermoneutral condition.…”

The metabolic regulation of dietary L‐carnitine in aquaculture nutrition: present status and future research strategies

“…The role of L‐carnitine dietary supplementation on growth promotion has been verified in different species such as broilers (Rodehutscord et al . ; Zhan et al . ; Khadem et al .…”