Effects of dietary L-carnitine on the performance and egg quality of laying hens from 65–73 weeks of age

Abstract

The effects of L-carnitine supplementation (50-500 mg/kg diet) of a practical layer diet, based on maize, soyabean and wheat, on the performance of laying hens and some indices of egg quality were studied for 8 weeks, using 65-week-old hens kept in cages. Albumen quality (albumen height and Haugh (1937) unit score) was improved, while yolk index and yolk colour score were not affected by dietary L-carnitine. The percentage of egg-white increased and that of egg yolk decreased in response to dietary supplementation of L-carnitine. Dietary L-carnitine did not influence laying performance (egg production rate, mean egg weight, daily feed intake, daily egg mass and feed conversion) or external egg quality measured by egg weight, egg-shape index or by eggshell quality, either measured directly as shell breaking strength or indirectly as shell weight, shell thickness or shell weight per unit surface area. Based on the results of the present study, L-carnitine had a beneficial effect on albumen quality and could modify the components of the edible part of the egg, during the late laying period.

Use of L-carnitine and humate in laying quail diets

“…In conformity with the results of this study, carnitine (Leibetseder, 1995;Rabie et al, 1997;Çelik et al, 2003) and humate (Yörük et al, 2004) supplementation had no effect on the feed consumption of laying hens. Some researchers also found that the values of feed consumption in broilers were not affected by humate (Yalçın et al, 2003;Özçelik and Yalçın, 2004), carnitine (Buyse et al, 2001;Lien and Horng, 2001;Özçelik and Yalçın, 2004) and carnitine + humate (Özçelik and Yalçın, 2004) supplementation.…”

“…Similarly, some researchers found that L-carnitine (Leibetseder, 1995; Rabie et al, 1997;Çelik et al, 2003) had no significant effect on egg production of laying hens. However, the egg production values of laying quails fed 500 ppm L-carnitine (Bayram et al, 1999) and of laying hens fed 0.1 and 0.2% humate (Yörük et al, 2004) and fed 0.1, 0.2, 0.3 and 0.4% humate (Tancho, 1999) were higher than those of the control group.…”

“…Studies with poultry have shown some favourable responses to added dietary L-carnitine (Rabie et al, 1997;Bayram et al, 1999) or humate (Eren et al, 2000;Yörük et al, 2004) supplementation. However, as far as we know, there are no published reports about supplemental humate or humate + L-carnitine for laying quails.…”

Broyler hindi rasyonlarına L-karnitin ilavesinin performans, kan parametreleri ve bağışıklık sistemi üzerine etkileri

“…Günlük erkek hindi palazları ile 21 günlük yapılan bir çalışmada (4) canlı ağırlığın rasyona 50 ve 100 mg/kg düzeylerinde L-karnitin ilavesi ile etkilenmediğini bildiren bulgularıyla da uyum içerisindedir. Buna karşılık bazı araştırıcılar da (13,24,25,27) broyler rasyonlarına L-karnitin ilavesinin canlı ağırlık artışını olumlu yönde etkilediğini kaydetmişlerdir.…”

“…Aksine bazı araştırmalarda ise herhangi bir etkisinin görülmediği bildirilmiştir (9,18,25,27). Karnitinin hindiler üzerinde yapılan çalışma ise sınırlıdır (4).…”