Effects of carrot leaves on digestibility of feed, and cholesterol and β-carotene content of egg yolks

The purpose of this study was to evaluate the effects of carrot leaf supplementation on feed digestibility and the cholesterol and β-carotene contents of the yolks of eggs produced by Lohmann Brown laying hens. A feeding trial was conducted using 240 healthy 30-week-old laying hens kept in colony cages to evaluate the effect of dietary supplementation with carrot leaves. Carrot leaf extract (CLE) was prepared by macerating carrot leaves in distilled water (1:1, w/w). The hens were fed diets i) without carrot leaves (C0), ii) supplemented with 2% carrot leaf flour (CLF)(C1); iii) supplemented with 2% CLE(C2); and iv) supplemented with 1% CLF and 1% CLE (C3). Supplementation of CLE, CLF and in combination increased dry matter, organic matter and protein digestibility significantly. Feed efficiency was improved, and eggshell thickness, yolk colour and β-carotene content in yolk increased. Supplementation with CFL or CLE produced significantly lower serum and yolk cholesterol contents. Dietary supplementation of laying hens with CLF and CLE also increased egg production and β-carotene contents in yolk.