Relation between carotenoids content in egg yolk and hatching egg quality according to the time laying hens are fed diet containing leaf meal

Abstract

The purpose of this research was to determine the relationship between carotenoid content in egg yolk and hatching egg quality depending on the period length in which laying hens were fed diets containing leaf meal. Experiments were conducted мon 2 400 laying hens divided into 4 groups of 600 hens. The control group (CG) was provided with basal diet (BD) containing 2 750 kcal of metabolic energy (ME)/1 kg, 17% crude protein (CP) and no leaf meal. Three experimental groups (EG1, EG2, and EG3) were fed diets that contained 6% cassava leaf meal (CLM), 6% leucaena leaf meal (LLM), and 6% stylo grass meal (SGM) respectively but had the same ratios of ME and CP as the basal diet. Eggs were collected on the following experimental days: 1, 3, 5, 7, 9, 11, 13 and 15. Some chemical elements and carotenoid content of eggs were analyzed; at the same time, 360 eggs/group on each day mentioned above were incubated. The results showed that the longer the hens were fed diet containing leaf meal, the higher carotenoid content in egg yolk increased. The increase of carotenoid content improved the quality of hatching eggs in terms of (i) the rate of embryonated eggs, (ii) the rate of chicks/embryonated eggs and (iii) the rate of chicks class I/incubated eggs. The relation was firm with R2 = 0.8645, 0.8236 and 0.8075 equivalent to the three above criteria of quality.