Calcium and zinc levels in laying hens diet: Effect on egg quality traits
CHANDRA DEO, H.P.SHRIVASTAVA, PRAVEEN K. TYAGI AND D.P.SINGH
Central Avian Research Institute, Izatnagar - 243 122
An experiment was conducted to study the response of graded levels of dietary calcium (2.5 and 3.0%) and zinc (30,50 and 80 mg/kg) on egg quality characteristic in naked neck x WL layers during 31-47 weeks of age (112 days) through a 2x3 factorial experiment. Six experimental diets of desired calcium and zinc levels were prepared by supplementing limestone and zinc sulphate in measured proportion. Each of such diets was offered to 17 laying hens reared in individual laying cages. Egg quality parameters were recorded for three consecutive days during 34-36, 72-74 and 110-112 d of experimental period. Results indicated that the main effect of calcium significantly affected the albumen index (P<0.05), shell thickness (P<0.01) and shell weight (P<0.01). The shell thickness and shell weight being significantly (P<0.01) higher in 3.0% calcium level than 2.5% calcium diet. However, other parameters did not differ significantly due to calcium level. The main effect of zinc did not significantly influence albumen index, yolk index, shape index, Haugh unit, shell thickness and shell weight. The calcium x zinc interaction significantly affected albumen index (P<0.01), yolk index (P<0.05), Haugh unit (P<0.01) and eggshell weight (P<0.01). However, other parameters of egg quality traits did not differ due to calcium x zinc interaction. It is concluded that a dietary level of 3.0% calcium and 30mg/kg zinc in diet is optimum for egg quality traits in naked neck x WL layers.