Effect of Supplemental Biotin on the Performance of Aged Fayoumi Hens and Progeny Performance

A 12-wk laying trial, using 240 hens and 24 cocks of 52-wk old Fayoumi chicken strain, was conducted to determine whether hatchability can be improved by dietary biotin supplementation during the late stages of egg production and to study its effect on progeny performance. Birds were divided into 4 equal groups of 6 replicates each. A corn-soybean meal basal layer diet was formulated to contain 16.5 % CP & 2700 kcal ME/kg diet (as a control diet). Also, a corn-soybean meal basal starter diet was formulated to contain 18.5 % CP & 2814 kcal ME/kg diet (for feeding offspring). The vitamin mineral premix used in the basal diet supplied 50 μg biotin per kg of diet. Three experimental layer diets were formulated to contain similar composition as the control diet except for it contains 100, 162.75 and 325.5 μg biotin/kg of diet, respectively. Therefore, four experimental dietary treatments were studied during the laying trial period. The studied criteria for laying hens included egg number, egg weight, egg mass, feed intake, feed conversion ratio, early embryonic mortality %, late embryonic mortality %, healthy chicks, culled chicks %, hatch chick weight, fertility %, hatchability %, egg shape index, shell thickness, yolk index, Haugh unit, egg albumen %, egg yolk % and egg shell %. The studied criteria for progeny included hatch chick weight as well as body weight, body weight gain, feed intake, feed conversion ratio and mortality rate at 8 weeks of age. The results showed that biotin addition to layers diets at levels of 325.5 μg/kg diet gave the best improvement in egg production %, egg number, egg mass and feed conversion ratio as well as the highest increase in egg shape index, yolk index and Haugh unit. Also, such biotin level gave significant improvement in hatchability %, healthy chicks % and hatch chick weight. It also gave significant decrease in early embryonic mortality %, late embryonic mortality % and culled chicks % as well as significant improvement in body weight gain and feed conversion ratio for offspring at 8 wks of age. The results also showed that egg albumen % and shell % were significantly increased by adding biotin to layers diets at levels of 162.75 or 325.5 μg/kg diet compared to other treatments. However, birds fed biotin-supplemented layer diets had similar feed intake values and yolk % compared to control birds. Under the present experimental conditions, it is advisable to add 325.5 μg biotin/kg of laying hen diet. Such practice helps in improving laying performance, hatchability parameters, egg quality, egg albumin and offspring performance.