Riboflavin Requirement of Breeding Hens in a Humid Tropical Environment

Abstract

Abstract Arijeniwa, A., Ikhimioya, I., Bamidele, O.K. and Ogunmodede, B.K 1996. Riboflavin requirment of breeding hens in a humid tropical environment. J. Appl. Anim. Res., 10: 163–166. Six isocaloric and isonitrogenous diets containing 2.5, 4.5, 6.5, 8.5, 10.5 and 12.5 mg riboflavin per kg diet were fed to 240 layers of the Hubbard bleed that had attained 50% henday production. Egg production was subsequently assessed for 8 weeks. At the beginning of the 9th week, cocks of the same age and breed were introduced at a mating ratio of 1:5. After seven days and subsequently for six weeks, eggs were collected for incubation in order to determine fertility, hatchability and embryonic mortality during incubation. Hen-day egg production and percent hatchability improved significantly (P<0.05) with increasing dietary riboflavin up to 8.5 mg. Embryonic death similarly significantly declined as dietary riboflavin increased up to 8.5 mg. On the other hand, egg weight, egg shell thickness,% egg fertility and body weight of newly hatched day old chicks were not significantly affected by dietary riboflavin levels. It is recommended to include 8.5 mg riboflavin per kg diet of breeding hens in a humid tropical environment to increase hatchability and reduce embryonic death during incubation.