RESPONSE OF WHITE LEGHORN AND RHODE ISLAND RED BREEDER HENS TO DIETARY DEFICIENCIES OF SYNTHETIC VITAMINS. 1. EGG PRODUCTION, HATCHABILITY AND CHICK GROWTH

Abstract

Thirty-week-old purebred strains of Single Comb White Leghorn (WL) and Rhode Island Red (RIR) breeder hens were offered a control corn-soybean meal diet or the control diet with one of the following vitamins omitted from the supplement: biotin, B12, E, folacin, niacin, pantothenate and riboflavin. For each strain, four randomly distributed cages of four birds were offered each diet. Birds were inseminated weekly with 0.05 ml of pooled White Leghorn (WL) semen. Egg production, fertility and hatchability were recorded. After 15 wk, the vitamins omitted were added to the diets, and observations continued for a further 5 wk. With the exception of biotin, each unsupplemented diet had an adverse effect on egg production of RIR (P < 0.05), although few significant effects were observed with WL. Diet had no effect on fertility. Lack of added riboflavin had the most effect on hatchability, with 0% being recorded for both strains after 13 wk of treatment. All other treatments depressed hatchability for RIR (P < 0.05), although the pattern was not as well defined with W.L. Both breeds responded to re introduction of vitamins, such that at the end of the trial no significant (P > 0.05) differences in production or hatchability were recorded. There was no difference in growth rate of chicks hatched from eggs produced during the 8th wk of treatment.