Vitamin Profiles of Eggs as Indicators of Nutritional Status in the Laying Hen: Riboflavin Study

Abstract

Two experiments determined the effect of dietary riboflavin supplementation on egg yolk and albumen riboflavin concentrations, egg production, egg weight, shell thickness, hen weight, hatchability, incidence of clubbed down, and incidence of hemorrhagic embryos. In the first experiment, hens were fed rations containing 1.55, 2.20, 4.40, and 8.80 mg of riboflavin/kg of diet for 27 wk. Significant (P < .05) depressions in both yolk and albumen riboflavin concentrations were noted at the two lower riboflavin levels after 1 wk. Egg production, egg weight, hatchability, and hen weight were all significantly depressed by the two lower riboflavin levels later in the experiment when compared with the two higher levels. Results indicate that egg riboflavin concentrations are related to important production parameters that may be used to predict future dietary riboflavin inadequacies. In the second experiment, hens were fed either an unsupplemented diet or a riboflavin-adequate diet. Measurements of egg albumen riboflavin content, egg production, hatchability, and embryo abnormalities were made twice each week. Results showed depressed albumen riboflavin concentrations and hatchability and increased incidence of hemorrhagic embryos and clubbed down without changes in egg production during the 4- to 7-day period following feeding of the unsupplemented diet. These results show that low albumen riboflavin content immediately affect hatchability and embryonic development. The estimated minimum critical albumen riboflavin concentrations needed to support maximum reproductive function are between 1.9 and 2.9 micrograms of riboflavin/g of egg albumen. These critical values might be used to evaluate riboflavin status of laying and breeding flocks.

Effects of Dietary Fortification of Vitamin A and Folic Acid on the Composition of Chicken Egg

“…The regression equation was y = 0.1172x + 528.175, where y is egg retinol (i.u/100g), and x is dietary retinyl palmitate (i.u/kg), indicating that egg retinol increased linearly as dietary vitamin A rose. These data are in agreement with previous reports indicating the influence of dietary vitamin A on its concentration in the egg yolk (Squires and Naber, 1993;Qui and Sim, 1998). The addition of increasing levels of dietary folic acid showed a trend to reduce the yolk retinol content, decreasing in 47.69, and 34.03%, respectively for 0.5, and 1.0 mg of supplemental folic acid/kg of diet, in comparison with the control group (Table 4).…”

Research Note: Early Detection of the Absence of a Vitamin Premix in Layer Diets by Egg Albumen Riboflavin Analysis

“…Two hundred H and N female chickens 3 were assigned randomly to four groups of 50 pullets each at 40 wk of age under the same conditions of management and housing described for Experiment 2 by Squires and Naber (1993). The basal diet employed was the corn and soybean meal diet used in Experiment 2 above except that the vitamin premix [see Table 1, Footnote 2 of Squires and Naber (1993)] containing vitamin A, cholecalciferol, vitamin E, vitamin K, pantothenic acid, niacin, and vitamin B 12 was omitted and no riboflavin was added to the basal diet.…”

“…Egg riboflavin content decreases very rapidly after laying hens are fed diets without a riboflavin supplement (Squires and Naber, 1993). Such changes are detectable within 4 to 7 days, and egg riboflavin concentrations return to normal values within the same time period when riboflavin is returned to the deficient diet.…”

“…Although egg production is not affected by the short-term absence of riboflavin in the diet, hatchability of eggs is quickly Received reduced. Long-term riboflavin deficiency not only reduces egg production but also reduces egg weight and hen body weight (Squires and Naber, 1993).…”

Improvement of flock productivity through supply of vitamins for higher laying performance and better egg quality

“…Vomiting, resorption disorders and diarrhoea, due to inflammation of the mucous membranes of the digestive tract, have been described and in hens, egg laying is disturbed. Squires and Naber (1993b) investigated the relationship between dietary riboflavin supplementation of laying hens (1.55-8.8 mg/kg) and egg production as well as riboflavin content in eggs. Egg production, egg weight, hatchability and hen weight Vitamins and laying performance: G.M.…”