Effect of dietary supplemental pyridoxine levels on the hatchability of turkey eggs.
Two identical experiments were conducted each with 120 Large White turkey hens in individual cages to determine the value of dietary pyridoxine supplementation for increasing hatchability. The hens were fed a basal corn and soybean meal diet. Weekly data responses were averaged across 5- to 6-wk timespans and recorded in three grouped time periods over the reproduction cycles. The hens were photostimulated at 31 wk of age and at 33 wk of age were assigned to dietary treatments containing 0, 6, 12, and 18 mg of supplemented pyridoxine/kg of diet. Thirty hens were fed each dietary treatment. In Experiment 1, eggs were collected for 4 days in the middle of each time period and egg yolk and albumen were assayed separately for vitamin B6. Although the vitamin B6 concentration in egg yolk was stable (1.9 micrograms/g dried basis), concentrations of vitamin B6 in egg albumen increased with incremental dietary pyridoxine levels; however, the average level of vitamin B6 in egg albumen was only 4% of the average level in egg yolk. About 37 micrograms of vitamin B6 per egg (82 g) was assayed in eggs from all treatments in the production periods. Incremental dietary levels of supplemented pyridoxine above the basal (unsupplemented pyridoxine) diet level did not result in increasing hatchability or egg vitamin B6 levels. Differences were not observed for 7-day or 28-day embryo deaths among treatments within the three 5- or 6-wk production periods of both experiments.