Effect of dietary folate and vitamin B12 on egg composition and liver triglyceride of laying hens at 64 weeks of age

The experiment was conducted to determine the effects of supplemental dietary folate and vitamin B12 on egg composition, reproductive traits and triglyceride content in liver of laying hens at 64 weeks of age. Four levels of dietary folate (0, 0.5, 4 and 10 mg/kg) and three levels of dietary vitamin B12 (0, 0.01 and 0.08 mg/kg) were fed in 4x3 factorial in a complete randomized design. The basal diet was based on corn and soybean meal. There were four replicates of twelve layers per each treatment. The experimental diets and water were offered ad libitum for 8 weeks. The results showed that egg production, feed intake, egg weight, egg mass, oviduct weight, liver weight, and liver triglyceride of the hens were not affected by both folate and vitamin B12 supplementation (P>0.05). However, increasing the vitamin B12 caused significantly higher ovary weight (2.75, 2.67 and 3.03% of BW.) and albumen percentage (64.07, 64.27 and 64.93%), but significantly lower yolk percentage (26.36, 26.10 and 25.62%) and yolk:albumen ratio than the unsupplemented group (0.41, 0.40 and 0.39%) (P<0.05)

Effect of storaged fishmeal on layer performance

Two experiments were conducted to study the effect of stored fishmeal on layer performances. Experiment 1 determined the chemical composition and rancidity (TBA-number) in 16 samples of 4 grades of fishmeal (prime quality, grade 1, 2 and 3) during 3 months warehouse storage. In experiment 2 various qualities of fishmeal were compared. Three hundred laying hens (12 wk of age) were divided into 6 groups with 5 replications and randomly fed an experimental diet until 18 wk of age as following. Conventional fishmeal and soybean meal were used as protein source in groups 1 and 2, respectively. While groups 3, 4 and 5 used stored fishmeal (prime quality, grade 1 and 2, respectively) which had been kept for 4 months at 3.5% of diets. In group 6, stored fishmeal grade 2 was used as 6% of the diet. The results showed that there were no significant differences in nutrients composition among 4 grades of fishmeal during storage time. TBA-number had a tendency to increase with time. There were relationships between some compositions in fishmeal ie. protein with ether extract, protein with ash and ash with ether extract. Using of stored fishmeal (3 grades) for prelaying diets had no effect on growth performances when compared with the control groups. After changing all experimental diets to commercial laying diet in laying period (18-41 weeks), there was no significant difference in egg production, composition and quality in each experimental group