Effects of hen production cycle and egg weight on egg quality and composition, hatchability, duckling quality, and first-week body weight in Pekin ducks.

This study was conducted to determine the effect of hen production cycle (HPC) and the effect of egg weight (EW) at the same egg production level on egg quality, egg composition, hatchability, duckling quality, and first-week BW in Pekin ducks. For HPC, hatching eggs were obtained from different Pekin-duck breeder flocks, aged 31 wk for the first production cycle (HPC1) and 78 wk for the second production cycle (HPC2). For EW, there were 3 categories: heavy (H), medium (M), and light (L). Ten eggs from each HPC and EW group were analyzed for the determination of egg quality, and albumen and yolk compositions. Ninety eggs from each HPC and EW group were incubated for the determination of hatchability, and duckling weight and quality. After quality scoring, 20 ducklings (10 male and 10 female) from each group were weighed, and reared to 1 wk of age in a brooder machine to determine relative growth (RG). The results showed that the albumen index; Haugh unit; shell percentage; yolk moisture, ash, protein, lipids, and triglycerides; albumen moisture, ash, and protein; yolk fatty acid contents; hatching weight; duckling weights at 1 wk of age; and RG were significantly affected by HPC. Egg weight affected shell thickness, yolk and albumen indices, Haugh unit, yolk and albumen percentages, yolk to albumen ratio, shell percentage, yolk fatty acid content, hatching weight, duckling weight at 1 wk of age, and RG.