Behavior and Well-Being Posters

Onion and its flavonoid component, quercetin, increase bone density in rabbits, rodents, and humans. The purpose of this study was to determine whether there is a similar effect of onion on laying hens. Thirty-two Hy-line W36 White Leghorn hens at 30 weeks of age were randomly divided into 2 groups, i.e., control and treatment (n = 16). The hens were kept at 2-hen cages, each cage providing 658 cm2 per hen. The hens were fed regular layer diet or layer diet containing 5% onion powder (by wt) for ad libitum consumption for 4 weeks. The hens were evaluated for body weight (BW) at wk 1, 2, 3, and 4; egg production and eggshell weight at wk 2 and 4; and blood calcium and bone mineral contents at wk 4. Data were analyzed using an ANOVA and repeated measures analysis when required. There was no differences in BW between the controls and treated hens from wk 1 to 3 (P > 0.05) while it was reduced in the treated hens at wk 4 (P < 0.05). Compare with the controls, both egg production and eggshell weight of the treated hens were increased at wk 2 (P < 0.05) but eggshell weight was reduced at wk 4 (P < 0.05). Blood calcium concentrations were lower at wk 4 in the treated hens compared with those of controls (P < 0.05). The weight of bone ash of the femur, tibia, and ulna was not affected by the onion supplement (P > 0.05); but the levels of phosphorus in the femur and ulna ash was higher for the treated hens (P < 0.05). These results indicate that onion consumption affects bone contents and metabolisms in laying hens. It provides signs for further investigating the effects of onion on stimulating bone plasticity in laying hens, especially in aged hens.