Document Type: Original Articles
Faculty of Animal Science, Gorgan university of Agricultural Sciences & Natural Resources University, Gorgan, Iran
Department of Animal Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
Genistein (GEN), a soybean isoflavone, is structurally and functionally similar to endogenous estrogen; therefore, it has potential to enhance estradiol properties. This study was designed to evaluate the effects of GEN on the reproductive performance and bone status of laying hens. Eighty 40-wk-old (the late stage of egg production cycle) Hyline W-36 with initial body weight of 1,230 ± 15.8 g (Mean±S.E.M) and similar egg production, egg weight, were randomly assigned to two groups with 10 replicates and 4 birds in each replicate (40 laying hens per group). Laying hens fed diets with 0 (control) and 20 mg/kg GEN (white powder, Sichuan Guanghan co. Ltd., purity of 98.5%) for 6 weeks (41 to 46). At the end of experiment 20 hens (one hens from each replicate) were slaughtered and samples of bone and shell gland (approximately 50 mg) for Real-time PCR were surgically taken immediately after slaughter. Results indicated that dietary GEN increased egg production, feed intake, egg mass and decreased egg weight (P＜0.05). Feed conversion ratio was greater in birds received GEN than those in control group (P＜0.05). Genistein enhanced egg quality indexes including eggshell strength, eggshell thickness and eggshell percentage (P＜0.05). Mechanical properties of tibia such as weight, length, and breaking strength were increased by GEN (P＜0.05). Dietary GEN increased calcium content of tibia (P＜0.05). The mRNA expression of calbindin-D28k (CaBP-D28k) and transient receptor potential vanilloid channel type 6 (TRPV6) up-regulated in egg shell glands of hens treated with GEN paralleled to control (P＜0.05). In conclusion, the findings of the present study showed that GEN has potential to improve the bone physical characteristics and mineralization and productive performance of Hy-line W-36 laying hens in their post peak period.