Artificial photoperiod regulates reproductive cycle and its effects on hatchability andfertility in breeder geese

• Main Authors: Rong-Huei Jian, 簡榮輝
• Other Authors: Shuen-Ei Chen
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/5899xv

碩士 === 國立中興大學 === 動物科學系所 === 106 === Domestic geese have seasonal changes in reproductive behaviors and physiology. In Taiwan, White Roman geese are active in reproduction during autumn (September) to early spring (April) next year; namely seasonal breeding during short day length. In the commercial goose production, artificial photoschedule is often used to manipulate reproductive cycle and thereby controls gosling production. Under natural day length, goose breeders tend to exhibit much poor reproductive performances during the 3rd breeding season when compared to their previous 2 seasons, by which their age tend to exceed 3 years. Artificial photoperiod apparently can be used to improve reproductive efficacy and therefor lower the cost of gosling production. The purpose of the study used artificial photoschedules to manipulate geese breeders to experience 3 breeding seasons within age of 3 years. The artificial photoschedules (AL) followed the ones optimized in our previous studies. Geese at age of 20 weeks received the photoschedule to impose their breeding seasons during Apr. to Sep. of the first year, Dec. to next Mar., and Jul. to Apr. in the 2nd year. A photoschedule simulating the natural day length served as a control (NL). In each group, ganders were distributed 1 vs. 5 females. At the beginning, middle and end of each change of light regimes, blood samples were collected for hormone analyses. Egg production was recorded and collected eggs were used for quality analysis and for artificial incubation to examine fertility and hatchability. In first one and half years of experiment, AL regulates the onset of lay and following egg production in non-breeding seasons (2017/03/13-2017/09/11) and (2017/12/25-2018/06/25). Geese with AL had a higher egg yield than that of the NL group (54.61 vs. 42.29 eggs/geese). The egg quality and hatchability of eggs produced by AL geese during the non-laying season were not different with those of NL group. The plasma levels of E2 and P4 increased consistently with the time of egg laying duration. AL geeses also had a significantly higher fertility (74% vs. 84%) and production of goslings (37.32 vs. 27.77 goose) than those of NL group, suggesting that. AL has a better reproductive performance than that of the natural photoperiod group. Therefore, the artificial photoschedule apparently is a feasible method to impose geese breeder to lay three times within three years with a high egg reproduction and fertility.