INFLUENCE OF JAPANESE QUAIL EGG SHAPE INDICES ON CHICK SEX RATIO

Résumé

Japanese quails are still in the domestication process and it has been observed that while in captivity,they do not sit on their eggs to hatch them. Separation of the males and females such that the recommended ratio is kept in a covey, is necessary for-profit maximization. Presently, sexing in quails is only possible at post hatch even, with the most popular Japanese vent examination technique. Besides, these techniques may be inaccurate, require expertise, facilities and may not be affordable by many farmers hence, the need to use egg shape to predetermine Japanese quail chicks. Egg length,
width and indices were used to categories the egg shapes into Round (44), Oval (139), Spherical (9) and Elliptical (60). The 252 Japanese quail eggs were set in an artificial incubator. At hatch, the number of eggs hatched was recorded per egg shape. At 3 weeks of post hatch, the chicks’ sex was identified using the breast feather colour and the number of male and female chicks was recorded. Out of the 252 Japanese quail eggs incubated, 191 representing 75.8% hatched, whereas in 44 Round eggs incubated 36 hatched, 139 Oval eggs (102 hatched), 9 Spherical eggs (7 hatched) and in 60 Elliptical eggs, 46 hatched. While hatchability varied between 73.3 and 81.9% in all the egg shapes examined, the male to female chick sex ratio was 13:23, 20:31, 7:0 and 11:12 in Round, Oval, Spherical and Elliptical eggs, respectively. Since both sexes were recorded in all the egg shapes (except, Spherical eggs), Japanese quail egg shape may not influence chick sex. Thus, use of egg indices may not be a veritable technique to predetermine Japanese quail chick sex.