• Asian-Australasian Journal of Animal Sciences
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• v.3 no.2
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• pp.121-123
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• 1990

A CRD experiment with unequal numbers of hens were assigned at random to three treatment groups, 1) separation of chicks from hen at 21 days after hatching 2) separation of chicks from hen at 7 days and 3) hens were allowed to brood the chicks(no separation) up to 10 weeks of age, to determine the productive and reproductive performance of hens and their chicks. The mean cycle length (one hatch to another) was 72.8 days for the 7-day group as compared with 87.7 days and 83.4 days for the 21-day and the no separation groups, respectively (p<.0l). The broody period was 28.5 days for the 7-day group compared with 43.9 and 42.6 days for the 21 days and the no separation groups, respectively (p<.0l). The end of the broody period to the start of lay varied from 8.0 to 8.7 days. The number of eggs laid per clutch were 12.3 for the 21-day group, compared with 11.5 and 10.1 for the 7-day and no separation groups, respectively (p<.05). This is due to the longer (p<.05) clutch length of the 21-day group as compared with the 7-day and no separation groups, respectively. The chicks separated from the hens at 21 and 7 days were heavier (p<.01) than the chicks not separated from the hens. Mortalities were highest (p<.05) for chicks separated at 7 days as compared with chicks separated at 21 days and those not separated. We concluded that separating chicks at 7 days from the hen gave the shortest cycle length and broody period, separating the chicks at 21 days gave the longest clutch length and the maximum number of eggs, separating the chicks at 21 and 7 days resulted in heavier chicks and separating the chicks at 7 days resulted in the highest mortality.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1647-1654
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• 2001

In poultry, the selection against broodiness took up presumably naturally occurred mutations in the White Leghorn breed and led to an almost complete loss of the avian form of parental behaviour (incubation of eggs). Early studies on the genetics of broodiness demonstrated that the trait is polygenic with a major sex-linked effect. The reassessment of the studies on putative genes located on the Z chromosome, which are implicated in the control of broodiness, has resulted in the denial of this hypothesis. The recent experiments bear witness that incubation behaviour in chickens is not controlled by a major gene (or genes) on Z chromosome and there must, therefore, be major autosomal genes contributing to the expression of the behaviour. If a broody gene does exist on the Z chromosome it is one of at least three genes including two dominant autosomal genes, one causing and other one inhibiting incubation behaviour, with probably equal influence.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.2
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• pp.192-195
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• 1997

Thirty adults Desi and Khaki Campbell ducks were distributed to 6 farmers of Chakcharpur village of Mymensingh district. These ducks were subjected 3 types of mating e.g. Desi ${\times}$ Desi, Khaki Campbell ${\times}$ Khaki Campbell and Khaki Campbell ${\times}$ Desi-having 10 ducks (male : female = 1 : 4) in each mating group. Each mating group was then divided into two having 5 ducks(male : female = 1 : 4) and distributed to 2 farmers. After collecting eggs from each mating category, these were hatched by broody hens from which a total of 90 day old ducklings, 30 from each genotype were raised from birth to 90 days after the onest of laying. Although the weight of the day old chicks were similar in all genotypes (40-43 g), body weight was the highest (p <0.01) for Khaki Campbell ${\times}$ Desi (1,543) before the onset of laying followed by Khaki Campbell (1,552 g) and Desi (1,448 g) ducks. Khaki Campbell attained maturity at an earlier (p < 0.01) age (147 days) followed by Khaki Campbell ${\times}$ Desi, (154 days) and Desi (161 days) ducks. Khaki Campbell laid maximum (p < 0.01) number of eggs (46) compared to Khaki Campbell ${\times}$ Desi, (30) and Desi (18) ducks 90 days after the onset of laying. However, eggs were heavier (p < 0.01) in Desi (61.9) ducks compared to other genotypes. Fertility and hatchability were also higher in Desi ducks than the other two genotypes. Mortality was also lover in Desi ducks (3.33%) followed by Khaki Campbell ${\times}$ Desi (6.66%) and Khaki Campbell (16.66%) ducks. The results presented here indicated the superiority of Desi ducks over the other two genotypes with respect to egg weight, fertility, hatchability and mortality under village condition. Pure and crossbreds, on the other hand, were heavier at sexual maturity at relatively younger age and laid more eggs.