Influence of dwarf gene on post-maturity body weights and sexual maturity of ‘Narmada-XL’ egg layer, dwarf and Broiler pullets
Indian Journal of Animal Science
Sep 1, 1983
Core Idea
This 1983 poultry genetics study examines how the sex-linked recessive dw (dwarf) gene affects the timing of sexual maturity and post-maturity body weight in three genotypes of pullets, 'Narmada-XL' egg-layers, dwarf broilers, and normal broilers, finding that the dw gene consistently delays maturity and suppresses body weight, though the effect on weight plateaus after 20 weeks of age.
Audience
Practising veterinarians, veterinary students, Researchers.
Key Takeaways
01
The dw Gene Delays Sexual Maturity by About a Week
Pullets carrying the dw gene reached sexual maturity roughly 7.1 days later than normal broiler pullets on an individual bird basis, a statistically significant genotype effect. This delay was consistent with prior literature on dw gene expression in egg-type and broiler pullets.
02
Body Weight Divergence Is Steepest Early, Then Levels Off
Dwarf broiler and normal broiler pullets showed a 33.31% body weight gap at 20 weeks of age, which grew to about 40% by 30 weeks but barely increased further by 40 weeks. This suggests the dw gene's suppressive effect on growth is largely established during the juvenile period rather than continuing to compound in adulthood.
03
Early Maturity and Early Body Weight Are Negatively Linked
Genetic correlation analysis found a significant negative relationship between age at sexual maturity and 20-week body weight, meaning pullets that matured earlier tended to be heavier at that early age. However, low correlations between body weights at different ages indicated this early heaviness didn't reliably predict which birds would be heaviest later on.