Selection of laying hens
2020-12-16
There are two ways to select layers: homogeneous matching and heterogeneous matching.
1. Homogeneous selection The essence is the directional mating of roosters with high breeding value with the same advantages and hens. Homogeneous mating is based on kinship mating or "similar and similar" mating. The mating of individuals with similar phenotypes may not necessarily consolidate the same traits, especially traits with low heritability. Only when roosters with similar phenotypes and genotypes are matched with hens, can the traits to be selected be fixed more reliably.
Inbreeding may occur in long-term homogeneous matching. Mating with individuals of different families with similar genotypes can avoid the adverse effects of inbreeding and fix the breeding traits of the offspring at the proper level.
2. In order to maintain the high yield of the line and the heterosis obtained when the line is crossed, it is necessary to carry out heterogeneous selection. The selection of roosters and hens with obvious differences in traits is called heterogeneous selection. This selection can be used for inter-line crosses or intra-quality crosses. The latter method is to choose roosters and hens from different families. Heterogeneous selection can be based on both phenotype selection and genotype selection. The selection and mating of individuals with different genotypes guarantees the appearance of heterosis in the line or matching cross combination, which is conducive to maintaining the production performance at a higher level. At present, the high-yield supporting lines at home and abroad all use the heterogeneous selection method, and the medium-sized brown-shell layer is more obvious.
