49 results about "Reciprocal cross" patented technology

The invention provides a breeding method capable of improving a white feather rate and class of semi-muscovy ducks. Male and female parent samples of the semi-muscovy duck are systematically bred by mainly using reciprocal cross, self cross and subculture selection methods. The breeding method has the advantages that the white feather rate and class A of the semi-muscovy ducks can be efficiently and systematically improved, the white feather quality of the semi-muscovy duck is comprehensively improved, the high-quality and first-class feather and the white and attractive carcass are provided for market, the market competitiveness and farming benefit of the semi-muscovy duck are increased, and the method is favorable for promoting the white-feather semi-muscovy duck industry to be developed to a higher level.

The invention discloses an undersized white feather broiler breeding method. An undersized yellow chicken and a white feather broiler are used for being in reciprocal cross and after that the yellow chicken and the white feather broiler are in horizontal cross fixing. Then, shutting breeding can be proceeded to breed a breed of undersized white feather broilers. The undersized white feather broiler breeding method is used for breaking through a traditional thought that a large-sized cock is mated with a large-sized hen to give birth to a parents-generation white chicken in a normal bodily form in the prior art. An undersized cock is chosen to mate the large-sized hen to give birth to the parents-generation white chicken in a grain-saving type. A method that an undersized yellow chicken (contains a dw gene) is half-bred with a white fast-growing chicken is used for choosing and breeding a breed of dominance undersized white chickens. High isozygoty and high stability of the dw gene can be guaranteed, and absolute security of resource can be guaranteed. An adult chicken is shapely in body and gesture, rounded in bodily form, huge in head, thick in neck, compact and shining in feathers and strong and muscular in chest-leg muscles. Chicken herd is good in uniformity and strong in disease resistance. Hens which enter into pheasantries for 66 weeks can lay 170-175 eggs. The weight of each egg is 50-60 grams. Passing percent of hatching egg is more than 95%. Emergence rate of hatching is 90%.

The invention discloses a breeding method of common mudflat shellfish by convergent cross. The method comprises the steps: mudflat shellfish parents from more than four different geographic populations are collected; the shellfish parents of different geographic populations are carried out eco-maturing; then dual reciprocal cross is carried between two geographic populations; a first filial generation of dual reciprocal cross combination is bred up by a three-stage method; then the convergent cross of the first filial generation of dual reciprocal cross is carried out so as to obtain a first filial generation of convergent cross; and the above steps are repeated on the basis thereof till the filial generation of convergent cross accumulates the good genes of all the geographic populations. The method overcomes the geographic isolation and the biological differences of sexual maturity and breeding among different geographic populations. Compared with the existing mudflat shellfish varieties, the shellfish integrates the good genes from more than four different geographic populations; the heterozygosity is improved greatly, thus causing the converged half-bred individual to presentcharacteristics of fast growing and high stress resistance.