Abstract:
Objective Purifying and cross-matching the male line D of Cyan-shank Partridge chickens were studied to sustain a desired appearance and performance for commercial breeding.
Method Using PCR, the breeder cocks with TYR heterozygous genotype were eliminated to achieve feather color selection, disease eradication, body weight, and egg laying. A synthesized D line was obtained by pure breeding for 3 generations, and then, employed as the terminal male parent for performance testing on a 3-line crossing.
Result (1)A consistent feather color on the D line was reached by eliminating the heterozygote of TYR gene in the cocks from generation 1 (G1) to generation 3 (G3). The proportion of white feather on the cocks decreased from 50.49% in G1 to 1.89% in G3. Through the phenotypic selection, the proportion of chickens with wild-quail-like feather increased from 21.12% in G1 to 93.78% in G3. (2)A significant result on the pullorosis eradication in each generation was realized with a positive disease rate reduced from 14.6% in G1 to 2.4% in male D3, and from 6.83% in G2 to 2.08% in female G3 chickens.(3)The body weights of the 43-week-old G3 roosters and hens were 3 993.70 g and 3 397.14 g, respectively, being 174.64 g and 67.6 g, respectively, heavier than G1 counterparts (P>0.05). Those hens laid 60.3 eggs per week with an average weight of 63.38 g per egg in G1 increasing to 82.5 eggs per week with an average weight of 64.42 g in G3. The average generation-to-generation improvements were 12.27% on egg production and 1.64% on egg weight. (4)D♂× (K♂×Y♀) produced a breed more productive in meat than the other 4 crosses. In 80 d, the average body weights of the DKY male and female broilers reached 2992.46 g and 2395.7 g, the half-eviscerated percentage of 85.57% and 85.27%, and the pectoral muscle percentage of 19.19% and 21.56%, respectively.
Conclusion After 3 generations of breeding, the appearance and meat productivity of the paternal D line Cyan-shank Partridge chickens had been greatly improved for the commercial breeding.