| 1.Breeding of the dwarf pink egg cross-stains. Introducing advantage white egg chickens into breeding programs, a dwarf pink egg cross strains was set up based on dwarf brown egg pure line using synthetic stain breeding technology. The cross contained three lines, such as dwarf brown egg line (W) and slow feather white egg line (LD) and fast feather white egg line (LC), in which W was the end feather and LD was mother' feather and LC was mother's mother. The commercial chick can be feather sexed and laid pink eggs. The selection on egg number was based on part records in order to get one generation a year. The dam was selected on the value of her family and her selfs. The sire was selected on the value of his sisters. In order to increase late egg numbers after peak production of the W line, a method was raised of using line equation to imitate egg numbers after 44 wk age. The main traits such as egg numbers increased generally in the processing. There were 2.5 eggs improved and 1 day shorter in a generation for W line. Egg numbers at 44wk age of LC reached 142.2 in 3rd generation, 11.1 eggs more than 0 generation. LD and LC had lower hereditability on EW40. The genetic correlation between BW140 and FEA was negative, while LD and LC were positive. The genetic correlation between FEA and EW40 were positive for three lines. The genetic correlation between EN40 and BW140 was -0.27 for W line and positive values for LD and LC line. The performance tests showed that the dwarf chickens had significant lower body weight than the normal chicken from 6wk age (<0O.05). The dwarf pink egg cross (DWF) produced more eggs than the DWB, its egg number was 289.8, closing the normal white egg chickens (NW) (291.3 eggs), about 15 eggs lower than the normal brown egg chickens (NB) and the normal pink egg chicken (NF). Its average egg weight was 55.9g, and mass egg weight 16.21kg at 72wk age, and feed conversion ratio was 2.06. The DWF had the best feed conversion efficiency in the five groups, about 14% to 18% higher than the normal. The DWF can get more profit about 8 to 14 Yuan than the normal chickens in same feed and egg price condition.2.Breeding of color sexing cross-stains. The genetic pattern on feather color of the dwarf brown egg chicken was studied through test mating. From the results, another 'sal' gene on the s/S gene loci of dwarf brown line was concluded first time, and a dwarf male line with golden feather gene 's' without sal gene was bred. The offspring can be color sexed using the dwarf male cross Rhode Island Whites.3. Mating feeding technology of the dwarf egg chicken. The cage, which was designed for the dwarf layers, was on the base of measuring their body shape. The dwarf layer cage was four-story step cage. Compare to the normal layer cage, the dwarf layer cage has the nearly same outside shape because its single cage is 8 cm short than the normal. 4 dwarf layers can be feed in one suit of the dwarf layer cage. There are 374 cm2 cage bottom area and 11.7 cm feed length for one dwarf layer. The feeding density would be increased 33% because of one more story and 128 dwarf layers can be feed in one group. The dwarf layer should intake CP 14.13g and s-AA 0.558g per day to maintain its need for peak production. The suitable cure protein (CP) should be about 17.3% and metabolically energy (ME) being 2700kcal/kg (11.3Mj/kg) in the feed for the dwarf layers if the feed intake was 85g to 90g. Using B -dextran enzyme in the feed can reduce the stress in unsuitable season. The rearing temperature should be about 1 癈 to 2癈 higher than normal chicks for the dwarf chicks. |
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