A Study on the Reproduction Performances of Commercial Taiwan Country Chickens

Autor: Ya-Mei Huang, 黃雅梅
Rok vydání: 2003
Druh dokumentu: 學位論文 ; thesis
Popis: 91
In order to realize the probable existing problems of reproductive performance in commercial breeders of Taiwan Country chickens, reproduction performance, including traits of egg production, semen characteristics, fertility, hatchability, immunity, and morality, of breeders of the two major types, black and red feather varieties, were tested. Following the method generally used by commercial breeders, male and female birds at 9—13 weeks of age were collected from each of ten commercial farms located in the central and south parts of Taiwan, and were housed at the livestock research farm of the National Chung-Hsing University for testing their reproductive performance. Chickens for experiment were caged individually, fed restrictly, and water was given ad libitum. Results indicated consistent performance difference between black and red feather birds. The black feather bird sexually matured earlier, had higher egg production, and lower body weight and egg weight than the red feather bird (P < 0.01). Least square means of black and red feather birds were as follows: age at first egg (AFE) were 166.3 d and 185.5 d, age and rate of lay at peak of egg production were 28 wks 69.5 % and 33 wks 51.2 %, hen-housed egg production from AFE to 40 wks were 69.7 and 45.1 eggs, from 40 to 60 wks were 62.0 and 36.5 eggs, and from AFE to 60 wks were 126.2 and 77.3 eggs, hen-day egg rate from AFE to 40 wks were 64.5 and 53.5 %, from 40 to 60 wks were 40.8 and 24.7 %, and from AFE to 60 wks were 51.3 and 36.0%, body weight at AFE were 2247 and 3159 g, at 40 wks were 2322 and 3028 g, at 50 wks were 2379 and 3172 g, and egg weight at AFE were 36.4 and 43.4 g, at 40 wks were 47.5 and 51.9 g, and at 50 wks were 52.4 and 56.3 g, respectively. In the semen traits, no matter at 30, 45, or 60wks of age, sperm motility and sperm concentration of black feather bird were significantly better than those of the red feather bird (P < 0.05). Neither semen volume nord total sperm per collection were significantly different between two types (P>0.05). Semen contamination of red feather bird, however, was more serious than the black. Semen traits were significantly affected by aging in both types of birds. Fertility, and hatchabilities of fertile eggs and all eggs set were tested by artificial insemination. The results, in general, indicated that the performance of black feather bird were better than the red, and the best fertility of both was at 30 wks of age when they were at their peak of egg production. Average at 12 and 28 weeks of age, breeder birds were injected of mixed vaccines of New Castle disease (ND), Infectious Bronchitis (IB), and Infectious Bursar disease (IBD), then the blood was taken at 16 and 30 weeks of age to determine the immunocompetence of ND, IB, and IBD. ND antibody titer, except of those of the first and second farm obviously had been infected with virus in the field, were in generanl in the safe range, averages were between 64 and 978 (29.6). Mean ND titer of red feather birds were lower and with larger variation suggested that more birds were infected virus than the black feather birds. Based on the titer of IB indicated that both red and black feather birds had obviously been infected with IB virus, which rendered low egg production. In addition, very high IBD titer also suggested that there were serious problems of vacctionation program in the rearing period.
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