| Titles |
|
English :
|
Genetic and environmental trends for post- weaning body weights in New Zealand White and Z- line rabbits using the animal model approch
|
|
| Abstract |
Genetic and environmental trends were evaluated for post- weaning body weights of 20677 weaned rabbits of New Zealand White (NZW) and Z- Line born between 1982 and 1996 from 1212 sires and 3168 dams. Multi- trait animal model was used for such evaluation taking into account body weight at 8 and 12 weeks of age. Heritability estimates for the two body weight in NZW were higher than those in Z- line; being 0.34 and 0.30 in NZW and 0.10 and 0.25 in Z- line at 8 and 12 weeks of age, respectively. Common litter effects were higher in Z- line (averaged 37.65%) than those in NZW (averaged 29.95%). All correlations between the two body weights were moderate or high; being 0.73 and 0.69 for genetic correlations, 0.60 and 0.64 for phenotypic correllatios, 0.49 and 0.64 for common- litter correlations and 0.45 and 0.68 for environmental correlations in NZW and Z- line rabbits, respectively. The ranges in predicated breeding values (PBV) for body weights at 8 and 12 weeks of age were 572 and 639 gram in NZW, while they were 216 and 449 gram in Z- line, respectively, i.e. wide variations in PBV of body weights between the two strains were in favor of Z- line rabbits. The accuracies ( ra) of minimum and maximum estimates of PBV were mostly higher in NZW than those in Z- line for the two weights; ranging from 0.48 to 0.73 in NZW and 0.38 to 0.62 in Z – line. Genetic trends indicate that PBV were mostly positive in NZW and negative in Z- line over the whole period of the study. In NZW rabbits, the trend indicates that the plateau for the breeding values reached soon at the beginning years, while in Z- line the rates of change in breeding values were very low during the five years of the study. Plots of year- season trends indicate that environmental effects ( i.e. seasonal – annual variations ) play a large role in improvement of the two body weight in both lines.
Keywords: Body weight, Animal model approach, heritability, correlations, breeding values, genetic trend.
|
| Publication year |
2002
|
| Pages |
89-101
|
| Availability location |
معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة
|
| Availability number |
|
| Organization Name |
Animal Production Research Institute (APRI)
|
| City |
الغردقة
|
| serial title |
3rd Science Conference On Rabbit production in Hot Climates
|
| Author(s) from ARC |
|
| External authors (outside ARC) |
محمود مغربى عراقى
جامعة بنها
علاء الرفا
جامعة الاسكندرية
ماهر حسب النبى خليل
جامعة بنها
|
| Agris Categories |
Animal husbandry
|
AGROVOC
TERMS |
Body weight.
Dams.
Fathers.
Heritability.
Rabbits.
|
| Proposed Agrovoc |
genetic trend;breeding values;correlations;Animal model approach;
|
| Publication Type |
Conference/Workshop
|