| Titles |
|
English :
|
Crossbreeding components for some lifetime milk production and longevity traits in up- grading trails of domiaticattle with three dairy cattle breeds in Egypt
|
|
Arabic :
|
مكونات الخلط لبعض صفات انتاج اللبن خلال الحياة الانتاجية و طول العمر في تجارب تدريج الابقار الدمياطى مع ثلاث سلالات ماشية لبن في مصر
|
|
| Abstract |
Three trails of upgrading Egyptian Domiati cows with Friesian (Friesian trial). Dairy Shorthorn (Shorthorn trial) and Jersey (Jersey trail) bulls were carried out in three experimental stations of the Animal Production Research Institute (APRI) in Egypt. Lifetime traits in the three upgrading trials were genetically evaluated. The number of cows used in the analyses were, 464, 329 and 169 in Friesian, Shorthorn and Jersey trials, respectively. Direct (GI) and maternal (GM) additive effects, direct (HI) and maternal (Hm) heterotic effects and direct (RI) and maternal (R?M) recombination effects for lifetime milk production [lifetime total milk yield (LTMY), lifetime 305- day milk yield (L305M), lifetime days in lactation (LLP), milk yield per day of lactation (MDLLP), milk yield per day of herd live (MDHL) and milk yield per day of productive live (MDPL)] and longevity [ length of herd life (LHL), length of productive life (LPL)and number of lactations completed per cow (NLC)] traits were estimated. In Friesian and Shorthorn trials, grades generally showed better performance in traits of LTMY, L305M, LLP, LHL, LPL, NLC than those of its paternal purebred group. In Jersey trail, grades showed higher means than local Domiati only. In the three trails, estimates of G1 and GM for all lifetime traits were generally in favor of the European breeds. In Friesian and Jersey trails, estimates of direct heterosis (HI) for all lifetime traits were positive, and the estimates recorded in Shorthorn trail were positive for lifetime milk production traits except for LLP and negative for longevity traits. Estimates of HI ranged from 3.5 to 48.5% in Friesian trail and from 6.8 to 40.5% in Jersey trail. Positive estimates of HM were recorded for all lifetime traits in Friesian and Jersey trails and negative in Shorthorn trail. The estimates ranged from 4.9 to 20.4% in Friesian trail and from 2.5 to 48.9% in Jersey trail. Estimates of RI were positive for all lifetime traits in the three trails. Estimates of RM for all lifetime traits in Friesian and Shorthorn trials were positive, while those in Jersey trial were mostly negative. It could be concluded that crossing Egyptian cattle with exotic dairy breeds may improve lifetime traits. Estimates of linear regression of lifetime traits on age at first calving were generally negative in the three trials, which show that a reduction in age at first calving is desirable for dairy breeders to improve lifetime traits. Estimates of linear regression of lifetime traits on first lactation 305- day milk yield in the three trials were positive, which indicate that selection for high first lactation milk yield would lead to an increase in lifetime milk production traits and to prolong length of both herd and productive life.
Keywords: Egyptian Domiati cows, Up- grading, lifetime traits, longevity traits, Additive, Heterotic and Recombination effects.
|
| Publication year |
2001
|
| Pages |
1501-1516
|
| Availability location |
معهد بحوث الانتاج الحيوانى- شارع نادى الصيد- الدقى - الجيزة
|
| Availability number |
|
| Organization Name |
Animal Production Research Institute (APRI)
|
| City |
مشتهر
|
| serial title |
Animals of Agriculture Science
|
| Department |
Cattle Breeding Research Department
|
| Author(s) from ARC |
|
| Agris Categories |
Animal husbandry
|
AGROVOC
TERMS |
Cows.
Crossbreeding.
Dairy cattle.
Egypt.
Longevity.
Milk production.
Recombination.
|
| Publication Type |
Journal
|