VETS20015 Lecture Notes - Lecture 7: Heterosis, Crossbreed, Breeder Reactor
Document Summary
Crossbreeding: used a lot in pig industry, poultry industry and dog industry etc. In general: the greater the genetic difference in the strains, the greater the. If the 2 strains of animals are fairly distantly related- more heterotic effect: heterosis is greatest for traits associated with reproduction and viability, cross bred animas- better reproductive and survival. Wt of calf weaned per cow joined: individual heterosis +8%, maternal heterosis +14. 8%. therefore x bred calves from xbred cows +23. 3% 4 way cross: maternal, paternal and individual heterosis: exploits advantages of. 2 way cross: exploits individual heterosis alone (complementarity may also exist) By crossing with a naturally polled breed- angus. Cattle: polled allele dominant: gen 3 offspring indistinguishable from horned except for no horn- can breed polled to polled to close off (use diverse initial sample of angus) Q- crossbreeding has been very widely adopted in australian sheep meat industry but not in the fine wool industry, which exclusively uses purebred merinos.