عنوان مقاله [English]
Introduction One of the animal breeding aims is increasing the economic efficiency. Therefore, mating among selected animals in order to enhance economic efficiency should also supply variation in population for next generations’ selection. This study was performed to estimate performance in cross breed lambs resulting from crosses of shal, moghani, afshari and varamini rams with varamini ewes, compained it to pure varamini lambs.
Materials and Methods The objective of this study was the progeny evaluation from slaughter in one way crossing between Varamini ewes with Shal, Afshari, Moghani and Varamini rams and comparing their progeny efficiency. Thus, three 1.5 and 3 years rams were selected from each of Shal, Afshari, Moghani and Varamini breeds. A sample was separated from 10, 11 and 12 ribs was separated for examination of the fat, meat and bone percentage in different breed group lambs carcass. Data statistical analyze was done by GLM procedure of SAS 9.1 software.
Results and Discussion Afshari crossbreed lambs had better carcass performance rather than the other breed groups although before slaughtering live weight of Shal and Moghani lambs were higher. Male lambs had better live weight and carcass quality before slaughtering than female lambs. The analyze of carcass parts percentage indicated that crossbreed lambs from Afshari rams with Varamini ewes had the highest efficiency and lowest rump percentage between genetic groups about valuable parts total percentage of thigh, roast, wristband and low price flank steak, brisket and neck. The analyze results of carcass tissue proportions combination showed Shal, Moghani and Afshar crossbreeds had more meat percentage and lower fat percentage on numbers 10, 11 and 12 of ribs than Varamini net breed.
Conclusion According to our findings about cross surface and length from carcass the highest amount of them was belong to Shal and Afshari breeds, although difference amount between breeds was not significant. Finally, male had more significantly cross surface than female. Average percentage for lion, thigh, flank, brisket, neck, longissmus muscle area and carcass length, full and empty digestive system in different genetic group has no significant difference, also, average for, shoulder, legs, tail, heat, lean percentage and bone in 10-12 vibs sample and skin and fat percentage in this sample was significantly different in various groups. Sex effect on total removable fat and percentage of various carcass sections expect of thigh, lion and neck percentages, other carcass sections have significant differences in two finishing periods.