The reproduction characteristics of 343 sows in six different breeding groups were analyzed to estimate the crossbreeding parameters. The results indicated that the ovulation rate and the weights of uterus and ovary a...The reproduction characteristics of 343 sows in six different breeding groups were analyzed to estimate the crossbreeding parameters. The results indicated that the ovulation rate and the weights of uterus and ovary are mainly determined by the additive genetic effects while the nonadditive genetic effects play an important role in embryonal traits and litter performance. The heterosis effects in the first litter are larger than those in the second litter because of heterosis x environment interaction. The results also showed the existence of a highly significant maternal heterosis effect on the fertility traits of sows.展开更多
To understand the fattening performance of Duroc x Landrace×Yorkshire and Duroc×Yorkshire x landrace, 48 individuals of two kinds of three-way crossbreeding lean type commercial pigs were selected to determi...To understand the fattening performance of Duroc x Landrace×Yorkshire and Duroc×Yorkshire x landrace, 48 individuals of two kinds of three-way crossbreeding lean type commercial pigs were selected to determine average daily feed intake, average daily gain and feed gain ratio. The backtat thickness and eye muscle area of pigs were measured at the end of trial. The results showed that Duroc × Landraee × Yorkshire and Dttroc × Yorkshire x Landrace had similar fattening performance, and could be applied under scientific management conditions. The study is of great significance for development of pig industry.展开更多
The carried out experimental work aimed at the improvement of the native rabbit zootechnical performances. The goal was to run a genetical progress of an exotic breed ＂the Californian＂ through a crossbreeding with a...The carried out experimental work aimed at the improvement of the native rabbit zootechnical performances. The goal was to run a genetical progress of an exotic breed ＂the Californian＂ through a crossbreeding with a native rabbit. Ten females have been crossed with two native males （L × C） compared to controls Native × Native （N × N） and Californian × Californian （C × C）. The reproduction and growth performances are clearly improved by crossbreeding effect, the recorded heterosis are： 9.43%, 16.34% and 21.93%, respectively for the alive litter size, alive and weaned; 10%, 16.75% and 2.57%, respectively for the alive litter weight, alive and weaned; 2.57% for the individual weight at birth; 10% and 7% for post weaning performances, respectively day mean gains and feed conversion ratio. Weight at slaughter is improved with 167 g, which representing a considerable level for the native population. Genetic crossbreeding between the Algerian native rabbit and the Californian, raised under rearing conditions of the Blida university farm experiment showed its efficiency on the most zootechnical performances. The complementary effect turned up positively on the crossbred rabbits Their post-weaning growth performance is comparable to those of the Californian with a better viability at weaning and slaughtering age.展开更多
In order to improve the meat production performance of local sheep varieties in Gansu Province, Dorset was introduced to crossbreed with the local sheep varieties, including Tan sheep, Small Tail Han sheep and Mongoli...In order to improve the meat production performance of local sheep varieties in Gansu Province, Dorset was introduced to crossbreed with the local sheep varieties, including Tan sheep, Small Tail Han sheep and Mongolia sheep. The offspring of different crossbreeding combinations were sampled randomly at different growth stages, and their growth and development traits were measured so as to screen out the best crossbreeding mode. The results showed that under the same crossbreeding mode, the growth rate of F3 was higher than that of F2, and of F2 was higher than that of F1. Among the F3 population, the growth rates of Dorset ×Han and Dorset × Mongolia hybrids were higher. Compared with those of Dorset ×Tan F3 hybrids, the body weights of male and female Dorset × Han and Dorset ×Mongolia F3 hybrids were increased by 5.59%, 4.40%, 5.93% and 3.76%, respectively. Among the F2 population, the growth rates of Dorset × Han and Dorset ×Mongolia hybrids were also higher. The body weights of male and female Dorset ×Han and Dorset × Mongolia F2 hybrids were higher than those of Dorset × Tan ×Han F2 hybrids by 5.99%, 3.67%, 9.80% and 5.00%, respectively. In the F1 population, the growth rates of Dorset × Han and Dorset × Mongolia hybrids were higher.Compared with those of Tan × Han F1 hybrids, the body weights of male and female Dorset × Han and Dorset × Mongolia F1 hybrids were increased by 11.32%,5.22%, 7.60% and 7.20%, respectively. Therefore, in the feeding area of Small Tai Han sheep, Mongolia sheep and Tan sheep, Dorset was the best sire for producing hybrid lambs. The economic benefit of crossbred offspring was obvious.展开更多
文摘The reproduction characteristics of 343 sows in six different breeding groups were analyzed to estimate the crossbreeding parameters. The results indicated that the ovulation rate and the weights of uterus and ovary are mainly determined by the additive genetic effects while the nonadditive genetic effects play an important role in embryonal traits and litter performance. The heterosis effects in the first litter are larger than those in the second litter because of heterosis x environment interaction. The results also showed the existence of a highly significant maternal heterosis effect on the fertility traits of sows.
文摘To understand the fattening performance of Duroc x Landrace×Yorkshire and Duroc×Yorkshire x landrace, 48 individuals of two kinds of three-way crossbreeding lean type commercial pigs were selected to determine average daily feed intake, average daily gain and feed gain ratio. The backtat thickness and eye muscle area of pigs were measured at the end of trial. The results showed that Duroc × Landraee × Yorkshire and Dttroc × Yorkshire x Landrace had similar fattening performance, and could be applied under scientific management conditions. The study is of great significance for development of pig industry.
文摘The carried out experimental work aimed at the improvement of the native rabbit zootechnical performances. The goal was to run a genetical progress of an exotic breed ＂the Californian＂ through a crossbreeding with a native rabbit. Ten females have been crossed with two native males （L × C） compared to controls Native × Native （N × N） and Californian × Californian （C × C）. The reproduction and growth performances are clearly improved by crossbreeding effect, the recorded heterosis are： 9.43%, 16.34% and 21.93%, respectively for the alive litter size, alive and weaned; 10%, 16.75% and 2.57%, respectively for the alive litter weight, alive and weaned; 2.57% for the individual weight at birth; 10% and 7% for post weaning performances, respectively day mean gains and feed conversion ratio. Weight at slaughter is improved with 167 g, which representing a considerable level for the native population. Genetic crossbreeding between the Algerian native rabbit and the Californian, raised under rearing conditions of the Blida university farm experiment showed its efficiency on the most zootechnical performances. The complementary effect turned up positively on the crossbred rabbits Their post-weaning growth performance is comparable to those of the Californian with a better viability at weaning and slaughtering age.
文摘In order to improve the meat production performance of local sheep varieties in Gansu Province, Dorset was introduced to crossbreed with the local sheep varieties, including Tan sheep, Small Tail Han sheep and Mongolia sheep. The offspring of different crossbreeding combinations were sampled randomly at different growth stages, and their growth and development traits were measured so as to screen out the best crossbreeding mode. The results showed that under the same crossbreeding mode, the growth rate of F3 was higher than that of F2, and of F2 was higher than that of F1. Among the F3 population, the growth rates of Dorset ×Han and Dorset × Mongolia hybrids were higher. Compared with those of Dorset ×Tan F3 hybrids, the body weights of male and female Dorset × Han and Dorset ×Mongolia F3 hybrids were increased by 5.59%, 4.40%, 5.93% and 3.76%, respectively. Among the F2 population, the growth rates of Dorset × Han and Dorset ×Mongolia hybrids were also higher. The body weights of male and female Dorset ×Han and Dorset × Mongolia F2 hybrids were higher than those of Dorset × Tan ×Han F2 hybrids by 5.99%, 3.67%, 9.80% and 5.00%, respectively. In the F1 population, the growth rates of Dorset × Han and Dorset × Mongolia hybrids were higher.Compared with those of Tan × Han F1 hybrids, the body weights of male and female Dorset × Han and Dorset × Mongolia F1 hybrids were increased by 11.32%,5.22%, 7.60% and 7.20%, respectively. Therefore, in the feeding area of Small Tai Han sheep, Mongolia sheep and Tan sheep, Dorset was the best sire for producing hybrid lambs. The economic benefit of crossbred offspring was obvious.
