Analysis On The Effect Of Breed Conservation And Selection Of Chengdu Ma Goat

Chengdu Ma Goat is an excellent local goat breed in China,because of its good meat quality,excellent skin,and wide adaptability.For a long time,due to excessive introduction of other breeds and lack of comprehensive and systematic work of breed conservation and selection,the population characteristics have been seriously degraded.In 1988,Chengdu Ma Goat was officially included in the "National Genetic Resources Bank for Livestock and Poultry Breeds" by the Ministry of Agriculture,and in 2015,it was included in the "National protection list of livestock and poultry genetic resources" by the Ministry of Agriculture.Since 2008,Chengdu Xilingxue Agricultural Company has been committed to the conservation and breeding of Chengdu Ma Goat.This study is based on the Chengdu Ma Goat farm of Xilingxue Agricultural Company.By measuring the main production performance data of the protected population,analyzing the genetic structure of the protected population and measuring the main production performance data of the breeding population,the effects of conservation and breeding were evaluated.This study provides a reference for the conservation and breeding of Chengdu Ma Goat.The main results are as follows:(1)By carrying out conservation work,the population has obvious physical features,such as “thrush eye” and “cross hair band”.The goat hair is red bronze,or hemp brown,or maroon.The original physical features of Chengdu Ma Goat were kept basically.(2)By analyzing the main body measurement data of Chengdu Ma Goat in 2015-2018,the results show that the preserved population has basically maintained the body shape of Chengdu Ma Goat.At present,the average birth weight,weaning weight,6-month-old and1-year-old weights of rams in preserved population are 1.79 kg,8.96 kg,21.40 kg,and 30.10 kg,respectively.The average birth weight,weaning weight,6-month-old and 1-year-old weights of ewes are 1.57 kg,8.72 kg,17.1 kg,and 23.90 kg,respectively.The lambing rate of primiparous ewes is 149.7%,and the lambing rate of multiparous ewes is 216.6%.The preserved population has basically maintained the main production performance level of the original Chengdu Ma Goat,indicating that the effect of breed conservation is good.(3)Analysis of the results of Restriction site-Associated DNA sequencing(RAD)revealed that there is a certain differentiation of conserved population.The heterozygosity value of about 30% SNP markers in the whole genome ranged from 0.3 to 0.4,indicating that the population still possessed genetic diversity.The average observed heterozygosity(0.1921)ofthe population was lower than the average expected heterozygosity(0.203),indicating that there was a low degree of inbreeding in the conserved population.(4)Through the continuous breeding work in recent years,the main production performance of Chengdu Ma Goat has been significantly improved..The average birth weight,6-month-old and 1-year-old weights of rams reached 1.98 kg,25.63 kg and 34.10 kg,respectively.The average birth weight,6-month-old and 1-year-old weights of ewes reached1.82 kg,19.85 kg and 26.78 kg,respectively.The lambing rate of primiparous and multiparous ewes is 165.3%,and 228.8%,respectively.The weaning survival rate reached95.8%.The carcass weight of 1-year-old wether was 19.25 kg,the dressing percentage was53.07%,the net meat weight was 16.60 kg,and the meat percentage was 86.22% after slaughter.Compared with the Chengdu Ma Goat Local Standard(DB51/T654-2007),the rams in the breeding groups have reached the standards of premium goat and first-class goat,and the ewes have basically reached the target of first-class goat.The results of this study provide an important reference for the formulation and implementation of preserved program,and the selection and improvement of Chengdu Ma Goat.