The Formulation And Application Of Seed Selection And Matching Plan Of Simmental Cattle In Core Breeding Farms In Xinjiang

In this study,the milk production traits of adult Simmental cows in core breeding farms in Xinjiang,a total of 13 scoring traits on a 9-point scale for body type and external appearance identification,and a total of 20 traits on actual measured trait data were used to study the collected body type and performance data for the purpose of scientifically formulating selection and selection plans for different regional farms,accelerating the construction of core herds,and speeding up the process of genetic improvement of Chinese Simmental cattle.The preliminary analysis of the collected body size data and production performance data was carried out using SPSS 19,CFC and R software.The average inbreeding coefficient of the herd was calculated,and while avoiding the inbreeding decline of the herd,the core herd and the frozen semen of the bulls used were selected in line with the total performance index,and the following results were obtained by combining the bloodline genealogy chart and the body size of the bulls and females to develop a perfect selection and matching plan for the field.(1)The results showed that the total number of individuals in the foundation herd was 919 and the total number of individuals in the non-foundation herd was 2216,of which 879 were retained as production females and produced 1482 offspring;107 were full siblings,with an average lineage content of 2.18,of which the largest lineage content was 4 and the smallest lineage content was 2.content was 4 and the smallest lineage content was 2.The inbreeding coefficient was 0.00 < F ≤ 0.05 for 2 individuals,0.10 < F ≤ 0.15 for 3 individuals,and 0.20 <F ≤ 0.15 for 3 individuals.There were 15 cows between 0.20 < F ≤ 0.25 and 1 cow between0.35 < F ≤ 0.40.The average inbreeding coefficient of the inbred lines was 0.215402,with the largest inbreeding coefficient being 0.375 and the smallest inbreeding coefficient being0.0078125.(2)In the present study,the total performance index of the bulls used from 2011 to 2021 was obtained by querying the information on the frozen semen of the bulls in the two farms and ranking the frozen semen of the bulls with the total performance index developed by the group in the early stage,and the total performance index of the bulls used from 2011 to 2021 was obtained through the bull lineage chart.The descriptive statistics of the measured body size data of the lactating cows in the herd revealed that the uniformity in the trait of suspensory ligament was poor in both farms and needed urgent improvement,and the key traits that directly affect milk production were obtained through the path analysis of udder traits and milk production: hind udder width and hind udder area length.(3)By calculating the individual estimated breeding values of the in-herd females in Xinjiang Hutubi Breeding Farm Herd 3 and Ili Chuangjin Herding Ranch,and then using the total performance index of Simmental cattle in Xinjiang region developed by the group earlier to line up 261 core herd Simmental females as the core herd in Xinjiang Hutubi Breeding Farm Herd 3,and 471 Simmental females as the core herd in Ili Chuangjin Herding Ranch,and then using a combination of homogeneous and heterogeneous matching to develop a matching plan,the selection and matching plan of the in-herd females in both farms was finally completed.