Genetic Trend Analysis of Genome Selection in Holstein Dairy Cows in Hebei Province
The objective of this study was to analyze the lgentity production index(IPI),net merit dollar(NM),milk yield,fat yieid,protein yieid,somatic cell score,productive life,daughter pregnancy rate,udder structure,body height and body size of approximately 15,000 cattle born in Hebei Province from 2015 to 2022 and compare them with the national average.The results revealed that the average IPI of cattle born in Hebei province in 2020 was 2098,which was 0.47% higher than the national average of 2088.Notably,the IPI for Hebei-born cattle reached its peak in 2022 at an impressive awerage of 2304,which was an annual growth rate of approximately 103 over the past three years.Moreover,in 2020,the average milk yield of Hebei-born cattle was 257,surpassing the national average by a substantial margin of 23.56% .In 2022,the average milk yield of Hebei born cattle reached 539,and the average milk yield increased by 141/year over the last three years.