Genetic Analysis Of Calf Passive Immunity And Cow Colostrumquality In Chinese Holsteins

Calf stage is the most important period in a cow’s life.The health status and nutrition level of calves in the calf stage directly affect the reproductive efficiency and lactation performance in the later stage.The immune system of newborn calves is not fully developed in function,and its humoral immune system cannot respond effectively to the invasion of foreign antigens,so it must absorb sufficient colostrum immunoglobulin to obtain passive immunity.This study around the holstein calves cattle early passive immunity levels and cow milk quality,and the two characters,collect the 31 scale40 198 holstein cattle ranch head calf serum total protein and 27 854 cow colostrum Brix,delving into the two groups of the and influence factors,and the two traits are genetic analysis.The results of this study are beneficial to improve the level of colostrum feeding and colostrum quality management of calves,improve the passive immunity level and colostrum quality of calves,and increase the benefit of pasture.The results showed that the management of colostrum collection,comprehensive colostrum detection,timely colostrum and sufficient feeding should be strengthened in Holstein pasture.In the Chinese Holstein population,the average serum total protein of calves was 7.26 ± 1.01 g/d L,and the passive immunity failure and success accounted for 2.21% and 63.98%,respectively.The serum total protein of calves showed a decreasing trend year by year.Test field,birth year,birth season and colostrum quality had significant effects on the passive immunity level of calves(P < 0.05).The passive immunity level of calves was a low heritability trait(0.122),and there were different degrees of approximate genetic correlations with the production,body size,reproduction,disease and longevity of adult calves.The average Brix of colostrum was 23.51 ± 2.61%,and the qualified rate and excellent rate of colostrum were 92.67% and 71.34%,respectively,which were close to the level of developed animal husbandry countries.The colostrum BRIX showed an increasing trend year by year.The test field,calving year,calving season,calving number and time from calving to first lactation had significant effects on colostrum BRIX of adult cows(P < 0.05).Colostrum quality is a low heritability trait,and there are different degree of approximate genetic correlation between colostrum quality trait and cow’s own production,body shape,reproduction,disease and longevity.To sum up,this study of Chinese holstein cattle group conducted early passive immunity levels and cow dairy calf qualitative traits relating to explore and genetic analysis,the results provide theoretical reference for pasture colostrum management,for the Chinese holstein calves passive immunity levels and dairy products quality,and the conventional breeding cattle laid the foundation parameters.