Biomaterial Database

Adjustment factors and genetic evaluation for somatic cell score and relationships with other traits of Canadian Holsteins. 1994

W C Zhang, and J C Dekkers, and G Banos, and E B Burnside

Department of Animal and Poultry Science, University of Guelph, ON, Canada.

Test day SCC records were obtained from the Ontario DHI and converted to somatic cell score using a logarithmic transformation. Adjustment factors for stage of lactation and calendar month were obtained for first and later lactations. Effects of stage of lactation were significant and followed a systematic pattern. Seasonal effects were small. Sire estimated breeding values for lactation mean adjusted test day somatic cell scores were obtained from an animal model based on first, later, and all lactations, assuming a heritability of .11 and repeatability of .27. Mean accuracy of estimated breeding values for sires with at least 30 daughters was .64 for first lactation, .76 for second to fifth, and .86 for all lactations. Genetic trends for somatic cell score were not significant. The correlation of breeding values estimated from first lactations with estimates based on later lactations was .62 for sires with at least 50 daughters, which resulted in an approximate genetic correlation of .72. Correlations of sire estimated breeding values for somatic cell score from first lactation with estimated breeding values for milk, fat, protein, fat percentage, protein percentage, and milking speed were .12, .05, .11, -.09, -.02, and .20. Correlations between sire estimated breeding values for somatic cell score and type traits were generally small, but favorable with mammary system, -.13, and fore udder, -.16, and unfavorable with dairy character, .24. Somatic cell score should be considered as an auxiliary trait in dairy cattle breeding programs.

UI	MeSH Term	Description	Entries
D007774	Lactation	The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.	Lactation, Prolonged,Milk Secretion,Lactations, Prolonged,Milk Secretions,Prolonged Lactation,Prolonged Lactations
D008297	Male		Males
D008414	Mastitis, Bovine	INFLAMMATION of the UDDER in cows.	Bovine Mastitides,Bovine Mastitis,Mastitides, Bovine
D008892	Milk	The off-white liquid secreted by the mammary glands of humans and other mammals. It contains proteins, sugar, lipids, vitamins, and minerals.	Cow Milk,Cow's Milk,Milk, Cow,Milk, Cow's
D008957	Models, Genetic	Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Genetic Models,Genetic Model,Model, Genetic
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D002452	Cell Count	The number of CELLS of a specific kind, usually measured per unit volume or area of sample.	Cell Density,Cell Number,Cell Counts,Cell Densities,Cell Numbers,Count, Cell,Counts, Cell,Densities, Cell,Density, Cell,Number, Cell,Numbers, Cell
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia