Association of Somatic Cell Score with Production Traits in Iranian Holstein Cows

Document Type : Research Article


1 Department of Animal Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

2 Department of Animal Science, Faculty of Agriculture, University of Zabol, Zabol, Iran


The objective of this study was to analyze the association of somatic cell score (SCS) with milk, fat and protein yields across parities. Records of production traits and somatic cell counts (SCC) from first, second and third parity that were collected by the Animal Breeding Center of Iran from 1993 to 2010 were used.All animals were grouped into six classes according to SCC and production traits were evaluated in these SCC classes. To obtain an approximate normal distribution, SCC records were transformed on the base of Loge to somatic cell score (LSCS, the lactation mean of the natural log of test-day somatic cell count). A single trait animal model that LSCS was fitted as covariate was used to assess relations of SCS with production traits in fist, second and third parities. Effect of SCS on production traits in all of parities was negative and significant (P<0.05). Ranges of depressing effects on milk, fat and protein production were 107.78-220.41, 2.32-7.08 and 2.1-5.2 kg per 1 unit increase in SCS.


Degroot B.J., Keown J.F., Van Vleck L.D. and Marotz E.L. (2002). Genetic parameters and responses of linear type, yield traits, and somatic cell scores to divergent selection for predicted transmitting ability for type in Holsteins. J. Dairy Sci. 85, 1578-1585.
Gilmour A.R., Cullis B.R., Welham S.J. and Thompson R. (2000). Asreml User Guide. Releasel 1.0. VSN., International Ltd.
Hagnestam C., Emanuelson U. and Berglund B. (2007). Yield losses associated with clinical mastitis occurring in different weeks of lactation. J. Dairy Sci. 90, 2260-2270.
Heringstad B., Rekaya R., Gianola D., Klemetsdal G. and Weigel K.A. (2003). Genetic change of clinical mastitis in Norwegian cattle: a threshold model analysis.J. Dairy Sci. 86, 369-375.
Ikonen T., Morri S., Tyriseva A.M., Ruottinen O. and Ojala M. (2004). Genetic and phenotypic correlations between milk coagulation properties, milk production traits, somatic cell count, casein content, and pH of milk. J. Dairy Sci. 87, 458-467.
Juozaitiene V., Juozaitis A. and Micikeviciene R. (2006). Relationship between somatic cell count and milk production or morphological traits of udder in Black-and-White Cow. Turk. J. Vet. Anim. Sci. 30, 47-51.
Miglior F., Burnside E.B. and Dekkers J.C.M. (1995). Non additive genetic effects and inbreeding depression for somatic cell counts in Holstein cattle. J. Dairy Sci. 78, 1168-1173.
Miller R.H., Norman H.D., Wiggans G.R. and Wright J.R. (2004). Relationship of test day somatic cell score with test day and lactation milk yields.J. Dairy Sci. 87, 2299-2306.
Odegard J., Gunnar K. and Bjorg H. (2003). Variance components and genetic trend for somatic cell count in Norwegian Cattle. Livest. Prod. Sci. 79, 135-144.
Penasa M., Cecchinato A., Battagin M., De Marchi M., Pretto D. and Cassandro M. (2010). Bayesian inference of genetic parameters for test-day milk yield, milk quality traits, and somatic cell score in Burlina cows. J. Appl. Genet. 51(4), 489-495.
Rekik B., Ajili N., Belhani H., Ben Gara A. and Rouissi H. (2008). Effect of somatic cell count on milk and protein yields and female fertility in Tunisian Holstein dairy cows. Livest. Sci. 11(6), 309-317.
Reneau J.K. (1986). Effective use of dairy herd improvement somatic cell couns in mastitis control. J. Dairy Sci. 69, 1708-1720.
Samore A.B., Groen A.F., Boettcher P.J., Jamrozik J., Canavesi F. and Banganato A. (2008). Genetic correlation patterns between somatic cell score and protein yield in the Italian Holstein-Friesian population. J. Dairy Sci. 91, 4013-4021.
SAS. (2007). SAS®/STAT Software, Release 9.1.3. SAS Institute, Inc., Cary, NC.
Schukken Y.H., Leslie K.E., Weersink A.J. and Martin S.W. (1992). Ontario bulk milk somatic cell count program. II. Population dynamics of bulk milk somatic cell counts. J. Dairy Sci. 75, 3359-3366.
Schutz M.M. (1993). Genetic evaluation of somatic cell scores for United States dairy cattle. J. Dairy Sci. 77, 2113-2129.
Smith K.L. (1996). Standards for somatic cells in milk: physiological and regulatory. IDF Mastitis Newsletter. 21, 7-9.
Teimurian M. (2009). Estimation of genetic parameters and genetic trend for production traits of Holstein dairy cattle of Khorasan Razavi. MS Thesis. Ferdowsi Univ., Mashhad, Iran.
Weller J.I. and Ezra E. (2004). Genetic analysis of the Israeli Holstein dairy cattle population for production and nonproduction traits with a multitrait animal model. J. Dairy Sci. 87, 1519-1527.
Weller J.I., Saran A. and Zeliger Y. (1992). Genetic and environmental relationships among somatic cell count, bacterial infection, and clinical mastitis. J. Dairy Sci. 75, 2532-2540.
Windig J.J., Calus M.P.L., Beerda B. and Veerkamp R.F. (2006). Genetic correlation between milk production and health and fertility depending on herd environment. J. Dairy Sci. 89, 1765-1775.
Yalcin C., Cevger Y., Trkyilmaz K. and Uysal G. (2000). Estimation of milk yield losses from subclinical mastitis in dairy cows. Turk. J. Vet. Anim. Sci. 24, 599-604.
Zhong G., Xiao Lin L., A-Juin X. and Zhi X. (2010). Relationship of somatic cell count with milk yield and composition in Chinese Holstein population. Agric. Sci. China. 9(10), 1492-1496.