Genetic Trends for Milk Yield, Persistency of Milk Yield,Somatic Cell Count and Calving Interval in Holstein Dairy Cows of Iran

Document Type : Research Article


Department of Animal Science, Faculty of Agriculture Science, University of Guilan, Rasht, Iran


The objective of the present study was to estimate genetic trends for lactation milk yield, persistency of milk yield, somatic cell count and interval between first and second calving in Holstein dairy cows of Iran. The dataset consisted of 210,625 test day and 25,883 first parity cows with milk yield recorded from July 2002 to September 2007 comprising 97 herds in Iran. Breeding values of animals were predicted with Best Linear Unbiased Prediction methodology under multi-trait animal model. Model included region, herd–year–season of calving and age at first calving as fixed effects and Holstein percentage (covariate) and random animal additive effect. Genetic trends of studied traits were estimated by regressing mean of breeding values on calving year. Phenotypic trends were estimated using annual averages of first lactation traits on calving year weighted by the number of animals in each year. Genetic trend was positive and significant for lactation milk yield (21 kg/yr; p < 0.01).Although not significant, favorable genetic trends for most studied traits were reported. Considering that selection emphasis in Iran was on lactation milk yield, progress for this trait was low during the years of the study.


Abdallah J.M. and Mc Daniel B.T. (2000). Genetic parameters and trends of milk, fat, days open, and body weight after calving in North Carolina experimental herds. J. Dairy Sci. 83, 1364-1370.
Atashi H., Moradi Shahrbabak M. and Moghimi Esfandabadi A. (2007). Investigation on the trend of milk yield over lactation time using mathematical functions in Holsteins cows of Iran. Iran. J. Agric. Sci. 38(1), 67-76.
Burnside E.B., Jansen G.B., Civati G. and Dadati E. (1992). Observed and theoretical genetic trends in a large dairy population under intensive selection. J. Dairy Sci. 75, 2242-2253.
De Vries A. and Risco C.A. (2005). Trends and seasonality of reproductive performance in Florida and Georgia dairy herds from 1976 to 2002.J. Dairy Sci. 88, 3155-3165.
Ghavi Hossein-Zadeh N., Nejati Javaremi A., Miraei Ashtiani S.R. and Kohram H. (2008). An observational analysis of twin births, calf stillbirth, calf sex ratio, and abortion in Iranian Holsteins. J. Dairy Sci. 91, 4198-4205.
Grosshans T., Xu Z.Z., Burton L.J., Johnson D.L. and Macmillan K.L. (1997). Performance and genetic parameters for fertility of seasonal dairy cows in New Zealand. Livest. Prod. Sci. 51, 41-51.
Haile Mariam M., Bowman P.J. and Goddard M.E. (2003). Genetic and environmental relationship among calving interval, survival, persistency of milk yield and somatic cell count in dairy cattle. Livest. Prod. Sci. 80, 189-200.
Hansen L.B., Freeman A.E. and Berger P.J. (1983). Yield and fertility relationships in dairy cattle. J. Dairy Sci. 66, 293-305.
Hare E., Norman H.D. and Wright J.R. (2006). Trends in calving ages and calving intervals for dairy cattle breeds in the United States. J. Dairy Sci. 89, 365-370.
ICAR. (2004). International Committee of Animal Recording. Rules, Standards and Guidelines for Milk Recording in Goats. Available in:
Interbull. (2000). National Genetic Evaluation Programmes for Dairy Production Traits Practised in Interbull Member Countries 1999-2000. Department of Animal Breeding and Genetics, Uppsala, Sweden, Bulletin 24.
Johansson I. and Hansson A. (1940). Causes of Variation in Milk and Butterfat Yield on Dairy Cows. Lantbruksaka demien, Tidskrift.
Juga J., Mantysaari E.A. and Poso J. (1999). Economic response to total merit selection in Finnish Ayrshire breeding. Pp. 79- 87 in Proc. Int. Workshop EU Concerted Action on Genetic Improvement of Functional Traits in Cattle (GIFT), Breeding Goals and Selection Schemes. Uppsala, Sweden, Interbull Bulletin.
Khorshidie R., Shadparvar A.A., Ghavi Hossein-Zadeh N. and Joezy Shakalgurabi S. (2012). Genetic trends for 305-day milk yield and persistency in Iranian Holsteins. Livest. Sci. 144, 211-217.
Mahoney C.B., Hansen L.B., Young C.W., Marx G.D. and Reneau J.K. (1986). Health care of Holsteins selected for large and small body size. J. Dairy Sci. 69, 3131-3139.
Meyer K. (2007). WOMBAT version 1.0 User notes. Uni New England, Armidale, NSW, Australia.
Muir B.L., Fatehi J. and Schaeffer L.R. (2004). Genetic relationships between persistency and reproductive performance in first-lactation Canadian Holsteins. J. Dairy Sci. 87, 3029-3037.
Ødegard J., Klemetsdal G. and Heringstad B. (2003). Variance components and genetic trend for somatic cell count in Norwegian cattle. Livest. Prod. Sci. 79,135-144.
Razmkabir M. (2005). Estimation of genetic trends for production traits in Iranian Holstein cattle. MS Thesis. Tehran Univ., Iran.
Roman R.M., Wilcox C.J. and Littell R.C. (1999). Genetic trends for milk yield of Jerseys and correlated changes in productive and reproductive performance. J. Dairy Sci. 82, 196-204.
Sadeghi Sefidmazgi A., Moradi-Shahrbabak M., Nejati-Javaremi A. and Shadparvar A. (2009). Estimation of economic values in three breeding perspectives for longevity and milk production traits in Holstein dairy cattle in Iran. Italian. J. Anim. Sci. 8, 359-375.
Sahebhonar M. (2007). Estimation of genetic trends for production traits and specification of some effective factors on these trends in Iranian Holsteins. MS Thesis. Tehran Univ., Iran.
SAS Institute. (2002). User’s Guide: Statistics, Version 9.1 Edition. SAS Inst., Inc., Cary, NC.
Solkner J. and Fuchs W. (1987). A comparison of different measures of persistency with special respect to variation of test-day milk yields. Lives. Prod. Sci. 16, 305-319.
Tekerli M., Akinci Z., Dogan I. and Akcan A. (2000). Factors affecting the shape of lactation curves of Holstein cows from the Balikesir Province of Turkey. J. Dairy Sci. 83, 1381-1386.
Van Tassell C.P. and Van Vleck L.D. (1991). Estimates of genetic selection differentials and generation intervals for four paths of selection. J. Dairy Sci. 74, 1078-1086.
Weller J.I., Ezra E. and Leitner G. (2006). Genetic analysis of persistency in the Israeli Holstein population by the multitrait animal model. J. Dairy Sci. 89, 2738-2746.
Wood P.D.P. (1967). Algebraic model of the lactation curve in cattle. Nature. 216, 164-165.