[en] The objective of this research was to examine the effects of inbreeding in the population of Holstein cattle in the Walloon region of Belgium. The effects of inbreeding on the global economic index and its components were studied by using data from the genetic evaluations of February 2004 for production, somatic cell score (SCS), computed from somatic cell counts and type. Inbreeding coefficients for 956,516 animals were computed using a method that allows assigning an inbreeding coefficient to individuals without known parents. These coefficients were equal to the mean inbreeding coefficient of contemporary individuals with known parents. The significance of inbreeding effects on the different evaluated traits and on the different indexes were tested using a t-test comparing estimated standard errors and effects. The inbreeding effect was significantly different from zero for the vast majority of evaluated traits and for all of the indexes. Inbreeding had the greatest deleterious effects on production traits. Inbreeding decreased yield of milk, fat, and protein during a lactation by 19.68, 0.96, and 0.69 kg, respectively, per each 1% increase in inbreeding. The regression coefficient of SCS per 1% increase in inbreeding was +0.005 SCS units. The inbreeding depression was thus relatively low for SCS, but inbred animals had higher SCS than non-inbred animals, indicating that inbred animals would be slightly more sensitive to mastitis than non-inbred animals. Estimates of inbreeding effects on evaluated type traits per 1% increase were small. The most strongly affected type traits were chest width, rear leg, and overall development on a standardized scale. For several type traits, particularly traits linked to the udder, the estimates suggested a favorable effect of inbreeding. The global economic index was depressed by around 6.13 Euro of lifetime profit per 1% increase in inbreeding for the Holstein animals in the Walloon region of Belgium.
Disciplines :
Animal production & animal husbandry Genetics & genetic processes
Ali, A. K. A., and G. E. Shook. 1980. An optimum transformation for somatic cell concentration in milk. J. Dairy Sci. 63:487-490.
Auvray, B., and N. Gengler. 2002. Feasibility of a Walloon test-day model and study of its potential as tool for selection and management. http://www-interbull.slu.se/bulletins/bulletin29/Auvray.pdf Interbull Bull. 29:123-127.
Auvray, B., G. R. Wiggans, F. Miglior, and N. Gengler. 2001. Method to establish average relationships among Holstein bull populations over time. J. Dairy Sci. 84(Suppl. 1):215. (Abstr.)
Casanova, L., C. Hagger, N. Kuenzi, and M. Schneeberger. 1992. Inbreeding in Swiss Braunvieh and its influence on breeding values predicted from a repeatability animal model. J. Dairy Sci. 75:1119-1126.
Cassell, B. G., V. Adamec, and R. E. Pearson. 2003. Effect of incomplete pedigrees on estimates of inbreeding depression for days to first service and summit milk yield in Holsteins and Jerseys. J. Dairy Sci. 86:2967-2976.
Coffey, E. M., W. E. Winson, and R. E. Pearson. 1986. Potential of somatic cell concentration in milk as a sire selection criterion to reduce mastitis in dairy cattle. J. Dairy Sci. 69:2163-2172.
Ducrocq, V., and B. Besbes. 1993. Solution of multiple trait animal models with missing data on some traits. J. Anim. Breed. Genet. 110:81-92.
Emmanuelson, U., B. Danell, and J. Philipsson. 1988. Genetic parameters for clinical mastitis, somatic cell counts, and milk production estimated by multiple trait restricted maximum likelihood. J. Dairy Sci. 71:467.
Gengler, N., and C. Croquet. 2005. Standard errors of solutions in large scale mixed models, application to linear and curvilinear effects of inbreeding on production traits. J. Dairy Sci. 88(Suppl. 1):73. (Abstr.)
Gengler, N., T. Dusseldorf, G. R. Wiggans, J. R. Wright, and T. Druet. 2001a. Heterogeneity of (co)variance components for Jersey type traits. J. Dairy Sci. 84:1772.
Gengler, N., T. Dusseldorf, G. R. Wiggans, J. R. Wright, and T. Druet. 2001c. Multitrait genetic evaluation of Jersey type with integrated accounting for heterogeneous (co)variances. http://www-interbull.slu.be/bulletins/ bulletin25/gengler.pdf Interbull Bull. 25:123-127.
Gengler, N., and P. Mayeres. 2003. Use of a weighted random regression test-day model to better relate observed somatic cell score to mastitis infection likelihood, http://www-interbull.slu.se/bulletins/bulletin31/Gengler. pdf Interbull Bull. 31:92-96.
Gengler, N., G. R. Wiggans, and J. R. Wright. 1999. Animal model genetic evaluation of type traits for five dairy cattle breeds. J. Dairy Sci. 82:1350.
Gengler, N., G. R. Wiggans, J. R. Wright, and T. Druet. 2001b. Simultaneous accounting for heterogeneity of (co)variance components in genetic evaluation of type traits. J. Dairy Sci. 84(Suppl. 1):247. (Abstr.)
Harville, D. A. 1979. Some useful representations for constrained mixed-model estimation. J. Am. Stat. Assoc. 74:200-206.
Henderson, C. R. 1974. General flexibility of linear model techniques for sire evaluation. J. Dairy Sci. 57:963.
Kearney, J. F., E. Wall, B. Villanueva, and M. P. Coffey. 2004. Inbreeding trends and application of optimized selection in the UK Holstein population. J. Dairy Sci. 87:3503-3509.
Lund, T., F. Miglior, J. C. M. Dekkers, and E. B. Burnside. 1994. Genetic relationships between clinical mastitis, somatic cell count, and udder conformation in Danish Holsteins. Livest. Prod. Sci. 39:243-251.
Meuwissen, T. H. E., and Z. Luo. 1992. Computing inbreeding coefficients in large populations. Genet. Sel. Evol. 24:305-313.
Miglior, F. 1994. Impact of inbreeding in dairy cattle. PhD Thesis. Department of Animal and Poultry Science. University of Guelph, ON, Canada.
Miglior, F., E. B. Burnside, and J. C. M. Dekkers. 1995. Non-additive genetic effects and inbreeding depression for somatic cell counts in Holstein cattle. J. Dairy Sci. 78:1168-1173.
Miglior, F., B. Szkotnicki, and E. B. Burnside. 1992. Analysis of levels of inbreeding and inbreeding depression in Jersey cattle. J. Dairy Sci. 75:1112-1118.
Misztal, I., T. J. Lawlor, and N. Gengler. 1997. Relationships among estimates of inbreeding depression, dominance and additive variance for linear traits in Holsteins. Genet. Sel. Evol. 29:319-326.
Mrode, R., G. J. T. Swanson, and M. F. Paget. 2004. Computing inbreeding coefficients and effects of inbreeding, heterosis and recombination loss on evaluations for lifespan and somatic cell count in the UK. http://www-interbull. slu.se/bulletins/bulletin32/Mrode.pdf Interbull Bull. 32:109-112.
Russell, J. E. 1947. Old cattle prints. Country Life 101, 2622:704-706.
Smith, L. A., B. G. Cassell, and R. E. Pearson. 1998. The effects of inbreeding on the lifetime performance of dairy cattle. J. Dairy Sci. 81:2729-2737.
Thompson, J. R., R. W. Everett, and N. L. Hammerschmidt. 2000. Effects of inbreeding on production and survival in Holsteins. J. Dairy Sci. 83:1856-1864.
Van Doormaal, B., F. Miglior, G. Kistemaker, and P. Brand. 2005. Genetic diversification of the Holstein breed in Canada and internationally. http://www.cdn.ca/committees/Apr2005/Diversification.pdf Accessed May 16, 2005.
VanRaden, P. M. 1992. Accounting for inbreeding and crossbreeding in genetic evaluation of large populations. J. Dairy Sci. 75:3136-3144.
VanRaden, P. M. 2000. Net merit as a measure of lifetime profit. http://aipl.arsusda.gov/reference/nmcalc-2000.htm Accessed May 16, 2005.
VanRaden, P. M., and L. A. Smith. 1999. Selection and mating considering expected inbreeding of future progeny. J. Dairy Sci. 82:2771-2778.
VanRaden, P. M., and M. E. Tooker. 2004. Genetic base change for February 2005. http://aipl.arsusda.gov/reference/base2005.htm Accessed May 16, 2005.
Van Vleck, L. D. 1992. The revolution in statistical computing from least squares to DFREML. Proc. 41st Annual National Breeders Roundtable, St. Louis, MO. http://www.poultryscience.org/pba/1952-2003/1992/1992%ZOVleck.pdf Accessed Mar. 22, 2006.
Weigel, K. A. 2001. Controlling inbreeding in modern breeding programs. J. Dairy Sci. 84(E. Suppl.):E177-E184.
Wiggans, G. R., P. M. VanRaden, and J. Zuurbier. 1995. Calculation and use of inbreeding coefficients for genetic evaluation of United States dairy cattle. J. Dairy Sci. 78:1584-1590.
Young, C. W., R. R. Bonczeck, and D. G. Johnson. 1988. Inbreeding of and relationship among registered Holsteins. J. Dairy Sci. 71:1659.
Young, C. W., and A. J. Seykora. 1996. Estimates of inbreeding and relationship among registered Holstein females in the United States. J. Dairy Sci. 79:502-505.
