Simple and Constrained Selection Indices with and without Calving Interval Included in Selection Goal Function for Holstein Cows of Iran
الموضوعات :
ا. دارنگ
1
(
Agriculture Jihad Organization of Guilan, Guilan, Rasht, Iran
)
ع.ا. شادپرور
2
(
Department of Animal Science, Faculty of Agricultural Science, University of Guilan, Rasht, Iran
)
م. گلشنی
3
(
Agriculture Jihad Organization of Guilan, Guilan, Rasht, Iran
)
الکلمات المفتاحية: Holstein, calving interval, constrained selection index, genetic growth,
ملخص المقالة :
Two selection goals of inclusion or exclusion of calving interval (CI) in the selection goal function for Holstein cows in Iran, besides milk yield, milk fat percentage, and milk protein percentage, were studied. Four selection indices were composed of using the information on production traits, CI and / or days from calving to first insemination (DFI). The results of the predicted genetic growth in selection goals showed that the index composed of all production and reproduction traits generated the greatest genetic growth. Although CI had a negative coefficient in the selection goal, it is genetic mean increased in any case. However, the magnitude of this undesirable increase was lower in the CI included selection goal. This implies that the inclusion of CI in the selection goal is necessary to control the undesirable growth of this trait. The comparison of indices in this goal reflected that the inclusion of CI along with the production traits resulted in a smaller undesirable change in this trait. Constraining the genetic change in CI in the selection goal impaired the selection efficiency. So, this constraint is not recommended for breeding programs.
Athari Mortazavi B. (2010). Comparison of economic values of milk yield and herd life traits of Holstein, hybrid and local cows in Guilan province.MS Thesis. Guilan Univ., Rasht, Iran.
Cole J.B. and VanRaden P.M. (2018). Symposium review: Possibilities in an age of genomics: The future of selection indices. J. Dairy Sci. 101(4), 3686-3701.
Evans R.D., Buckley P. and Berry F. (2006). Trends in milk productions, calving rate and survival of cows in 14 Irish dairy herds as results of introgression of Holstein Friesian genes. J. Anim. Sci. 82, 423-434.
Gholizadeh S., Ansari Mohayayi S., Riasi A. and Rokouei M. (2013). Estimation of inbreeding coefficient and its effect on some reproductive traits of daily herds in Isfahan province. Iranian J. Anim. Sci. Res. 5(3), 251-256.
Joezi Shekalgoorabi S. (2004). Establishment of an optimal selection index for Holstein cows in Iran.MS Thesis. Guilan Univ., Rasht, Iran.
Joezi Shekalgoorabi S. and Shadparvar A. (2009). The effects of culling herd life from selection goal in Iranian Holstein cows. Iranian J. Anim. Sci. 40(1), 13-20.
Kheirabadi K. and Alijani S. (2013). Effect of somatic cell counts on the production traits and estimation of genetic parameters for milk yield traits of Holstein cows. Anim. Prod. Res. 2(1), 65-76.
Liu Z., Jaitner J., Pasman E., Resing S., Reinhardt F. and Reents R. (2007). Genetic evaluation of fertility traits of dairy cattle using a multiple trait model. Interbull Bull. 37, 134-139.
McCarthy S., Horan B., Dillon P.O., Connor P., Rath M. and Shalloo L. (2007). Economic comparison of divergent. J. Dairy Sci. 90, 1493-1505.
Mohammadi G.R. and Sedighi A. (2009). Reasons for culling of Holstein dairy cows in Neishaboor area in northeastern Iran. Iranian J. Vet. Res. 28, 278-282.
Nazari M., Beigi Nasiri M. and Fayyazi J. (2007). Assessment of genetic and phenotypic capabilities of milk yield, fat, and fat percentage of Najdi dairy cows using single and two-trait animal model. Iranian Vet. J. 3(4), 73-80.
Pourtaher S., Ra'fat S., Moghaddam G. and Shoja J. (2016). Estimation of genetic parameters for production traits and some reproduction disorders of dairy cows in one of the East Azerbaijan herds. J. Anim. Sci. Res. 25(4), 1-9.
Pryce J.E., Coffey M.P., Brotherstone S.H. and Woolliams J.A. (2002). Genetic relationship between calving interval, body condition score conditional on milk yield. J. Dairy Sci. 85, 1590-1595.
Pryce J.E., Royal M.D., Garnworthy P.C. and Mao I.L. (2004). Fertility in the high producing dairy cow. Lives. Prod. Sci. 86, 125-135.
Sivanadian B. and Smith C. (1997). The effect of adding further traits in index selection. J. Anim. Sci. 75, 2016-2023.
Sölkner J. and Fuerst C. (2002). Breeding for functional traits in high yielding dairy cow. Pp. 23-29 in Proc. 7th World Congr. Genet. Appl. Livest. Prod., Montpellier, France.
Togyani S. (2007). Estimation of genetic parameters of production, reproduction and type traits in Holstein cows of Iran MS Thesis. Guilan Univ., Rasht, Iran.
