Genetic Parameters for Functional Longevity, Type Traits, and Production in the Serbian Holstein

Radica Djedović; Natascha Vukasinovic; Dragan Stanojević; Vladan Bogdanović; Hasan Ismael; Dobrila Janković; Nikolija Gligović; Muhamed Brka; Ljuba Štrbac

doi:10.3390/ani13030534

Genetic Parameters for Functional Longevity, Type Traits, and Production in the Serbian Holstein

Animals (Basel). 2023 Feb 2;13(3):534. doi: 10.3390/ani13030534.

Authors

Radica Djedović¹, Natascha Vukasinovic², Dragan Stanojević¹, Vladan Bogdanović¹, Hasan Ismael¹, Dobrila Janković³, Nikolija Gligović¹, Muhamed Brka⁴, Ljuba Štrbac³

Affiliations

¹ Institute of Animal Science, Faculty of Agriculture, University of Belgrade, 11080 Belgrade, Serbia.
² Zoetis Veterinary Medicine Research and Development (VMRD), Kalamazoo, MI 49001, USA.
³ Department of Animal Science, Faculty of Agriculture, University of Novi Sad, 21000 Novi Sad, Serbia.
⁴ Department of Animal Science, Faculty of Agriculture and Food, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina.

Abstract

In this study, the authors focused on the evaluation of the genetic parameters of longevity, milk yield traits, and type traits in dairy cattle populations in the Republic of Serbia. The total dataset used consisted of production records and pedigree data for 32,512 Holstein cows that calved from 1981 to 2015. The animal model was applied to determine the variance and covariance components and genetic parameters of the analyzed traits by applying the restricted maximum likelihood (REML) approach and using the programs VCE6 and PEST. The heritability of longevity traits was estimated using the Survival Kit V6.0 software package. Variance and covariance were estimated for five production traits: milk yield (MY), fat yield (FY), protein yield (PY), milk fat content (MC), and protein content (PC), and three longevity traits: length of productive life (LPL), lifetime milk yield (LMY), and the number of lactations achieved (NL) as well as for 18 standard type traits. Heritabilities for the milk, fat, and protein yield traits were 0.20 (MY), 0.15 (FY), and 0.19 (PY), respectively. The estimated coefficients of heritability for the longevity traits were higher when using the Weibull proportional hazards model compared to the traditional linear methods and ranged from 0.08 for NL to 0.10 for LPL. Heritability values for the type traits varied from a low of 0.10 (RLSsv-rear legs set-side view) to medium values of 0.32 (ST-stature). Genetic correlations were found between MY and the following longevity traits: LPL, LMY, and NL with values of -0.18, -0.11, and -0.09, respectively. Genetic correlations were found between MY and a number of linear type traits and varied from 0.02 (between MY and RUH-rear udder height) to 0.28 (between MY and FUA-fore udder attachment). Genetic correlations between the 18 investigated type traits ranged from -0.33 between TL (top line) and RTP (rear teats position) to 0.71 between AN (angularity) and RUH (rear udder height). Genetic correlations between most linear type traits and longevity traits (LPL, LMY, and NL) were generally negative and very low. The highest positive genetic correlation was found between UD and LPL (r_xy = 0.38).

Keywords: Holstein; longevity; milk traits; type traits.

Grants and funding

451-03-68/2022- 14/200116/Ministry of Education, Science and Technological Development of the Republic of Serbia