Using spline test-day model for estimating the genetic parameters for cows milk yield

Rodica Stefania Pelmus, Mircea Catalin Rotar, Horia Grosu, Elena Ghita, Cristina Lazar

Abstract


Genetic parameters of Montbeliarde cows were estimated for test-day milk yield with a random regression spline model. The spline model has been considered as a good alternative to Legendre polynomials to direct interpretation of parameters. With this model the lactation curve is divided into sections by knots. The milk yield between any two knots is assumed to be changing linearly. The random regression was fitted with linear splines with five knots: 7, 54, 111, 246, 302. The herd-test-day is the fixed effect of the model. The heritability estimates for test-day milk yield ranged from 0.346 at 65th day in milk, to 0.422 at 35th day in milk. Genetic correlations between individual test days were positive and tended to decrease with an increase in days between when the yields were measured. Random regression models using linear splines were proved to be useful for genetic evaluations of cows.


Keywords


cows; genetic evaluation; heritability; linear spline

Full Text:

PDF

References


Misztal, I. , Properties of random regression models using linear splines, J. Anim. Breed. Genet., 2006, 123, 74-80

Bohmanova, J., Miglior F., Jamrozik J., Misztal I., and Sullivan P.G., Comparison of random regression models with Legendre polynomials and linear splines for production traits and somatic cell score of Canadian Holstein cows, J. Dairy Sci., 2008, 91, 3627-3638;

White, I. M., Thompson R., and Brotherstone S., Genetic and environmental smoothing of lactation curves with cubic splines, J. Dairy Sci., 1999, 82, 632-638

Misztal, I, Bohmanova J., Tsurata S., and Iwaisaki H., Use a linear spline to simplify longitudinal analyses. 55th Annual EAAP Meeting, Bled, Slovenia, 2004

Iwaisaki, H., Tsuruta S., Misztal I., and Bertrand J.K., Genetic parameters estimated with multitrait and linear spline-random regression models using Gelbvieh early growth data, J. Anim. Sci., 2005, 83, 757-763

Bohmanova, J., Misztal I., and Bertrand J.K., Studies on multiple trait and random regression models for genetic evaluation of beef cattle for growth, J. Anim. Sci., 2005, 83, 62-67

Silvestre A.M., Petim-Batista F., and Colaco J., Genetic parameter estimates of portuguesse dairy cows for milk, fat and protein using a spline test- day model, J. Dairy Sci., 2005, 88, 1225-1230

DeGroot B.J., Keown J.F., Van Vleck L.D., and Kachman S.D., Estimates of genetic parameters for Holstein cows for test-day yield traits with a random regression cubic spline model, Faculty Papers and Publications in Animal Science, Paper 240, 2007, http://digitalcommos.unl.edu/animalscifacpub/240

Macciotta N. P.P., Miglior F., Dimauro C., and Schaeffer L.R., Comparison of parametric, orthogonal, and spline functions to model individual lactation curves for milk yield in Canadian Holsteins, Italian Journal of Animal Science, 2010, 9:E87, 460-464

Druet, T., F., Jaffrezic F., Boichard D., Ducrocq V., Modeling lactation curves and estimation of genetic parameters for first lactation test-day records of French Holstein cows, J. Dairy Sci., 2003, 86, 2480-2490

Grosu, H., Schaeffer L., Oltenacu P.A., Norman D., Powell R., Kremer V., Banos G., Mrode R., Carvalheira J., Jamrozik J., Draganescu C., and Lungu S., History of genetic evaluation methods in dairy cattle, The Publishing House of the Romanian Academy, Bucharest, 2013

Grosu, H. and Rotar M.C., Estimarea valorii de ameliorare la taurine, pe baza modelelor zilei de control (test day models), Ceres, Bucuresti, 2015


Refbacks

  • There are currently no refbacks.


Copyright (c)

Scientific Papers Animal Science and Biotechnologies publish open access articles under the terms of the Creative Commons Attribution 4.0 Licence (read full legal code).

LUCRARI STIINTIFICE ZOOTEHNIE SI BIOTEHNOLOGII (SCIENTIFIC PAPERS ANIMAL SCIENCE AND BIOTECHNOLOGIES)

ISSN print 1841 - 9364
ISSN online 2344 - 4576
ISSN-L  1841 - 9364
(former ISSN 1221-5287, E-ISSN 1841-9364)

PUBLISHER: AGROPRINT Timisoara, Romania
PAPER ACCESS: Full text articles available for free
FREQUENCY: Semiannual
PUBLICATION LANGUAGE: English
_________________________________________________________________

Banat´s University of Agricultural Sciences and Veterinary Medicine "King Michael I of Romania" from Timisoara
Bioengineering Faculty of Animal Resources
300645, Timişoara, Calea Aradului 119, Romania

E-mail: spasb [at] animalsci-tm.ro
Phone: +40-256-277160, Fax.: +40-256-277110