Random regression models for milk, fat and protein in Colombian Buffaloes
Objective. Covariance functions for additive genetic and permanent environmental effects and, subsequently, genetic parameters for test-day milk (MY), fat (FY) protein (PY) yields and mozzarella cheese (MP) in buffaloes from Colombia were estimate by using Random regression models (RRM) with Legendre polynomials (LP). Materials and Methods. Test-day records of MY, FY, PY and MP from 1884 first lactations of buffalo cows from 228 sires were analyzed. The animals belonged to 14 herds in Colombia between 1995 and 2011. Ten monthly classes of days in milk were considered for test-day yields. The contemporary groups were defined as herd-year-month of milk test-day. Random additive genetic, permanent environmental and residual effects were included in the model. Fixed effects included the contemporary group, linear and quadratic effects of age at calving, and the average lactation curve of the population, which was modeled by third-order LP. Random additive genetic and permanent environmental effects were estimated by RRM using third- to- sixth-order LP. Residual variances were modeled using homogeneous and heterogeneous structures. Results. The heritabilities for MY, FY, PY and MP ranged from 0.38 to 0.05, 0.67 to 0.11, 0.50 to 0.07 and 0.50 to 0.11, respectively. Conclusions. In general, the RRM are adequate to describe the genetic variation in test-day of MY, FY, PY and MP in Colombian buffaloes.
Key words: Cattle, genetics, zootechnics (Source: EuroVoc).
Tonhati H, Lima A, Lanna D, Camargo G, Baldi F, Albuquerque L, Montrezor J. Milk fatty acid characterization and genetic parameter estimates for milk conjugated linoleic acid in buffaloes. J Dairy Res 2011; 78(2):178−183. http://dx.doi.org/10.1017/S0022029911000045
Seno L O, Cardoso V, Tonhati H. Valores econômicos para as características de produção de leite de búfalas no Estado de São Paulo. R Bras Zootec 2007; 36(6):2016−2022.
El Faro L, Cardoso Vera L, Albuquerque LG. Variance component estimates applying random regression models for test-day milk yield in Caracu heifers (Bos taurus Artiodactyla, Bovidae). Genet Mol Biol 2008; 31(3):665-673.
Jamrozik J, Schaeffer LR. Estimates of Genetic Parameters for a Test Day Model with Random Regressions for Yield Traits of First Lactation Holsteins. J Dairy Sci 1997; 80(4):762−770.
Silvestre A, Petim-Batista F, Colaço J. Genetic parameter estimates of Portuguese dairy cows for milk, fat and protein using a spline test-day model. J Dairy Sci 2005; 88(3):1225-1230.
Aspilcueta RB, Sesana RC, Mu-oz-Berrocal M, Seno LO, Bignardi AB, El Faro L, et al. Genetic parameters for milk, fat and protein yields in Murrah buffaloes (Bubalus bubalis Artiodactyla, Bovidae). Genet Mol Biol 2010; 33(1):71-77.
Sesana RC, Bignardi AB, Aspilcueta RA, El Faro L, Baldi F, Albuquerque LG, Tonhati H. Random regression models to estimate genetic parameters for test-day milk yield in Brazilian Murrah buffaloes. J Anim Breed Genet 2010; 127(5):369−376.
Martínez CA, Elzo M, Manrique C, Grajales LF, Jimenez A. Random Regression Models for Estimation of Covariance Functions, Genetic Parameters and Prediction of Breeding Values for Rib Eye Area in a Colombian Bos indicus-Bos taurus Multibreed Cattle Population. Rev Colomb Estad 2012; 35(2):309-330.
Borghese A, Mazzi M. Buffalo Production And Research. Rome: Editorial Food and Agriculture Organization of The United Nations; 2005.
Meyer K WOMBAT. A tool for mixed model analyses in quantitative genetics by REML, J Zhejiang Uni 2007; 8:815-821.
De Roos APW, Harbers AGF, de Jong G. Random herd curves in a test-day model for milk, fat, and protein production of dairy cattle in The Netherlands. J Dairy Sci 2004; 87(8): 2693−2701.
Rosati A, Van Vleck LD. Estimation of genetic parameters for milk, fat, protein and mozzarella cheese production for the Italian river buffalo Bubalus bubalis population. Livest Prod Sci 2002; 74 (2):203−217. http://dx.doi.org/10.1016/S0301-6226(01)00293-7
Munera BOD, Herrera RAC, Cerón-Mu-oz MF. Componentes de (co) varianza y parámetros genéticos para producción y valor económico de la leche a través de modelos de regresión aleatoria en hembras Holstein de primera lactancia. Livest Res Rural Dev 2013;25(12): art 208.
Herrera RAC, Munera OD, Cerón-Mu-oz MF. Variance components and genetic parameters for milk production of Holstein cattle in Antioquia (Colombia) using random regression models. Rev Col Cien Pec 2013; 26:90-97.
Breda F , Albuquerque L, Euclydes RF, Bignardi A B. Baldi F, Torres RA, Barbosa L, Tonhati H. Estimation of genetic parameters for milk yield in Murrah buffaloes by bayesian inference. J Dairy Sci 2010; 93(2):784-791. http://dx.doi.org/10.3168/jds.2009-2230