The Revista Brasileira de Zootecnia (RBZ) is a publication dedicated to the broad field of Animal Science. We publish high-quality, original scientific research that spans across diverse areas within the discipline. The scope of RBZ encompasses a wide range of topics, including aquaculture, biometeorology and animal welfare, forage crops and grasslands, animal and forage plants breeding and genetics, animal reproduction, ruminant and non-ruminant nutrition, meat science and muscle biology, precision livestock, and animal production systems and agribusiness.
The Revista Brasileira de Zootecnia (RBZ) is a publication dedicated to the broad field of Animal Science. We publish high-quality, original scientific research that spans across diverse areas within the discipline. The scope of RBZ encompasses a wide range of topics, including aquaculture, biometeorology and animal welfare, forage crops and grasslands, animal and forage plants breeding and genetics, animal reproduction, ruminant and non-ruminant nutrition, meat science and muscle biology, precision livestock, and animal production systems and agribusiness.
The Revista Brasileira de Zootecnia (RBZ) is a publication dedicated to the broad field of Animal Science. We publish high-quality, original scientific research that spans across diverse areas within the discipline. The scope of RBZ encompasses a wide range of topics, including aquaculture, biometeorology and animal welfare, forage crops and grasslands, animal and forage plants breeding and genetics, animal reproduction, ruminant and non-ruminant nutrition, meat science and muscle biology, precision livestock, and animal production systems and agribusiness.
01/Oct/2007
Cláudio Manoel Rodrigues de Melo, Irineu Umberto Packer, Claudio Napolis Costa, Paulo Fernando Machado, Mateus Patrício
DOI: 10.1590/S1516-35982007000600011
Data consisting of 263.390 test day records (PDC) of 32.448 first lactation Holstein cows were used to compare three random regression test-day models (RR), a repeatability test-day model (RM) and a 305-d lactation model (P305) for breeding value (EBV) prediction of milk yield. One RR model used the logarithmic function of Ali & Schaeffer (AS) and the other two models used the exponential Wilmink function in its standard form (W) and a modified form (W*). The required covariance parameters were […]
Keywords: genetic evaluation; random regression model; selection; test day model
01/Jun/2005
Cláudio Manoel Rodrigues de Melo, Irineu Umberto Packer, Cláudio Nápolis Costa, Paulo Fernando Machado
DOI: 10.1590/S1516-35982005000300011
Covariance components for test day records and lactation milk yield using 263.390 records of 32.448 first lactation Holstein cows, were estimated using animal models by REML. Besides the lactation model, two alternative repeatability models (RM) were analyzed. Lactation model included fixed effects of herd-year-season and age of cow with linear and quadratic terms, and random effects of animal and error. The first model for test-day yield (RMF) included the same effects, but fixed effect of contemporary group, defined as herd-year-month […]
Keywords: genetic evaluation; genetic parameters; milk yield; multivariate analysis; selection; test day model; variance components