Abstract #T90

# T90
Genetic trends in dairy production of Brazilian Holstein cow.
Victor B. Pedrosa*1, Altair A. Valloto2, Jose A. Horst2, Avelino M. Figueiredo2, Adriana S. Martins1, 1Universidade Estadual de Ponta Grossa, Ponta Grossa, Parana, Brazil, 2Associacao Paranaense dos Criadores de Bovinos da Raca Holandesa, Curitiba, Parana, Brazil.

Production and pedigree monitoring in Holstein cattle is carried out for many years but a only a few farmers effectively use breeding programs in Brazil. In the year 2014, the Holstein Association of ParanĂ¡ State in partnership with the State University of Ponta Grossa created the State breeding program of cows, to accelerate genetic progress and consequently increase dairy production. Therefore, this study aimed to evaluate the genetic trend obtained in the last 10 years for milk, fat, and protein yield and thus increase the genetic evaluation of female population in the country. The database contained information on 54,224 first lactation cows born between 2001 and 2011, with 81,336 records on pedigree file. Genetic trends were estimated from the linear regression of annual averages of breeding values. Estimates of breeding values were obtained based on the methodology of mixed models through BLUP solutions using the PEST software. Analyses were performed considering the contemporary group (same herd-year) as fixed effect and the age of cow as a covariate. The average production of milk, fat, and protein were respectively 8,693.17 kg, 286.51 kg and 264.28 kg. The estimated genetic trend was 6.62 kg/yr for milk, 0.44 kg/yr for fat and 0.34 kg/yr for protein. The results show that even with low adherence to animal breeding programs by dairy farmers there was a significant genetic progress for the 3 studied traits. This result might be explained by the use of imported genetic material of quality bulls from markets such as the United States, Canada and the Netherlands. However, it is essential to mention the importance of the farmers to increase selection based on genetic values estimated in a national selection program, reducing possible negative effects caused by the use of imported genetic material, selected in a different environment. Thus, it is expected that the new breeding program of cows provide greater genetic and productive advances for Brazilian herds.

Key Words: breeding program, milk yield, selection