Avaliação genética de touros da raça Gir para produção de leite no dia do controle e em 305 dias de lactação

• Autor(a) principal: Ledic, Ivan Luz
• Data de Publicação: 2002
• Outros Autores: Da Silva Verneque, Rui, El Faro, Lenira, Tonhati, Humberto [UNESP], Martinez, Mário Luiz, Dal Secco De Oliveira, Mauro [UNESP], Costa, Cláudio Nápolis, Teodoro, Roberto Luiz, De Oliveira Fernandes, Leonardo
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/231719
• topic: Animal breeding; Dairy cattle; Milking control; Rank correlation

Data from 32,779 monthly milk production, from 3,605 lactations until 305 days (PL305), from 2,082 Gir breed cows, sired by 281 bulls, calving from 1987 to 1999, in 11 herds, were utilized to verify the viability of using daily milk production control (PLDC) in sires genetic evaluation. Univariates analysis for PLDC1 to PLDC10 and P1305 were performed utilizing the restricted maximum likelihood method within an animal model, which included the three first lactations as replicate measures of the same dams unit. Animals were grouped according to the criterion of contemporaneous group of herd-year-season, and according to calving-age and to the interval calving-first control in PLDC1. The observed averages (kg) and the respective standard deviations for PLDC1 to PLDC10 and PL305 were: 11.97±4.64; 11.93±4.68; 10.98±4.40; 10.18±4.12; 9.66±3.88; 9.20±3.69; 8.63±3.51; 8.08±3.33; 7.59±3.27; 7.22±3.15 and 2,746.17± 1,299.90. Heritability estimates for PLDC1 to PLDC10 were: 0.26; 0.19; 0.18; 0.20; 0.15; 0.13; 0.14; 0.10; 0.11 e 0.10, respectively; for PL305 it was 0.18. Spearman correlations between predicted genetic values for 281 sires according to the analysis on PLDC vs PL305 were large, oscillating from 0.85 to 0.94. In selecting above 5% of the top sires for PL305, there was an overlapping of above 80% of the animals for PLDC. In some PLDC the coincidence level of the sires rank correlation with PL305 was very low.