Genetic parameters and genetic trends for production traits in dairy Gir cattle
| Autor: | Nathã Silva de Carvalho, Darlene dos Santos Daltro, Juliana Demesntshuk Machado, Emmanuel Veiga de Camargo, Jaime Araújo Cobuci |
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| Jazyk: | English<br />Portuguese |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Ciência Rural, Vol 53, Iss 11 (2023) |
| Druh dokumentu: | article |
| ISSN: | 1678-4596 0103-8478 68973721 |
| DOI: | 10.1590/0103-8478cr20210541 |
| Popis: | ABSTRACT: The objective of this research was to estimate genetic parameters and genetic trends (GT) for 305-day milk yield (MY305) and 305-day fat yield (FY305) of purebred Dairy Gir animals of the National Dairy Gir Breeding Program. The restricted maximum likelihood method was used in an animal model. GT were obtained via linear regression and divided into two periods (1935-1992 and 1993-2013 for PL305; 1935-1992 and 1993-2010 for MY305). The estimated heritabilities were 0.23 (MY305) and 0.10 (FY305). The GT (kg/year) values for MY305 in the 2nd period for measured females (25.49), females (26.11), and males (35.13) were higher than those found in the 1st period (2.52; 2.06, and 1.00, respectively). The heritability estimated for MY305 confirmed the possibility of genetic improvement by selection and indicated a lower additive genetic effect on FY305 of purebred animals. The genetic progress for MY305 in all purebred population is denoted by the more expressive gains found from 1990’s, when the first bull catalogs were published. |
| Databáze: | Directory of Open Access Journals |
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