Genetic parameters and trends for growth traits in Blanco Orejinegro cattle

Abstract

Since 1940, efforts have been made to preserve the Blanco Orejinegro (BON) cattle breed by maintaining gene banks. Nine years ago, a BON genetic improvement program was implemented to increase genetic gain based on control of productivity and the use of performance tests, polygenic and genomic evaluations, and selection indices. The objective of this study was to estimate genetic parameters and trends for growth traits by using polygenic (PM) and genomic-polygenic (GPM) models. Productive information from years 1980 to 2019 was used. The following data were used: 7304 birth weight (BW) records, 1281 records of body weight adjusted to 120 days (W120), 4791 records of weight adjusted to 240 days (W240), 3339 records of weight adjusted to 480 days (W480), and 1364 records of weight adjusted to 720 days (W720). The relationship matrix included 13612 pure animals belonging to the Colombian Corporation for Agricultural Research - AGROSAVIA and the Producer Network program. A total of 1224 individuals were genotyped with chips of different densities and all were imputed up to 50932 SNPs. Polygenic and genomic-polygenic models were used to estimate genetic parameters and correlations between the genetic values estimated by each model. A generalized additive model with smoothing was used to estimate trends of genetic values from 1980 to 2019. Heritabilities between 0.29 and 0.40, genetic correlations between 0.13 and 0.94, and phenotypic correlations between 0.23 and 0.72 were observed. Close-to-zero genetic growth was observed for BW and W120. Genetic trends for the other traits were positive, with higher growth in the last seven years. The heritabilities observed in this population indicate that the traits measured would respond to selection. Greater genetic progress can be achieved in W240, W480 and W720 by continuing with genetic evaluations and developing performance tests and strategies to make genetic material readily available to producers.

Genetic parameters in traits of productive importance in lines of Bombyx mori L.

“…Reports of CL heritability are scarce in literature, possibly because silkworm studies on genetic parameters focus mainly on other traits that are easy to measure and also fundamental for sericulture economy (Ghanipoor et al, 2007). According to the scale proposed by Bavera (2000), the estimated heritability in the present study was high, suggesting that phenotypic variations of traits depend mainly on genetic variation with scarce influence from the environment (Ramírez et al, 2020). These results indicate that CL, CW and SW traits can be improved through selection processes within the evaluated populations (Quijano & Echeverri, 2015;Sabhat et al, 2009).…”

Características de crecimiento del ganado criollo Blanco Orejinegro y efectos ambientales responsables de su variación

“…En el estudio de las diferentes características de crecimiento se encontró un potencial productivo y una variabilidad fenotípica apreciable en la raza BON, en comparación con otros trabajos realizados con uno o varios hatos de BON. Así, para PN los resultados son superiores a los reportados anteriormente en ganado BON de 30±4 kg (Correa et al, 2011), 27.5±3.7 kg (Gallego et al, 2006;Martínez et al, 2012) y 28.3±3.6 kg (Ramírez-Toro et al, 2019). La tendencia a generar animales con mayores PN podría llevar a ciertas dificultades al parto, a pesar de que Tabla 1.…”

Phenotypic variability for conformation traits of BON cattle in Colombia

“…The Blanco Orejinegro (BON) is a colombian creole cattle originated from cattle brought by the Spaniards in the fteenth century during colonization (Ramírez et al 2019). It currently has the greatest animal inventory with respect to creole bovine breeds existing in the country (Ocampo et al 2020), with a production target oriented to growth and meat production (Ramírez et al 2019(Ramírez et al , 2020.…”

“…Productive monitoring alongside accompaniment to producers resulted in comparisons of either productive or linear classi cation characteristics that constituted a rst point in decision making for the development of the breed. In this regard, breed-oriented work allowed generating genetic parameters and values for growth characteristics (Ramírez et al 2020). However, the conservation of the breed's phenotypic characteristics, the search for animals with body conformation for meat or the market requirements transfered to producers can de ne phenotypic aspects that require consideration of a balance between productivity and conservation.…”