Identification of Runs of Homozygosity Islands and Genomic Estimated Inbreeding Values in Caqueteño Creole Cattle (Colombia)

The Caqueteño Creole (CAQ) is a native breed of cattle from the Caquetá department (Colombia), adapted to tropical conditions, which is extremely important to production systems in those regions. However, CAQ is poorly studied. In this sense, population structure studies associated with runs of homozygosity (ROH) analysis would allow for a better understanding of CAQ. Through ROH analysis, it is possible to reveal genetic relationships between individuals, measure genome inbreeding levels, and identify regions associated with traits of economic interest. Samples from a CAQ population (n = 127) were genotyped with the Bovine HD BeadChip (777,000 SNPs) and analyzed with the PLINK 1.9 program to estimate FROH and ROH islands. We highlighted a decrease in inbreeding frequency for FROH 4−8 Mb, 8−16 Mb, and >16 Mb classes, indicating inbreeding control in recent matings. We also found genomic hotspot regions on chromosomes 3, 5, 6, 8, 16, 20, and 22, where chromosome 20 harbored four hotspots. Genes in those regions were associated with fertility and immunity traits, muscle development, and environmental resistance, which may be present in the CAQ breed due to natural selection. This indicates potential for production systems in tropical regions. However, further studies are necessary to elucidate the CAQ production objective.

Genetic-quantitative uni- and bi-trait analysis for growth traits in the Colombian creole breed Blanco Orejinegro (BON)

The Blanco Orejinegro (BON) is a Colombian creole cattle breed that is not genetically well characterized for growth traits. The aim of this work was to estimate genetic parameters for birth weight (BW), weaning weight (WW), yearling weight (YW), daily weight gain between birth and weaning (DWG), time to reach 120 kg of live weight (T120), and time to reach 60% of adult weight (T60%), and establish the selection criteria for growth traits in the BON population of Colombia. Genealogical and phenotypic information for BW, WW, YW, DWG, T120, and T60% traits of BON animals from 14 Colombian herds were used. These traits were analyzed with the AIREML method in a uni- and bi-trait animal model including the maternal effect for BW, WW, DWG, and T120. The direct heritability estimates values were 0.22 ± 0.059 (BW), 0.20 ± 0.057 (WW), 0.20 ± 0.153 (YW), 0.17 ± 0.07 (DWG), 0.26 (T120), and 0.44 ± 0.03 (T60%). The maternal heritability estimates values were 0.14 ± 0.040 (BW), 0.15 ± 0.039 (WW), 0.25 ± 0.06 (DWG), and 0.16 (T120). The direct genetic correlations were high ( >|0.60|) among all the traits, except between T60% with BW, WW, YW, and DWG (ranged from - 0.02 to - 0.51), all in a favorable direction. The results showed that there is genetic variation in the growth traits associated with the additive genetic effect, and they might respond to selection processes. Furthermore, genetic gains would improve through selection, especially for YW and T60% when WW is used as criterion.

Evaluation of the productive characteristics of the Caqueteño Creole cattle breed

The objective of this research was to evaluate the productive and reproductive characteristics of the Caqueteño Creole cattle breed. Data was taken from 655 animals organized into 6 groups: group 1 (n = 185), pure Caqueteño Creole cattle breed (Caqueteño); group 2 (n = 34), Caqueteño Creole cattle breed crossing for multiracial animals (Caqueteño 50% × multiracial 50%); group 3 (n = 10) (Caqueteño 75% × Bos indicus 25%); group 4 (n = 56), crossbreed F1 (Bos taurus × B. indicus); group 5 (n = 168), animals with B. taurus percentage greater than 50% (B. taurus > 50%); group 6 (n = 202), animals with B. indicus percentage greater than 50% (B. indicus > 50%). Subsequently were done descriptive statistics and analysis of variance (ANOVA) with the LSD Fisher test (P < 0.05), with the software InfoStat version 2018. A significant difference was found (P < 0.05); in weight at birth (WB), Caqueteño presented the smallest value (29.8 kg); in daily weight gain (DWG), weight adjusted at 9 months (W9), and weight adjusted at 18 months (W18), Caqueteño presented highest values corresponding to 574.5 g/day, 183.0 kg, and 343.6 kg, respectively; in age at the first service (AFS), the lowest value was obtained by B. taurus × B. indicus (24.5 months), and in calving interval (CI), no significant differences were found (P > 0.05). In conclusion, the Caqueteño Creole cattle breed is efficient in the productive variables (daily weight gain, adjusted weight at 9 and 18 months); in age at the first service, the F1 group indicated precocity, followed by Caqueteño Creole.

Evaluación de la variabilidad y potencial genético de poblaciones de bovinos criollos colombianos

El presente trabajo presenta un análisis de la variabilidad y el potencial genético de las poblaciones de bovinos criollos utilizados en un Programa Nacional de Fomento, desarrollado por organimos gubernamentales (Ministerio de Agricultura y Desarrollo Rural, Instituto Colombiano Agropecuario y Corpoica). Se hizo el análisis de la información productiva de poblaciones de las razas Romosinuano, Costeño con Cuernos, Sanmartinero y Blanco Orejinegro, mediante el uso de la metodología BLUP, se calcularon los valores genéticos directos para peso al nacimiento, destete, 16 meses y ganancia de peso al destete y se realizó el análisis de la distribución de los animales por sus valores genéticos. Se encontró que en cada una de las razas existe una alta proporción de animales con valores genéticos positivos, siempre superior al 50%, lo cual indica una amplia variabilidad genética y posibilidad de selección de individuos mejoradores, que asegurarán el progreso genético en el programa de fomento que será desarrollado.