Data from a monitoring program of a sample of 80 adult female goats per heard for three years were used to estimate the phenotypic and genetic parameters of body measurement traits in Venezuelan Creole goat population. The study was carried out in five herds, three in Paraguana, two in Pedregal, and one in Carora. The observed breed composition was 90, 2, and 8 % creole, exotic, and crossbred, respectively, and all genotypes were managed with common shepherding areas. The body weight and biometric traits were determined in adult female goats. Data were recorded from limbs: forearm, thigh, metacarpus, and metatarsus perimeter, anterior and posterior hoof perimeter, and anterior and posterior hoof height; from the pelvic: the anterior and posterior rump width, rump length, scapulaischial length, and body length; from the thorax: chest width, depth, and height, wither height, heart girth, and the abdominal perimeter; and from the cephalic region: face length and width, eye separation, and horn and ear length. SAS (2016) was used to evaluate for fixed effects, and single and twotrait animal model analyses were run with the MTDFREML Package to estimate genetic parameters. The model included the year of birth and the locations as fixed effects, the fraction of genetic groups as covariables, and the animal was fit as a random factor. Estimates of heritability for limbs’ traits range from 0.11 to 0.38; pelvic traits from 0.00 to 0.13; thoracic traits from 0.02 to 0.14; and cephalic traits from 0.24 to 0.79. Most traits resulted in moderately to highly genetic correlation. Body measurements revealed moderate to high genetic correlations. In conclusion, differences in body measurements were insufficient to discriminate the Venezuelan Creole population by region. Outbreeding did not appear to be an adequate strategy to make favorable changes, at least morphologically, in the Creole goat population studied. The additive or heritable fraction out of the total phenotypic variance found in this study indicated that most traits evaluated can be improved through selection, which should be considered in any breeding program.
Goat genetic and phenotypic variation of body measurement traits in a sample of the Venezuelan creole goat population
Vincenzo Landi
2023-01-01
Abstract
Data from a monitoring program of a sample of 80 adult female goats per heard for three years were used to estimate the phenotypic and genetic parameters of body measurement traits in Venezuelan Creole goat population. The study was carried out in five herds, three in Paraguana, two in Pedregal, and one in Carora. The observed breed composition was 90, 2, and 8 % creole, exotic, and crossbred, respectively, and all genotypes were managed with common shepherding areas. The body weight and biometric traits were determined in adult female goats. Data were recorded from limbs: forearm, thigh, metacarpus, and metatarsus perimeter, anterior and posterior hoof perimeter, and anterior and posterior hoof height; from the pelvic: the anterior and posterior rump width, rump length, scapulaischial length, and body length; from the thorax: chest width, depth, and height, wither height, heart girth, and the abdominal perimeter; and from the cephalic region: face length and width, eye separation, and horn and ear length. SAS (2016) was used to evaluate for fixed effects, and single and twotrait animal model analyses were run with the MTDFREML Package to estimate genetic parameters. The model included the year of birth and the locations as fixed effects, the fraction of genetic groups as covariables, and the animal was fit as a random factor. Estimates of heritability for limbs’ traits range from 0.11 to 0.38; pelvic traits from 0.00 to 0.13; thoracic traits from 0.02 to 0.14; and cephalic traits from 0.24 to 0.79. Most traits resulted in moderately to highly genetic correlation. Body measurements revealed moderate to high genetic correlations. In conclusion, differences in body measurements were insufficient to discriminate the Venezuelan Creole population by region. Outbreeding did not appear to be an adequate strategy to make favorable changes, at least morphologically, in the Creole goat population studied. The additive or heritable fraction out of the total phenotypic variance found in this study indicated that most traits evaluated can be improved through selection, which should be considered in any breeding program.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
