Influência de fatores genéticos e ambientais sobre as características produtivas no rebanho eqüino do Exército Brasileiro

Abstract

Objetivou-se estimar parâmetros genéticos e fenotípicos para peso e altura (4.860 registros) em cavalos de quatro grupos genéticos - Brasileiro de Hipismo (BH), Puro-Sangue Inglês (PSI), Hanoveriano (HAN) e Sem Raça Definida (SRD) - por meio de informações de 1629 animais do Exército Brasileiro coletadas entre 1977 e 2002. Foram considerados fixos os efeitos de ano e mês de nascimento, idade da mãe, sexo do potro, ano e mês de mensuração e grupo genético. O mês de nascimento não afetou a altura ou o peso na população, exceto nos animais mais velhos. O sexo influenciou a altura, mas não afetou o peso dos animais de 21 meses e dos adultos e a raça influenciou a altura somente nos animais de 18 a 21 meses de idade e nos adultos. A influência dos efeitos fixos foi menor nos animais BH que nos SRD. As herdabilidades para o peso dos animais BH foram altas nas diversas idades, mas foram baixas para a altura. O comportamento do peso e da altura foi semelhante para as raças BH e SRD. De modo geral, nos dois grupos genéticos (BH e SRD), a herdabilidade do peso aumentou conforme as faixas etárias.

Morphometric measurements and animal-performance indices in a study of racial forms of Brazilian Sport Horses undergoing training for eventing

“…The authors claimed that, owing to correlations of genetics and reduced performance, indirect selection based on morphometrics has limited value. Campos et al (2007) evaluated the useful characteristics in the horse herd of the Brazilian Army, including Brazilian Sport Horses and mixed-breed horses, and claimed that selection by weight could obtain gains in height. However, that study was on animals during their growth stage, which is approximately from six to 48 months.…”

Heritability estimates for body weight and height at withers in Brazilian army horses

“…In Brazil, for this trait, the heritability reported was low. For No Defined Breed and Brazilian Show jumper horses, CAMPOS et al (2007) estimated heritability values equal to 0.01, 0.08, 0.08 and 0.02 and 0.04, 0.12, 0.00 and 0.0, at 1, 2, 3 and 4 years of age, respectively, showing that this feature is not able to respond to individual selection. The authors suggest that, once there is a strong selection pressure for height in the populations evaluated, the reduced genetic variability contributed to these results.…”

“…High heritability values for weight were also estimated by CAMPOS et al (2007) for No Defined Breed horses, with heritability values for weight at two, Heritability estimates for body weight and height at withers in Brazilian army horses.…”

Occurrence of Leptospira spp. and factors associated with the infection in horses from a military contingent in the Rio Grande do Sul State, Brazil

“…These animals participate in different activities, such as military ceremonies, patrolling and guarding border areas and instruction camps, as well as in sports, such as dressage, jumping, full riding competition, and polo. Moreover, these horses are usually housed in stables with strict sanitary management and rigorous reproductive control (Campos et al, 2007).…”