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1.
Trop Anim Health Prod ; 53(2): 260, 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33852073

RESUMO

This study was realized to analyze the combinations of climatic, physical, and socio-economic variables on distribution of breeding values for performance characteristics and scrotal circumference of Brangus cattle. Records of 84,703 Brangus animals, born from 2000 to 2010 distributed in 65 farms in Brazil were used. The characteristics analyzed were average daily gain from birth to weaning and from weaning to yearling (WW and YW), visual scores of conformations (WC and YC), muscle score (WM and YM), precocity score (WP and YS), and size score (WS and YS) at weaning and yearling and scrotal circumference (SC) at yearling. Components of (co)variance estimated through the animal model employing methodology to AIREML. Mean estimates of direct heritability obtained for visual scores at weaning (WC 0.16, WM 0.16, WP 0.19, and WS 0.22) were lower than those obtained at yearling (YC 0.28, YM 0.26, YP 0.24, and YS 0.40). WW had heritability greater than YW (0.27 and 0.12) and a heritability of 0.36 obtained for SC. Canonical, discriminant, and cluster analyses were performed in the SAS® 9.4 program. Three clusters of genetic values averages per farm were formed according to climatic, physical, and socio-economic variables. Brangus animals are from states of RS, PR, SP, MG, GO, MG, and MS. The highest breeding values were strongly related to thermal amplitude and municipality area. Spatial distribution of the breeding value of Brangus animals can help in the development of environmental indices, genetic evaluations, and the choice of animals for certain environments.


Assuntos
Fatores Econômicos , Escroto , Animais , Peso Corporal , Brasil , Bovinos/genética , Masculino , Desmame
2.
Ciênc. rural ; 44(12): 2258-2264, 12/2014. tab
Artigo em Português | LILACS-Express | LILACS | ID: lil-729814

RESUMO

Objetivou-se estimar as correlações fenotípicas (r) entre os escores comportamentais de reatividade aplicados durante e após a pesagem e os ganhos médios diários de peso (GMD) de cordeiros cruzados Suffolk x Île-de-France, aos 30, 60 e 90 dias de idade, bem como estudar o efeito da habituação dos animais ao manejo. As variáveis avaliadas por meio de escores foram: interferência do avaliador para o animal entrar na balança (INT), vocalização (VOC), movimentação (MOV), tensão (TEN), movimentos exploratórios (ME), postura de orelhas (ORE) e o teste de tipos de marcha (TM). Os resultados das correlações de Spearman obtidos entre os escores indicam que VOC, MOV e TEN podem ser consideradas como características importantes na expressão da reatividade de ovinos em ambiente de restrição. Já o GMD parece não estar associado com a reatividade dos cordeiros avaliados. Por fim, aos 90 dias de idade, os cordeiros apresentaram-se menos reativos, em função do aprendizado por habituação.


The aim of this study was to estimate the phenotypic correlations (r) between behavioral reactivity scores obtained during and after weighing, and the average daily weight gains (ADG) of Suffolk x Île-de-France cross lambs, at 30, 60 and 90 days of age, as well as to study the effect of habituation towards handling. The variables assessed through scores were: interference of the observer for the animal to enter the weighing crate (INT), vocalization (VOC), movement (MOV), tension (TEN), exploratory movements (EM), ears posture (EP) and the gait speed test (qualitative flight time test) (GS). The results of the Spearman correlations indicate that VOC, MOV and TEN may be considered important traits in the expression of reactivity in sheep assessed while restrained. On the contrary, ADG does not seem to be correlated with reactivity. Finally, at 90 days of age, the lambs were less reactive, due to learning by habituation.

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