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Titre du document / Document title

Relationships among heat production, body weight, and age in Finnsheep and Rambouillet ewes

Auteur(s) / Author(s)

FREETLY H. C. (1) ; NIENABER J. A. (1) ; BROWN-BRANDL T. (1) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) USDA-ARS, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, NE 68933-0166, ETATS-UNIS

Résumé / Abstract

It was the objective of this study to quantify heat production across ages of Rambouillet and Finnsheep ewes and to evaluate the previous hypothesis that breed differences can be accounted for by scaling for proportion of mature body weight. Seventy-two Finnsheep and 55 Rambouillet ewes were sampled. Heat production was estimated based on individual animal gaseous exchange, which was determined from 55 through 71 h of the feed restriction. Heat production per unit BW decreased as sheep aged, and the breed-specific functions fit the data better than the pooled functions. The rate of decrease in heat production was greater in Finnsheep ewes until 37 wk of age. The rate of growth of Rambouillet ewes was greater than that of Finnsheep ewes over the first 52 wk of age, and Rambouillet ewes reached 95% of their mature BW at an earlier age (71 wk) than did Finnsheep ewes (113 wk). At any given age, Rambouillet ewes had achieved a greater proportion of their mature BW and had a lower heat production per unit BW than Finnsheep ewes. This study demonstrated the necessity of accounting for both age and breed when estimating metabolic rate in sheep. Furthermore, this study suggested that breed and age differences in metabolic rate could be accounted for by scaling for proportion of mature BW and that daily heat production per unit BW (kcal/kg) of Finnsheep, Rambouillet, Suffolk, and Texel ewes can be described by the function f(BW, matBW) = 59.5e-0.797(BW/matBW), where BW = body weight and matBW = mature body weight.

Revue / Journal Title

Journal of animal science    ISSN  0021-8812 

Source / Source

2002, vol. 80, no3, pp. 825-832 (14 ref.)

Langue / Language

Anglais

Editeur / Publisher

American Society of Animal Science, Champaign, IL, ETATS-UNIS  (1942) (Revue)

Mots-clés anglais / English Keywords

Ruminant animal

;

Farming animal

;

Vertebrata

;

Mammalia

;

Ungulata

;

Artiodactyla

;

BREEDS (ANIMALS)

;

Race specificity

;

Sheep

;

Experimental study

;

Comparative study

;

Calorimetry

;

Energy metabolism

;

Age

;

Body weight

;

Heat production

;

Physiology

;

Mots-clés français / French Keywords

Animal ruminant

;

Animal élevage

;

Vertebrata

;

Mammalia

;

Ungulata

;

Artiodactyla

;

RACE (ANIMAL)

;

Spécificité race

;

Mouton

;

Etude expérimentale

;

Etude comparative

;

Calorimétrie

;

Métabolisme énergétique

;

Age

;

Poids corporel

;

Production chaleur

;

Physiologie

;

Mots-clés espagnols / Spanish Keywords

Animal rumiante

;

Animal cría

;

Vertebrata

;

Mammalia

;

Ungulata

;

Artiodactyla

;

RAZAS (ANIMALES)

;

Especificidad raza

;

Carnero

;

Estudio experimental

;

Estudio comparativo

;

Calorimetría

;

Metabolismo energético

;

Edad

;

Peso corporal

;

Producción calor

;

Fisiología

;

Localisation / Location

INIST-CNRS, Cote INIST : 3247, 35400010038157.0350

Nº notice refdoc (ud4) : 13540477



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