Reprod. Nutr. Dev. 45 (2005) 87-99
DOI: 10.1051/rnd:2005006

Effect of genotype and overfeeding on lipid deposition in myofibres and intramuscular adipocytes of breast and thigh muscles of ducks

Pascal Chartrin^a, Achille Schiavone^b, Marie Dominique Bernadet^c, Gérard Guy^c, Jacques Mourot^d, Michel J. Duclos^a and Elisabeth Baéza<sup>a

a</sup>  Station de Recherches Avicoles, INRA Tours, 37380 Nouzilly, France
^b  Dipartimento di Produzioni Animali, Epidemiologia ed Ecologia, 10095 Grugliasco (TO), Italy
^c  SEPFG, INRA Artiguères, 40280 Benquet, France
^d  URVMP, INRA, 35590 St Gilles, France

(Received 21 September 2004; accepted 15 November 2004)

Abstract - We conducted a study to evaluate the effects of genotype (Muscovy, Pekin and their crossbred, hinny and mule) and overfeeding (14 days from 12 weeks of age) on lipid deposition in myofibres and intramuscular adipocytes of breast and thigh muscles of ducks. Birds of the four genotypes were also reared contemporaneously with a growing diet distributed ad libitum. Muscle samples (Pectoralis major and Sartorius) were collected at 14 weeks of age on 8 ducks per treatment. The muscle fibre typing, the total lipid and triglyceride contents in myofibres and the relative surface occupied by adipocytes on the cross-sectional area of the muscles were determined by histological and image analysis. Overfeeding induced a marked increase of body weight but had no significant effect on the muscle weight, the cross-sectional area (CSA) of myofibres and the muscle typology. In muscles, overfeeding induced a large accumulation of lipids, mainly in adipocytes whose relative surface increased 1.5 fold in P. major and 2.1 fold in Sartorius and an increase in triglyceride content of fast twitch oxydo-glycolytic and glycolytic fibres in P. major only (+ 37 and + 16% respectively). Genotype had no significant effect on the muscle typology. By comparison with the other genotypes, Muscovy ducks exhibited the highest body weight, the highest muscle weight which could partly be explained by the highest fibre CSA and the lowest intramuscular fat content in adipocytes and myofibres (only fast twitch oxydo-glycolytic fibres in P. major). We observed the reverse situation for the Pekin ducks. The crossbred ducks always presented intermediate values except for body weight.

Key words: lipids / myofibres / adipocytes / muscles / ducks

Corresponding author: Pascal Chartrin chartrin@tours.inra.fr

© INRA, EDP Sciences 2005