Effects of nutritional level on muscle development, histochemical properties of myofibre and collagen architecture in the pectoralis muscle of male broilers

Abstract

1. The effects of nutritional level on muscle development, histochemical properties of myofibre and collagen architecture in the pectoralis muscle were evaluated using male broilers of Red Cornish x New Hampshire stock, reared on diets of high nutritional value for up to 80 d (H80d) and low nutritional value for up to 80 d (L80d, same age as H80d) or 95 d (L95d, same body weight as H80d). 2. The total live weight and the weight of pectoralis muscle were lower in L80d than in both H80d and L95d. The muscle weight as a percentage of live weight was 8.7% in L80d, 10.7% in H80d and 11.5% in L95d. 3. Pectoralis muscle was composed only of type IIB myofibres and showed no differences in myofibre type composition among the chicken groups. The largest diameter of type IIB myofibres was observed in L95d, followed by H80d and the smallest in L80d. 4. The total amount of intramuscular collagen did not differ among the chicken groups (1.92 to 1.99 mg/g). Types I and III collagens were immunohistochemically detected in both the perimysia and endomysia. The thin perimysia around the primary myofibre fascicles showed larger width in H80d than L80d and L95d, and also the thick perimysia around the secondary fascicles in H80d than L80d. 5. The collagen structure of the perimysium was most developed in H80d, followed by L95d and on the least in L80d. The development of perimysial collagen fibres could be enhanced by a rapid growth rate of the muscle induced by high nutritional level and depressed by a slow growth rate with low nutritional foods. 6. The endomysial collagen architecture was observed as a felt-like tissue of the fibril bundles with many slits. The thinnest endomysial wall was observed in L80d, followed by H80d and the thickest in L95d. 7. From these results, it was indicated that foods of high nutritional value could enhance growth of the pectoralis muscle of broilers, and this is accompanied by hypertrophy of the type IIB myofibres and development of the perimysial collagen architecture.

Effects of divergent selection for 8-week body weight on postnatal enzyme activity pattern of 3 fiber types in fast muscles of male broilers (Gallus gallus domesticus)

“…In contrast to this response, during growth from wk 3 to 12, all 3 fiber types in PP muscles reached similar diameters in both lines. These findings are in agreement with a previous Smith and Fletcher (1988), but are in contrast to those of Roy et al (2006). It has been reported that the largest diameter of type IIB fibers (50.5 μm) was noted in the pectoralis muscle at 95 d in a group of broilers given feed of a low nutritional value.…”

Passive stiffness of rat skeletal muscle undernourished during fetal development

“…The effects of nutritional status on the regulation of skeletal muscle collagen content are varied. Roy et al26 reported no influence of nutritional level in muscle collagen content in pectoralis muscle of broilers but with some differences in the collagen structure of the perimysium. In the gastrocnemius muscle of adult mice deprived of food for 2 days, Jagoe et al27 showed a decrease in gene expression for many extracellular matrix proteins like collagen.…”

Collagen content and architecture of thepuboischiofemoralismuscle in male chicks and broilers with different growth rates on various nutritional planes

“…The intramuscular connective tissue, especially the fibrous collagen components, could increase passive tension. However, in the central belly of the PIF muscle from chickens the perimysial collagen fibres did not develop as well as those of the iliotibialis lateralis and pectoralis muscles and the endomysial collagen sheets were similar in the latter two muscles (Roy et al, 2006(Roy et al, , 2007Oshima et al, 2007a, b). While PIF muscle maintains posture (Raikow, 1985;Vollmehrhaus, 1992;Iwamoto et al, 1993a), active myofibre contraction is needed to carry out its role.…”

“…Although a few portions of the thick perimysium contained many collagen fibres, the perimysia were generally composed of sparsely distributed collagen fibres and a reticulum of fine collagen baskets for adipocytes. Moreover, the endomysial sheets did not show any difference in collagen structure from fast-twitch muscles such as pectoralis and iliotibialis lateralis (Nakamura et al, 2003a;Oshima et al, 2007a, b;Roy et al, 2006Roy et al, , 2007. Nakamura et al (2003b) observed much thicker endomysial wall in the slow-tonic cranial part than the fast-twitch caudal part of the latissimus dorsi muscle in broilers.…”