Feed Restriction and Muscle Fibre Characteristics of Pectoralis Major in Broiler Chickens

The aim of the study was to evaluate the effect of one-week quantitative feed restriction (in days 8-14 of age) on histological characteristics of musculus pectoralis major in broiler chickens during the fattening period. Cockerels of Ross 308 (1215 chicken) were divided into 3 groups: ad libitum fed (AL; 3 × 135), restricted 80% of AL (R80; 3 × 135), and with limited feed intake 65% of AL (R65; 3 × 135). Eight cockerels per group were slaughtered in weekly intervals from day 14 of age till the end of experiment at 35 days to determine changes in the muscle fibre characteristics. The number of muscle fibres in pectoralis major decreased (P ≤ 0.001) with increasing age. Fibre cross sectional area was s ignificantly (P ≤ 0.027) affected by the interaction of group and age. At the end of feed restriction at 14 days all groups had similar fibre area (519-539 μm2), the differences between groups were observed at 35 days of age with the largest fibre area in R65 chickens (2296 μm2), while R80 did not differ from AL (1728 μm2 and 1667 μm2). There was no effect of feeding regime on giant muscle fibre incidence.

Histological analysis of muscles of Landes geese

The aim of this study was histological and histochemical analyze of musculus pectoralis major (MPM) and musculus biceps femoris (MBF) of 12-weeks old Landes geese husbandry by sex from Hruboňovo (Czech Republic). The geese had live weight of 3979.0 g and the ganders had live weight of 4779.0 g. Higher α White fiber percentage representation of musculus pectoralis major and musculus biceps femoris of 12-weeks old Landes geese histological analyses we followed. Representation of sex identical MBF was 60.0% (gander) and 64.1% (geese) and MPM was 47.6% (ganders) and 51.1% (geese). The lowest α Red fibre percentage content in MPM was 6.7% (ganders) and 4.7% (geese) and β Red fiber in MBF was 10.7% (ganders) and 9.5% (geese). No statistically significant differences (P ≥ 0,05) among sex in the fat cells thickness of geese were found, but significant differences (P ≤ 0,01) was found in MBF fat cells between ganders (26.3 μm) and geese (21.9 μm). Highest thickness of α White fibre in muscles breast and femoral were found in both sex and lowest was found in β Red fibre. Muscles fibres thickness was higher femoral muscles in average (59.9 μm – ganders; 58.3 μm – geese) opposite breast muscles (47.7 μm – ganders, 44.9 μm – geese), what is the mean higher consistence of femoral muscles for consumer. In term of lowest musculus fiber thickness of Landes geese in average were 44.9 μm – MPM, 58.3 μm – MBF opposite of ganders 47.7 μm – MPM, 59.9 μm – MBF. Higher α White fibre representation was both muscles (51.1% – MPM, 64.1% – MBF). We recommended for experience used in­di­vi­dual rearing of male.