Relationship between muscle fibre characteristics and meat sensory properties in three nutria (Myocastor coypus) colour types

Abstract

AbstRAct:The study determined the muscle fibre characteristics and sensory properties of the longissimus lumborum muscle (LL) of eight-month-old nutrias of three colour types and the correlations between meat histochemical measurements and eating quality. The following nutria colour types were used in the experiment: Standard (ST), Moravian Silver (MS), and Prestice Multicolour (PM). The nutria colour type significantly (P < 0.001) affected the number of type IIB fibres with the lowest number in ST (108 per mm 2 ). The proportion of type I fibres varied between 10.6 and 14.2%; type IIA fibres varied between 6.1 and 7.8%; and type IIB fibres varied between 78.2 and 83.4% and it was not affected by colour type. The cross-sectional area (CSA) was 2.565-2.841 µm 2 in type I, 2.867-3.010 µm 2 in type IIA, and 4.698-5.517 µm 2 in type IIB fibres. The CSA of type IIB fibres (P < 0.001) was the largest in ST. The sensory trait of tenderness (P < 0.05) was the lowest in MS. Correlations between the proportion of fibres and sensory traits were not observed. The CSA of type I fibres correlated with flavour (0.19) and the CSA of type IIB fibres with tenderness (0.10).

The effect of limited feed intake on carcase yield and meat quality in early weaned rabbits

“…However, during the realimentation period, when rabbits are again fed ad libitum, compensatory growth with greater future intake can be detected. Tůmov a, Volek et al (2016) observed the higher feed intake in one week after the end of feed restriction. According to the study of , compensatory growth is not associated with over-eating by restricted rabbits due to the intake of numerous (30-40) smaller meals during the day.…”

“…For example, Gidenne et al (2012) observed 5 to 10% lower slaughter weights in restricted rabbits compared with the AL group. However, when feed restriction is mild, applied early or for a shorter period followed by a longer realimentation period, the differences in live weight may disappear (Tůmov a, Volek et al 2016;Birolo et al 2017). In the present study, one week of feed restriction applied from 32 days of age did not affect the live weight at the end of the experiment, which can be explained by the lower intensity of the feed restriction as well as the earlier age at application, so the restricted rabbits had a longer realimentation period.…”

“…According to the study of , compensatory growth is not associated with over-eating by restricted rabbits due to the intake of numerous (30-40) smaller meals during the day. Tůmov a, Volek et al (2016) found compensatory growth to be associated with the morphological and physiological development of the small and large intestines and the caecum during the restriction period and the rapid growth of these organs in the first week of realimentation. However, in most studies, early restricted rabbits did not reach the live weight of rabbits fed ad libitum by the end of the growth period (Gondret et al 2000;Tůmov a, Volek et al 2016).…”

“…Tůmov a, Volek et al (2016) found compensatory growth to be associated with the morphological and physiological development of the small and large intestines and the caecum during the restriction period and the rapid growth of these organs in the first week of realimentation. However, in most studies, early restricted rabbits did not reach the live weight of rabbits fed ad libitum by the end of the growth period (Gondret et al 2000;Tůmov a, Volek et al 2016). Although the live weight of restricted rabbits decreased, the results of Tůmov a et al 2006and showed that limited feed intake did not greatly affect carcase characteristics, but the dressing out percentage has been found to decrease with the intensity of feed restriction (Larzul et al 2004;.…”

“…Limited feed intake has a positive effect on feeding efficiency (Gondret et al 2000;Di Meo et al 2007;Gidenne et al , 2012, and it reduces carcase fat. Improved feed conversion ratios were observed in restricted rabbits by , but other authors have found the feed conversion ratio of restricted rabbits to be similar to that of groups fed ad libitum (Tůmov a et al 2002;Tůmov a, Volek et al 2016). Furthermore, feed restriction influences the growth of rabbits.…”