engleski

The analysis of the histometabolic properties of some sceletal muscles of Lika's Pramenka breed male lambs as a possible basis for assessment of improving the race

The samples of m. triceps brachii (caput longum), m. longissimus lomborum, m. psoas major, m. gluteobiceps, m. semitendinosus, m. semimembranosus and m. quadricepsfemoris (m. rectus femoris) of the Licka pramenka lambs 3 months old and weighing 20 - 25 kg were used to present histochemical activity of dehydrogenase lactate and succinate and of adenosintriphosphatase Investigated were the number and surface of the large- and medium-diameter fibres, the number, diameter and surface of the oxidative, oxidative-glycolytic and glycolytic fibres, and the number of rapid and slow-contracting fibres. The results were compared with previous comparative studies employing the crossbreeds between the Istarska plamenka and the Sardinian, domestic Merino-Wurttemberg and East-Friesian rams. The studied muscles comprising short-diameter fibres accounted for 60.88 - 87.91% and the medium-diameter fibre muscles accounted for 12.09 - 39.12%, whereas the large-diameter fibre muscles were not present. The oxidative, glycolytic and oxidative-glycolytic fibres accounted for 36.64 - 45.92%, 31.24 - 40.16% and 21.18 - 24.38% respectively, depending upon a muscle and a lamb. Out of the small-diameter fibres the oxidative ones comprised 39.29 - 53.61% of all the fibres and 36.53 - 50.43% of the whole surface ; oxidative-glycolytic fibres comprised 22.60 - 26.43% of all the fibres and 21.66 - 28.92% of the whole surface, and glycolytic fibres comprised 21.94 - 35.30% of all the fibres and 24.07 - 37.57% of the whole surface of the muscular cross-section. Out of the medium-diameter fibres the oxidative ones comprised 17.46 - 37.25% of all the fibres and 7.04 - 36.01% of the whole surface ; oxidative-glycolytic fibres comprised 12.50 - 20.00% of all the fibres and 6.93 - 20.77% of the whole surface, and glycolytic fibres comprised 50.00 - 63.64% of all the fibres and 51.06 - 74.27% of the whole surface depending on a lamb and a muscle. Slow-contracting fibres accounted for 35.20 - 46.80% and rapid-con-tracting muscles accounted for 53.20 - 64.80%. In the similar muscles of the Istarska pramenka crossbreeds oxidative fibres, oxidative-glycolytic fibres and glycolytic fibres accounted for 20.38 - 31.02%, 17.99 - 27.54% and 44.80 - 62.04% respectively, and the slow-contracting and rapid-contracting ones accounted for 19.60 - 33.95% and 66.05 - 89.29% of all the fibres respectively. The small-diameter fibres accounted for 1.5 - 45.6%, medium-diameter fibres 26.4 - 79.4% and large-diameter fibres 2.1 - 63.3%. It has been shown that the crossbreeds' muscles comprised more glycolytic and rapid-contracting fibres and the medium- and large-diameter fibres than the muscles of the Licka pramenka lambs. The comparison of the muscular histo-metabolic characteristics of the Licka pramenka lambs and the Istarska pramenka crossbreeds has shown that irrespective of the equal body weight and older age of the Istarska pramenka lambs their muscular development was inferior to that in the studied crossbreeds. Present study has shown that monitoring of the muscular histo-metabolic characteristics is suitable for assessment of the advantages conferred to the low-performing sheep breeds, especially in the terms of muscular development and meatiness.

lamb; Likas Pramenka; muscular fibre diameter; enzymatic activity of LDH; SDH and ATP

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