MODULATION OF FIBER MUSCLE SKELETAL DEPENDING ON THE BODY MASS, THE DIET AND ITS RELATIONSHIP WITH THE QUALITY OF SHEEP MEAT

This study aimed to determine the modulation of skeletal muscle fibers of Longissimus dorsi, Semitendinosus and Supraspinatus, due to the variation in body weight and diet, evaluating its relationship with meat quality of lambs of Texel. For assessment of body mass were used thirty lambs distributed in five treatments with six replicates each: six lambs were slaughtered at 20 kg (slaughter control), 24 animals were slaughtered at 25, 30, 35 and 40 kg. For the evaluation of the influence of diet twenty-four lambs were randomly divided into four treatments, where six lambs were soon slaughtered after adjusting the experimental conditions (slaughter control), 12 animals were submitted to two food restriction levels (55 and 70% of ad libitum intake, six per group) and 6 animals were submitted to ad libitum consumption and slaughtered with a body mass of 40 kg. The different body mass slaughter, provided modulation of muscle fibers type IIB and IIC for type IIA fibers to the Longissimus dorsi, Semitendinosus and Supraspinatus, and provide changes in diameter, area and relative frequency of muscle fibers. Regarding the quality of meat, observed effect (P <0.05) of different body masses, the moisture, lipids, cholesterol, pH, hardness, color and lipid profile. Already, for different levels of food restriction it was observed that animals submitted the restrictions 55 and 70% had lower values of the characteristics of muscle fibers, whereas the opposite for animals submitted to ad libitum intake. Food restriction also influenced the meat quality characteristics, such as moisture, ash, protein, lipids, cholesterol, loss of cooking and color attributes. Thus, we conclude that different body mass slaughter and different feeding systems influence meat quality characteristics and the modulation of skeletal muscle fibers.Objetivou-se determinar a modulação das fibras musculares esqueléticas dos músculos Longissimus dorsi, Semitendinosus e Supraspinatus, em função da variação da massa corporal e do regime alimentar, avaliando sua relação com a qualidade da carne de cordeiros da raça Texel. Para avaliação da massa corporal foram utilizados trinta cordeiros, distribuídos em cinco tratamentos com seis repetições cada: seis cordeiros foram abatidos com 20 kg (abate controle), 24 animais foram abatidos aos 25, 30, 35 e 40 kg. Para a avaliação da influência do regime alimentar, foram utilizados vinte e quatro cordeiros, distribuídos em quatro tratamentos, onde seis cordeiros foram abatidos logo após adaptação as condições experimentais (abate controle), 12 animais foram submetidos a dois níveis de restrição alimentar (55 e 70% do consumo ad libitum, seis por grupo) e 6 animais foram submetidos ao consumo ad libitum e abatidos com massa corporal de 40 kg. As diferentes massas corporais ao abate, proporcionaram modulação das fibras musculares do tipo IIB e IIC para fibras do tipo IIA para os músculos Longissimus dorsi, Semitendinoso e Supraspinatus, além de proporcionar alterações no diâmetro, área e frequência relativa das fibras musculares. Em relação a qualidade da carne, observou efeito (P