Aditivos naturais na dieta de ruminantes e seus efeitos na qualidade da carne

• Ano de defesa: 2018
• Autor(a) principal: Rivaroli, Dayane Cristina
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Zootecnia; Maringá, PR; Centro de Ciências Agrárias
• Palavras-chave em Português: Nutrição animal; Antioxidantes; Extratos de plantas; Óleos essenciais - Nutrição; Ciências Agrárias; Zootecnia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/4727

The study with crossbred heifers, finished in feedlot, fed with diets containing essential oils mix (oregano, garlic, lemon, rosemary, thyme, eucalyptus and sweet orange) was carried out to evaluate the effect on meat quality (chemical composition, water holding capacity and texture) and fat (lipid oxidation and fatty acid profile). Thirty animals (12 months-old and 219.8 kg) (½ Angus vs. ½ Nellore) were allocated in individual pens for 3 months with one of the following diets (90% concentrate and 10% sugarcane bagasse pelletized): without addition of essential oils (E0.0), with 3.5 (E3.5) or 7 (E7.0) g/animal/day of essential oils? blend. Chemical composition, fatty acid profile on Longissimus muscle and meat color were evaluated. In addition, the effect of ageing (1, 7 and 14 days) was evaluated on water holding capacity, texture and lipid oxidation. Essential oils had no influence (P > 0.05) on chemical composition, meat colour, water holding capacity and texture, but the inclusion of 7.0 g.d-1 had a tendency (P < 0.10) to increased lipid oxidation. The addition of 7.0 g/animal/day had a pro-oxidant effect (P < 0.05) on meat during the ageing and showed higher values for lightness at 14 days. Ageing reduced (P < 0.05) meat texture. The second study was to evaluate the sensory acceptability of meat from 57 crossbred (½ Angus - ½ Nellore ) animals of different sexes [heifers n=30, and young bulls n=27], finished in feedlot with isoenergetic and isonitrogenous diets, in different levels of supplementation (0.0, 3.5 or 7.0 g/animal/day) of a commercial mix of essential oils (Mixoil®) from seven plants: oregano, garlic, lemon, rosemary, thyme, eucalyptus and sweet orange. 120 consumers who scored tenderness acceptability, flavor acceptability and overall acceptability using a hedonic nine-point scale evaluated the Longissimus thoracis muscle, with 24 hours of maturation. The essential oils inclusion affected tenderness acceptability and flavor acceptability (P ? 0.01), with a tendency (P < 0.10) for overall acceptability. Meat from heifers was more appreciated by consumers than that from young bulls for all attributes (P? 0.001), however, different groups of consumers had different preferences. The inclusion of essential oils mix in beef diets was well accepted by consumers and could improve the meat acceptability from young bulls, when added at a concentration of 3.5 g/animal/day during the last 4 months of fattening. The third work was carried out to investigate the influence of sainfoin pellets supplementation on fat skatole and indole concentration, fat and meat color and chop sensory attributes in grazing lambs. Fifty-four lambs (Romane) were separated in different groups for at least 87 days before slaughter: feedlot (SI), pasture-fed alfalfa (M. sativa) (AF) and pasture-fed alfalfa plus sainfoin (O. viciifolia) pellets (AS). Perirenal and dorsal fat skatole concentrations were below quantification limit for all SI lambs. Sainfoin pellet supplementation in grazing lambs reduced perirenal and dorsal fat skatole concentration. The treatments did not affect subcutaneous caudal fat and Longissimus thoracics et lumborum muscle color, except for lightness (L*) on fat. The sainfoin pellet supplementation for grazing lambs can be a strategy to reduce perirenal and dorsal fat skatole concentration