Use of Tithonia diversifolia (hemsl) A. Gray in the diet of growing lambs / [Uso de tithonia diversifolia (hemsl) A. Gray na dieta de cordeiros em crescimento]

Two assays were conducted to study the Tithonia diversifolia (Td) plant: (1) chemical analysis and in vitro dry matter digestibility (IVDMD) of plant parts and (2) productive performance of lambs fed a traditional diet or a Td diet (30% of Td plus 70% of the traditional diet). The plant parts studied were leaves (L), leaves and petioles (LP); and leaves, petioles and stems (LPS). Feed intake, weight gain and feed conversion were registered weekly during five weeks of experimentation. The L showed higher (P<0.05) crude protein content (26.7%) than LP and LPS (25.5 and 19.7%, respectively). Crude fiber (11.2%), neutral detergent fiber (45.4%), cellulose (16.9%) and hemicellulose (33.5%) were lower in L than in LP (12.5, 46.7, 18.0 and 35.7%, respectively) and LPS (22.6, 59.2, 27.0 and 43.5%, respectively). The L and LP showed the highest IVDMD (89.2 and 88.2%, respectively vs. 77.2% of LPS). The Td diet resulted in greater feed intake and weight gain and lower feed conversion than the traditional diet. Therefore, Tithonia diversifolia is a forage plant of good quality for lambs which does not affect the productive performance.(AU)

Dois ensaios foram realizados para estudar a planta de Tithonia diversifolia (Td): (1) análise química e digestibilidade in vitro da matéria seca (DIVMS) de partes de plantas e (2) desempenho produtivo de cordeiros alimentados com dieta tradicional ou dieta Td (30% de Td mais 70% da dieta tradicional). As partes vegetais estudadas foram folhas (L), folhas e pecíolos (LP); folhas, pecíolos e caules (LPS). O consumo de ração, o ganho de peso e a conversão alimentar foram registrados semanalmente, durante cinco semanas de experimentação. O L apresentou maior (P<0,05) conteúdo de proteína bruta (26,7%) que o LP e o LPS (25,5 e 19,7%, respectivamente). Fibra bruta (11,2%), fibra em detergente neutro (45,4%), celulose (16,9%) e hemicelulose (33,5%) foram menores em L do que em LP (12,5, 46,7, 18,0 e 35,7%, respectivamente) e LPS (22,6, 59,2, 27,0 e 43,5%, respectivamente). O L e o LP apresentaram o maior DIVMS (89,2 e 88,2%, respectivamente vs. 77,2% do LPS). A dieta Td resultou em maior consumo de ração e maior ganho de peso e menor conversão alimentar que a dieta tradicional. Portanto, Tithonia diversifolia é uma planta forrageira de boa qualidade para cordeiros que não afeta o desempenho produtivo.(AU)

Dietary supplemented and meat-added antioxidants effect on the lipid oxidative stability of refrigerated and frozen cooked chicken meat.

The oxidation of fatty acids decreases the quality and shelf-life of meats. To reduce this process, dietary supplemented and meat-added antioxidants were evaluated on the lipid oxidative stability of cooked chicken meat. Broilers were fed 2 levels of vitamin E (10 or 100 mg•kg(-1) of feed; VE-10 and VE-100, respectively) or oregano essential oil (100 mg•kg(-1) of feed; OR-100). Additionally, honey (3%) or butylated hydroxytoluene (0.02%; BHT) were added to chicken meat from the control treatment (VE-10). Breast meat was ground, formed into patties, and cooked on electric grills until it reached an internal temperature of 74°C. Cooked meat was cooled at room temperature, packaged, and stored under refrigeration for 9 d (4°C) or frozen for 45 d (-20°C). The 2-thiobarbituric acid reactive substance test was used to quantify malondialdehyde (MDA) values in the meat. Data were analyzed using a repeated measures design, 5 treatments with 12 replications each, and the least squares means were compared with 4 orthogonal contrasts. The results showed that the meat of the VE-10 treatment had higher values of MDA (P ≤ 0.05) compared with the other antioxidant treatments in all the storage days. There were no differences (P ≥ 0.05) in MDA values between the dietary supplemented and meat-added antioxidant treatments. The meat added with honey had lower MDA values than the one with BHT (P ≤ 0.05). Meat of the VE-100 treatment showed lower MDA values than the one of OR-100 (P ≤ 0.05) in most storage days. In conclusion, supplementation of 10 mg•kg(-1) of vitamin E to the diet resulted in a higher development of lipid oxidation in the meat. Both dietary supplemented or meat-added antioxidants had similar effects on the lipid oxidative stability. The addition of honey maintained longer the lipid oxidative stability of the meat than BHT. Finally, dietary supplementation of vitamin E at the same level of oregano oil, 100 mg•kg(-1), resulted in a higher antioxidant effect on the meat.

Effects of dietary oregano essential oil and vitamin E on the lipid oxidation stability of cooked chicken breast meat.

The antioxidant effect of oregano essential oil and vitamin E was evaluated in cooked chicken breast meat. In total, 480 broilers were randomly assigned to 6 treatments and 4 replications. Broilers were raised with a corn-soybean meal diet including either crude soybean oil or acidulated soybean oil soapstock, each supplemented with vitamin E at 10 or 100 mg or oregano essential oil at 100 mg/kg of feed. At 42 d, broilers were slaughtered and their breast meat was prepared into strips (1.5 × 10 cm) or patties (150 g). Fatty acid composition of the muscle was determined. For lipid oxidation stability, both meat strips and patties were cooked to an internal temperature of 74°C and malonaldehyde contents were assessed during 0, 3, 6, and 9 d of storage at 4°C. Each storage day had 4 replications per treatment. The meat lipid oxidative stability was estimated by content of malonaldehyde values. Results showed that feed consumption, weight gain, and feed conversion were not affected by the dietary oils or antioxidants, except for the mortality in acidulated soybean oil soapstock with the 10-mg vitamin E treatment. The fatty acid composition of the meat was similar between the 2 diets given the same antioxidant supplement. The oxidation stability of meat lipids in both types of meats showed a significant (P < 0.05) interaction between oils, antioxidants, and storage time. In the crude soybean oil oil diet, the malonaldehyde value in the 10-mg vitamin E treatment was the highest, followed by oregano essential oil, and then the 100-mg vitamin E treatment at 9 d of storage, whereas the value of oregano essential oil in the acidulated soybean oil soapstock diet was the highest, followed by the 10-mg vitamin E, and then the 100-mg vitamin E treatment during the 9 d of storage. In conclusion, the dietary oils and antioxidants used can be included in broiler diets without negative effects on their productivity. The antioxidant effect of vitamin E was higher with a higher supplementation level, regardless of the oil treatment, whereas the antioxidant effect of oregano essential oil was better in crude soybean oil than in the acidulated soybean oil soapstock diet.