Abstract. The nutritional requirements can be met, and carcass quality can be achieved by using concentrate supplementation in the diets of grazing lambs. This study evaluated the effects of different concentrate supplementation rates (0 %, 1.5 %, and 3 % of body weight) and tropical pastures (Panicum maximum cv. `Aruana' and Brachiaria brizantha cv. `Marandu') on lamb carcass traits. Thirty-six male Suffolk lambs, with an initial body weight of 22.54 ± 2.72 kg, were evaluated in a 3 × 2 factorial experimental design. The concentrate used consisted of milled soybean, maize, and oat grains. The pasture species affected empty body weight and commercial cuts. The use of concentrate supplementation affected carcass weight, yield, indexes, and commercial cuts. Also, the use of concentrate supplementation improved the weight of muscle and fat content. Based on discriminant analysis it is possible to identify the rearing systems, when all variables where used, or the level of concentrate supplementation when variables of weight were used. Carcasses of animals on grass-only diets were different and easier to discriminate. The use of concentrate supplementation on rearing lambs improves the quality of carcass traits. The period of finishing can be shorted with supplementation of 3 % of body weigh in Aruana and Marandu grass. The discriminant analysis can identify the differences between rearing systems based on all carcass traits. This analysis can be used to develop carcass traceability systems.

Background and Aim: Ultrasound is a non-invasive technique that enables animal evaluation and body condition classification of animals. Although it is not difficult to obtain an image, the analysis of this image can influence results quality. This study aimed to evaluate the repeatability and reproducibility of the technician trained in image interpretation obtained using different ultrasound frequencies. Materials and Methods: Ninety-six lambs were used, ranging in weight from 15 to 40 kg. The images were captured using a linear probe of 13 cm, with a 3.5 megahertz (MHz) frequency and an acoustic couplant aid "standoff" or using a multifrequency transducer (6 and 8 MHz), on B mode, with a linear probe and 8.0 MHz frequency. All measurements were performed by the same technician, on the left side, between the 12th and 13th rib. Five different evaluators, at two different times, with aid of Image J software measured the loin eye area (LEA; only for images obtained with 3.5 MHz), Longissimus thoracis et lumborum depth (DLM), subcutaneous fat thickness (SFT), subcutaneous fat thickness plus skin (SFST), and skin thickness (ST). Results: For LEA, DLM, SFT, SFST, and ST, variation was observed (p<0.01) between evaluators; however, there was no difference (p>0.05) between the 2 times of evaluation. Images measurements obtained with a frequency of 8.0 MHz had better repeatability indices and reproducibility indices. Accordingly, the identity test demonstrated that measurements performed on images obtained using 3.5 or 8.0 MHz were not equivalent. Conclusion: Ultrasound image measurements obtained using an 8.0 MHz frequency were more accurate and precise. It is important to use only one evaluator or providing the simultaneous training for all evaluators.

Objectives of this study were to evaluate effects of grazing tropical forage species and level of supplementation with grain on characteristics of lamb meat. Ninety-day-old lambs (n = 36) (22.54 ± 2.72 kg) were randomly assigned to a 2 x 3 factorial arrangement of pasture types (Aruana and Marandu) and levels of concentrate supplementation (0%, 1.5% and 3% of bodyweight). Water retention capacity, shear force, weight loss after cooking, pH, colour, and intramuscular lipid content of the meat were evaluated. A panel of 145 consumers evaluated the appearance, flavour, fat flavour, odour, and softness of the meat and provided an overall assessment. Supplementation at 3% of bodyweight reduced the luminosity of the meat. The appearance of meat from lambs that grazed Aruana grass was deemed preferable to that of meat from lambs that grazed Marandu grass. Total branched-chain fatty acids (BCFAs) were increased when grazing Marandu grass compared to Aruana grass. Lambs supplemented with concentrate had reduced BCFA/kg of meat and its content of both monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acids were increased. Supplementation with concentrate at 1.5% and 3.0% of bodyweight increased n-6 PUFAs by 16.8% and 90.0%, decreased n-3 PUFAs by 49.7% and 35.9%, and thus increased the n-6/n-3 ratio by 135.0% and 183.8%, respectively. Lambs that were finished on grass without supplementation had a more healthful fatty acid profile and received better scores for flavour and global appreciation. To improve the quality of fatty acids in the meat, the pasture system is recommended. Keywords: Brachiaria brizantha, lipid content, Longissimus thoracis et lumborum, Panicum maximum, sheep feeding

No abstract

RESUMOA produção de carne bovina depende basicamente da produção de pastagens, assim, o objetivo dessa pesquisa foi avaliar a altura do dossel e as produções de matéria seca de lâminas foliares e colmo do capim Urochloa brizantha cv. Piatã em função das frequências de cortes, estações do ano com e sem irrigação. O delineamento foi inteiramente casualizado em esquema fatorial 4x2x3, sendo quatro idades de corte (21, 28, 35 e 42 dias entre cortes), irrigado e não irrigado, e três estações do ano (outono, inverno e primavera) com seis repetições por tratamento (canteiros experimentais). Os parâmetros avaliados foram: altura de dossel e as produções de massa seca total de lâminas foliares e colmo. Os resultados indicaram que na primavera, as maiores alturas do dossel foram registradas em pastos cortados aos 28 dias com 39,6 cm de altura. As produções de massa seca de lâminas foliares foram maiores no intervalo de corte de 42dias, sendo as maiores produções durante o Outono com 1,364 kg ha -1 com irrigação. A primavera foi à estação que apresentou as melhores produções de massa seca de colmos com 0,141 kg ha -1 de MS aos 42 dias sem irrigação. A irrigação aumenta a altura do dossel durante o inverno. Estas informações podem ser recomendadas na alimentação de animais ruminantes. Palavras-chave: produção animal, gramíneas tropicais, características estruturais. ABSTRACTThe beef production depends basically on the production of pastures, thus the main goal of this research was to evaluate the dossal height and dry matter production of leaf blades and grass stalk Urochloa brizantha cv. Piatana depending on cutoff frequency, seasons and irrigation. The experimental design used was completely randomized in factorial scheme (4x2x3) with four cutoff frequencies (21, 28, 35 and 42 days between cuts) irrigated and non-irrigated, and three seasons (fall, winter and spring) with six repetitions per treatment (experimental plots). The parameters evaluated were: dossal height and total dry mass production of leaf blades and stem. The results showed: in spring season, the highest of the dossal were observed in pastures cut to 28 days with 39.6 cm. The dry mass production of leaf blades was higher at 42 days cutting, with the largest production (1.364 kg ha -1 ) in autumn with irrigation. In spring season without irrigation was the best dry matter production of stalks with 0.141 kg ha -1 at 42 days. The dossal height increases with irrigation in winter. This information may be recommended in the feeding of ruminant animals.

El objetivo de esta investigación fue verificar mejoras en el proceso fermentativo del ensilaje de Pennisetum purpureum cosechados en tres edades de corte con la inclusión de diferentes dosis de glicerina bruta (GB). El experimento fue realizado en un delineamiento completamente al azar en esquema factorial 4x3x3, cuatro dosis de glicerina bruta (0, 10, 20 y 30% de la materia seca [MS] ensilada) y tres edades de corte (30, 45 y 60 días) con tres repeticiones por tratamiento (minisilos). Fueron determinados, pH, producción de efluente (PE), pérdidas por gases (PG) y pérdidas de materia seca (PMS). Los resultados fueron sometidos a un análisis de varianza al 5% de probabilidad. Se ha verificado mejoras en el proceso fermentativo del ensilaje de P. purpureum con la adición de glicerina bruta y reducción de pérdidas. PE se redujo 12,05% para las dosis de 30% de glicerina bruta en el primer corte, para el segundo corte, se redujo del 17,63% en relación al T1 (Testigo) 0% de GB. Las reducciones en las PG en el primer y segundo corte fueron de 22,30% y 82,16% respectivamente, así también la mayor dosis (30% GB) fue la que arrojo mejores resultados con una reducción del 57,3 por ciento. En cuanto a PMS, el ensilaje producido con la mayor dosis de GB (30%) fue el que produjo mejor resultado comparando con las demás dosis. GB puede ser utilizada en el ensilaje de Pennisetum purpureum para promover mejoras en el proceso fermentativo y reducción de las perdidas cualitativas.

No abstract

El maíz transgénico que expresa la toxina de Bacillus thuringiensis (Bt) produce un cristal (Cry) de proteína tóxica para las orugas de las hojas y los tallos de maíz Bt, pero es atóxica para chinches. Los objetivos de este estudio fueron identificar la cantidad de plantas de maíz atacadas y no por la chinche barriga verde Dichelops melacanthus, evaluar los daños foliares a través del número de punturas, la altura de plantas y la producción en peso de granos de las plantas de maíz atacadas y no. La investigación se realizó en una granja agrícola de producción comercial en una superficie de 700 m2. Los datos fueron registrados en hoja impresa, tabulada en planilla electrónica Excel y analizados estadísticamente por el test T-Student con una significancia del 5 % para comparación de dos grupos de muestras independientes. Los resultados obtenidos indican que el 80,7 % de las plantas de maíz fueron atacadas por la chinche D. melacanthus presentando punturas foliares. La altura promedio de las plantas atacadas fue de 41,2 ± 2,2 cm y 41,5 ± 3,3 cm de las no atacadas. En relación a la producción se ha verificado una reducción significativa del 23 %. El peso de los granos de maíz por planta atacada tuvo un promedio de 3,048 ± 199 g y 3,956 ± 269 g en planta no atacada, demostrando así que los daños ocasionados por D. melacanthus reducen el rendimiento del maíz Bt.