Resumen Este estudio evaluó los efectos de diferentes fuentes de energía, como sustitutos del maíz, sobre la calidad de la carcasa y la carne de los corderos. Se identificaron, pesaron y distribuyeron 24 corderos machos no castrados en cuatro tratamientos: maíz, pulpa de cítricos, salvado de arroz y cáscaras de soya. Los corderos fueron confinados en corrales de engorde y cuando alcanzaron los 30 kg de peso vivo fueron sacrificados. Para el análisis de resultados se utilizó un diseño completamente aleatorio con diferentes réplicas y se utilizó la prueba de Tukey-5%. Para las variables de peso de la carcasa caliente y fría, el salvado de arroz fue inferior a los otros tratamientos. Para el color rojo de la carne, la pulpa de los cítricos presentó un resultado superior al maíz, mientras que el color de la carne y la grasa, la ternura objetiva y el área del ojo del lomo no difirieron entre tratamientos. Las diferentes fuentes de energía utilizadas en las dietas de terminación de corderos no alteraron la composición química de la carne ni las características de calidad.

Abstract This study evaluated the effects of different energy sources, as corn substitutes, on the carcass characteristics and meat quality of lambs. Twenty-four intact ram lambs were identified, weighed, and assigned to one of four dietary treatments: corn, citrus pulp, rice bran, and soybean hulls. The ram lambs were confined in feedlots, and when they reached 30 kg of live weight, they were slaughtered. A completely randomized design with different replicates was used for the analysis, along with the Tukey-5% test. For hot and cold carcass weight, rice bran produced lower values than the other dietary treatments. For the red color content of the meat, citrus pulp presented superior values when compared to corn, whereas meat and fat color, loin eye area, and objective tenderness did not differ between treatments. Different energetic sources used to replace corn in ram lambs finishing diets did not affect the proximate composition and quality of the meat.

O propósito deste trabalho foi determinar a similaridade genética entre acessos de germoplasma e cultivares comerciais de três espécies de Brachiaria (inter e intraespecífica), por meio de marcadores RAPD. Sementes foram utilizadas como fonte de DNA. 10 "primers" decâmeros foram selecionados de 120 "primers" avaliados, produzindo 107 bandas polimórficas, as quais foram utilizadas para a análise de variância molecular (Amova), o coeficiente de similaridade de Jaccard e índices de fixação gênica. 24,40% da variabilidade genética total estão contidas entre as espécies e 75,60% dentro destas, com índice de fixação gênica (FST) 0,24. No dendrograma, houve a formação de dois ramos, um formado por P. maximum e B. arrecta e o outro subdividido em três: todas amostras de B. ruziziensis; todos os acessos de B. decumbens e três acessos de B. brizantha e o último com dois acessos de B. brizantha mais as B. brizantha comerciais e a B. decumbens cv. 'Basilisk'. Foi possível agrupar os acessos e as cultivares de Brachiaria por meio de RAPD. O índice de variabilidade genética entre espécies foi considerado baixo, sendo inferior a valores determinados em algumas espécies autógamas. B. brizantha apresenta maior variabilidade genética e menor FST indicando maior fluxo gênico intra-específico do que as outras.

The aim of this work was to determine intra and intergenetic similarity among three Brachiaria species for germplasm accesses and commercial cultivars using RAPD markers. Seeds were used as DNA source. 10 decamer 'primers' were selected among 120 'primers', and 107 polymorphic bands were used to perform the analysis of molecular variance (Amova), Jaccard similarity coefficient and species fixation index. 24.4% of the total variability was contained between species and 75.6% within species, with a species fixation index (FST) of 0.24. The tree showed that two major branches were formed: one with the three outgroup species and another with the species, the latter split into three minor branches: one with all B. ruziziensis samples; another with all B. decumbens accessions and three of B. brizantha; and the last with two B. brizantha accesses, all commercial cultivars and B. decumbens cv. 'Basilisk'. It was possible to group, through RAPD, Brachiaria accesses and cultivars. The genetic variability index between species was considered low, and somewhat low when compared with autogamous species. B. brizantha showed the highest genetic variability and the lowest FST, which means that there is a higher intra specific genetic flux than the others.