This study determined the chemical composition, in situ ruminal nutrient disappearance and in vitro gas production kinetics of three cactus varieties grown in northeastern Brazil. The varieties were Gigante, IPA-20 and Miúda. Results of the chemical analysis showed no significant differences in ash, ether extract, crude protein (CP) and neutral detergent fibre (NDF) between the cactus varieties. However, acid detergent fibre was highest (P < 0.05) for IPA-20, intermediate (P < 0.05) for Gigante, and lowest (P < 0.05) for Miúda. Fractionation of carbohydrate and true protein based on rates of ruminal degradation indicated that the main carbohydrate component was the rapidly degradable fraction, whereas the main true protein component was the intermediately degradable fraction. No differences in carbohydrate or protein fractions were observed between the cactus varieties. Results of the in situ experiment showed no differences in ruminal dry matter (DM, average 803 g kg −1 of DM), CP (900 g kg −1 of CP) and NDF (611 g kg −1 of NDF) disappearance between the three cactus varieties after 48 h of ruminal incubation. Potential gas production at the end of 48 h of incubation was higher (P < 0.05) for Gigante than for the Miúda or IPA-20 variety. However, rate of gas production and lag time in gas production were similar for the three cactus varieties at 6.8% h −1 and 0.6 h respectively. Our results showed little or no differences in chemical composition or ruminal nutrient degradabilities between the three cactus varieties.

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RESUMO -Este experimento foi realizado com o objetivo de avaliar o efeito da substituição do feno de capim-elefante por palma forrageira (Opuntia ficus indica, Mill), como fonte de forragem, sobre o consumo e a digestibilidade aparente dos nutrientes e das características ruminais de carneiros. Cinco dietas isoproteícas foram formuladas, em que a palma forrageira substituiu 0, 14, 28, 42 e 56% do feno de capim elefante na dieta. Cinco ovinos machos não-castrados foram distribuídos em um delineamento em quadrado latino 5 x 5 (cinco períodos, cinco níveis de palma e cinco repetições). Cada período experimental teve duração de 13 dias -sete para adaptação e seis dias para coleta de dados e amostras. Os consumos de MS, MO, EE, PB, CT, CNF e NDT aumentaram linearmente com a substituição do feno de capim-elefante por palma forrageira na dieta. O consumo de água diminuiu linearmente e o de FDN apresentou efeito quadrático com a substituição do feno de capim-elefante por palma forrageira na dieta. Os coeficientes de digestibilidade aparente de EE, PB, CNF e FDN não foram influenciados, enquanto os de MS, MO e CT aumentaram linearmente com a substituição do feno de capim-elefante por palma forrageira na dieta. O pH e a concentração de NH 3 ruminal decresceram linearmente com a substituição do feno de capim-elefante por palma forrageira na dieta. A substituição do feno de capim-elefante por palma forrageira na dieta melhora a ingestão e o aproveitamento dos nutrientes.Palavras-chave: carboidratos, consumo, energia, Opuntia, volumoso Spineless cactus in replacement of elephantgrass hay. Effect on intake, apparent digestibility and ruminal fermentation characteristics in sheepABSTRACT -A study was conducted with the objective to evaluate the effects of replacing elephant-grass by spineless cactus (Opuntia ficus indica, Mill) as a forage source on intake, apparent digestibility of the nutrients and of ruminal fermentation characteristics of sheep. Five iso-nitrogenous diets were formulated where spineless cactus replaced 0, 14, 28, 42 and 56% of elephantgrass in the diet. Five non-castrated male sheep were allotted to a 5 x 5 Latin square design (five periods, five spineless cactus levels and five replications). Each experimental period last 13 day -seven days for adaptation and 6 days for collection of data and samples. Intakes of DM, OM, EE, CP, TC, NFC, and TDN linearly increased as the elephantgrass was replaced by spineless cactus in the diet. Water intake linearly decreased and NDF intake showed a quadratic effect as the elephant grass was replaced by spineless cactus in the diet. The coefficient of apparent digestibilities of EE, CP, NFC and NDF were not affected by spineless cactus, while, apparent digestibilities of DM, OM and TC linearly increased as the elephantgrass was replaced by spineless cactus in the diet. Ruminal pH and N-NH 3 concentration linearly decreased as the elephantgrass was replaced by spineless cactus in the diet The replacement of elephantgrass by spineless cactus in the diet improve the nutrien...

RESUMO -Foram utilizados 22 cabritos não-castrados (10 Moxotó e 12 Canindé com peso médio inicial de 15 kg) confinados em baias individuais. Os animais foram distribuídos em um delineamento inteiramente casualizado, em arranjo fatorial 2 x 2 (duas raças e dois níveis de alimentação: AV = à vontade e AR = 30% de restrição). Foram avaliados os rendimentos de carcaça quente (RCQ), verdadeiro (RV) e comercial (RC), os cortes da carcaça e o rendimento dos componentes não-carcaça em relação ao peso do corpo vazio (PCV). Cabritos alimentados à vontade apresentaram maiores RCQ e RC e porções comestíveis da carcaça. O rendimento verdadeiro não foi influenciado pelo maior nível de alimentação. Após o abate e resfriamento da carcaça, foram feitos os seguintes cortes: pescoço, paleta, costelas (1ª-5ª), costelas (6ª-13ª), lombo, perna e baixo. Apesar do maior peso (kg) dos cortes dos animais alimentados AV, não foi observada diferença entre seus rendimentos em relação ao peso da carcaça fria. O rendimento da perna foi afetado pelo nível de alimentação, sendo menor para os grupos com nível de alimentação AV. Os rendimentos do fígado, da cabeça e do trato gastrintestinal foram influenciados pelo nível de alimentação. A raça não foi determinante de diferenças nas características de carcaça e dos componentes não-carcaça, assim como no rendimento dos cortes quando o peso e o tamanho à maturidade foram semelhantes. A restrição alimentar afetou o desenvolvimento e a deposição de tecidos nos animais, resultando em menores rendimentos e quilogramas de carcaça fria a ser comercializada. Palavras-chave: caprinos, carne, cortes comerciais, rendimento, vísceras Characteristics of carcass and non-carcass components of Moxotó and Canindé male kids under two feeding levelsABSTRACT -Twenty-two non-castrated male kids (10 Moxotó and 12 Canindé) averaging 15 kg of initial body weight and housed in individual pens were used in this trial. Animals were assigned to a completely randomized design in a 2 x 2 factorial arrangement of treatments [two breeds and two feeding levels: ad libitum (AL) or 30% of feed restriction (FR). Animals fed AL had greater yields of hot carcass, cold carcass, and carcass edible parts compared to those fed FR. It was not observed a significant feeding level effect on true carcass yield. After slaughter and cooling of the carcasses the following cuts were done: neck, shoulder clod, ribs (1 st -5 th and 6 th -13 th ), loin, leg and breast. Although animals fed AL had greater body weights than FR kids, no significant differences were found between treatments for the different carcass cuts when expressed as percentage of cold carcass weight. Hind leg yield was affected by feeding level being lower in animals fed AL. Yields of liver, head, and gut, as percentage of empty body weight, were also affected by feeding level. Feed restriction had a negative effect on development and tissue deposition leading to lower cold carcass yield and weight. It can be concluded that when size and mature weight were similar, breed was not re...