This study was conducted to evaluate the effects of urea addition on fermentation characteristics, losses and chemical composition of silage of sorghum (Sorghum bicolor) ‘BRS Ponta Negra’. The sorghum plant was chopped and treated with different levels of urea (0.1756, 0.3512, 0.7024 and 1.4048 g per 10 kg fresh forage for the respective proportions of 0.5%, 1.0%, 2.0% and 4.0% of forage (dry matter [DM] basis), and packed into quintuplicate experimen- tal silos to determine its effects on fermentation, losses and chemical composition of sorghum silages. Addition of urea increased lactic acid bacteria up to the level of 60 g kg−1 (DM basis). Compared with control silage, the addition of urea (p < 0.05) reduced DM losses. Urea-treated silages linearly increased (p < 0.05) the ammoniacal nitrogen and crude protein contents, and linearly reduced (p < 0.05) the ethanol content. The pH in urea-treated silages indicated better preservation of substrates obtained from fermentation. The intermediate level of 2.0%...

The current study aimed to select the strains of lactic acid bacteria (LAB) isolated from forage cactus plants and silage and assess their effects on silage fermentation and aerobic stability. Forty wild isolates from plant and cactus silage, classified as LAB, were evaluated for metabolite production and identified by 16S ribosomal DNA sequencing. These wild isolates were identified asLactobacillus plantarum,Weissella cibaria,Weissella confusaandWeissella paramesenteroidesand the LAB populations differed among the silage. The use of microbial inoculants did not influence gas or effluent losses in forage cactus silage. The silage inoculated with the microbial strain GP15 showed the highest number of LAB populations. The amounts of water-soluble carbohydrates (WSC) and ammonia nitrogen differed among the silage. The silage inoculated with the GP1 strain presented the highest WSC. Populations of enterobacteria and yeasts and moulds were below the minimum detection limit (<2.0 log cfu/g silage) in all the silage studied. The predominant action of inoculants was to maximize dry matter recovery of the silage, which could be the criterion adopted to select the strains of LAB for use as inoculants inOpuntiasilage.

The present study aimed to evaluate the effect of cactus silage and an intermittent water supply for lambs on carcass traits and meat quality. Thirty-six crossbreed lambs with an initial average weight of 19.8 ± 2.1 kg and average age of 6 months were randomly assigned to a 3 × 3 factorial design comprising three addition ratios of cactus silage to the diet (0, 21, and 42% based on dry matter) and three water supply intervals (0, 24, and 48 h) with four replicates. There was no interaction (P > 0.05) between the cactus silage ratio and intermittent water supply for any of the evaluated variables, with the exception of the yield of the half carcass commercial cuts. There was no significant effect of intermittent water supply (P > 0.05) on the carcass characteristics or meat quality. The addition of forage cactus silage as a substitute for Tifton hay affected the morphometric measurements (P < 0.05) and carcass compactness index (P < 0.05). The addition of 42% cactus silage to the diet increased (P < 0.05) the rib eye area (13.98 cm²). The addition of cactus silage as a substitute for Tifton hay positively affected (P < 0.05) the carcass weight of commercial cuts of the lambs. To the physical and chemical parameters of the Longissimus lumborum, the addition of 42% cactus silage to the diet reduced the color meat parameters (P < 0.05) and pH_{0 and 24h}, cooking losses, and shear force were not affected (P > 0.05). The addition of forage cactus silage to the lambs’ diet affected (P < 0.05) the composition of some saturated fatty acids in the meat. A water supply interval of up to 48 h does not influence carcass characteristics and meat quality. Therefore, the use of cactus silage can be recommended in situations of water scarcity without harming the production or meat quality of crossbreed lambs.

Background: There is a comprehensive understanding of the role of dietary fiber as a nutrient and its function during digestion in cattle. On the other hand, the role of fiber digestion in goats has not received similar attention. Objective: To evaluate the effects of different ratios of forage neutral detergent fiber (fNDF) and non-fibrous carbohydrates (NFC) on ruminal fermentation products, and in vitro neutral detergent fiber (NDF) digestibility in goats. Methods: A 3 × 5 factorial arrangement in a completely randomized design with three fNDF levels (100, 190, and 290 g/kg) and five NFC levels (350, 400, 450, 500, and 550 g/kg) was used. The experiment was performed in vitro. Two ruminally fistulated goats were used as rumen liquid donors. Results: The ratios between fNDF and NFC affected all ruminal parameters (p<0.05). Increasing NFC levels in diets containing 100 and 290 g/kgfNDF resulted in linear increase (p0.05) for pH values. Total volatile fatty acids (VFA) and their individual molar proportions were affected (p0.05) by fNDF or NFC levels, except for diets containing 290 g/kg fNDF, which were fit to a quadratic model (p<0.05). Conclusion: The relationship between fNDF and NFC concentrations affect the fermentation end products and in vitro NDF digestibility. NFC plays a more consistent role than fNDF in the ruminal microbial ecosystem of goats during in vitro fermentation.Keywords: digestion, energy, microbial protein, physically effective fiber, rumen. Resumen Antecedentes: Aunque hay una amplia comprensión del papel que juega la fibra dietética como nutriente y su función durante la digestión en el ganado vacuno, el papel de la digestión de la fibra en las cabras no ha recibido una atención similar. Objetivo: Evaluar los efectos de diferentes proporciones de fibra detergente neutra proveniente del forraje (fNDF) y carbohidratos no fibrosos (NFC) sobre los productos de la fermentación ruminal y la digestibilidad in vitro de la fibra detergente neutra (NDF) en cabras. Métodos: Se utilizó un arreglo factorial de 3 × 5, distribuidos en un diseño completamente aleatorizado con tres niveles de fNDF (100, 190 y 290 g/kg) y cinco niveles de NFC (350, 400, 450, 500 y 550 g/kg). El experimento se realizó in vitro. Se utilizaron dos cabras fistuladas en rumen como donantes de líquido ruminal. Resultados: La relacion entre fNDF y NFC afectó todos los parámetros ruminales estudiados (p<0,05). El aumento de los niveles de NFC en dietas con 100 y 290 g/kg de fNDF resultó en aumento lineal (p0,05) para valores de pH. Los ácidos grasos volátiles totales y sus proporciones molares individuales se afectaron (p0,05) por los niveles de fNDF ni NFC, con excepción de las dietas con 290 g/kg fNDF, que se ajustaron a un modelo cuadrático (p<0,05). Conclusión: La relación entre las concentraciones de fNDF y NFC afecta los productos finales de fermentación y la digestibilidad in vitro de NDF. Los niveles de NFC juegan un papel más consistente que fNDF en el ecosistema microbiano ruminal de la cabra durante la fermentación in vitro.Palabras clave: digestión, energía, fibra físicamente efectiva, proteína microbiana, rumen. ResumoAntecedentes: Embora exista um compreensível entendimento do papel que a fibra dietética desempenha como nutriente e sua função durante a digestão em bovinos, o papel da digestão das fibras em caprinos não recebeu atenção semelhante. Objetivo: Avaliar os efeitos de diferentes relações da fibra em detergente neutro advindo de forragem (fNDF) e carboidratos não-fibrosos (NFC) sobre produtos da fermentação ruminal e digestibilidade in vitro da fibra em detergente neutro (NDF) em caprinos. Métodos: Utilizou-se um esquema fatorial de 3 × 5 distribuídos em um delineamento inteiramente casualizado com três níveis de fNDF (100, 190 e 290 g/kg) e cinco níveis de NFC (350, 400, 450, 500 e 550 g/kg). O experimento foi realizado in vitro. Duas cabras fistuladas no rúmen foram utilizadas como doadoras de líquido ruminal. Resultados: As relações entre fNDF e NFC impactaram todos os parâmetros ruminais estudados (p<0,05). O aumento dos níveis de NFC em dietas contendo 100 e 290 g/kg de fNDF resultou em um aumento linear (p0,05) para valores de pH. Os ácidos graxos voláteis totais e suas proporções molares individuais foram afetados (p0,05) pelos níveis de fNDF e NFC, com exceção de dietas experimentais contendo 290 g/kg fNDF, que foram ajustadas a um modelo quadrático (p<0,05). Conclusão: A relação entre as concentrações de fNDF e NFC afeta os produtos finais de fermentação e a digestibilidade in vitro de NDF de dietas experimentais. Os níveis de NFC desempenham um papel mais consistente do que o fNDF no ecossistema microbiano ruminal de cabras durante a fermentação in vitro.Palavras-chave: digestão, energia, fibra fisicamente efetiva, proteína microbiana, rúmen.

The current study aimed to evaluate the application effects of the preactivated Lactobacillus buchneri and urea on the fermentative characteristics, chemical composition and aerobic stability in corn silages. The design was completely randomized, in a 6 × 5 factorial arrangement, with six types of additive and five opening times. The treatments consisted of corn silage; corn silage with freeze-dried inoculant; corn silage with freeze-dried inoculant +1.0% urea; corn silage with activated inoculant; corn silage with activated inoculant +1.0% urea, and corn silage with 1.0% urea. Populations of lactic acid bacteria stabilized at the 70th day, with average values of 8.91 and 9.15 log cfu/g for corn silage with freeze-dried inoculant +1.0% urea and corn silage with freeze-dried inoculant, respectively. In contrast, the silages without additives showed significantly lower values of 7.52 log cfu/g forage at the 70th day. The silages with urea (isolated or associated with the inoculant) increased the total nitrogen content. The maximum temperature values were highest in the corn silages without additives, indicating that these silages were more prone to deterioration. The use of Lactobacillus buchneri activated proved to be more efficient in improving the fermentative profile of corn silages than the freeze-dried inoculant. The use of urea as an additive reduced the losses and improved the nutritional value and aerobic stability of corn silages. Additionally, the combination of Lactobacillus buchneri activated and urea may be used as a technique to improve the fermentative profile, chemical composition and aerobic stability of corn silages.