A.J.V. Pires

Degradabilidade ruminal do feno de alguns alimentos volumosos para ruminantes

Avaliou-se a degradabilidade ruminal da materia seca (MS), proteina bruta (PB), fibra em detergente neutro (FDN), da fibra em detergente acido (FDA) e hemicelulose dos fenos de capim-elefante (Pennisetum purpureum), palma (Opuntia ficus), guandu (Cajanus cajan) e parte aerea da mandioca (Manihot esculenta) utilizando tres bovinos mesticos machos, castrados, canulados no rumen e mantidos em regime de pasto. Amostras de 4g de cada alimento foram incubadas em duplicata no rumen dos animais, nos periodos de 0, 6, 12, 24, 36, 48 e 72 horas. A degradabilidade potencial da PB dos fenos de capim-elefante e guandu foi semelhante, 83,9 e 81,2%, respectivamente. Os maiores valores foram observados para os fenos de palma (94,2%) e parte aerea da mandioca (91,7%). A degradabilidade efetiva (DE) foi obtida considerando as taxas de passagem de 2, 5 e 8%/hora. A maior DE observada para MS (60,5%), PB (81,1%), FDN (21,6%), FDA (27,9%) e HEM (58,0%), na taxa de passagem de 5%/h, ocorreu com o feno de palma.

Degradação ruminal de silagem de capim-elefante emurchecido ou com diferentes níveis de farelo de cacau

The experiment was conducted to evaluate dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) ruminal degradation of elephantgrass silages wilted under the sun light for eight hours or with addition of 0, 7, 14, 21, and 28% of cocoa meal (CM) at the ensiling. Samples of each silage type were incubated in the rumen of three Holstein cows for 0, 6, 12, 24, 48, 72, 96, 120, and 144 hours. The CM inclusion reduced the degradation potential of DM, which showed greater values for silages without CM (wilted or non-wilted). The CP and NDF potential degradability showed small variations, with mean values near 80 and 46%, respectively. Considering a passage rate of 5%/h, all silages showed high CP effective degradability (over 55%). Although the ruminal degradation estimate for silages with CM showed a reduction tendency, all silages presented DM and CP potential degradability over 65 and 75%, respectively. The CM addition to elephantgrass can be considered an alternative that offers a fast and abundant availability of nutrients to the ruminal system.

Características fermentativas de silagens de capim-elefante emurchecido ou com adição de farelo de cacau

The experiment was carried out to evaluate the fermentation characteristics of eight hours sun light wilted elephant grass silage in comparison to no sun light exposed silage added by 0, 7, 14, 21, and 28% of cocoa meal during the ensilage process. PVC silos, measuring 0.15m diameter x 0.30m height, were used to ensilage the elephantgrass using a compacting pressure of 500kg/m3. Soluble carbohydrates decreased but pH and N-NH3 increased (P<0.05) as the cocoa meal level increased in the silage. No difference between wilted and no wilted elephantgrass silages was observed for organic acid content. Addition of 0, 7, 14, 21, and 28% of cocoa meal caused an increase of 2.23, 2.48, 3.14, 3.49, and 3.87% of lactic acid contents. Addition of cocoa meal during the ensilage process enhanced fermentation quality of elephantgrass silage.

Productivity, chemical composition and agronomic characteristics of different forages

The objective of this work was to evaluate nutrient production and extraction of different forages. Four crops were implanted: corn, Sudan sorghum, forage sorghum and sunflower in an experimental design in randomized blocks, with four treatments and five repetitions. Sunflower and Sudan sorghum had the highest green matter production, while corn and sorghum forages excelled over the other crops for dry matter production. The highest values of fibrous fraction were observed for Sudam sorghum. Sunflower crop extracted the highest amount of calcium, potassium and magnesium, while Sudan sorghum showed the highest phosphorus extraction. Extraction of nitrogen and sodium was not different among crops. Corn is the best forage for silage because it has the highest ear proportion in relation to the rest of the plant.

Degradabilidade ruminal da matéria seca e da proteína bruta de folhas e folíolos de forrageiras tropicais

Foram determinadas as degradabilidades in situ da MS e PB dos foliolos de tres leguminosas tropicais leucena (Leucaena leucocephala (Lam.) de Wit), guandu (Cajanus cajan (L.) Millsp.) e soja perene (Neonotonia wightii) e de folhas de outras duas forrageiras tropicais rami (Boehmeria nivea (L.) Gaudich) e mandioca (Manihot esculenta Crantz). Amostras de 3 g (guandu, soja e rami) ou 5 g (leucena e mandioca) do material foram incubadas no rumen de quatro novilhos por periodos de 3, 6, 12, 18, 24 e 48 horas. As degradabilidades efetivas da MS e da PB para a taxa de passagem de 5% hora foram elevadas (acima de 60%). As taxas de degradacao, exceto a do guandu, tambem foram consideradas elevadas. As forrageiras apresentaram alta digestibilidade total da proteina (acima de 88%), exceto os foliolos de guandu (69%). O guandu foi a forrageira com menor potencial de degradacao da proteina.

Valor nutritivo da cana-de-açúcar hidrolisada com hidróxido de sódio ou óxido de cálcio

Avaliaram-se o valor nutritivo e a temperatura de estabilidade aerobia da cana-de-acucar hidrolisada com hidroxido de sodio (NaOH) ou oxido de calcio (CaO). Utilizou-se um esquema fatorial 2 × 4, com dois aditivos (NaOH e CaO) e quatro doses (0; 0,75; 1,5 e 2,25%, com base na materia natural), em delineamento inteiramente ao acaso com quatro repeticoes. O material foi acrescido dos aditivos e armazenado por 24 horas em baldes plasticos com capacidade de 10L. Ambos os aditivos controlaram o aumento da temperatura da cana-de-acucar, e o NaOH mostrou-se mais eficiente. Os teores de materia seca e materia mineral aumentaram linearmente, enquanto os constituintes da parede celular diminuiram com o aumento das doses dos aditivos. Tanto o NaOH quanto o CaO promoveram acrescimo nos valores de digestibilidade da materia seca da cana-de-acucar. O NaOH e o CaO melhoram o valor nutritivo da cana-de-acucar, e o NaOH e mais eficiente.

Perdas na ensilagem de capim-elefante aditivado com farelo de cacau e cana-de-açúcar

The effects of the addition of cocoa meal and sugarcane in the elephant-grass silage losses were studied. A 2 x 4 factorial scheme was used, being 0 and 15% of cocoa meal and 0, 15, 30, and 45% of sugarcane, with four repetitions, in a completely randomized design. The elephant-grass showed 29.2% of dry matter and the silages were produced in PVC experimental silos, using 600 kg/m3 silage compaction. The silos were opened 60 days after ensilage, when ammonia nitrogen content and pH of the silages were determined. Cocoa meal was effective in the reduction of moisture and ammonia nitrogen concentrations. It is recommended the inclusion of up to 22.4% of the sugar-cane, cv-IAC86-2480, in the elephant-grass ensiling with 29% of dry matter, which can be increased to 45%, since 15% of cocoa meal be used.

Desempenho de novilhas leiteiras alimentadas com silagem de capim-elefante com adição de diferentes níveis de bagaço de mandioca

The effect of cassava bagasse addition levels (5, 10, 15 and 20%) to elephantgrass silage on dairy heifers performance was evaluated. Sixteen ¾ Holstein x Zebu heifers with 15 months of age and 144kg of initial body weight were used in a completely randomized block design with four replicates and four treatments. The experiment was carried out for 56 days after and adaptation period of 14 days in which the heifers were fed the respective treatment diets. Weight, withers height and thoracic circumference were recorded often 16 hours fasting at the beginning of the experiment and at days 28 and 56. No differences between treatments were observed for day mother (DM) and crude protein daily intake. The neutral detergent fiber and acid detergent fiber showed a linear reduction behavior. No treatment effects were observed for final body weight, daily weight gain, thoracic perimeter, withers height and DM feed efficiency.

Bagaço de mandioca na ensilagem do capim-elefante: qualidade das silagens e digestibilidade dos nutrientes

Sixteen ¾ Holstein-Zebu heifers aging 15 month-old averaging 144kg were used to evaluate the effect of the additions of different levels of cassava bagasse (5; 10; 15 and 20%) to elephant grass (Pennisetum purpureum, Schum) ensilage on the diet quality and nutrients digestibility. The treatments consisted of four diets containing, as roughage, elephant grass silage with four different levels of cassava bagasse plus balanced concentrate, with four repetitions per treatment. Silages quality, diet nutrients intake and nutrients digestibility of the silages and total diets were evaluated. Cassava bagasse increased the dry matter (DM) content, of the silages preserving them with a pH varying from 3.85 to 4.07 and N-NH3/NT ratio from 6.2 to 7.85. Daily dry matter and crude protein (CP) mean intakes did not differ among the treatments (P>0.05). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) mean intakes showed a decreasing linear behavior (P 0.05) for DM (DMD), NDF (NDFD) and ADF digestibility (ADFD). The total digestible nutrients (TDN) of the silages were similar in all the treatments. The CP (CPD), ether extract (EED) and non-fiber carbohydrates digestibility (NFCD) of the silages decreased linearly (P 0.05) in DMD, CPD, NDFD, ADFD, EED, NFCD and TDN among the experimental diets. The 5% cassava bagasse addition to its elephant grass silage was satisfactory to preservation resulting in good digestibility of the elephant grass silage.

Características físico-químicas e custo do leite de cabras alimentadas com farelo de cacau ou torta de dendê

Avaliaram-se o efeito de dietas contendo farelo de cacau (FC) ou torta de dende (TD) em substituicao ao concentrado padrao, a base de milho e farelo de soja, sobre a composicao fisico-quimica e o resultado economico da producao de leite. Foram utilizadas cinco cabras da raca Saanen com 41,66kg de peso e 60 dias de lactacao, no delineamento experimental em quadrado latino 5×5. Os periodos experimentais foram de 14 dias, com 10 dias para adaptacao e quatro para a coleta dos dados. As racoes concentradas isoproteicas (13,2%) foram calculadas para uma producao de 2kg de leite/dia. As dietas constituiram-se de 36% de volumoso e 64% de concentrado. Utilizaram-se silagem de milho e concentrado-padrao (milho e farelo de soja) com 0, 15 e 30% de substituicao pelo FC ou TD. As dietas nao influenciaram (P>0,05) as caracteristicas fisico-quimicas do leite. A substituicao reduziu o custo das dietas e apenas as com 15% de FC e 15% de TD apresentaram margem bruta superior a da dieta-controle.