ABSTRACT The objective of this study was to evaluate the influence of a commercial product, a soil bioactivator, on the establishment and efficiency of symbiosis between rhizobia and Arachis pintoi (forage peanut). The experiment was conducted in a greenhouse in 8 dm3 pots and 12 treatments were used, ten inoculated with different strains of rhizobia and two without inoculation (presence or absence of mineral nitrogen), associated or not with the application of soil bioactivator. The experimental design used was a randomized block design with four repetitions. The experiment was conducted until the time of flowering, when the agronomic characteristics referring to the shoot dry matter (SDM) and root (RDM), relative symbiotic efficiency (RS), number (NN) and nodule dry matter (NMS) and the bromatological characteristics, given by the content of crude protein (CP), neutral detergent fiber (NDF) and acid (ADF) were evaluated. The use of soil bioactivator did not influence the bromatological characteristics, but potentiated the inoculation with rhizobia strains, UNIFENAS 03-16, UNIFENAS 03-31 and UNIFENAS 03-36, effectively contributing to increases in the values of SDM, RS and NN, thus constituting a sustainable alternative for the production of A. pintoi.

ABSTRACT Studies have shown the synergism of co-inoculation with symbiotic and non-symbiotic N2-fixing bacteria, efficiently contribute to plant development. However, for crops such as forage legumes, data on the use of co-inoculation are still incipient, requiring studies to identify the contribution of this technique for application in pasture areas, thus ensuring greater sustainability. The objective of this study was to evaluate the effects of co-inoculation of Azospirillum brasilense (Ab-V5) and native rhizobia isolated from two forage legumes, Crotalaria spectabilis and Lupinus albus. Two experiments were installed in pots with 8dm3. Both were conducted in a randomized block design (DBC) with four replications and an 8 x 2 factorial scheme with six bacterial strains and two control treatments without inoculation (with presence or absence of mineral nitrogen), co-inoculated or not with the Ab-V5 strain. Plants were cultivated until the time of flowering when shoot (SDM) and root dry matter (RDM), number (NN) and nodule dry matter (NDM), and relative symbiotic efficiency (RSE) were evaluated. Isolates 05-21 and 06-03, for C. spectabilis and L. albus, respectively, indicated higher potential to promote plant growth when co-inoculated with Ab-V5, showing potential to act as substitutes for nitrogenous chemical fertilizers, reducing costs and increasing the sustainability of production.

RESUMO O objetivo do estudo foi analisar a capacidade das bactérias diazotróficas, isoladas da rizosfera de Brachiaria brizantha, crescer em meios com diferentes valores de pH e concentrações salinas, de produzir ácido 3-indol acético (AIA) e solubilizar fosfato. Os testes de acidez e salinidade foram realizados em meio FAM sólido. Para acidez foram usados os valores de 4.0, 5.0, 6.0 e 7.0. Para salinidade foram utilizadas as seguintes concentrações: 0.01; 5.02; 9.99; 14.96; 19.98; 24.95; 29.98; 34.94; 39.97; 44.94 and 49.96 gꞏL-1. No teste de produção de AIA, as estirpes foram cultivadas em meio DYGS líquido, na ausência e presença de triptofano (Trp). A solubilização de fósforo, foi realizada em meio GL líquido. Todas as estirpes foram capazes de crescer em todos os valores de pH analisados. Já em relação aos testes de diferentes concentrações salinas, produção de AIA e solubilização de fosfato, foi verificada alta diversidade, havendo estirpes que se destacaram. As estirpes UNIFENAS 100-51; UNIFENAS 100-52; UNIFENAS 100-60; UNIFENAS 100-63 e UNIFENAS 100-65, foram as que apresentaram maior crescimento nas três maiores concentrações salinas. Na presença de triptofano, as estirpes UNIFENAS 100-63 e UNIFENAS 100-69 foram as que apresentaram maior produção de AIA. Já em solubilização de Fosfato in vitro, a estirpe UNIFENAS 100-52 foi a que obteve melhor resposta. Baseado nesses resultados, observa-se a importância de estudos relacionados às características fisiológicas e metabólicas de bactérias diazotróficas, de modo a garantir maior sucesso no campo.

ABSTRACT The objective of this study was to evaluate the ability of diazotrophic bacteria isolated from Brachiaria brizantha rhizosphere to grow at different pH values and salt concentrations, to produce indoleacetic acid (IAA), and to solubilize phosphate. Both acidity and salinity tolerance tests were performed on modified solid FAM medium. Acidity resistance tests were performed at pH values of 4.0, 5.0, 6.0, and 7.0, while, salt resistance was evaluated at concentrations of 0.01, 5.02, 9.99, 14.96, 19.98, 24.95, 29.98, 34.94, 39.97, 44.94, and 49.96 gL-1 NaCl. For the IAA production assay, bacterial strains were cultivated in liquid DYGS medium both in the absence and presence of tryptophan (Trp). In addition, phosphorus solubilization assay was performed in GL liquid medium. All strains grew at every pH value tested, and a high diversity was observed after salt resistance, IAA production, and phosphate solubilization testing. Strains UNIFENAS 100-51, UNIFENAS 100-52, UNIFENAS 100-60, UNIFENAS 100-63, and UNIFENAS 100-65 were those with the best growth at the highest salt concentrations. Furthermore, in the presence of Trp, strains UNIFENAS 100-63 and UNIFENAS 100-69 were the ones with the highest IAA production. Strain UNIFENAS 100-52 showed the best response to the in vitro phosphate solubilization assay. Based on these results, it can be seen that studies related to the physiological and metabolic characteristics of diazotrophic bacterial strains are important to ensure greater success in the field.

Resumo A adubação nitrogenada em cobertura é imprescindível para a produção de forragem, mas o elevado custo dos fertilizantes estimula a busca por novas tecnologias, como o uso de bactérias diazotróficas, que podem fixar o nitrogênio atmosférico. Para avaliar o potencial dessa tecnologia em suprir a quantidade de nitrogênio requerida pelo capim-xaraés em cobertura, as plantas foram adubadas em plantio com dose equivalente a 100 kg ha-1 de N e inoculadas com estirpes de bactérias diazotróficas e Azospirillum brasilense, e comparadas com plantas que receberam 100 kg ha-1 de N em plantio e em cobertura, durante dois períodos de crescimento da parte aérea (58 dias no primeiro período e 26 dias no segundo período), em vasos de 20 dm3. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste Scott-Knott a 5% de significância. A área foliar do capim-xaraés inoculado com a estirpe UN42 foi semelhante a das plantas que receberam adubação nitrogenada em cobertura. Todavia, a produção de massa do capim foi maior quando houve adubação nitrogenada em cobertura. A inoculação das plantas com Azospirillum brasilense e as estirpes UN16, UN17, UN21, UN33, UN49 e UN78 aumentou os teores de proteína bruta do capim-xaraés em relação à adubação nitrogenada em plantio sem inoculação. Porém, a inoculação do capim com as bactérias diazotróficas não substitui totalmente a adubação nitrogenada em cobertura.

Abstract: Nitrogen topdressing is essential for forage production, but the high cost of fertilizers stimulates the search for new technologies, such as the use of diazotrophic bacteria, which can fix the atmospheric nitrogen. To evaluate the potential of this technology in providing the amount of nitrogen requested by xaraés grass as topdressing, plants were fertilized at planting with an N rate of 100 kg ha-1, inoculated with strains of diazotrophic bacteria and Azospirillum brasilense, and compared with plants that received 100 kg ha-1 of N at planting and as topdressing during two periods of shoot growth (58 days in the first period and 26 days in the second period) in 20-dm3 pots. The data were subjected to analysis of variance and means compared by the Scott-Knott test at 5% significance. The leaf area of xaraés grass inoculated with strain UN42 was similar to that of plants that received nitrogen topdressing. However, grass biomass production was higher when nitrogen topdressing was applied. Plant inoculation with Azospirillum brasilense and strains UN16, UN17, UN21, UN33, UN49, and UN78 increased crude protein contents of xaraés grass when compared to nitrogen fertilization at planting without inoculation. However, grass inoculation with diazotrophic bacteria does not replace nitrogen topdressing completely.

RESUMO A espécie Panicum maximum cv. Mombaça é uma forrageira adaptada às diversas condições edafoclimáticas encontradas no Brasil; no entanto, necessita de altas doses de fertilizantes nitrogenados para garantir altas produtividades. Objetivou-se avaliar o efeito da inoculação com estirpes de bactérias diazotróficas associativas nas características produtivas e bromatológicas do capim Mombaça. Utilizou-se delineamento em blocos casualizados, constituído por 25 tratamentos, sendo 23 inoculados com bactérias diazotróficas e dois sem inoculação (um com e o outro sem nitrogênio mineral), com quatro repetições. As variáveis analisadas foram: diâmetro do colmo; largura e comprimento da folha; produtividade da matéria seca das folhas, colmos e raiz; proteína bruta; fibra em detergente ácido e neutro. Para as variáveis matéria seca da raiz, diâmetro do colmo e fibra em detergente ácido, não foram observadas diferenças entre os tratamentos. Para as demais, verificou-se contribuição positiva da inoculação com bactérias diazotróficas, destacando-se as seguintes estirpes Unifenas: 100-06, 100-13, 100-26, 100-30, 100-35, 100-54, 100-69, 100-71 e 100-94. Isto revela o potencial destas estirpes bacterianas para uso em produção sustentável do capim Mombaça com redução de insumos nitrogenados.

ABSTRACT The Panicum maximum species (cv. Mombaça) is a forage plant well adapted to the different edaphoclimatic conditions found in Brazil; however, it requires high nitrogen fertilizer doses to ensure high yields. The present study aimed to assess the inoculation effect with associative diazotrophic bacteria strains on the yield and bromatological characteristics of the Guinea grass. A randomized block design was used, consisting of 25 treatments, being 23 of them inoculated with diazotrophic bacteria and two without inoculation (one with and the other without mineral nitrogen), with four repetitions. The analyzed variables were stem diameter; leaf width and length; leaf, stem and root dry mass yield; crude protein; acid and neutral detergent fibers. There were no differences among the treatments for root dry mass, stem diameter and acid detergent fiber. For the remaining variables, a positive effect of the inoculation with diazotrophic bacteria was observed, particularly for the following Unifenas strains: 100-06, 100-13, 100-26, 100-30, 10-35, 100-54, 100-69, 100-71 and 100-94. This reveals the potential of these bacterial strains for use at the sustainable production of the Guinea grass with a reduction in the use of nitrogen inputs.

Resumo Objetivou-se avaliar as características bromatológicas, microbiológicas e perdas fermentativas da silagem de grão de milho reidratado com água ou soro de leite associado a diferentes níveis de inclusão do resíduo de tilápia. Utilizou-se um delineamento inteiramente casualizado em esquema fatorial 5x2 (cinco níveis de inclusão do resíduo de tilápia: 0; 12,5; 25; 37,5 e 50% em substituição ao milho reidratado e duas fontes de reidratação do grão de milho: água ou soro de leite) para produção de silagem). A produção de gases da silagem com até 25% de inclusão do resíduo de tilápia foi 62,7% maior para o milho reidrato com soro de leite (P <0,01). A quantidade de bactérias ácido láticas foi menor em todos os níveis de inclusão de resíduo de tilápia quando a fonte de reidratação foi a água (P<0,01). Os teores de matéria mineral, matéria orgânica, proteína bruta, extrato etéreo, cálcio e fósforo foram maiores nas silagens reidratadas com soro de leite com o aumento do nível de inclusão de resíduo de tilápia (P<0,01). A silagem de resíduo de tilápia com milho reidratado é uma alternativa que pode ser utilizada na dieta de aves e suínos, entretanto, o seu uso está condicionado às avaliações do melhor nível de inclusão dentro de uma categoria animal.

Abstract The objective of this study was to evaluate the microbiological, chemical characteristcs and fermentative losses of corn silage rehydrated with water or whey associated to different levels of tilapia residue inclusion. A completely randomized design was used in a 5x2 factorial arrangement (five inclusion levels of tilapia residue: 0; 12.5; 25; 37.5 and 50% in substitution of dehydrated corn; and two sources of rehydration of corn: water or whey) for silage production. The production of gases of the silage with up to 25% inclusion of the tilapia residue was 62.7% greater for the corn rehydrate with whey (P <0.01). The amount of lactic acid bacteria was lesser for all levels of inclusion of tilapia residue when the source of rehydration was water (P <0.01). The levels of mineral matter, organic matter, crude protein, ethereal extract, calcium and phosphorus were greater in silages rehydrated with whey with the increase of the inclusion level of tilapia residue (P <0.01). Tilapia residue silage with rehydrated corn is an alternative that can be used in the poultry and swine diet, however, its use is conditioned to the evaluation of the best level of inclusion within an animal category.

RESUMO O objetivo com este estudo foi investigar as características de silagens preparadas com um resíduo seco de padaria hidratado com soro ácido de leite ou água associado ou não à ureia. O experimento foi conduzido em um arranjo fatorial 3 (três níveis de hidratação: 250, 300 e 350 mL kg−1 de subproduto) × 3 (três níveis de aplicação de ureia: 0, 5 e 10 g kg−1 de subproduto) × 2 (dois líquidos usados na hidratação: soro ácido de leite ou água). Mini silos foram utilizados como silos experimentais e permaneceram fechados por 30 dias. Em geral, silagens hidratadas com soro ácido de leite apresentaram maior (P<0,01) produção de ácido lático (19,6 vs. 18,5 g kg−1 de matéria seca [MS]), ácido acético (2,5 vs. 1,8 g kg−1 de MS) e ácido propiônico (8,0 vs. 5,4 g kg−1 de MS), e menores (P<0,05) contagens de fungos (5,35 e 5,01 ufg g−1 de silagem fresca) comparadas às silagens hidratadas com água. A maior hidratação das silagens aumentou a produção total de ácidos (P<0,01) reduzindo os valores de pH; mas o aumento na hidratação reduziu (P<0,01) a recuperação de MS das silagens. Silagens hidratadas com água e soro ácido de leite a 250 mL kg−1 e combinado com 5 e 10 g kg−1 de ureia exibiram maior (P<0,05) recuperação de MS. Silagens de resíduo seco de padaria hidratadas com soro ácido de leite apresentaram melhor padrão fermentativo, podendo representar uma estratégia prática para evitar o descarte de ambos os subprodutos no ambiente.

SUMMARY The objective of this study was to investigate the characteristics of silages prepared with a dry bakery by-product hydrated with acid whey or water associated or not at urea. The trial was a 3 (hydration at three moisture levels: 250, 300, and 350 mL kg−1 of by-product) × 3 (three application rates of urea: 0, 5, and 10 g kg−1 of by-product) × 2 (liquid used at hydration: acid whey or water) factorial arrangement. Mini-silos were used as experimental silos and remained closed for 30 days. Overall, silages hydrated with acid whey had higher (P<0.01) production of lactic (19.6 vs. 18.5 g kg−1 of dry matter [DM]), acetic (2.5 vs. 1.8 g kg−1 of DM) and propionic acid (8.0 vs. 5.4 g kg−1 of DM), and lower (P<0.05) fungi counts (5.35 and 5.01 cfu g−1 of fresh silage) compared to silages hydrated with water. Increased hydration led to the higher production of total acids (P<0.01), decreasing silage pH; but increased hydration reduced DM recovery (P<0.01). Silages hydrated with water and acid whey at 250 mL kg−1 and combined at 5 and 10 g kg−1 of urea exhibited higher DM recovery (P<0.05). Silages of a dry bakery by-product hydrated with acid whey had a better fermentation pattern and could represent a practical strategy to avoid discarding both by-products into environment.

Our objective was to evaluate the chemical composition, fermentation profile, and aerobic stability of cabbage silages treated with ground corn and inoculant. The evaluated treatments were: addition of 200, 300, 400, 500, and 600 g of ground corn per kilogram of cabbage (fresh matter basis), with or without a bacterial inoculant composed of Lactobacillus plantarumand Pediococcus pentosaceus. As expected, ground corn additions increased the dry matter (DM) content of cabbage silage, and high values were observed for the highest level of addition (540 g kg−1). Conversely, the crude protein, neutral detergent fiber, acid detergent fiber, and lignin contents decreased with ground corn additions. The in vitro dry matter digestibility coefficients increased slightly with ground corn additions, but all cabbage silages had digestibility higher than 740 g kg−1 of DM. In the fermentation process, the pH values of cabbage silages increased linearly because of the high levels of ground corn addition. Cabbage ensiled with 200 and 300 g kg−1 of ground corn had high ammonia N production and fermentative losses (effluent and gas). Cabbage silage treated with 600 g kg−1 of ground corn had lower maximum pH values during aerobic exposure, but all silages had constant temperature during aerobic exposure. The ensiling of wasted cabbage is possible and we recommend the application of 400 g kg−1ground corn to improve the silage quality, whereas the use of the inoculant is unnecessary.

Our objective was to investigate the effect of the replacement of aruana grass by gliricidia on the fermentative losses, chemical composition, and aerobic stability of silages. For ensiling, whole-crop aruana grass (75 d of growth) was chopped (275 g kg-1 dry matter - DM) and ensiled alone or associated with gliricidia (270 g kg-1 DM; 150 d of growth). For gliricidia, we used only the leaves and stalks to ensile. The evaluated treatments were different ratios of aruana grass to gliricidia (100:0, 75:25, 50:50, 25:75, and 0:100), with four replicates (mini-silos). The silage composed only of gliricidia exhibited a lower pH than the other silages. Dry matter recovery was not affected by the treatments, although effluent losses were affected. The replacement of aruana grass by gliricidia 50% at ensiling resulted in a higher lactic acid bacteria count. The aruana grass silages displayed lower protein contents and a higher neutral detergent fiber content than the gliricidia silages after 40 d of fermentation. Consequently, the silage consisting of 100% gliricidia showed higher in vitro DM digestibility, presenting an increase of 8.13% after 40 d of fermentation compared with 100% of aruana grass silage. After silo opening, the gliricidia silage was very stable (>72 h). The low quality of aruana grass silage is improved by replacing this grass with significant amounts of gliricidia (approximately 75%).

Objetivou-se com este estudo avaliar as perdas fermentativas, composição bromatológica e digestibilidade in vitro da matéria orgânica de silagens de milho produzidas em diferentes estádios de maturidade, inoculadas microbiologicamente. Aplicaram-se dois inoculantes comerciais nas silagens produzidas nos estádios SLL, 1/3 LL, 1/2 LL, 2/3 LL e CN, permanecendo ainda um tratamento sem inoculação (silagem controle), configurando um esquema fatorial 3x5. A inoculação com BAL resultou em menores perdas fermentativas (P=0,0348), ao passo que silagens produzidas com plantas mais secas também apresentam menores perdas de MS (P<0,01). A inoculação das silagens resultou em maiores concentrações de PB nas silagens produzidas nos estádios SLL, 2/3 LL e CN (P=0,0033). O uso do inoculante Maize All® resultou em menor concentração de FDN (P=0,0140) no estádio CN e acréscimo dos coeficientes de DIVMO quando as plantas foram colhidas com 2/3 LL e CN (P=0,0006). As perdas fermentativas diminuem devido à utilização dos inoculantes bacterianos e também em silagens produzidas com plantas mais secas. A aplicação de bactérias ácido-láticas (inoculante Maize All®) em silagens de milho produzidas com plantas em estádio de maturidade mais avançado melhora a composição química e digestibilidade in vitro.

The aim of this study was to evaluate the fermentative losses, chemical composition and in vitro organic matter digestibility of corn silages produced in different maturity stages microbiologically inoculated. Two commercial inoculants were applied in the silages produced in stages SLL, 1/3 LL, 1/2 LL, 2/3 LL and CN, remaining an uninoculated treatment (control silage), illustrating a factorial scheme 3 x 5. The lactic acid bacteria (LAB) inoculation resulted in lower fermentative losses (P=0.0348), whereas silages produced with dried plants present lower DM losses (P<0.01). Because of inoculant application, there was higher concentrations of CP in the silages produced in stages SLL, 2/3 LL and CN (P=0.0033) and concentration lower of NDF (P=0.0140) in CN stage because of the Maize All® inoculant. This inoculant provided increase in the IVOMD coefficients when the plants were harvested with 2/3 LL and CN (P= 0.0006). Fermentative losses decreased because of the use of microbial inoculants, and this fact it is also observed in silages produced with dried plants. Application of lactic acid bacteria (Maize All® inoculant) in corn silages produced with plants harvested in more advanced stages of maturity improve the chemical composition and in vitro digestibility.

Objetivou-se avaliar doses e formas de aplicação do potássio nas características agronômicas e bromatológicas na cultura do milho para ensilagem. O experimento foi conduzido na UNIFENAS durante o ano agrícola de 2008/2009. A adubação de plantio e a semeadura foram realizadas manualmente, utilizando-se 120 kg ha-1 de P2O5, 30 kg ha-1 de N, o potássio foi aplicado de acordo com os tratamentos. O delineamento experimental utilizado foi em blocos casualizados, em arranjo fatorial 4x2, com quatro repetições, fazendo-se uso de quatro doses (0; 60; 90 e 120 kg ha-1) e duas formas de aplicação do K (100% no plantio e 50% no plantio + 50% em cobertura). A interação entre os fatores doses e forma de aplicação do potássio não foi significativa (p>0,05) para as variáveis estudadas, passando-se a estudar o efeito principal de cada fator. Não houve efeito (p>0,05) das doses de K sobre as porcentagens de MS e plantas acamadas, produtividade de MS e grãos e participação de grãos na massa. A maior produtividade de grãos foi obtida empregando-se o K totalmente no plantio (p<0,05). Elevadas doses de potássio não proporcionaram mudanças para MS, porcentagem de plantas acamadas, produtividade de MS, produtividade de grãos e porcentagem de grãos na planta. As diferentes doses e formas de aplicação de potássio não alteram as características bromatológicas da silagem de milho.

The aim was to evaluate levels and forms of application of potassium on the agronomic and alimentary characteristics of corn used for silage. The experiment was carried out at UNIFENAS during the agricultural year of 2008/2009. Fertilization at planting and sowing was performed manually using 120kg ha-1 P2O5 and 30kg ha-1 N, the potassium being applied according to the treatments. The experimental design used was of randomized blocks in a 4 x 2 factorial arrangement with four replications, using four amounts (0; 60; 90 and 120 kg ha-1) and two forms of application of K (100% at planting and 50% at sowing+50% coverage). The interaction between the factors of amount and forms of application of the potassium was not significant (p>0.05) for the variables studied: the main effect of each factor was then investigated. There was no effect (p>0.05) for K levels on the percentage of dry matter (DM) and bedded plants, DM and grain productivity and grain participation in the mass. The highest grain yield was obtained when using K at planting (p<0.05). High doses of potassium did not produce changes in DM, percentage of bedded plants, DM production, grain yield or grain percentage of the plant. The different levels and forms of application of potassium do not alter the alimentary characteristics of corn silage.

Objetivou-se, nesta pesquisa, avaliar o efeito de inoculantes bacterianos em silagens produzidas com plantas de milho em diferentes estádios de maturidade quanto às perdas fermentativas e estabilidade aeróbia. Utilizou-se o delineamento inteiramente casualizado, em esquema fatorial 3x5, e avaliaram-se dois inoculantes (Silobac® e Maize All®) e uma silagem controle em 5 estádios de maturação fisiológica do milho, com 4 repetições. Verificou-se efeito positivo dos inoculantes quanto às perdas fermentativas, e a adição de Silobac® e Maize All® promoveram perda de matéria seca (PMS) 1,78 e 1,75 pontos percentuais a menos que a silagem controle (7,95%). As silagens produzidas com 2/3 de linha de leite e camada negra (CN) apresentaram menor PMS, o que se deve principalmente a menor produção de efluente. A silagem que levou maior tempo para apresentar quebra da estabilidade aeróbia foi aquela produzida a partir de plantas de milho no estádio camada negra e inoculada com Maize All®, ao passo que se notou menor estabilidade para outras silagens inoculadas com esse mesmo produto em virtude do aumento no teor de umidade das silagens. Os inoculantes utilizados neste trabalho são eficientes em diminuir as perdas de MS durante o processo fermentativo, contudo, contribuem com maior aporte de nutrientes nas silagens, o que resulta em menor estabilidade após a abertura dos silos. Silagens produzidas com maior concentração de MS apresentam menores perdas de MS durante a fermentação, assim como são mais estáveis em contato com o oxigênio.

The aim of this work was to evaluate the inoculation of lactic acid bacterial in corn silages produced in different development stages on the fermentative losses and aerobic stability. The experimental design was completely randomized in factorial scheme 3x5 evaluating two commercial inoculants (Silobac® and Maize All®) and a control treatment (silage untreated) in five maturity stages with four replicates. The application of Silobac® and Maize All® decreased the dry matter losses during the fermentative process in 1.78 and 1.75 percentage points when compared to control silage (7.95%). The silages produced with 2/3 of milk line and black layer presented lower dry matter losses due mainly to the lower effluent production. The higher aerobic stability was observed in a silage produced with corn plants in the black layer stage and inoculated with Maize All®, where there was lower aerobic stability than other silages inoculated with the same product due to increase of moisture of the silages. The inoculants used in this work are efficient in decrease the dry matter losses during the fermentative process, however, there is higher concentration of nutrients in this silages resulting in lower stability after the opening of the silos. Silages produced with higher dry matter content present higher dry matter losses, as well as more stability during the aerobic exposure.

Objetivou-se com esta pesquisa avaliar a composição química e a digestibilidade in vitro da massa seca (MS) da cana-de-açúcar acrescida de ureia, mantida à sombra e sol em diferentes tempos de estocagem. O delineamento experimental utilizado foi inteiramente ao acaso em esquema fatorial 6x2, com seis tempos de estocagem após a mistura (0; 2; 4; 6; 12 e 24 horas) e dois locais de armazenamento (sombra e sol), e três repetições. A cana-de-açúcar utilizada apresentava 12 meses de desenvolvimento e foi desintegrada para aplicação da mistura (nove partes de ureia para uma de sulfato de amônio) a 1,0 kg/100,0 kg de cana-de-açúcar fresca. As amostragens realizadas com 12 horas de estocagem indicaram que houve acréscimo no teor de MS e de proteína bruta (PB) da cana-de-açúcar comparada ao momento da mistura (307,6 vs. 294,2 g/kg de MS e 115,2 vs. 99,3 g/kg de MS, respectivamente), e o menor teor de fibra em detergente neutro (FDN) foi observado por volta de 12 horas de estocagem (465,0 g/kg de MS). Os coeficientes de digestibilidade in vitro da MS (DIVMS) variaram de 0,558 para 0,612 nos tempos 0 e 12 horas, respectivamente. O tempo de estocagem altera a composição química da cana-de-açúcar acrescida de ureia. O local de armazenamento altera o teor de massa seca e valores de pH.

The objective of this research was to evaluate the chemical composition and in vitro dry mass (DM) digestibility of sugar cane with urea, maintained in the shade and sun, at different storage times. The utilized design was the completely randomized in a factorial scheme 6x2, that is, six storage times after the mixing (0; 2; 4; 6; 12 and 24 hours) and two storage location (shade and sun), with three replicates. The sugarcane utilized presented 12 months of development and was disintegrated for application of mixture (nine parts of urea for one of ammonium sulfate) to 1.0kg/100.0kg of fresh sugarcane. The samples taken with 12 hours of storage indicated that was an increase in the content of DM and crude protein (CP) of sugar cane compared to the moment of the mixture (307.6 vs. 294.2g/kg of DM and 115.2 vs. 99.3 g/kg of DM, respectively), and the smaller content of neutral detergent fiber (NDF) was observed around of 12 hours of storage (465.0g/kg of DM). The coefficients of in vitro dry mass digestibility (IVDMD) ranged of 0.558 to 0.612 in the times 0 and 12 hours, respectively. The length of storage changes the chemical composition of sugar cane plus urea. The storage location changes the dry mass content and pH values.

Objetivou-se com este trabalho avaliar a produção e a composição do leite em vacas alimentadas com silagens contendo batata. Foram selecionadas 12 vacas: 9 delas com 50 a 70 meses de idade e 3 de 36 a 42 meses, lactantes, com peso aproximado de 550 kg. O delineamento experimental foi em três quadrados latinos 4 × 4, composto de quatro períodos experimentais e quatro tratamentos (silagens): silagens de milho (SM); capim-elefante (SC); capim-elefante com 7% de batata (SC 7%); e capim-elefante acrescido de 14% de batata (SC14%). Os animais que receberam as dietas com SM, SC 14% e SC 7% apresentaram ingestões mais altas de MS em comparação àqueles que ingeriram dietas à base de silagem de capim-elefante puro. O fornecimento de silagem de capim-elefante formulada com 14% de resíduo de batata proporcionou aos animais maior produção de leite e de leite corrigida para 3,5% de gordura, kg de gordura, kg de proteína, kg de sólidos totais, kg de extrato seco desengordurado (ESD) e kg de lactose em comparação à adição de 7% de batata. A silagem de milho foi superior às demais, pois promoveu maior produção de leite, em kg de proteína, kg de ESD e kg de lactose. A silagem de capim-elefante foi inferior às demais para as produções de ESD e de lactose. Não houve diferença entre as silagens para os teores de gordura, proteína, sólidos totais, ESD, lactose e N-ureico no leite - NUL (mg/dL). A adição de 14% de resíduo de batata em silagens de capim-elefante melhora a ingestão de MS e as produções de leite e leite corrigida para 3,5% de gordura.

The objective of this study was to evaluate production and composition of milk from cows fed silages containing potato. Twelve females were selected: nine between 50 and 70 months of age and three between 36 and 42 months of age, lactating, with approximate weight of 550 kg. The experimental design consisted of 12 cows in three 4 × 4 Latin Squares, with four experimental periods and four treatments: silages of corn (CS); elephant grass (ES); elephant grass activated with 7% potato residue (ES7%) and elephant grass activated with 14% potato residue (ES14%). The animals submitted to the diets with the silages CS, ES 14% and ES 7% presented greater ingestions of DM than those that ingested diets based on silage of pure elephant grass. Supply of diet of elephant grass silage with addition of 14% potato residue presented greater production of milk and milk corrected for 3.5% fat, kg of fat, kg of protein, kg of total solids, kg of degreased dry extract and kg of lactose compared with the addition of 7% potato. The corn silage was superior to the others in production of milk, kg of protein, kg of degreased dry extract (DDE) and kg of lactose. Elephant grass silage presented smaller production than the other silages for kg of DDE and lactose. There was no difference between treatments for fat contents, protein, total solids, DDE, lactose, or milk urea-N (mg/dL). The addition of 14% of potato residue in the elephant grass silage improves ingestion of DM and production of milk.

The objective of this study was to evaluate the effects of stalk/leaf ratio and the stage of maturity on the digestibility of the corn plant. Hybrids AG1051, AG4051, AG5011, DOW2B710, DOW2C577, DOW2A525, NB7315 and P30F90 were used, harvested at the one-half milk line (½ ML), three-quarters milk line (¾ ML) and black layer (BL) stages. A randomized block design was used in an 8 (hybrids) × 3 (stages of maturity) factorial design, with three replications. The means generated were used for grouping into high and low stalk/leaf ratio and a new analysis of variance was generated in a 2 × 3 (two groups and three stages of maturity) factorial design. The whole plant and its stalk, leaf, husk, cob and grain components were incubated in situ in the rumen of three cows for determination of degradability of dry matter and degradable neutral detergent fiber. Stalk/leaf ratio did not influence neutral detergent fiber content or the degradability of dry matter and neutral detergent fiber of any of the components, except for the cob, in which the high ratio group had greater degradable neutral detergent fiber contents. There was a reduction in the degradability of all the parts, except for the stalk and cob, and an increase in the neutral detergent fiber contents of the vegetative parts, except for the stalk. Unlike the vegetative components, the neutral detergent fiber contents of the whole plant decreased throughout the stages evaluated. For degradable neutral detergent fiber, there was a reduction in the whole plant and in its components. The advance of maturity reduces the quality of the vegetative components; however, this loss in the entire plant is moderated by grain filling. Forage quality depends more on the quality of the components than on their proportions in the dry matter.