ABSTRACT. The objective of this study was to evaluate the activity of invertases and amylases in Brachiaria brizantha cv. Marandu under various shade and nitrogen fertilization conditions. The experiment was carried out in a greenhouse using a 4 x 2 factorial scheme (shading levels of 0, 30, 50, and 80% and fertilization with 0 and 100 kg N ha-1). The activity of the enzymes, cytosol-neutral invertase (Inv-N), vacuole acid (Inv-V) and cell-acidic acid (Inv-CW), reducing sugars (RS), and α and β-amylases were evaluated (α = 0.05). The interaction was significant for Inv-N within the leaf. In the first cycle, the highest activity was in fertilized plants with 30, 50, and 80% shading. For Inv-CW in the 1st cycle, the highest activity occurred with 0, 30, and 50% shading. However, the interaction for Inv-V leaf activity was not significant in the 1st and 2nd cycles. The highest activity observed for Inv-V was in the fertilized plants, suggesting that fertilization increased the enzymatic activity. The activity of the invertases increased both under 30-50% shaded conditions and in full sun. Furthermore, invertase activity was directly linked to the osmoregulatory system. The reduction in RS was related to a low photosynthetic rate, and an increase α and β-amylase was associated with the use of reserve energy sources to meet energetic needs.

ABSTRACT. The aim in this study was to evaluate the feeding behavior of goat kids fed diets containing peach palm meal replacing corn (0, 10, 40, 60, and 85 % on a dry matter basis). Thirty crossbred Boer kids, with 90 days old and initial body weight of 16.7 ± 3.5 kg were distributed in a completely randomized design with six replicates. Diets were daily supplied ad libitum to allow 10-20 % leftovers. Three collections were performed every 28 days. Diets were isoenergetics and isonitrogenous, composed of corn, soybean meal, peach palm meal, mineral supplement and Tifton 85 hay, with roughage: concentrate ratio of 30:70. There was a linear reduction in the intakes of dry matter (DM) and neutral detergent fiber (NDF) with a respective decrease of 35.7 % and 58.8 % comparing the diet with 85 % replacement and the control diet. The rumination and chewing times increased in diets with peach palm meal. The feeding and rumination rates decreased with reducing intakes of DM and NDF. The peach palm meal affects the feeding behavior and decreases the feed intake in response to palatability, fat and fiber composition, and it is recommended until 10 % replacing corn.

Resumo: O objetivo deste trabalho foi avaliar a amonização com ureia em silagens de milheto com diferentes densidades de compactação, quanto aos seus efeitos sobre a composição químico-bromatológica, as perdas no processo de ensilagem, o perfil fermentativo, a contagem de populações microbianas e a estabilidade aeróbia. Utilizou-se o delineamento inteiramente casualizado, em arranjo fatorial 2×4, com duas densidades de compactação (600 e 800 kg m-3) e quatro níveis de ureia (0, 2, 4 e 6% com base na matéria seca), com cinco repetições. Na avaliação da estabilidade aeróbia, utilizou-se o delineamento experimental inteiramente casualizado, em arranjo fatorial 2×4, com dois tempos (0 e 72 horas) e quatro níveis de ureia (0, 2, 4 e 6%, com base na matéria seca), com cinco repetições. Os níveis de ureia interagiram significativamente com a densidade, quanto aos teores de matéria orgânica, proteína bruta, proteína insolúvel em detergente neutro e q uanto à recuperação de matéria seca; e com o tempo de exposição, quanto aos teores de fibra em detergente ácido e de lignina. Não se observaram mofos e leveduras nas silagens amonizadas. A densidade de compactação de 800 kg m-3 reduziu as perdas no processo de ensilagem do milheto e proporcionou silagem de maior valor nutritivo do que a compactação a 600 kg m-3. O uso de ureia não reduz as perdas e não melhora a estabilidade aeróbia das silagens; no entanto, controla o crescimento de mofos após a exposição da silagem ao ar.

Abstract: The objective of this work was to evaluate the effects of urea ammoniation of pearl millet silage, at different compaction densities, on chemical composition, losses in the ensilage process, fermentation profile, microbial population count, and aerobic stability. The experimental design was completely randomized, in a 2×4 factorial arrangement, with two compaction densities (600 and 800 kg m-3) and four urea levels (0, 2, 4, and 6% on a dry matter basis), with five replicates. For the aerobic stability assay, the experimental design was completely randomized, in a 2×4 factorial arrangement, with two times (0 and 72 hours) and four urea levels (0, 2, 4, and 6%, on dry matter basis), with five replicates. The urea levels interacted significantly with density as to the contents of organic matter, crude protein, neutral detergent insoluble protein, and as to dry matter recovery; and with exposure hours as to the contents of acid detergent fiber and lignin. Molds and yeasts were not observed in the ammoniated silages. The 800 kg m-3 density reduced losses in the fermentation process of pearl millet silage, and promoted better nutritive value than the compaction at 600 kg m-3. The use of urea does not reduce losses and does not improve the aerobic stability of silages; however, it controls mold growth after silage exposure to air.

RESUMO O experimento foi desenvolvido para avaliar os efeitos do emurchecimento e da inclusão de níveis de farelo de mandioca sobre o valor nutritivo, as características fermentativas e as perdas por gases e efluente da silagem de capim-elefante. Foi adotado o esquema fatorial 4 x 2, com quatro repetições, no delineamento inteiramente casualizado. Os fatores avaliados foram níveis de farelo de mandioca (0; 7,5; 15 e 22,5 % da matéria natural, MN) e emurchecimento (com e sem). Foram usados silos de PVC, com 50 cm de altura e 10 cm de diâmetro para a produção das silagens, que foram abertos após 60 dias. O emurchecimento e a adição do farelo de mandioca tiveram efeito linear crescente sobre o teor de matéria seca (MS). As silagens com farelo de mandioca apresentaram redução dos teores de nitrogênio total, extrato etéreo, nitrogênio insolúvel em detergente ácido, fibra em detergente neutro isenta de cinzas e proteína, fibra em detergente ácido, celulose, hemicelulose e lignina e elevação do teor de matéria orgânica, da digestibilidade in vitro da MS e dos nutrientes digestíveis totais. No que concerne às características fermentativas das silagens, o pH apresentou comportamento quadrático. Quanto ao nitrogênio amoniacal, observou-se comportamento quadrático e linear decrescente para as silagens sem e com emurchecimento, respectivamente. O emurchecimento e a inclusão do farelo de mandioca propiciaram menores perdas por efluente. O emurchecimento e a adição de farelo de mandioca melhora o valor nutritivo e as características fermentativas das silagens estudadas.

SUMMARY The experiment was developed to evaluate the effects of wilting and inclusion of cassava meal level on nutritive value, fermentative characteristics and losses of elephant grass silage. The 4 x 2 factorial scheme was adopted, with four repetitions, in a completely randomized design. The factors evaluated were wilting (without and with) and cassava meal level (0; 7.5; 15 and 22.5% of natural matter, DN). PVC silos with 50 cm height and 10 cm diameter were used for silages production, which were opened after 60 days. The wilting and cassava meal addition had increasing linear effect on DM content. Silages with cassava meal showed reduction of total nitrogen, ether extract, acid detergent insoluble nitrogen, neutral detergent fiber ash and protein free, acid detergent fiber, celluloses, hemicelluloses and lignin contents and increase of organic matter content, DM in vitro digestibility and total digestible nutrients. Relative to variables inherent to silages’ fermentative characteristics, pH presented quadratic behavior. Concerning to ammonia nitrogen, it was observed quadratic and decreasing linear behavior for silages without and with wilting, respectively. Wilting and cassava meal inclusion provided smaller effluent losses.

RESUMO. O objetivo deste estudo foi avaliar o efeito de diferentes doses de nitrogênio em pastos de Urochloa brizantha cv. Marandu diferidos, e suas implicações sobre a viabilidade econômica da produção de novilhas da raça Nelore. Utilizou-se o delineamento inteiramente ao acaso, com quatro tratamentos (T1 = pasto diferido sem adubação nitrogenada; T2 = pasto diferido com 50 kg de N ha-1; T3 = pasto diferido com 100 kg de N ha-1; T4 = pasto diferido com 150 kg de N ha-1) e quatro repetições (16 piquetes adubados). Foram utilizadas, inicialmente, 48 novilhas da raça Nelore, com média de oito meses de idade e com peso corporal inicial de 178,69 ± 26,67 kg, sendo distribuídas três novilhas por piquete em todos os tratamentos em um sistema de pastejo sob lotação contínua, com taxa de lotação variável. Apenas o tratamento sem adubação nitrogenada apresentou valores monetários negativos de R$ -181,96; R$ ha-1 -72,79 e R$ @-1 -32,11. No entanto, o tratamento com 50 kg de N ha-1 apresentou os maiores valores monetários positivos com R$ 756,02; R$ ha-1 302,40 e R$ @-1 50,52. Os dados da viabilidade econômica na produção de novilhas de corte demonstram que o tratamento com 50 kg de N ha-1 é o mais viável financeiramente, nas condições de realização desta pesquisa.

ABSTRACT. The objective of this study was to evaluate the effect of different levels of nitrogen on deferred pastures of Urochloa brizantha cv. Marandu, and the implications on the economic viability of production of Nellore heifers. This was a completely randomized design with four treatments (T1 = deferred pasture without nitrogen fertilization; T2 = deferred pasture fertilized with 50 kg N ha-1, T3 = deferred pasture with 100 kg N ha-1, T4 = deferred pasture with 150 kg N ha-1) and four replications (16 fertilized paddocks). First, there were used 48 Nellore heifers, average eight months of age and initial body weight of 178.69 ± 26.67 kg, with three heifers in each paddock, in all treatments, in a continuous grazing system, with variable stocking rate. Only the treatment the without nitrogen fertilization showed negative monetary values of R$ -181.96, R$ ha-1 -72.79 and R$ @-1 -32.11. The treatment with 50 kg N ha-1 achieved the highest positive monetary values of R$ 756.02, R$ ha-1 302.40 and R$ @-1 50.52. Economic viability data in beef heifer production demonstrate that the treatment with 50 kg N ha-1 is the most financially viable under the conditions of this study.

RESUMO: Palma forrageira foi usada como fonte de nutrientes para a produção de enzimas celulolíticas durante a fermentação em estado sólido com auxílio dos fungos filamentosos Aspergillus niger e Rhizopus sp. Os efeitos da ativiade de água, do tempo de fermentação e da temperatura sobre a produção enzimática foram determinados segundo o protocolo padrão de Delineamento Box-Behnken. A condição ideal para produção das enzimas endoglucanase pelo fungo Aspergillus niger foi 70,35 h de fermentação, atividade de água de 0,875 e temperatura de 29,56 ° C enquanto que para o fungo Rhizopus sp. foi 68,12 h e 30,41 ° C. Entretanto, a celulase total produzida pelo fungo Rhizopus sp. foi otimizada em 74,27 h de fermentação e temperatura de 31,22 ° C e para o fungo Aspergillus niger foi 72,48 h e 27,86 ° C. A atividade de água só tinha uma influência significativa sobre a endoglucanase para Aspergillus niger. A alta estabilidade dos extratos enzimáticos em diferentes tepenraturas e pH's foram confirmadas após caracterização enzimática, indicando viabilidade em aplicações industriais. Os ensaios de desativação cinética indicaram que essas enzimas permaneceram ativas após o congelamento do extrato bruto. Com base nos resultados, utilizar a palma forrageira com matéria prima em bioprocessos é uma alternativa excelente para a produção de enzimas termoestaveis.

ABSTRACT: Prickly palm cactus husk was used as a solid-state fermentation support substrate for the production of cellulolytic enzymes using Aspergillus niger and Rhizopus sp. A Box-Behnken design was used to evaluate the effects of water activity, fermentation time and temperature on endoglucanase and total cellulase production. Response Surface Methodology showed that optimum conditions for endoglucanase production were achieved at after 70.35 h of fermentation at 29.56°C and a water activity of 0.875 for Aspergillus niger and after 68.12 h at 30.41°C for Rhizopus sp. Optimum conditions for total cellulase production were achieved after 74.27 h of fermentation at 31.22°C for Aspergillus niger and after 72.48 h and 27.86°C for Rhizopus sp. Water activity had a significant effect on Aspergillus niger endoglucanase production only. In industrial applications, enzymatic characterization is important for optimizing variables such as temperature and pH. In this study we showed that endoglucanase and total cellulase had a high level of thermostability and pH stability in all the enzymatic extracts. Enzymatic deactivation kinetic experiments indicated that the enzymes remained active after the freezing of the crude extract. Based on the results, bioconversion of cactus is an excellent alternative for the production of thermostable enzymes.

ABSTRACT The objective of this study was to evaluate the effect of different sources of lipids in the diets of dairy cows on the intake and digestibility of nutritional fractions, and milk production and composition. The experiment was conducted in a 42-hectare area divided into eight paddocks covered with Brachiaria brizantha. Twelve crossbred Holstein × Zebu cows were distributed into three simultaneous 4 × 4 Latin squares. The treatments consisted of different sources of lipids, as follows: diet with no extra source of lipids; diet with cottonseed as the source of lipids; diet with soy oil; and diet with used frying soy oil. The intakes of dry matter, neutral detergent fiber, crude protein, total carbohydrates, and non-fibrous carbohydrates were similar for all diets. The use of lipid sources caused a decrease in the apparent digestibility of dry matter, neutral detergent fiber, non-fibrous carbohydrates, and crude protein. The levels of protein, lactose, and defatted dry matter were reduced with the use of lipid sources but did not affect milk production. The use of cottonseed, soy oil, and used frying soy oil as sources of lipids in diets for lactating cows at pasture do not improve milk production, and their use is therefore optional.

Estudou-se o efeito da inclusão de 0; 5; 10 e 15% de bagaço de mandioca, com base na matéria seca da dieta total de vacas mestiças Holandesas vs. Zebu, sobre a produção e composição do leite e sobre os impactos no custo da alimentação. Os animais estavam no terço médio de lactação e pesavam em média 478,5 kg. A dieta com 15% de bagaço de mandioca acrescentou 13,2% à produção, comparada à dieta controle. A conversão alimentar apresentou efeito quadrático com ponto mínimo em 4,2% de inclusão de bagaço de mandioca. A proteína bruta, único componente do leite que sofreu alteração, aumentou linearmente com os níveis de inclusão de bagaço de mandioca. O tratamento com 15% de bagaço de mandioca representou maior custo operacional efetivo (42,8% mais elevado em relação ao tratamento controle) e o maior ponto de nivelamento para a produção e preço do leite. Observaram-se os menores pontos de nivelamento para os tratamentos com 5 e 10% de inclusão de bagaço de mandioca, os quais apresentaram melhores resultados econômicos. O concentrado foi o principal responsável pela elevação dos custos, particularmente, quando ocorre a redução da razão volumoso : concentrado em função dos maiores teores de inclusão de bagaço de mandioca.

The addition of 0; 5; 10 and 15% cassava bagasse, based on the dry matter of the total diet of crossbred Holstein v. Zebu cows, was evaluated on milk production and composition and on the impacts of diet costs. The animals, weighing an average of 478.5 kg, were in the middle third lactation period. Diet with 15% cassava bagasse provided a 13.2% increase in production when compared to control. Feed conversion had a quadratic effect with minimum point at 4.2% of cassava bagasse inclusion. Crude protein, the only milk component that changed, increased linearly with the inclusion of cassava bagasse levels. Treatment with 15% cassava bagasse caused a more effective operational cost (42.8% higher when compared to control) and the highest leveling point for milk production and price. The lowest leveling points were treatments with 5 and 10% inclusion of cassava bagasse, which had the best economic results. Concentrates caused cost increase, particularly when roughage : concentrate ratio decreased due to higher cassava bagasse inclusion levels.

RESUMO: O processo de enriquecimento protéico da palma (Nopalea cochenillifera (L.) Salm-Dyck por fermentação em estado sólido com auxílio dos fungos filamentosos Aspergillus niger e Rhyzopus sp. foi estudado visando a elevação dos teores nutricionais para o uso como ração animal. Os experimentos foram realizados no Laboratório de Resíduos Agroindustrial da Universidade Estadual do Sudoeste da Bahia (UESB). O efeito da fermentação em estado sólido sobre a palma forrageira foi avaliado comparando os teores de proteína, celulose, hemicelulose e lignina, além da degradabilidade potencial, com os valores in natura. A bioconversão foi realizada utilizando como único substrato a palma forrageira e água, sem a suplementação de fontes alternativas de nitrogênio, minerais ou vitaminas. O fungo Aspergillus niger elevou os teores proteicos em aproximadamente 78% e promoveu a redução nos teores de celulose, hemicelulose e lignina em aproximadamente 40%, 36% e 28%, respectivamente. Por sua vez essa biotransformação elevou a degradabilidade potencial em 66% após 240 h. Enquanto que o fungo Rhyzopus sp. demonstrou ser menos eficiência no enriquecimento proteico, com um aumento de aproximadamente 69 %, e a redução no teores de celulose, hemicelulose e lignina de 30%, 28% e 18%. Ainda para este fungo a degradabilidade potencial teve uma elevação de aproximadamente 51%. Portanto a fermentação da palma forrageira com auxílio dos fungos filamentosos Aspergillus niger e Rhyzopus sp. promoveram um enriquecimento nos teores proteicos desta cactacea além de elevar a sua degradabilidade potencial. Com base nesses resultados, a bioconversão da palma forrageira empregando o método de fermentação em estado sólido pode ser uma excelente alternativa na alimentação de ruminantes em terras áridas ou semiáridas.

ABSTRACT: The process of protein enrichment of cactus pear (Nopalea cochenillifera (L.) Salm Dyck by solid state fermentation with the use of Aspergillus niger and Rhyzopus sp. was studied for improving the nutritional value of this cactus species for use as animal feed. The experiments were conducted in the Agro-industrial Waste Laboratory of State University of Southwest Bahia (Brazil). To this end, we have evaluated the effects of biotransformation on the levels of protein, cellulose, hemicellulose, and lignin, as well as the potential degradability. Bioconversion was carried out using cactus pear as the only substrate, without supplementation with nitrogen, mineral and vitamin sources. The fermentation with Aspergillus niger promoted a 78% increase in/of protein content and reductions of cellulose, hemicellulose, and lignin of 40%, 36%, and 28%, respectively. Degradability, in turn, was observed to have increased by 66 % after 240 h. On the other hand, the fermentation with Rhyzopus sp. was less efficient, with a 69% increase in protein content, and reductions in cellulose, hemicellulose, and lignin contents of 30%, 28%, and 18%. In turn, degradability was seen to have increased by 51%. The fermentation of cactus pear by Aspergillus niger and Rhyzopus sp. exhibited the protein enrichment and increased protein degradability of this Cactaceae. Moreover, this is the most ever efficient micro-organism used in bioconversion. Based on the results, bioconversion of cactus is an excellent alternative to ruminant feeding in arid or semi-arid land.

This experiment was conducted to study the substitution of soybean meal with peanut cake in the supplement by assessing the feeding behavior and the interaction between the thermal environment and the physiological responses of eight crossbred cows with an average live weight of 500 kg. Cows were divided into two 4 × 4 Latin squares and managed on pasture. The peanut cake was included at the levels of 0, 330, 660, and 1,000 g kg-1 in the supplement as a replacement for soybean meal. The feeding behavior variables were not affected by the levels of peanut cake. No differences were found for the physiological parameters of the animals with the replacement of soybean meal for peanut cake in the supplements. Peanut cake can replace up to 100% soybean meal in the supplement of grazing lactating crossbred cows without altering the feeding behavior or physiological parameters of the animals.

The experiment was conducted to assess the effect of substituting corn for soybean hulls on the apparent digestibility of nutrients, carcass performance and characteristics, and yield of cuts of 25 non-castrated male Santa Ines lambs with an initial body weight of 20±2 kg, at approximately 6 months of age, sheltered individually in stalls (1.10 × 1.0 m), considering a totally randomized design, fed 600 g/kg of forage and 400 g/kg of concentrate. Soybean hulls replaced corn at 0, 250, 500, 750, and 1,000 g/kg of dry matter. The intake of dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), acid detergent fiber (ADF), NDF corrected for ash and protein (NDFap), total carbohydrates (TC), non-fibrous carbohydrates (NFC) and total digestible nutrients (TDN) in g/day, and the digestibility of NFC increased linearly with the soybean hull replacement. Crude protein intake displayed a quadratic response, whereas the intake of EE in g/day, the apparent digestibility coefficients of DM, OM, CP, EE, NDF, ADF, NDFap and TC, TDN, average daily gain, carcass characteristics, and yield of cuts were not affected by the soybean hull levels. Soybean hull substitution increased the intake of DM and nutrients, making it possible to replace up to 1,000 g/kg of dry matter in the diets for confined sheep, as it does not compromise performance, digestibility, carcass characteristics, or yield of cuts when used in sheep nutrition.

Objetivou-se avaliar o efeito da utilização de cana-de-açúcar in natura, silagem de cana sem ou com Lactobacillus buchneri e cana queimada sem ou com L. buchneri sobre o comportamento ingestivo, balanço de nitrogênio e síntese de compostos nitrogenados microbianos em vacas lactantes. Foram utilizadas cinco vacas mestiças, ¾ Holandês x Gir, distribuídas em um quadrado latino 5 x 5 e alimentadas com dietas compostas por 60% de volumoso e 40% de concentrado na base da matéria seca, para atender um peso corporal médio de 550 kg e produção média de 15 kg de leite por dia. A cana-de-açúcar in natura proporcionou maiores valores (p < 0,05) para eficiência de alimentação da matéria seca (3.133,3 vs 2.234,47 g MS h-1) e de ruminação (1.642,3 vs 1.222,93 g MS h-1) em relação às silagens. Observou-se menor tempo de mastigação total (58,7 vs 81,5 min. kg-1 de MS) para cana-de-açúcar in natura quando comparada às silagens sem inóculo. A utilização do aditivo microbiano na ensilagem da cana-de-açúcar não alterou (p > 0,05) o consumo e o balanço de nitrogênio, porém propiciou maior (p < 0,05) síntese de nitrogênio microbiano. Não houve diferença entre as dietas (p > 0,05) para eficiência microbiana, cujo valor médio foi de 204,32 g PB microbiana kg-1 de TDN.

This study evaluated the effect of using fresh sugar cane, sugar cane silage with or without Lactobacillus buchneri, and burnt sugar cane silage with or without L. buchneri on ingestive behavior, nitrogen balance and synthesis of microbial nitrogen compounds of dairy cows. Five ¾ Holstein x Gir crossbred cows, assigned to a 5 x 5 Latin square design, were given diets with a 60:40 forage: concentrate ratio on a dry matter basis, to meet an average body weight of 550 kg and production of 15 kg of milk per day. The treatment with fresh sugar cane showed higher values (p < 0.05) for dry matter feed efficiency (3,133.3 vs 2,234.47 g DM h-1) and rumination (1,642.3 vs 1,222.93 g DM h-1) compared to the silages. There was a shorter total chewing time (58.7 vs 81.5 min. kg-1 DM) for fresh sugar cane when compared to silages without inoculum. The addition of microbial additive during ensiling of sugar cane did not alter (p > 0.05) the nitrogen intake and balance, but led to a greater (p < 0.05) synthesis of microbial nitrogen. Microbial efficiency was not affected (p > 0.05), and showed an average value of 204.32 g microbial crude protein kg-1 total digestible nutrients.

Objetivou-se avaliar a viabilidade econômica de dietas contendo quatro silagens de cana-de-açúcar: sem aditivo; com 1% de ureia; com 0,5% de CaO + 0,5% ureia; e com 1% de CaO. Utilizaram-se oito vacas mestiças Holandês × Gir, distribuídas em dois quadrados latinos 4 × 4, compostos de quatro dietas, quatro animais e quatro períodos. A cana-de-açúcar utilizada foi a variedade SP 79-1011, com produção de 140 t/ha/ano, no terceiro corte. O corte da cana-de-açúcar foi feito manualmente e a cana, desintegrada em picadeira estacionária. O custo de produção dos volumosos, do concentrado e da dieta total foi analisado e, de acordo com os preços obtidos no mercado local, também foi calculado o COE (custo operacional efetivo). A dieta contendo silagem de cana-de-açúcar com 1% de ureia foi menos eficiente, pois resultou em baixo consumo e maior perda de peso das vacas podendo afetar a produção de leite e o escore corporal das vacas no decorrer da lactação.

This aimed to evaluate the economic viability of diets containing four sugar cane silages: without additive, with 1% urea, with 0.5% CaO + 0.5% urea and ; with 1% CaO. Eight crossbred cows (Holstein x Gir) were used, arranged in two 4 x 4 Latin squares compounds of the: four diets, four animals and four periods. The sugar cane used was the variety SP 79-1011, with a yield of 140 t/ha/year in the third cut. The cut of sugar cane was done manually and the cana disintegrated in stationary chopper. The production costs of the roughage, concentrated and total diet were analyzed of the according to the prices of the local market, it was also estimated the EOC (effective operational cost). The diet containing silage sugar cane with 1% urea was less efficient because low consumption and resulted in greater weight loss of cows may affect milk production and body condition score of cows during the lactation period.

O objetivo deste trabalho foi avaliar o consumo voluntário e o desempenho de novilhas leiteiras em pastos de Urochloa decumbens diferidos com dois períodos de diferimento. O delineamento experimental adotado foi inteiramente casualizados com dois tratamentos e sete repetições, que consistiram em dois períodos de diferimento: T1= 95 e T2= 140 dias. Foram utilizadas 14 novilhas Holandês/Zebu com peso corporal (PC) médio de 300 kg. O consumo de matéria seca da forragem representou 2,5 e 1,2% do PC para os tratamentos 95 e 140 dias, respectivamente. Para o tratamento T2 os animais tiveram um consumo de apenas 139,5 g de PB, consequência do baixo teor deste nutriente, 3,4% de PB, na forragem disponível. Verificou-se um consumo de FDN 1,7 e 1,0% do PC para os tratamentos T1 e T2, respectivamente. O ganho de peso médio diário foi de 785,8 g dia-1 para o tratamento T1, enquanto no T2 houve perda de peso, em média -31,1 g dia-1. Na prática, o diferimento de pastos de Urochloa decumbens por 95 dias que permitam uma estrutura com índice de acamamento de 1,5 proporciona maior consumo e desempenho de novilhas leiteiras. Na prática, o diferimento de pastos de Urochloa decumbens que permitam uma estrutura com índice de acamamento de 1,5 proporciona maior consumo e desempenho de novilhas leiteiras.

Voluntary intake and performance of dairy heifers grazing on Urochloa decumbens pastures with two deferral periods are evaluated. The totally randomized experimental design consisted of two treatments and seven replications, with two deferral periods: T1 = 95 and T2 = 140 days. Fourteen Holstein-Zebu heifers, average body weight (BW) 300 kg, were used. Intake of forage dry matter was 2.5% and 1.2 BW respectively for treatments 95 and 140 days. In treatment T2 the animals had an intake of only 139.5 g of CP, due to low nutrient content, or rather, 3.4% of CP in the forage available. There was an intake of NDF of 1.7% and 1.0 of BW for T1 and T2, respectively. The average daily weight gain was 785.8 g day-1 for T1 and average weight loss of -31.1 g day-1 for T2. Deferral of pastures Urochloa decumbens for 95 days to allow a 1.5 lodging index provides greater consumption and performance of dairy heifers. Deferral of Urochloa decumbens pastures to allow a 1.5 lodging index provides greater intake and performance of dairy heifers.

The objective of this study was to evaluate intake, performance and nutrient digestibility of sheep supplemented with sugarcane ensiled with four levels of calcium oxide (0.0, 0.8, 1.6 and 2.4%) and urea (1.5%), on a natural matter basis. Twenty castrated Santa Ines lambs with 24.09 kg average weight were housed in individual 1.5 m² pens, distributed in a completely randomized design. The diet supplied had a roughage:concentrate ratio of 70:30 and the experimental period lasted 77 days, of which 14 days were used for adaptation to the diet and three 21-day periods for data collection. No differences were observed for the average daily intake of dry matter, ether extract, neutral detergent fiber, neutral detergent fiber corrected for ash and protein, total carbohydrates, hemicellulose and total digestible nutrients. The treatment with urea showed differences for the intake (kg/day) of crude protein, acid detergent fiber and non-fibrous carbohydrates. There was no effect of diets on the digestibility of dry matter, ether extract, neutral detergent fiber, acid detergent fiber or total digestible nutrients, but there was a quadratic effect for total carbohydrates and increasing linear effect for non-fibrous carbohydrates. The calcium intake increased as the levels of calcium oxide in the sugarcane were elevated. The calcium:phosphorus ratio in the silage of calcium oxide was different from the silage with urea and control. No effect was observed for the performance characteristics of sheep. Sugarcane silages with calcium oxide levels of up to 2.4% or with urea do not improve the intake or weight gain of sheep.