Resumen La suplementación surge como una estrategia simple para mejorar la productividad animal en sistemas que adoptan praderas diferidas de pasto como dieta básica. Este estudio tuvo como objetivo evaluar el efecto de los niveles de suplementación de harina de vaina de mezquite sobre la ingesta, la digestibilidad de los nutrientes y la ganancia de peso corporal (PC) de caprinos en pastoreo diferido. Treinta y cinco (35) caprinos machos (24.0 ± 2.9 kg PC) se distribuyeron en un diseño completamente al azar, con cinco tratamientos y siete repeticiones. Los tratamientos consistieron en un control de suplemento (0.05 % de PC de sal proteico-mineral) y niveles crecientes a 0.5; 1.0; 1.5 y 2.0 % de PC de suplementación con harina de vaina de mezquite. La ingesta de materia seca y nutrientes del forraje y la dieta total aumentaron linealmente (P<0.0001) en función de los niveles del suplemento. Se observó un efecto cuadrático (P<0.0001) para las variables de digestibilidad, excepto para el extracto etéreo y los carbohidratos no fibrosos, que presentaron un efecto lineal creciente (P<0.0001). Los niveles de suplementación aumentaron linealmente las variables de rendimiento (P<0.05). Se recomienda la suplementación del concentrado al 2.0 % de PC con harina de vaina de mezquite al 30 % en su composición para promover la reducción del ciclo productivo de los caprinos en praderas diferidas de pasto Urochloa.

Abstract Supplementation emerges as a simple strategy to improve animal productivity in systems that adopt deferred grass pasture as the basic diet. This study aimed to evaluate the effect of levels of supplementation of mesquite pod meal on intake, digestibility of nutrients, and body weight (BW) gain of goats in grazing deferred. Thirty-five (35) goat males (24.0 ± 2.9 kg BW) were distributed in a completely randomized design, with five treatments and seven replications. Treatments constituted a supplement control (0.05% BW of protein-mineral salt) and increasing levels at 0.5; 1.0; 1.5, and 2.0% BW of supplementation with mesquite pod meal. Dry matter intake and nutrients of the forage and total diet increased linearly (P<0.0001) as a function of the levels of the supplement. A quadratic effect was observed (P<0.0001) for the digestibility variables, except for ethereal extract and non-fiber carbohydrates, which presented an increasing linear effect (P<0.0001). Supplementation levels increased linearly on the performance variables (P<0.05). It is recommended the concentrate supplementation at 2.0% BW with mesquite pod meal at 30 % in its composition for promoting the reduction of the productive cycle of goats in deferred Urochloa grass pastures.

Abstract The N-(n-butyl) thiophosphoric triamide (NBPT), a urease inhibitor, has been reported as one of the most promising compounds to reduce losses by volatilization, and to maximize the use of urea nitrogen (N) in agricultural systems. A field study was carried out to examine urease inhibitors' potential about volumetric density and forage mass grass (Brachiaria brizantha cv. Xaraés) to N application. The experiment was carried out from September 2017 to September 2018. The experimental design used was complete randomized blocks in the 3×2×4 factorial array, considering: three periods of the year (wet season, dry season, and the transition), two sources of urea (conventional urea and NBPT-treated urea), and four N rates (0, 80, 160 and 240 kg N ha-1 yr-1), replicated three times. Nitrogen sources promoted a positive effect (P<0.0001) on bulk density, forage mass, and in the grazing stratum during the wet season and the transition season, with increasing N rates in pastures. The leaf: stem ratio decreased linearly (P<0.0045) as increased N rates, and the higher ratio during the wet season and lower in the dry season of the year. For the rates of 80 kg N ha-1 yr-1, there was a significant difference (P=0.0042) between sources, with greater (P=0.0006) forage mass of 0-30 cm, post-grazing forage mass (P=0.0042) and forage volumetric density (P=0.0006), when utilized the conventional urea. The application of N, regardless of the source, provides an increase in forage mass and volumetric density in Xaraés grass pastures up to a dose of 240 kg N ha-1 yr-1, in the transition season and wet season.

Resumen La N-(n-butil) triamida tiofosfórica (NBPT) es un inhibidor de la ureasa usado en los sistemas agrícolas para reducir las pérdidas por volatilización de NH3 y maximizar el uso del nitrógeno ureico (N). Se realizó un estudio de campo para evaluar el efecto de la urea tratada con NBPT sobre la densidad volumétrica y la masa de forraje en el pasto Brachiaria brizantha cv. Xaraés. El periodo experimental fue de un año (septiembre 2017 a septiembre 2018). El diseño experimental fue de bloques completamente aleatorios con un arreglo factorial de 3×2×4: tres estaciones del año (lluvia, sequía y transición), dos fuentes de urea (convencional y tratada con NBPT), y cuatro tasas de N (0, 80, 160 y 240 kg N ha-1 año-1). Se hicieron tres réplicas. Ambas fuentes de nitrógeno tuvieron un efecto positivo (P<0.0001) sobre la densidad aparente, la masa de forraje y el estrato de pastoreo durante la estación de lluvia y la de transición. También produjeron aumentos de N en los pastos. La relación hoja:tallo disminuyó linealmente (P<0.0045) a medida que aumentaron las tasas de N; la relación mayor fue durante la estación de lluvia y la menor en la estación de sequía. A la tasa de 80 kg N ha-1 año-1, hubo una diferencia (P=0.0042) entre las fuentes de N. A esta tasa la urea convencional produjo una mayor (P=0.0006) masa de forraje total, masa de forraje pospastoreo (P= 0.0042) y densidad volumétrica del forraje (P=0.0006). En las estaciones de lluvia y de transición, la aplicación de N, cual sea la fuente, resultó en un aumento en la masa y la densidad volumétrica del forraje en praderas de pasto Xaraés hasta la tasa de 240 kg N ha-1 año-1.

Abstract Chicha (Sterculia striata) is a native plant of the Cerrado biome that has only recently been explored nutritionally. The aim of this study was to determine its fatty acid profile and obtain the proteomic analysis of chicha nut. The nut was found to be composed of 22.19% protein, 20.62% lipids, 3.91% moisture, 3.63% ash, 53.56% carbohydrates, 19.99% neutral detergent fiber and 3.99% acid detergent fiber. With regard to fatty acids; 5 components were identified, of which 56.2% were unsaturated fatty acids. Oleic acid presented the highest fatty acid content in chicha, followed by palmitic acid. With regard to the nut’s protein content; 2 proteins were identified, legumin, a soluble globulin, and prurin-1, the most allergic component of 11S globulins. The identification of the characteristics of chicha provides nutritional and functional information regarding this plant and its contribution to food products.

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.

Abstract The objective of this study was to evaluate the economic viability, through different supplementation strategies, of the post-weaning and finishing stages of cattle supplemented on Brachiaria brizantha cv. Marandu pastures during the rainy and dry seasons. The experimental period was 447 d. The study comprised the post-weaning and finishing stages of 22 intact male crossbred (½ Holstein-Zebu) cattle with an average initial weight of 164.09 ± 12.13 kg and an average age of 7 mo. The animals were distributed in a randomized design with 11 replications per treatment. The following supplementation strategies were tested: strategy 1 (S1): Mineral mix in the 1st and 3rd periods and protein-energy supplementation at 0.2 % of the body weight (BW) in the 2nd period; and strategy 2 (S2): protein-energy supplementation at 0.4 % BW in the 1st and 3rd periods, and protein-energy supplementation at 0.6 % BW in the 2nd period. Strategy 1 resulted in a lower cost per arroba produced and lower cost per hectare, generating a greater net profit per hectare and consequently a higher internal rate of return. When herbage is available, mineral supplementation supplied during the rainy season, associated with low levels of protein-energy supplementation in the dry season (S1), is of greater economic attractiveness for the development of the project, as it leads to higher internal rates of return and net present values in the entire period.

Resumen El objetivo fue evaluar la viabilidad económica, a través de diferentes estrategias de suplementación, de las etapas post destete y finalización del ganado bovino suplementado en pastoreo de Brachiaria brizantha cv. Marandú durante las temporadas de lluvias y secas. El periodo experimental fue de 447 días. El estudio comprendió las etapas post destete y finalización de 22 bovinos machos (1/2 Holstein-Cebú) enteros con un peso inicial promedio de 164.09 ± 12.13 kg y una edad promedio de 7 meses. Los animales se distribuyeron en un diseño aleatorio con 11 repeticiones por tratamiento. Se probaron las siguientes estrategias de suplementación: estrategia 1 (E1): mezcla de minerales en el 1er y 3er periodos y suplementación de proteína y energía al 0.2% del peso corporal (PC) en el 2do periodo; y estrategia 2 (E2): suplementación de proteína-energía a 0.4% PC en los períodos 1º y 3º, y suplementación de proteína-energía a 0.6% PC en el 2º período. La estrategia 1 dio como resultado un menor costo por arroba producido y un menor costo por hectárea, generando una mayor ganancia neta por hectárea y, en consecuencia, una mayor tasa interna de retorno. Cuando se dispone de forraje, la suplementación de minerales suministrada durante la temporada de lluvias, asociada con bajos niveles de suplementación de proteína y energía en la estación seca (S1), es de mayor atractivo económico para el desarrollo del sistema, ya que conduce a mayores tasas internas de valores de retorno y valores netos presentes en todo el periodo.

Resumo: O objetivo deste trabalho foi avaliar diferentes taxas de arraçoamento no desempenho produtivo de bijupirá (Rachycentron canadum) criado em águas salobras. Para o experimento, 1.600 juvenis foram distribuídos em 16 cercados instalados em viveiro, em área estuarina. Foram avaliados quatro diferentes níveis de arraçoamento: 1, 3, 5 e 7% do peso vivo (PV) por dia. Avaliaram-se os seguintes parâmetros de desempenho: sobrevivência, biomassa final, taxa de crescimento específico, ganho de peso diário, conversão alimentar aparente, taxa de eficiência proteica, taxa de eficiência lipídica e índice hepatossomático. A sobrevivência foi superior a 80% em todos os níveis de arraçoamento. A conversão alimentar aparente mais eficiente foi obtida com a taxa de arraçoamento de 5% do PV por dia, que também resultou em melhores valores para o índice hepatossomático. A taxa de 5% do PV por dia proporciona melhor desempenho produtivo para o bijupirá em águas salobras.

Abstract: The objective of this work was to evaluate different feeding rates on the productive performance of cobia (Rachycentron canadum) grown in brackish waters. For the experiment, 1,600 juveniles were distributed in 16 enclosures installed in an estuarine pond. Four different feeding rates were evaluated: 1, 3, 5, and 7% live weight (LW) per day. The following performance parameters were assessed: survival, final biomass, specific growth rate, daily weight gain, apparent feed conversion, protein efficiency rate, lipid efficiency rate, and hepatosomatic index. Survival was greater than 80% at all feeding rates. The most efficient feed conversion rate was obtained with the feeding rate of 5% LW per day, which also resulted in better values for the hepatosomatic index. The rate of 5% LW per day provides a better productive performance for cobia in brackish waters.

ABSTRACT The objective of this study was to evaluate the effect of substituting soybean meal for urea in diets based on deferred buffelgrass on the performance of feedlot sheep. Thirty mixed-breed sheep with an average initial body weight of 17±1.5 kg were distributed in a completely randomized design in which the experimental treatments consisted of five diets with six replicates. Diets were composed of deferred buffelgrass plus concentrates and calculated to be isoproteic. Treatments were represented by the substitution of soybean meal for the urea levels (0, 25, 50, 75, and 100%). Nutrient intake did not differ among animals fed diets with urea levels. Hot and cold carcass weights, hot and cold carcass dressing percentages, initial and final pH, and weight of commercial cuts did not differ among animal fed diets with urea levels. There was no difference for non-carcass components among animals, except for the empty carcass, gall bladder, and perirenal fat weights, which were influenced by dietary urea levels. Substituting the crude protein from soybean meal for the protein from urea provides a similar performance in sheep consuming deferred buffelgrass.

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 objetivo com este estudo foi avaliar a utilização de silagens de diferentes cultivares de sorgo através do consumo, digestibilidade dos nutrientes e desempenho de ovinos. O experimento foi conduzido na Estação Experimental de Pendência, da Empresa Estadual de Pesquisa Agropecuária da Paraíba S.A. Para o experimento, foram utilizados trinta e cinco carneiros, sem raça definida, com peso vivo médio de 17,7 kg, distribuídos em um delineamento em blocos casualizados, com cinco tratamentos e sete repetições para determinar o consumo e desempenho; e 25 carneiros não castrados, sem raça definida, distribuídos em um delineamento inteiramente casualizado, com cinco tratamentos e cinco repetições, para determinar a digestibilidade dos nutrientes. O consumo médio diário de matéria seca foi, em média, 994,66 g. Somente os consumos médios de extrato etéreo, fibra em detergente neutro e carboidratos não-fibrosos, foram afetados pelas dietas. O ganho de peso (GP), conversão alimentar e eficiência alimentar dos animais que receberam as dietas não foram afetados pelos diferentes cultivares utilizados. Silagens de sorgo BRS 655, 610, 800, 810 e Ponta Negra promoveram consumo e digestibilidade de nutrientes semelhantes. A utilização de silagens de diferentes cultivares de sorgo (BRS 610, BRS 655, BRS 800, BRS 810 e Ponta Negra) em dietas para ovinos em confinamento promove desempenho e consumo similar.

SUMMARY The aim of this study was to evaluate the use of silages of different sorghum cultivars through digestibility and nutrient intake and performance of sheep. The experiment was conducted at the Pendência Experimental Station, of the State Company for Agricultural Research of Paraíba S.A. For the experiment, thirty-five rams were used, without defined breed, with average live weight of 17.7 kg, distributed in a completely randomized block design, with five diets and seven replicates to determine intake and performance; and 25 non-castrated rams, without defined breed, distributed in a completely randomized design with five diets and five replicates, to determine the digestibility of nutrients. The average daily intake of dry matter was, on average, 994.66 g. Only the average intakes of ether extract, neutral detergent fiber and non-fibrous carbohydrates, were affected by the diets. The weight gain (WG), feed conversion and feed efficiency of the animals receiving the diets suffered no effect. Silages of BRS 655, 610, 800, 810 and Ponta Negra provided similar intake and digestibility of nutrients. The use of silages of different sorghum cultivars (BRS 610, BRS 655, BRS 800, BRS 810 and Ponta Negra) in diets for confined sheep provide similar performance and intakes.

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.

Objetivou-se avaliar a degradabilidade ruminal in situda matéria seca, proteína bruta e fibra em detergente neutro de silagens de capim-elefante aditivadas com farelo de milho e inoculante da microbiota autóctone. Para as silagens foi utilizado esquema fatorial 4x2 (quatro níveis de farelo de milho - 0, 5, 10 e 20 dag/kgx com e sem inoculante) e cinco repetições, em delineamento inteiramente casualizado. No ensaio de degradabilidade, o delineamento experimental utilizado foi o de blocos ao acaso, com parcelas subdivididas, no qual os três animais representaram os blocos; as silagens representam os sete tempos de incubação dos alimentos no rúmen (0, 6, 12, 24, 48, 96 e 144 horas), as subparcelas. Houve acréscimo da fração solúvel nas silagens com adição do farelo de milho, sendo que no tratamento com 20dag/kg proporcionou o maior resultado, com 31,49 e 29,02%, para os tratamentos sem e com inoculante, respectivamente. A fração insolúvel potencialmente degradável, da matéria seca, foi maior nas silagens com 20dag/kg de farelo de milho. Na fibra em detergente neutro, os maiores valores fração insolúvel potencialmente degradável foram observados nas silagens sem farelo de milho, 56,52 e 57,19%, respectivamente, nas silagens de capim sem e com inoculante da microbiota autóctone. A adição de farelo de milho em silagens de capim-elefante melhora a degradabilidade da matéria seca das silagens e diminui a da fibra em detergente neutro.

This study aimed to evaluate the in situ degradability of dry matter, crude protein and neutral detergent fiber of elephant grass silage with corn bran and inoculation of autochthonous microbiota. For the silages used a 4 x 2 factorial arrangement (four levels of corn bran - 0, 5, 10 and 20dag/kg x with and without inoculation) and five replications, in a completely randomized design. In degradability trial, the experimental design was a randomized block, split plot in which three animals represented the blocks; silages represent the treatments, and the seven incubation times of food in the rumen (0, 6, 12, 24, 48, 96 and 144 hours), the subplots. With the addition of corn bran was increase the soluble fraction in the silages, and so treatments with 20dag/kg of corn bran resulted in higher values of the soluble fraction of the dry matter, 31.49 and 29.02%, for treatments with and without inoculant, respectively. The insoluble potentially degradable fraction of dry matter was higher in silages with 20 dag/kg of corn bran. In neutral detergent fiber, higher values of insoluble potentially degradable fraction were observed in the silage without corn bran, 56.52 and 57.19%, respectively, in the silages with and without inoculation of autochthonous microbiota. The addition of corn bran of elephant improves dry matter degradability of silages and decreases of neutral detergent fiber.

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 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.

The objective of this study was to evaluate agronomic characteristics of 32 sorghum cultivars (Sorghum bicolor(L). Moench) in the Brazilian semi-arid region. The experimental design was set up in randomized blocks with three replications. Treatments were the 32 sorghum cultivars. The evaluated variables were: plant height, stem diameter, tiller density, number of green leaves per tiller, average leaf length, dry matter content, fresh matter production and dry matter production (DMP) in kg/ha, and the percentage of the components panicle, leaf blade and stem. To avoid associative effects due to the presence of positive correlation with DMP, the variables plant height, number of plants per hectare and fresh matter production were excluded for being part of the discriminatory variables of the cluster. Based on the cluster analysis and subjective cutting in 20% dissimilarity, five groups were hierarchically set up. It was not possible to find groups with higher values of panicle and DMP simultaneously; however, group number 5 met significant values for both variables, with mean values of 15,037.63 kg/ha of DMP and 11.36% of panicle, besides 13.65% of leaf. Groups 3, 4 and 5 show high potential for dry matter production, especially group 5. The presence of evident variation among cultivars allows for a selection of more productive and, thus, more suitable cultivars for silage production in semi-arid regions.