ABSTRACT The objective of this study was to analyze dairy farm characteristics as a function of milk urea nitrogen (MUN) content in the north and west of the state Paraná, Brazil. Milk urea nitrogen serves as an indicator of protein utilization by cows. In view of the high costs of protein in animal diets, this study evaluated farm characteristics that could influence MUN content. For this, 32 dairy farms were randomly selected for application of a questionnaire assessing qualitative and quantitative variables. Interviews and samplings of bulk tank milk were carried out from October 2018 to October 2019. Three clusters of farms were identified: cluster 1, low MUN content (8.07 mg/dL); cluster 2, high MUN content (21.60 mg/dL); and cluster 3, intermediate MUN content (11.90 mg/dL). Clusters 1, 2, and 3 comprised 19, 4, and 9 farms, respectively. No association was found between MUN content and production system (conventional or agroecological). However, clusters differed significantly (P<0.05) in total number of cows and number of lactating cows. Differences (P<0.05) were also found for milk fat and total solids contents. As MUN is highly influenced by diet protein levels and the analyzed farms used feed based on the same ingredients (corn and soybean), it was not possible to identify which factors influenced MUN content for the studied farm groups.

ABSTRACT: The research was conducted to test the hypothesis that the inclusion of coffee husk (Coffea sp.) would improve the fermentative characteristics and quality of pearl millet silage (Pennisetumglaucum). Thus, the objective was to assess the effect of the inclusion of different levels of coffee husk in pearl millet silage on the chemical composition, fermentative characteristics and degradability in situ of silage. The experimental design used was completely randomized and the treatments consisted of the silage of the whole pearl millet plant with the inclusion of increasing levels of coffee husk: 0%, 7%, 14% and 21%, based on natural matter. After 60 days of fermentation, the silages were evaluated for chemical characteristics, fermentative, degradability in situ dry matter (DM) and neutral detergent fiber (NDF). The inclusion of coffee husk did not alter (P > 0.05) the contents of crude protein (11.94%), NDF (44.89%) and total digestible nutrients (65.09%). There were increases in the concentrations of DM and fiber in acid detergent, accompanied by a reduction in the concentrations of mineral matter and ether extract, as the proportion of coffee husks in silages increased. There was an increase in the lignin content up to the level of 7.59% inclusion of the coffee husk. There was no effect of the inclusion of the coffee husk on the pH of the silage (3.60). However, the inclusion of coffee husk resulted in a reduction in temperature, gas losses, and degradability in situ of silage DM and NDF. It is recommended to include coffee husk up to the level of 14.0% of the natural matter to improve the fermentation pattern and the quality of the pearl millet silage.

RESUMO: A pesquisa foi conduzida para testar a hipótese de que a inclusão de casca de café (Coffea sp.) melhoraria as características fermentativas e a qualidade da silagem de milheto (Pennisetum glaucum). Assim, objetivou-se avaliar o efeito da inclusão de diferentes níveis da casca de café na ensilagem de milheto sobre a composição química, características fermentativas e degradabilidade in situ da silagem. O delineamento experimental utilizado foi inteiramente casualizado e os tratamentos constituíram-se pela silagem da planta inteira de milheto com a inclusão de níveis crescentes de casca de café: 0%, 7%, 14% e 21%, com base na matéria natural. Após 60 dias de fermentação, as silagens foram avaliadas quanto às características químicas, fermentativas, degradabilidade in situ da matéria seca (MS) e da fibra em detergente neutro (FDN). A inclusão da casca de café não alterou (P > 0,05) os teores de proteína bruta (11,94%), FDN (44,89%) e nutrientes digestíveis totais (65,09%). Houve aumentos nas concentrações de MS e fibra em detergente ácido, acompanhados de uma redução nas concentrações de matéria mineral e extrato etéreo, à medida que se aumentou a participação da casca de café nas silagens. Houve um aumento no teor de lignina até o nível de 7,59% de inclusão da casca de café. Não houve efeito da inclusão da casca de café sobre o pH da silagem (3,60). Entretanto, a inclusão de casca de café acarretou na redução da temperatura, perdas por gases, degradabilidade in situ da MS e FDN da silagem. Recomenda-se a inclusão de casca de café até o nível de 14,0% da matéria natural para melhoria do padrão de fermentação e da qualidade da silagem de milheto.

ABSTRACT: In Brazil, urea is the most used nitrogen (N) fertilizer to improve forage production. However, their excessive use can cause environmental impacts through N losses, such as ammonia (NH3) volatilization. Therefore, the current study adjusted and estimated the NH3 volatilization from urea applied on tropical pastures in three rainfall conditions using mathematical models. Data were collected from Marandu grass (Brachiaria brizantha) fertilized with 50 kg N ha-1 during wet, intermediate, and dry conditions. Ammonia volatilization was measured in five semi-open chambers for 21 days. The linear, quadratic, exponential, Gompertz, Groot, and Richards models were tested for fitting and estimating the NH3 volatilization. The Gompertz, Groot, and Richards models generated predictions similar to the observed data, with a high determination coefficient, indicating a better fit of these equations to data, with precision and accuracy. However, the Groot model was selected due to the lowest root mean square error of prediction (0.29 % total N lost as NH3). The greatest N loss as NH3 volatilization occurred in the wet, followed by intermediate and dry conditions (20.2, 17.0, and 11.3 % total N lost as NH3, respectively). Therefore, nitrogen losses as NH3 volatilization after application of 50 kg N ha-1, as urea source, are altered according to the weather conditions, reaching 20% of N added in the wet rainfall period. The Groot model is recommended for fitting and estimating the NH3 volatilization from urea applied on Marandu grass pastures in the wet and dry rainfall conditions.

RESUMO: No Brasil, a ureia é o fertilizante nitrogenado mais utilizado para melhorar a produção de forragem. No entanto, seu uso excessivo pode causar impactos ambientais por meio de perdas de nitrogênio (N), como a volatilização da amônia (NH3). Portanto, o objetivo do presente estudo foi ajustar a volatilização de NH3 da ureia aplicada em pastos tropicais em três condições de chuva utilizando modelos matemáticos. Dados foram coletados de pastos de capim-marandu (Brachiaria brizantha) adubado com 50 kg N ha-1 em condições úmidas, intermediárias e secas. A volatilização da NH3 foi medida em cinco câmaras semiabertas durante 21 dias. Os modelos, linear, quadrático, exponencial, Gompertz, Groot e Richards foram testados para ajuste e estimativa da volatilização do NH3. Os modelos de Gompertz, Groot e Richards geraram predições semelhantes aos dados observados, com alto coeficiente de determinação, indicando um melhor ajuste dessas equações aos dados, com acurácia e precisão. No entanto, o modelo Groot foi selecionado devido ao menor erro quadrático médio das predições (0,29% de N total perdido como NH3). A maior volatilização de NH3 ocorreu em condições climáticas úmida, seguido por intermediária e seca (20,2; 17,0 e 11,3% de N total perdido como NH3, respectivamente). Portanto, as perdas de N como volatilização de NH3 após a aplicação de 50 kg N ha-1, como fonte de ureia, são alteradas de acordo com as condições climáticas, atingindo a 20% do N adicionado nas condições úmidas. O modelo Groot é recomendado para ajuste e estimativa da volatilização de NH3 da ureia aplicada em pastos de capim Marandu em condições úmidas e secas.

ABSTRACT: In traditional sheep production systems in tropical regions, the evaluation and monitoring of animal growth are not commonly practiced. This is primarily attributed to the limited adoption of technology and the high costs associated with acquiring livestock scales. The present study developed equations to predict body weight of Pelibuey ewe lambs using a Body Volume (BV) formula. BW and BV were obtained from 85 ewe lambs. The models evaluated were as follows: 1) linear, 2) quadratic, 3) cubic, 4) allometric, 5) exponential and 6) logarithmic. In addition, the models’ predictive ability for BW was assessed by k-fold (k=10) cross-validation. The BW and BV were 20.60 ± 8.73 kg and 17.54 ± 7.89 dm3, respectively. The quadratic model showed the highest r2 and the lowest values of mean square error, root mean square error, and bayesian information criterion, while the k-fold cross-validation technique also had the highest r2 and the lowest values of mean squared prediction error and mean absolute error. The quadratic model was the best performing mathematical model for predicting BW of growing Pelibuey ewe lambs using BV.

RESUMO: Nos sistemas tradicionais de produção de ovinos em regiões tropicais, a avaliação e monitoramento do crescimento dos animais não são práticas comuns. Isso se deve principalmente à adoção limitada de tecnologia e aos altos custos associados à aquisição de balanças para animais. O presente estudo teve como objetivo desenvolver equações para prever o peso corporal (PC) de borregas Pelibuey usando uma fórmula de Volume Corporal (VC). Foram obtidos dados de PC e VC de 85 borregas. Os modelos avaliados foram os seguintes: 1) linear, 2) quadrático, 3) cúbico, 4) alométrico, 5) exponencial e 6) logarítmico. Além disso, a capacidade preditiva dos modelos para o PC foi avaliada por meio de validação cruzada k-fold (k=10). O PC e VC foram 20,60 ± 8,73 kg e 17,54 ± 7,89 dm3, respectivamente. O modelo quadrático apresentou o maior r2 e os menores valores de erro do quadrático médio, raiz do erro do quadrático médio e critério de informação bayesiano, enquanto a técnica de validação cruzada k-fold também teve o maior r2 e os menores valores de erro quadrático médio de predição e erro médio absoluto. O modelo quadrático foi o melhor desempenho matemático para predizer o PC de cordeiras Pelibuey em crescimento usando o VC.

ABSTRACT. This study aimed to perform a strategic diagnosis on a property specialized in breeding, rearing and finishing beef cattle in the southern region of Piauí. It was conducted at Agropecuária Alvorada, located in the countryside, municipality of Bom Jesus, PI, Brazil. The farm develops the full cycle of beef cattle production, which is divided into breeding, rearing and finishing. A SWOT analysis (which stands for Strengths, Weaknesses, Opportunities and Threats) was carried out, consisting of an assessment of the property’s internal and external environments. To evaluate the internal environment, an interview was held for data collection by means of questionnaires. The evaluation included: breeding management, sanitary management, nutritional management, infrastructure, workforce, technologies used in pasture formation, conservation and recovery, pasture management and zootechnical indices. To analyze the external environment, a group of people (experts) with deep knowledge of the subject addressed during the study was used as source of information. A matrix was generated with all the information from the SWOT analysis, strengths, weaknesses, opportunities and threats, culminating with the establishment of strategies to increase the productive efficiency of the cattle raising activity.

ABSTRACT The effects of diets containing oilseeds were measured to evaluate the productive and economic parameters in the finishing of young, feedlot Nellore bulls. Twenty-four young Nellore bulls were used, with an initial body weight (BW) of 311.46±0.37 kg and 24 months of age, distributed into individual stalls ( 4 × 20 m) in a completely randomized design, totaling four treatments with six repetitions per treatment. Four diets (control, based on corn and soybean meal, and three diets containing cottonseed, soybean, and sunflower) were evaluated. Feed and orts were measured daily to calculate intake and costs. The dry matter intake of the control group was higher than soybean (10.64 kg/day), cotton (9.88 kg/day), and sunflower (9.30 kg/day) treatments, respectively. The cottonseed treatment showed the highest average neutral detergent fiber intake. There was a dietary effect of diets on average daily gain, total weight gain, and final weight. The soybean treatment showed the highest performance, total gain (232.55 kg), and final weight (544.38 kg). Oilseed intake can modify the fatty acids profile in the meat, decreasing its saturated fatty acid content. Whole soybean seed favors performance, improves feed efficiency, fatty acid profile, and fat distribution in the carcass, and can reduce production costs.

Resumen Este estudio se llevó a cabo para evaluar el tiempo para el establecimiento de gramíneas forrajeras tropicales en el bioma del “Cerrado”, con base en rasgos morfogenéticos y estructurales. Se distribuyeron tres cultivares (Paiaguás, Ipyporã y Marandu) de Brachiaria brizantha (Sin. Urochloa brizantha) y dos cultivares (Quênia y Tamani) de Panicum maximum (Sin. Megathyrsus maximus) en un diseño de bloques al azar con cuatro repeticiones. Los rasgos morfogenéticos y estructurales del pasto se evaluaron desde el día 35 hasta el día 65 después de la siembra, a intervalos de siete días. La altura del dosel aumentó linealmente con el período de establecimiento, en todos los cultivares. En los cultivares de Megathyrsus, la densidad de macollos disminuyó a medida que avanzaba el período experimental, mientras que el número de macollos en los cultivares de Urochloa aumentó. Los cultivares Ipyporã y Marandu tuvieron las tasas más altas de aparición foliar. Las tasas de elongación foliar más bajas se presentaron en los cultivares Paiaguás, Ipyporã y Tamani, y las tasas de elongación más altas en el cv. Quênia. Como resultado, el cv. Quênia mostró los valores más altos de longitud foliar final (64.9 cm) y masa de lámina foliar (3,352.9 kg MS ha-1). La mayor tasa de senescencia del cv. Tamani (2.1 cm macollo-1 d-1) dio como resultado que el mayor porcentaje de material muerto (1,815.5 kg ha-1) se encontrara en la masa de forraje de este cultivar. Los cultivares Paiaguás, Marandu y Tamani se establecieron a los 44 d, mientras que los cv. Quênia e Ipyporã se establecieron a los 51 y 58 días después de la siembra, respectivamente, en el Cerrado brasileño.

Abstract This study was carried out to evaluate the time for the establishment of tropical forage grasses in the “Cerrado” biome, based on morphogenetic and structural traits. Three Brachiaria brizantha (Syn. Urochloa brizantha) cultivars (Paiaguás, Ipyporã and Marandu) and two Panicum maximum (Syn. Megathyrsus maximus) cultivars (Quênia and Tamani) were distributed in a randomized-block design with four replicates. Morphogenetic and structural traits of the pasture were assessed from d 35 to d 65 after sowing, at seven-day interval. Canopy height rose linearly with the establishment period, in all cultivars. In the Megathyrsus cultivars, tiller density decreased as the experimental period progressed, whereas the number of tillers in the Urochloa cultivars increased. The cultivars Ipyporã and Marandu had the highest leaf appearance rates. The lowest leaf elongation rates occurred in the cultivars Paiaguás, Ipyporã and Tamani, and the highest elongation rates in cv. Quênia. As a result, cv. Quênia showed the highest values of final leaf length (64.9 cm) and leaf blade mass (3,352.9 kg DM ha-1). The higher senescence rate of cv. Tamani (2.1 cm tiller-1 d-1) resulted in the highest percentage of dead material (1,815.5 kg ha-1) being found in the herbage mass of this cultivar. Cultivars Paiaguás, Marandu and Tamani were established at 44 d, whereas cv. Quênia and Ipyporã were established at 51 and 58 d after sowing, respectively, in the Brazilian Cerrado.

Abstract This research article describes the effect of different concentrations of iodine in the teat-dipping before milking and post-dipping solution on milk, urine, thyroid hormone, chemical composition and somatic cell count. Four multiparous cows were distributed in a 4 x 4 Latin square experimental design in a tie-stall system. The treatments were 0.5%, 1%, and 2% iodine and the control was treated with chlorhexidine. The iodine concentration of milk, food and urine was quantified. Thyroid hormones were analyzed by chemiluminescence microparticle immunoassay. Milk composition by differential absorption of infrared waves and somatic cell countby (SCC) flow cytometry. There was no significant effect of iodine concentrations in teats soaking solution before milking on urine iodine concentration and thyroid hormones (T3 and T4). Likewise, no effect of treatments was observed for the contents of protein, fat, lactose, total solids, Milk urea nitrogen and SCC. However, increasing iodine concentrations in the teat soaking solution before milking linearly increased the iodine concentration in milk. Therefore, the iodine concentration in the pre-milking and post-dipping solutions can change the iodine concentration in the milk.

ABSTRACT This study examined the effect of different supplementation strategies for ewes in the last third of gestation, kept on a deferred Brachiaria brizantha cv. Marandu pasture, on their performance and the growth curve of their lambs. A total of 54 ewes, of no defined breed, with an average weight of 41.10±3.10 kg, were used in a completely randomized design, divided into three groups (18 ewes per treatment). In total, 61 lambs were born, 28 females and 33 males, with 3.70±0.55 and 3.68±0.69 kg birth weight, respectively. Treatments were as follows: multiple mixture ad libitum, concentrate supplement at 0.4% live weight (LW), and concentrate supplement at 0.8% LW. Average daily weight gain (ADG, g/animal/day) and total weight gain (TWG, kg/animal) were evaluated in ewes and lambs. Reproductive efficiency indices were measured in the ewes and biometric variables in the lambs. The ADG and TWG of ewes in the last third of gestation were higher in animals supplemented at 0.8% LW. Reproductive efficiency results were superior in ewes supplemented at 0.4% LW. The effect of ewe supplementation on lamb growth curve as estimated by the Gompertz model did not reveal differences between the curves of lambs born to ewes that received supplementation at 0.4 and 0.8% LW. However, supplementing ewes with a multiple mixture induced a reduction in the growth curve parameters of their lambs. The use of concentrated supplementation, at levels of 0.4 and 0.8% of LW, provides greater productive and reproductive performance for ewes and lambs.

RESUMO: O objetivo foi avaliar os efeitos das doses anuais de 100 e 200 kg ha-1 de nitrogênio (N) sobre as características morfogênicas e estruturais do capim-ipyporã, em lotação intermitente durante as estações do ano. O delineamento experimental foi em blocos ao acaso, com dois tratamentos e três repetições de área. Os pastos de capim-ipyporã foram submetidos ao pastejo por bovinos de corte. Foram avaliadas as características morfogênicas e estruturais do dossel forrageiro por meio da técnica de perfilhos marcados. Também foi avaliado o acúmulo de forragem e a densidade populacional de perfilhos (DPP). Foi observada interação significativa (P < 0,05) das doses de N e estações do ano para o período de descanso (PD), duração de vida das folhas (DVF), filocrono, taxa de alongamento de colmos (TAlC) e comprimento final das folhas (CFF). Durante o inverno, o PD foi menor (40 vs 50 dias) nos pastos adubados com 200 kg ha-1 de N. Em contra partida, no inverno, os pastos adubados com 100 kg ha-1 de N apresentaram maiores valores para DVF, filocrono e TAlC, e menores para o CFF. Não foi observado efeito isolado de doses de N (P > 0,05) para as taxas de acúmulo de forragem; de aparecimento, alongamento e de senescência de folhas, relação folha:colmo e para a DPP. No entanto, o efeito das estações foi significativo para estas variáveis, com os maiores valores observados durante a primavera e verão. O uso de 200 kg ha-1 de N para pastos de capim-ipyporã promove redução da estacionalidade de produção da forrageira.

ABSTRACT: This study examined the effects of annual nitrogen (N) rates of 100 and 200 kg ha-1 on the morphogenetic and structural traits of Ipyporã grass (Brachiaria brizantha × Brachiaria ruziziensis) under intermittent grazing during the seasons of the year. The experiment was laid out in a randomized-block design with two treatments and three area replicates. Ipyporã grass pastures were grazed by beef cattle. Morphogenetic and structural traits of the forage canopy were evaluated using the marked-tiller technique. Forage accumulation and tiller density (TD) were also evaluated. Significant interaction effects (P < 0.05) between N rates and seasons were observed for the rest period, leaf lifespan (LLS), phyllochron, stem elongation rate (SER) and final leaf length (FLL). During winter, the rest period was shorter (40 vs. 50 days) in the pastures fertilized with 200 kg ha-1 N. Conversely, in winter, the pastures fertilized with 100 kg ha-1 N showed higher LLS, SER and phyllochron values, but lower FLL values. There was no isolated effect of N rates (P > 0.05) on forage accumulation rate; leaf appearance, elongation or senescence rates; leaf:stem ratio; or TD. However, the effect of seasons was significant for these variables, with the highest values occurring during spring and summer. The use of 200 kg ha-1 N in Ipyporã grass pastures reduces the seasonality of forage production.

RESUMO: Este trabalho teve como objetivo avaliar o efeito da calagem (com e sem) e do biocarvão (com e sem) sobre o crescimento e a produção de forragem do sorgo forrageiro cv. BRS Ponta Negra e nas propriedades químicas do Neossolo Quartzarênico no ambiente Semiárido. O delineamento experimental foi em blocos casualizados, com tratamentos em esquema fatorial 2x2, correspondendo a aplicação ou não do calcário (0 e 2,5 t ha-1) e do biocarvão (0 e 12,5 t ha-1). O biochar era produzido a partir de galhos de caju. O experimento foi conduzido em parcelas de 16 m² onde foi cultivada a cultivar de sorgo forrageiro BRS Ponta Negra. Foram avaliadas as características químicas do solo, os atributos de produção e as características estruturais da cultivar de sorgo estudada. Não houve interação entre os fatores. O uso do biochar aumentou o pH e os teores de Ca e P no solo e contribuiu para o aumento da massa da panícula (2,51 t ha-1 de MS). A aplicação de calcário afetou o teor de Ca no solo, assim a dose de 2,5 t ha-1 resultou em maiores valores de diâmetro do colmo (15,25 mm), massa da panícula e massa do colmo (2,63 e 7,50 t ha-1 de MS, respectivamente). Portanto, esses resultados permitem traçar estrategias de uso do calcário e biochar para produção forrageira em ambientes semiáridos com solos arenosos. Pois, esses materias melhoram alguns atributos quimicos do solo e a produção do sorgo forrageiro. Vale ressaltar que as condições edofoclimáticas podem alterar os padrões de resposta observados nesta pesquisa. Portanto, a pesquisa em outras regiões é essencial.

ABSTRACT: This research evaluated the effect of liming (with and without) and biochar (with and without) on sorghum cv. BRS Ponta Negra growth and Arenosol chemical properties in the Semiarid environment. The experimental design was in randomized blocks, with treatments in a 2x2 factorial scheme, corresponding to the application or not of lime (0 and 2.5 t ha-1) and biochar (0 and 12.5 t ha-1). Biochar was produced from cashew branches. The experiment was conducted in 16 m² plots where the forage sorghum cultivar BRS Ponta Negra was cultivated. The soil chemical characteristics, the production attributes, and the structural characteristics of the sorghum cultivar studied were evaluated. There was no interaction between factors. The use of biochar increased the pH and Ca and P contents in the soil and contributed to increasing the panicle mass (2.51 t ha-1 of DM). Lime application affected the soil Ca content as the dose of 2.5 t ha-1 resulted in higher values of culm diameter (15.25 mm), panicle mass, and culm mass (2.63 and 7.50 t ha-1 of DM, respectively). Therefore, these results allowed to outline strategies for the use of limestone and biochar for forage production in semiarid environments in sandy soils. Because, these materials improve some chemical attributes of the soil and the production of forage sorghum. It is noteworthy that edophoclimatic conditions can change the response patterns observed in this research. Therefore, research in other regions is essential.

Abstract Our hypothesis was that different sources of unsaturated fatty acids from oilseeds (sunflower, soybeans, and cottonseed) could alter milk yield, fatty acid profile, and the amount of unsaturated fatty acids yielded in milk. It aimed to evaluate the effects of lipid sources on yield and composition and fatty acids in milk of primiparous Girolando cows. Five cows in lactation (35 ± 8 days), with 410 ± 7.15 kg BW were randomly distributed in a 5 x 5 Latin square. Five experimental diets, namely a control diet without an additional source of lipid and four diets with different lipid sources: cottonseed, sunflower seed, whole soybean, or soybean oil, as lipid source, to reach 70 g/kg of ethereal extract dry matter basis were used. Cottonseed and soybean oil addition reduced daily yield by 15 and 22%. Oilseed can alter fatty acid profile in milk. Whole soybean provided greater daily milk and fatty acids yields.

Abstract Thirty-two Santa Inês male lambs, not castrated, were distributed in a randomized block design to evaluate the effects of different tropical forage cultivars (two Panicum maximum (Syn. Megathyrsus maximus): Aruana and Massai, and two Brachiaria brizantha (Syn. Urochloa brizantha) Marandu and Piatã) on carcass characteristics, quality, physical composition, and meat chemistry. The data were subjected to an analysis of variance, and the means compared using the Tukey test at 5% significance. There was no effect of cultivars on body weight, slaughter weight, and biometric measurements of the carcass. The Aruana and Piatã cultivars provided higher weights of hot and cold carcasses when compared to the Massai and the Marandu had no significant differences compared to the others. The animals kept in the pasture of the Aruana cultivar showed higher shank yields. However, forage cultivars did not affect the ribeye area or subcutaneous fat thickness. There was also no effect of cultivar on pH, temperature, cooking losses, cooling losses, and meat shear strength. The cultivars did not change the quality and composition of the meat. However, the Aruana, Piatã, and Marandu cultivars were the ones that provided higher carcass weights and ham yields.

Abstract We hypothesize that lambs fed diets with different lipids sources from oilseeds would similar performance but fatty acids profile of meat superior to those fed with conventional diets. We evaluated the effects of inclusion of oilseeds on the ingestive behaviour, performance, carcass trait and meat quality in feedlot lambs. Three isonitrogenous (18.31% crude protein) diets were evaluated, where one diet was the standard (control), and the others two diets contained soybean and cottonseed. Fifteen Texel lambs, weighting 28.5 ± 1.65 kg were distributed in a completely randomized design by 56 days. Animals fed soybean diet demonstrated greater final body weight when compared to animals fed cottonseed diet and standard diet. The inclusion of cottonseed provided lower average daily gain and total weight gain. Ingestive behaviour of the animals fed diets with grains resulted in greater rumination time. Lambs fed cottonseed diet spent greater time during rumination and presented greater number of chews/day. The hot carcass and cold carcass weight presented lower values in animals fed cottonseeds diet. There was no significant difference in meat for marbling, maturity, fat texture and shear force. Meat from animals fed soybean diet had highest fat content. There was a diet effect for fatty acids composition in the meat. Meat of lambs treated with soybean have greater amounts for fatty acids mostly the unsaturated ones, related to the decrease in cholesterol levels, and lower risk of cardiovascular diseases, thus, lambs fed soybean enrich meat produced with fatty acids that benefit human health.

RESUMO O objetivo deste trabalho foi avaliar o efeito da inclusão de polpa cítrica na silagem de milho sobre a composição química e parâmetros de fermentação. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. Os tratamentos foram: Silagem de milho sem polpa cítrica (0%); silagem de milho com 10% 39 de polpa cítrica; silagem de milho com 20% de polpa cítrica; silagem de milho com 30% de polpa cítrica; silagem de milho com 40% de polpa cítrica e silagem de milho com 50% de polpa cítrica. O pH diminuiu linearmente com à inclusão de polpa cítrica, gerando valores distantes do considerado adequado (3,8 a 4,2). Por outro lado, é possível inferior que nem todos os parâmetros fermentativos foram comprometidos, uma vez que, com a inclusão de 33% de polpa cítrica, é possível estimar 30,82 g/kg total N. Com a utilização 45 de 49% de polpa cítrica, é possível obter 95,16 g/kg de proteína bruta. De 21% a 22% de polpa cítrica, foi obtido 549,89 g/kg de fibra em detergente neutro e 678,11 g/kg de nutrientes digestíveis totais. A inclusão de até 30% de polpa cítrica melhorará significativamente a composição química da silagem de milho, devido à redução nos valores de carboidrato estrutural e aumentos nos nutrientes digestíveis totais e proteína.

ABSTRACT The objective of this study was to evaluate the effects of including citrus pulp in maize silage on chemical composition and fermentation parameters. The experimental design was fully randomized with four replicates. Maize silage consisting of 0–50% citrus pulp was produced and analyzed. The pH linearly decreased with the increased inclusion of citrus pulp (3.49 at 50% citrus pulp), which is far below what is considered adequate (3.8–4.2). However, not all fermentation parameters were compromised. At 33% citrus pulp, we estimated 30.82 g/kg total nitrogen. At 49% citrus pulp, we estimated 95.16 g/kg of crude protein. At 21% and 22% citrus pulp, we estimated 549.89 g/kg of neutral detergent fiber and 678.11 g/kg of total digestible nutrients, respectively. Therefore, we conclude that the inclusion of up to 30% citrus pulp improves the complete chemical composition of maize silage owing to the reduction in structural carbohydrate values and increases in total digestible nutrient and protein content.