Hepatogenic photosensitization in lambs supplemented with different levels of extruded urea in Brachiaria spp. pastures in the Brazilian Cerrado: Case report.

The aim was to report cases and risk factors for hepatogenous photosensitization in lambs kept on Brachiaria spp. pastures and supplemented with levels of extruded urea (EU). The herd consisted of 69 Texel crossbred lambs with known parentage (fathers and mothers adapted to the consumption of forage of the genus Brachiaria), randomly divided into 5 groups and distributed in individual paddocks for each group. The animals were supplemented with increasing levels of EU (Amireia® 200S): 0, 6, 12, 18, and 24 g of EU per 100 kg-1 of body weight (BW). The concentration of protodioscin was estimated in the mixed pastures of Brachiaria spp. (cv. Marandu and cv. Basilisk), structural components (leaf, stem, and dead material), samples of each cultivar, and in the months of December (2018), February, and April (2019). The animals were examined daily, and when behavioral changes were identified, they underwent clinical examinations and anamnesis. Weighing was performed every 14 days, followed by necropsy and serum biochemical analysis, including gamma-glutamyltransferase (GGT). The highest concentrations of protodioscin (p < 0.0001) were found in the pastures used by animals supplemented without extruded urea (7.07 ± 0.56), in the Basilisk cultivar (11.35 ± 0.06), in the leaf blade components (2.08 ± 0.05), and thatch (2.20 ± 0.00), and in the month of April (7.34 ± 0.29) (the month with the lowest rainfall), respectively. Fourteen (20.29%) cases of photosensitization were observed in lambs, of which six recovered, and eight died. Serum GGT levels ranged from 42.2 to 225 IU/L; however, in animals that died, values ranged from 209.4 to 225 IU/L. The use of levels 12 g and 18 g per 100 kg-1 of body weight of extruded urea may contribute to the lower occurrence of photosensitization, as the animals selected pastures with lower protodioscin content, presenting a smaller number of cases.

Association of rainfall pattern with the disappearance of mineral mixtures fed cattle managed on tropical pastures.

The objective of the present study was to evaluate the association between rainfall and the disappearance of mineral mixtures in the supplementation of cattle on pasture. Supplement consumption and rainfall data were obtained from five experiments carried out between 2016 and 2022. The experiments lasted from 84 to 126 days and had 12 to 18 paddocks formed by Brachiaria spp. under grazing by beef cattle (n = 544), receiving mineral supplementation. Supplement disappearance (SD), difference between the amount offered and leftovers (considering intake and losses) and precipitation (PR), was measured over periods of 14 to 21 days. The periods (n = 565) were classified as very dry, dry, normal, rainy, and very rainy, using the Quantis method. The number of rainy days (RD) and the average precipitation per RD (APRD) per period and the average body weight (BW) of the animals in the periods were also determined. Linear regression analyses assessed the association between BW, PR, RD, and APRD. The average PR in the periods studied was 68.5 mm, ranging from 0.00 to 160.3 mm. Each period had up to six RD, with up to 129.5 mm precipitated. The average BW was 270 kg, ranging from 208 to 335 kg and the average SD was 82.2 g/animal/day, ranging from 0.52 to 176.7 g/animal/day. Differences in RD and APRD are consistent across precipitation classes. In the regression analysis, the model with the highest coefficient of determination was the one that contained the linear and quadratic terms for the RD variable. Including linear and quadratic terms of all variables in a multiple regression represented more than half of the variation in the disappearance of the supplement (R2 = 0.5823). There is no clear relationship between the intensity of precipitation, reflected in the form of classes, and the disappearance of supplements offered to cattle on pasture since dry and very rainy periods can be equivalent. However, variables that characterize the precipitation pattern are more relevant than animal live weight to explain existing variations in supplement disappearance. Among them, the frequency with which precipitation occurs (number of rainy days in the period) seems to be more important than the precipitation rate itself, probably because it is related to the volume of precipitation accumulated in the period.

Metabolic responses and performance of Holstein × Gyr heifers grazing Brachiaria decumbens supplemented with varied crude protein levels.

We aimed to evaluate the effect of supplemental CP on the nutritional characteristics and performance of Holstein × Gyr crossbreed heifers grazing intensively-managed Brachiaria decumbens throughout the year. Thirty-eight heifers with average initial body weight of 172.5 ± 11.15 kg (mean ± SE) and 8.2 ± 0.54 mo of age were randomly assigned to four treatments: three protein supplements (SUP) composed of soybean meal and ground corn fed at 5g/kg of BW, plus a control group (CON). The supplements had 12, 24 and 36% of CP for treatments S12 (n = 9), S24 (n = 10), and S36 (n = 9), respectively. The experiment latest one year, subdivided into four seasons: rainy, dry, rainy-dry transition (RDT), and dry-rainy transition (DRT). Feces and pasture samples were collected for 4 days in each season, using chromium oxide, titanium dioxide, and indigestible neutral detergent fiber (NDF) to estimate fecal excretion, supplement, and pasture intake, respectively. The data were analyzed using PROC GLIMMIXED of the SAS with repeated measures. No effects of supplementation were detected on pasture and NDF intake. However, SUP animals had a greater intake of DM, metabolizable energy, and metabolizable protein. A positive linear response on metabolizable protein intake was observed among SUP animals. We observed an interaction between treatment and season for all digestibility variables, with a positive linear response in CP digestibility among SUP animals during all seasons. For neutral detergent fiber (NDF) digestibility, we observed a positive linear response in RDT and rainy seasons and a quadratic response during the dry season. Furthermore, SUP animals had greater average daily gain (ADG) than non-supplemented animals, and among SUP animals, there was a quadratic response to ADG, with the greatest gain observed in S24. We observed greater nitrogen retention coefficient in SUP animals than in non-supplemented animals and a positive linear effect among SUP animals. Supplemental CP did not affect microbial protein production and efficiency. We observed an interaction between treatment and season for blood glucose, with SUP animals having greater glucose concentration in all seasons than non-supplemented animals. Additionally, we observed a quadratic response among SUP animals only during RDT and dry season, with the greatest glucose concentration in S24. SUP animals had greater blood concentrations of urea and IGF-1. In conclusion, SUP animals had greater intake, digestibility, and performance than non-supplemented animals, with the 24% CP supplement demonstrating the best metabolic responses and performance.

Inclusion of palm kernel cake in the supplement reduces nutrient digestibility but does not interfere with the performance of steers finished on tropical pasture.

The aim of this study was to evaluate the effect of increasing inclusion levels of palm kernel cake (PKC) in the supplement of steers finished on a Urochloa brizantha cv. Marandu pasture on intake, digestibility, feeding behavior, weight gain, and carcass traits. Forty 1/2 Holstein × 1/2 Zebu crossbred steers with an average body weight of 352.80 ± 3.32 kg, at 36 months of age, were supplemented with concentrate at 0.4% of their body weight. Four treatments were formulated (supplement containing 0, 15, 30, or 45% PKC, dry matter [DM] basis) and the animals were monitored for 240 days, weighed, and slaughtered. The inclusion of PKC in the supplement did not influence the intakes of total DM, crude protein, or neutral detergent fiber, but increased (P < 0.05) ether extract intake and reduced (P < 0.05) non-fibrous carbohydrate intake. The apparent digestibility of DM, crude protein, and neutral detergent fiber decreased (P < 0.05), whereas intake and rumination efficiencies by the dietary treatments. Average daily gain, carcass weight, and backfat thickness did not change in response to the inclusion of PKC in the supplement. We recommend the inclusion of 45% palm kernel cake in the concentrate of steers supplemented at 0.4% of their body weight and finished on Urochloa brizantha cv. Marandu pasture.

Effect of Brachiaria decumbens as a novel supplementation on the production performance of broiler chickens.

The primary goal of this research was to elucidate the novel influence of Brachiaria decumbens supplementation on broiler chicken growth performance, nutritional digestibility, cecal microbiota, intestinal histomorphology, carcass characteristics, and meat quality. A total of 300 male day-old Ross 308 broiler chickens were randomly subjected to six different treatment groups having five replicates per treatment with 10 birds in each replicate. In treatment 1, broiler chickens were fed commercial diets with no added additives; in treatment 2, broiler chickens were offered commercial diets containing 100 mg/kg of the antibiotic oxytetracycline. However, in treatments 3, 4, 5, and 6, broiler chickens received similar commercial diets supplemented with 25 mg/kg, 50 mg/kg, 75 mg/kg, and 100 mg/kg of B. decumbens ground leaf powder, respectively, without antibiotics. Throughout the 42-day trial, the body weight gain and total feed intake for each replicate were recorded every week to determine the growth performance. Then, on 21th and 42nd day, ten broilers from each treatment (two in each replicate) were randomly selected and slaughtered to assess the digestibility of nutrients, histomorphology of the small intestine, the population of the cecal microbiota, carcass characteristics, as well as quality of both breast and drumstick muscle. There were differences (p < 0.05) in the growth performance, apparent ileal nutrient digestibility, intestinal histomorphology, carcass characteristics, and meat quality. Animals supplemented with 25 mg/kg of B. decumbens had higher growth performance and better ileal nutrient digestibility of protein, fiber, and ether extract, as well as higher villi height and carcass percentage with superior meat quality. Besides, the growth of E. faecalis during the starter phase was inhibited. In summary, B. decumbens supplementation at 25 mg/kg may be suggested as an optimal dose of as a prophylactic as well as an alternative for antibiotic growth promoter in stimulating the productivity of commercial broilers. This unconventional phytobiotic supplementation could be the key to replacing unnecessary antibiotics used in poultry feed.

Economic impact of poisoning by Brachiaria grass in lambs from birth to finishing receiving to different levels of supplementation.

This study aims to evaluate the economic impact of poisoning by Brachiaria grass in lambs from birth to weaning (suckling) and from weaning to slaughter (finishing) different levels of energy protein supplementation (EPS). In addition, we estimated the economic efficiency of removing lambs from the pasture as a control measure to minimize the losses caused by Brachiaria grass poisoning. Seventy lambs were used in the suckling phase, distributed in two nutritional treatments (control and creep feeding). Hospitalization expenses were US$ 1580.80 for the control treatment and US$ 256.16 for the creep feeding treatment. In the finishing phase, 48 lambs were distributed in four nutritional treatments, which consisted of increasing levels of EPS (mineral salt, 0.8, 1.6 and 2.4% of LW). The largest difference in total revenue (US$) was observed between 2.4% of BW EPS and mineral salt (- 2300.28) treatments. Hospitalization expenses were similar between nutritional treatments, being higher in the treatment 1.6% of BW EPS (US$ 578.15). The biggest difference in gross income (US$) observed was between 2.4% of BW EPS and mineral salt (- 1439.43) treatments. The Brachiaria grass poisoning caused economic losses to the sheep farming system, due to the death of lambs, reduced weight gain and lower weights at weaning and in the finishing phase. Brachiaria grass poisoning caused economic damage to the production system. There were direct losses, with the death of the lambs without supplementation, in the suckling and finishing phases. The supplementation increases the performance and reduces the mortality. The supplementation in high levels is efficient in reducing the economic impact of poisoning by Brachiaria grass in both periods of suckling and finishing.

Botanical and chemical fungicides in the treatment of commercial seeds of Brachiaria brizantha and Panicum maximum.

Brazil is the largest producer, consumer, and exporter of forage seeds in the world. However, the high incidence of pathogens threatens the seed production system, resulting in decreases in production and quality. Currently, the emphasis has been placed on the use of alternative products as a way of maintaining productivity and environmental sustainability. Thus, the objective of this study was to evaluate the mycoflora associated with the commercial seeds of Brachiaria brizantha and Panicum maximum treated with chemical and alternative fungicide. To test with chemical and alternative treatments, seeds were subjected to fluazinam + thiophanate-methyl, fludioxonil + metalaxyl-M, noni essential oil, rosemary pepper essential oil, sulfuric acid. There was also an untreated control. The most efficient products in the control of incident fungi were, in decreasing order, fluazinam + thiophanate-methyl, fludioxonil + metalaxyl-M, noni essential oil, rosemary pepper essential oil, and sulfuric acid. Fungicides mainly controlled the genera Alternaria, Aspergillus, Bipolaris, Chaetomium, Cladosporium, Colletotrichum, Curvularia, Fusarium, Penicillium, Phoma and Rhizopus. Essential oils showed positive effects in controlling Bipolaris, Curvularia, and Fusarium. Sulfuric acid reduced the incidence of Bipolaris, Colletotrichum, Curvularia, Fusarium, Phoma, and Rhizopus. Seed treatment is one of the promising strategies for obtaining seeds of a healthy quality. As a result, the fungicides and botanical components listed above were promising in reducing fungi associated with forage seeds and can be used for seed treatments and in the development of new products with a natural base through essential oils.

AM fungi mediated bioaccumulation of hexavalent chromium in Brachiaria mutica-a mycorrhizal phytoremediation approach.

The experiment was designed to evaluate the roles of Rhizophagus irregularis on chlorophyll fluorescence and chromium bioaccumulation in a grass species (Brachiaria mutica) by supplementing Cr+6 at different concentrations. Arbuscular Mycorrhizal Fungi (AMF) association facilitated lessening of chromium level in contaminated soil and enhanced chromium bioavailability in Brachiaria mutica. The mycorrhizal inoculated increased the chlorophyll (0.925 mg/g), carotenoid (0.127 mg/g), protein (2.883 mg/g), proline (0.889 mg/g) contents and activities of antioxidant enzymes like catalase, ascorbate peroxidase and glutathione peroxidase. The mycorrhizal inoculated plants also showed enhanced overall photosynthetic performance (PIϕ = 2.473) and enhanced PS-II to PS-I electron transport as evident from yield parameter (0.712) and TR0/RC (2.419) for 60 mg/kg Cr+6 treatment. The observations suggest that AMF association could defend the plants from chromium stress by elevating the number of antioxidants in plants. Rhizophagus irregularis was found to maintain a successful symbiotic relationship with Brachiaria mutica in chromium contaminated soil. The observations recommended that Rhizophagus irregularis in association with Brachiaria mutica would be an innovative approach for decontamination of Cr+6.

Carcass traits and meat quality of Texel lambs raised in Brachiaria pasture and feedlot systems.

Our hypothesis suggests an improvement in carcass and meat quality of pasture-finished animals by introducing concentrate feed into diets. This study aimed to evaluate the effect of different levels of protein-energy supplementation on carcass and meat characteristics of Texel lambs raised on Brachiaria pastures, and compare the results with those obtained from confined animals. Thirty 2-month-old intact lambs were divided into five treatments: pasture with mineral supplementation, pasture containing daily supplies of 0.8, 1.6, and 2.4% BW protein-energy supplementation, and confinement (reference treatment). All animals were slaughtered 104 days after the beginning of the experiment. Lambs submitted to 1.6% and 2.4% BW supplementation presented similar characteristics to animals kept in confinement and were superior to animals treated with 0 or 0.8% of BW supplementation levels (p < .05). Increases of subcutaneous fat thickness were verified for 0.0, 0.8, 1.6, 2.4% BW, and confinement treatments, being respectively of 0.25, 0.74, 1.61, 1.69, and 1.98. Conversely, treatments had no influence on meat physical-chemical characteristics, being all considered moderately soft, juicy (tender), and with mild tastes and odors. Lambs raised on Brachiaria pastures have high-quality meat, but more protein-energy supplementation is needed to be an alternative for the feedlots for young animals.

Evaluation of the Phytotoxicity of Urochloa humidicola Roots by Bioassays and Microscopic Analysis. Characterization of New Compounds.

Herbicides are a key element in agriculture but they do cause environmental problems and natural alternatives are being sought. In this context, invasive plants could provide an as yet unexplored source for the development of future herbicides. Urochloa humidicola has great invasive potential in Brazilian environments as it hampers the establishment of other plants. The phytotoxicity of U. humidicola root extracts has been evaluated, and the major components have been identified. The phytotoxicity of the extract was assessed in the wheat coleoptile assay on seeds of troublesome weeds and on Anadenanthera colubrina, a tree species used in ecological restoration programs. The ethyl acetate extract showed the highest activity, and the most affected weeds were E. crus-galli, M. maximus, and A. viridis with the latter weed more affected by the extract than by the herbicide Logran. Microscopic ultrastructural analysis of A. colubrina roots indicated possible signals of cell death. Seven compounds were identified in the ethyl acetate extract of which one diterpene and four saponins are new. Six of these compounds were tested in the wheat coleoptile bioassay. The most active were diterpene 1 and saponins 2, 3, and 6. The phytotoxic activity of U. humidicola explains the issues observed in ecological restoration with A. colubrina in the presence of Urochloa species, and its effect on weeds reinforces its potential use in agriculture.

Performance, body composition and net requirements of protein and energy for weight gain in steers supplemented with or without addition of lipids / Desempenho, composição corporal e exigências líquidas de proteína e energia para ganho de peso em novilhos suplementados com ou sem adição de lipídios

This research aimed to evaluate the performance, body composition and net requirements for protein and energy in grazing Nellore steers supplemented with or without addition of lipids. Twenty-eight steers, 301 ± 5.8 kg BW, were used in the experiment. The comparative slaughter method was used, with four steers used as references. The remaining 24 steers were randomly distributed into four groups, during 180 days, according to treatment: only Panicum maximum cv. Mombasa grass; Mombasa grass with concentrated supplementation based on soybean meal; Mombasa grass with concentrate containing lipids from soybean oil; and Mombasa grass with concentrate containing lipids derived from soybean grains. The total DMI of the steers fed only the pasture did not differ (P > 0.05) from the average intake of the treatments with or without addition of lipids. There were no differences (P > 0.05) between treatments for total daily gain, carcass and non carcass for protein, energy and fat. The requirements of protein and energy did not differ (P > 0.05) among the treatments. When the pasture is of good quality, supplementation does not alter the body composition or the net requirements of protein and energy for weight gain. The supplementations with higher concentrations of lipids (oil and grain) were not enough to promote greater gains in fat and energy in carcass.

Esta pesquisa teve como objetivo avaliar o desempenho, composição corporal e requisitos líquidos para proteínas e energia de novilhos Nelore em pastejo suplementados com ou sem adição de lipídios.Foram utilizadas no experimento vinte e oito novilhos, 301 ± 5,8 kg PC. O método comparativo de abate foi utilizado, com quatro novilhos utilizados como referências. Os 24 restantes novilhos foram distribuídos aleatoriamente em quatro grupos, durante 180 dias, de acordo com o tratamento: apenas Panicum maximum cv. Grama Mombasa; Grama de Mombasa com suplementação concentrada à base de farelo de soja; Grama de Mombasa com concentrado contendo lipídios de óleo de soja; e Mombasa com concentrado contendo lipídiosderivados de grãos de soja. O CMS total dos novilhos alimentados apenas com a pastagem não diferiu (P>0,05) da ingestão média dos tratamentos com ou sem adição de lipídios. Não houve diferenças (P> 0,05) entre os tratamentos para o ganho diário total, carcaça e não carcaça para proteínas, energia e gordura. Os requisitos de proteína e energia não diferiram (P> 0,05) entre os tratamentos.Quando a pastagem é de boa qualidade, a suplementação não altera a composição corporal ou os requisitos líquidos de proteína e energia para ganho de peso. As suplementações com maiores concentrações de lipídios (óleo e grão) não foram suficientes parapromover maiores ganhos de gordura e energia na carcaça.

Growth performance and carcass traits of young nellore bulls supplemented with or without addition of lipids / Desempenho e características de carcaça de novilhos Nelore suplementados com ou sem adição de lipídios

The aim of research was to evaluate the performance and characteristics of the carcasses of Nellore young bulls in grazing supplemented with or without addition of lipids. Twenty­eight young bulls, 301 ± 5.8 kg in body weight, which four constituted the reference group and the twenty-four remnants were used in the experiment and randomly distributed into four groups according to treatment: only Panicum maximum cv. Mombasa grass; Mombasa grass with concentrated supplementation based on soybean meal; Mombasa grass with concentrate containing lipids from soybean oil; and Mombasa grass with concentrate containing lipids derived from soybean grains. The total dry matter intake of the animals fed only Mombasa grass did not differ from the average intake of the three treatments supplemented with concentrate. There were no differences (P>0.05) between Mombasa grass and diets with concentrate, supplementation with or without lipid and lipids sources in the carcass traits, gastrointestinal tract, organs and loin eye area. Nellore bulls receiving concentrate increased subcutaneous fat thickness compared with bulls that received only Mombasa grass. Nellore young bulls fed Mombasa grass only, supplemented with or without addition of lipids were similar regarding growth performance and carcass traits

Objetivou-se com esta pesquisa avaliar o desempenho e as características das carcaças de novilhos Nelore em pastejo suplementados com ou sem adição de lipídios. Vinte e oito novilhos, 301 ± 5,8 kg de peso vivo, sendo que quatro constituíram o grupo de referência e os vinte e quatro remanescentes foram utilizados no experimento e distribuídos aleatoriamente em quatro grupos de acordo com o tratamento: somente Panicum maximum cv. capim-mombaça; capim-mombaça com suplementação concentrada à base de farelo de soja; capim-mombaça com concentrado contendo lipídios do óleo de soja; e capim-mombaça com concentradocontendo lipídios derivados de grãos de soja. O consumo total de matéria seca dos animais alimentados apenas com capim-mombaça não diferiu da ingestão média dos três tratamentos suplementados com concentrado. Não houve diferenças (P>0,05) entre capim-mombaça e dietas com concentrado, suplementação com ou sem lipídeos e fontes de lipídeos nas características de carcaça, trato gastrintestinal, órgãos e área de olho de lombo. Os novilhos Nelore que receberam concentrado aumentaram a espessura de gordura em comparação aos novilhos que receberam apenas capim-mombaça. Novilhos Nelore criados em capim-mombaça, alimentados apenas com capim-mombaça ou suplementados com ou sem adição de lipídeos, foram semelhantes quanto ao desempenho de crescimento e características de carcaça.

Removal of phosphorous and nitrogen from wastewater in Brachiaria-based constructed wetland.

Considering the prevalence of eutrophication of water bodies, sustainable treatment technologies like constructed wetlands (CWs) have come up as a promising alternate for nutrient removal and wastewater treatment. The present study was undertaken to investigate the potential of Brachiaria-based constructed wetland for removal of phosphorus and nitrogen in different seasons of a sub-tropical region. The CW cell could efficiently remove phosphate and nitrogen under varying influent concentrations across different seasons. Average removal of total phosphate increased from 55.2% (winter) to 78.5% (spring), 80.7% (autumn), and 85.6% (summer), and maximum removal rate was 384.4 mg/m2-day during the summer season. The soluble/available phosphate was removed on priority owing to its easy bio-availability. The removal efficiency of Brachiaria increased with increasing influent phosphate concentration (5-20 mg/l), if supplemented with nitrogen maintaining the N:P ratio of 5:1. This highlighted the characteristic of Brachiaria to absorb chemical shocks w.r.t. phosphate. The neutral pH (6.2-8.3) and oxidising conditions in rhizosphere ruled out possibility of binding of phosphate with cations (Ca, Fe, and Al) in sediments. Ambient temperature and sunshine hours regulated evapotranspiration and hence nutrient removal. Simultaneous removal of nitrogen (75.6-84.6%) by Brachiaria indicated that it can serve dual purpose of nutrient removal and fodder-production for livestock, thus serving as a sustainable prototype for rural communities in sub-tropical regions.

Ingestive behaviour of steers grazing Brachiaria brizantha cultivar Marandu and in feedlot in Brazil.

The objective of this study was to evaluate the ingestive behaviour of steers grazing Brachiaria brizantha cv. Marandu and in feedlot regimen in Brazil. Fifty crossbred steers, with an average weight of 275 ± 8.18 kg, were distributed in a completely randomised design with five treatments and ten replicates per treatment (mineral supplementation, nitrogen supplementation, and concentrate supplementation at 0.1 and 0.2% of body weight and under feedlot conditions). Ingestive behaviour was assessed every 5 min for 24 h. No difference (P > 0.05) was found for grazing time among grazing systems. Conversely, rumination, idle, feeding, and chewing times showed differences (P < 0.05) only for feedlot animals. The time spent feeding at the trough was higher (P < 0.05) in animals receiving concentrate supplementation. The bite rate and the number of bites per day were similar (P > 0.05) among grazing systems. Feed and rumination efficiencies of dry matter and neutral detergent fibre corrected for ash and protein showed differences (P < 0.05) only in feedlot animals. Therefore, ingestive behaviour of steers varies with the raising system. Overall, feedlot animals showed better performance than grazing animals did, most likely due to longer rest periods.

Aqueous plant extracts in the control of Bidens pilosa L / Extratos aquosos vegetais no controle de Bidens pilosa L

Secondary compounds have allelopathic action on germination and growth, and initial development of seedlings and beggar tick can have its germination and growth affected by the action of allelopathic extracts. Thus, this work aimed to evaluate the allelopathic potential of Brachiaria (Brachiaria brizantha), sunflower (Helianthus annuus) and sorghum extracts (Sorghum bicolor) on germination and initial growth of beggar ticks (Bidens pilosa). For this, an experiment was conducted in a completely randomized design with four treatments and six replicates and brachiaria, sunflower and sorghum extracts and control (distilled water) treatments. Extracts were obtained using 200 g of plant material and 1,000 mL of distilled water. Seeds were distributed in gerbox containing two sheets of germitest paper moistened with treatments and taken to germination chamber. Germination was daily monitored, and ten days after, initial growth was evaluated. Extracts did not reduce germination. However, they caused increase in germination time, mainly by brachiaria extract. Seedlings submitted to brachiaria and sorghum extracts showed lower growth. Brachiaria and sorghum extracts showed no action on germination, but controlled the initial growth of beggar tick, being potential natural herbicides.(AU)

Compostos secundários têm ação alelopática sobre a germinação, crescimento e desenvolvimento inicial de plântulas, e a Bidens pilosa pode ter sua germinação e crescimento afetados pela ação dos extratos alelopáticos. Nesse sentido, objetivou-se avaliar o potencial alelopático de extratos de braquiária (Brachiaria brizantha), girassol (Helianthus annus) e sorgo (Sorghum bicolor) na germinabilidade e no crescimento inicial de picão-preto (Bidens pilosa). Para isso foi instalado um experimento no delineamento inteiramente casualizado, com quatro tratamentos e seis repetições, sendo eles extrato de braquiária, girassol, sorgo e o controle (água destilada). Os extratos foram obtidos utilizando 200 g de material vegetal fresco para 1.000 mL de água destilada. As sementes foram distribuídas em caixa gerbox contendo duas folhas de papel germitest umedecidas com os tratamentos e levadas para a câmara de germinação. Foi acompanhada diariamente a germinação e, após 10 dias, foi avaliado o crescimento inicial. Os extratos não causaram prejuízos à germinação, porém, provocaram demora em seu tempo de eclosão, sendo o extrato de braquiária o mais prejudicial. As plântulas submetidas aos extratos de braquiária e sorgo apresentaram menor crescimento. Os extratos de braquiária e sorgo não apresentaram ação sobre a porcentagem de germinação das sementes de picão-preto, mas controlaram o crescimento inicial das plântulas e podem ser indicados para possíveis herbicidas naturais.(AU)

Biological and economic performance of genetic groups under different diets / Desempenho biológico e econômico de grupos genéticos sob diferentes dietas

A grazing trial to evaluate biological and economic efficiencies for rearing young animals exclusively on pasture from weaning at 7 months of age, with average initial weight of 220 ± 12 kg, to slaughter was conducted from May 2006 to October 2007. Two levels of combined supplementation during the first dry period and four genetic groups (F1 Angus-Nellore; ½Braford-»Angus-»Nellore; ½Brahman-»Angus-»Nellore; and ⅝Charolais-⅜Nellore) were used following a 4 by 2 factorial arrangement and eight replications in a completely randomized design. During both dry periods, eight paddocks of deferredBrachiaria brizantha were utilized. During the first dry period, concentrated mix (CM) and protein-mineral mixture (PMM) were provided in quantities of 0.8% and 0.2% of body weight (BW), respectively, for 142 days. During the subsequent rainy period, the animals were transferred to eight guinea grass paddocks for 197 days. During the second dry period, the animals were allocated to the same eight palisade grass paddocks used during the previous dry season. Steers had received supplementary diet with the same CM used before at 0.8% of BW. Animals supplemented with CM gained more BW than those supplemented with PMM; however, during the rainy season, steers supplemented with PMM performed better than those receiving CM during the preceding dry period. Using concentrate since the first dry season is a risky option in economic terms, as only the Angus-Nellore group showed a positive but small gain.(AU)

O experimento foi conduzido de maio de 2016 a outubro de 2017 com o objetivo de avaliar as eficiências biológica e econômica de animais exclusivamente em pastos, da desmama ao abate. Foram avaliados dois níveis de suplementação alimentar combinados com quatro grupos genéticos durante o período seco: F1 Angus-Nelore; ½Braford-»Angus-»Nelore; ½Brahman-»Angus-»Nelore; e⅝Charolais-⅜Nelore, seguindo-se um arranjo fatorial 4 x 2 com oito repetições em delineamento completamente ao acaso. Durante os dois períodos secos avaliados, oito piquetes de Brachiaria brizantha diferida foram utilizados. No primeiro período seco, mistura concentrada (MC) e mistura mineral múltipla (MMM) foram fornecidas nas quantidades de 0,8 e 0,2% do peso vivo (PV), respectivamente, durante 142 dias. Durante a estação das águas subsequente, todos os animais foram transferidos para oito piquetes de Panicum maximum, por 197 dias. No segundo período seco, os animais foram alocados nos mesmos oito piquetes de braquiária utilizados no período seco anterior e receberam suplementação alimentar MC, no mesmo nível, 0,8% PV utilizado anteriormente. Animais suplementados com MC apresentaram maior ganho de peso que animais recebendo MMM; entretanto, durante o período chuvoso, estes animais apresentaram melhor desempenho que àqueles que receberam MC durante o período seco. Animais Angus-Nelore apresentaram desempenho superior aos demais cruzamentos, destacando-se a precocidade da raça em alcançar o ponto de abate. A utilização de suplemento concentrado desde a primeira seca após desmama é uma opção de risco econômico, uma vez que apenas o grupo genético Angus-Nelore apresentou pequeno incremento positivo de ganho.(AU)

Pleurotus spp. cultivation on Brachiaria sp. straw treatment with alkaline water: Oyster mushroom and substrate treatment.

The aim of this research was to evaluate the efficiency of aqueous alkali-treated Brachiaria straw for the cultivation of appropriate species of oyster mushroom. The substrate used in the cultivation of various Pleurotus spp. was soaked for 20min by using two different procedures: (i) 0.5-2.0% Ca(OH)2 in 100L water, and (ii) 50-250L water. As a result, 1% Ca(OH)2 dissolved in 100L water and 3.5kg of Brachiaria straw presented the best production. The most suitable species for the application of the present method were P. pulmonarius and P. sapidus. The success of this technique is directly related to the concentration of Ca(OH)2 and water, the species, and the origin and quality of raw material used as the substrate in the production of oyster mushroom.

Nutritional quality and organic matter degradability of Brachiaria spp. agronomically biofortified with selenium.

Selenium (Se) fertilisation in grazing systems can improve the quality of animal forage, but there are few studies addressing the influence of Se fertilisation on the chemical composition and ruminal degradability of forage fertilised with Se. The aim of this study was to evaluate the chemical composition and in vitro assays of truly degraded organic matter (TDOM), short-chain fatty acids (SCFA) total gas (GP) and methane (CH4 ) production of two harvests of Brachiaria brizantha cv. Marandu fertilised with urea coated with B, Cu and sodium selenate for 0, 10, 20, 40, 80 and 160 g/ha of Se. Selenium content in forage increased linearly with the different doses at 30 and 60 days after fertilisation. However, doses of 20 and 80 g/ha Se fertilisation yielded positive effects increasing Se content and truly degraded organic matter in vitro of Brachiaria brizantha cv. Marandu.

GID1 expression is associated with ovule development of sexual and apomictic plants.

KEY MESSAGE: BbrizGID1 is expressed in the nucellus of apomictic Brachiaria brizantha, previous to aposporous initial differentiation. AtGID1a overexpression triggers differentiation of Arabidopsis thaliana MMC-like cells, suggesting its involvement in ovule development. GIBBERELLIN-INSENSITIVE DWARF1 (GID1) is a gibberellin receptor previously identified in plants and associated with reproductive development, including ovule formation. In this work, we characterized the Brachiaria brizantha GID1 gene (BbrizGID1). BbrizGID1 showed up to 92% similarity to GID1-like gibberellin receptors of other plants of the Poaceae family and around 58% to GID1-like gibberellin receptors of Arabidopsis thaliana. BbrizGID1 was more expressed in ovaries at megasporogenesis than in ovaries at megagametogenesis of both sexual and apomictic plants. In ovules, BbrizGID1 transcripts were detected in the megaspore mother cell (MMC) of sexual and apomictic B. brizantha. Only in the apomictic plants, expression was also observed in the surrounding nucellar cells, a region in which aposporous initial cells differentiate to form the aposporic embryo sac. AtGID1a ectopic expression in Arabidopsis determines the formation of MMC-like cells in the nucellus, close to the MMC, that did not own MMC identity. Our results suggest that GID1 might be involved in the proper differentiation of a single MMC during ovule development and provide valuable information on the role of GID1 in sexual and apomictic reproduction.

Pleurotus spp. cultivation on Brachiaria sp. straw treatment with alkaline water

Abstract The aim of this research was to evaluate the efficiency of aqueous alkali-treated Brachiaria straw for the cultivation of appropriate species of oyster mushroom. The substrate used in the cultivation of various Pleurotus spp. was soaked for 20 min by using two different procedures: (i) 0.5-2.0% Ca(OH)2 in 100 L water, and (ii) 50-250 L water. As a result, 1% Ca(OH)2 dissolved in 100 L water and 3.5 kg of Brachiaria straw presented the best production. The most suitable species for the application of the present method were P. pulmonarius and P. sapidus. The success of this technique is directly related to the concentration of Ca(OH)2 and water, the species, and the origin and quality of raw material used as the substrate in the production of oyster mushroom.