Dinámicas de producción y emisiones modeladas de gases de efecto invernadero en sistemas regionales de producción lechera de Honduras / Production dynamics and greenhouse gas modeled emissions from regional dairy production systems in Honduras

RESUMEN El objetivo del estudio fue la caracterización productiva y de emisiones modeladas de gases de efecto invernadero (GEI) en 61 sistemas lecheros localizados en cinco regiones de Honduras. Durante las fases inicial (FI) y final (FF), con encuestas aplicadas individualmente a los productores, se identificaron aspectos técnicos y de productividad. Variables numéricas expresadas en Microsoft Excel ® permitieron, con el modelo FAO de evaluación ambiental de la ganadería global-interactivo (GLEAM-i, por sus siglas en inglés) de ciclo de vida, estimar emisiones anuales de metano (CH4), óxido nitroso (N2O) y dióxido de carbono (CO2) en cada finca. Cálculos intermedios (GEI/animal) fueron derivados de la modelización GLEAM-i en Excel®. Durante la FI las fincas conjuntamente emitieron 25.038 t CO2 equivalente (CO2-eq), mientras que dichas emisiones fueron 10,5% menores en la FF. Emisiones de GEI/animal (2,85 ± 0,08 t CO2-eq) y de GEI/kg de proteína láctea (96,91 ± 4,50 kg CO2-eq) durante la FI fue-ron 13 y 21% menores en la FF, respectivamente. Valores de 52,82 ± 1,64 (CH4) y 2,66 ± 0,10 (N2O) kg/animal en la FI fueron 13% y 17% menores en la FF, respectivamente. La región Centro-Sur-Oriente emitió la menor cantidad de CH4 (42,95 ± 2,37 kg/animal) y N2O (1,82 ± 0,15 kg/animal, mientras las regiones Occidente y Norte experimentaron una reducción del 27% en GEI/kg proteína láctea entre la FI y FF. Se concluyó que la metodologia usada identificó los impactos productivos y medioambientales, derivados de alternativas técnicas implementadas en sistemas de producción lechera de Honduras.

ABSTRACT The study aimed to characterize production dynamics and greenhouse gas (GHG) emissions from 61 dairy farms in five regions in Honduras. Farm data were collected through individual surveys during the initial and final phases (IP; FP). Using Microsoft Excel, data was incorporated into the global livestock environmental assessment model-interactive (GLEAM-i, FAO) life cycle framework to estimate annual emissions of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2) at the farm system level. Animal emissions (GHG/animal) were derived in Excel® from the GLEAM-i predictions. Together, farms during the IP emitted 25.038 t CO2 equivalent (CO2-eq) while these emissions were 10,5% lower in the FP. Emissions of GHG/animal (2,85 ± 0,08 t CO2-eq) and GHG/kg of milk protein (96,91 ± 4,50 kg CO2-eq) during the IP were 13% and 21% lower in the FP, respectively. Methane and N2O emission values (52,82 ± 1,64 vs. 2,66 ± 0,10 kg/animal) were 13% and 17% higher in the IP than in FP. The South-Central region emitted the lowest amount of CH4 and N2O (42,95 ± 2,37 kg/animal vs. 1,82 ± 0,15 kg/animal) while 27% lower GHG/kg milk protein was observed between the IP and FP of the Western and Northern regions. It was concluded that the used methodology identified productive and environmental impacts derived from implemented technical interventions in dairy production systems in Honduras.

Grass pollen sensitization in dogs in Paraná, Brazil: comparison between percutaneous and intradermal testing / [Sensibilização a polens em cães no Paraná, Brasil: comparação entre o teste percutâneo e o teste intradérmico]

Canine atopic dermatitis is an inflammatory, genetic, pruritic and chronic dermatosis that affects between 10 and 30% of dogs and one of the most important allergens is grass pollen. The objective of this study was to evaluate the sensitization to grass pollen allergens in dogs with canine atopic dermatitis and to compare intradermal skin test (IDT) with percutaneous test (PT). For this study, ten healthy dogs and 39 dogs with atopic dermatitis were tested. Dogs were submitted to IDT and PT for Lolium multiflorum, Cynodon dactylon and Paspalum notatum. The IDT and PT tests were compared using the Proportion Test. All healthy dogs were negative to both tests. Ten atopic dogs (25.6%) responded positively to the PT and none were positive in IDT. C. dactylon, L. multiflorum and P. notatum were responsible for positive reactions in 70%, 70% and 30% of positive dogs, respectively. The number of positive reactions in PT were statistically higher than IDT (P<0.05). In conclusion, grass pollen can be important source of allergens for dogs in Paraná state (Brazil) and the PT showed higher sensitization to grass pollen in dogs with atopic dermatitis than IDT.(AU)

A dermatite atópica canina é uma dermatose inflamatória, genética, prurítica e crônica que afeta entre 10% e 30% dos cães, e um dos alérgenos mais importantes são os polens de gramíneas. O objetivo deste estudo é avaliar a sensibilização a alérgenos de polens de gramíneas em cães com dermatite atópica e comparar o teste intradérmico (TID) com o teste percutâneo (TP). Para o estudo, 10 cães hígidos e 39 cães com dermatite atópica foram testados. Estes foram submetidos ao TID e ao TP para Lolium multiflorum, Cynodon dactylon e Paspalum notatum. TID e TP foram comparados usando-se o teste de proporção. Todos os cães hígidos foram negativos em ambos os testes. Dez cães atópicos (25,6%) responderam positivamente ao TP e nenhum ao TID. C. dactylon, L. multiflorum e P. notatum foram responsáveis por reações positivas de 70%, 70% e 30% dos cães positivos, respectivamente. O número de reações positivas no TP foi estatisticamente maior que no TID (P<0,05). Foi concluído que os polens de gramíneas podem ser importantes fontes de alérgenos para cães no estado do Paraná (Brasil) e que o TP mostrou maior sensibilização a polens em cães com dermatite atópica que o TID.(AU)

Use of the imazapic herbicide applied alone or tank mix with imazapyr as growth regulator of lawns

Successive mowing are the major maintenance costs of lawns. Thus, both the expenditure with mowing and the visual and physiological aspect of the lawn have led to the search for alternatives to mechanical management. Thus, this work aimed to study the effects of different rates of imazapic herbicide applied alone or combined with imazapyr as a growth regulator of Bahiagrass (Paspalum notatum) and St. Augustine grass (Stenotaphrum secundatum). The experimental design was a randomized block with four replicates, and the treatments consisted of six rates of imazapic herbicide (35; 70; 105; 140; 175 and 210 g a.i. ha-1) for both species, three rates of imazapic + imazapyr in tank mix (15.57 + 5.25; 23.625 + 7.875; 32.5 + 10.5 g a.i. ha-1) for Bahiagrass and four rates of imazapic + imazapyr mixture (7.875 + 2.625; 15.57 + 5.25; 23.625 + 7.875; 32.5 + 10.5 g a.i. ha-1) for St. Augustine grass. The effect of the treatments was evaluated by observing visible injury symptoms, canopy height, height and number of inflorescences and total dry matter of clippings. Applications of imazapic alone or combined with imazapyr were effective in reducing plant height, number and height of inflorescences and total amount of dry matter of clippings produced by Bahiagrass plants. Imazapic provided satisfactory control of St. Augustine growth, but its utilization caused an increase in the number of inflorescences present in the lawns.

Genetic Similarity Among Accessions of Paspalum notatum Flügge (Poaceae): a Potential to Parental Selection

HIGHLIGHTS Low genetic similarity in Paspalum notatum accessions. High genetic distance among diploid accessions. The accessions have good potential to breeding program.

Abstract Paspalum notatum is an important forage grass contributing significantly to the coverage of the natural fields of Southern Brazil. Simple sequence repeat (SSR) markers were used to evaluate the genetic similarity of strains within a P. notatum collection. Genomic DNA was extracted in bulk from young leaves of five plants from each accession obtained from the USDA. In the molecular analysis, the eight SSR markers evaluated formed seven distinct groups, and two isolated genotypes, with an average similarity index of 0.29, ranging from zero to 0.83. All the loci were polymorphic and the polymorphism information content ranging from 0.41 to 0.69. The results evidenced a low genetic similarity, which can be explored via parental selection in a breeding program.

Spatial patterns and interactions of dominant tree species in an Amazon tropical rainforest / Patrones e interacciones espaciales de especies arbóreas dominantes en un bosque tropical en la Amazonia

Abstract Knowledge of spatial patterns and interactions of tree species allows for understanding the ecological processes of spatiotemporal structures of tropical forests, becoming essential for the establishment of strategies for the conservation and management of their resources in the long term. The aim of this study was to investigate the spatial patterns and interactions of Astronium lecointei, Dinizia excelsa and Peltogyne paniculata, three dominant timber tree species in the Jamari National Forest, Rondônia, Brazilian Amazon. The Kernel estimator was used aiming to verify the possible influence of first-order factors on species distributions. Inhomogeneous K-functions were applied to analyze species spatial patterns and interactions by means of second-order factors. Univariate analyses revealed different scale-dependent spatial patterns for the species. Aggregation related to ecological characteristics, such as habitat preference and dispersal limitation, was verified for A. lecointei and P. paniculata. D. excelsa presented a random spatial pattern, explained by specific features of its establishment, such as the need for clearings due to light requirements. Interspecific associations were evidenced by bivariate analyses, in which spatial attraction of species resulted from the same preference for microhabitats and the repulsion was a result of niche segregation. Rev. Biol. Trop. 66(3): 1009-1017. Epub 2018 September 01.

Resumen El conocimiento de los patrones e interacciones espaciales de las especies arbóreas permite la comprensión de los procesos ecológicos de estructuración espacio-temporal de los bosques tropicales, tornándose imprescindible para el establecimiento de estrategias de conservación y manejo de sus recursos a largo plazo. El objetivo de este estudio fue investigar los patrones y las interacciones espaciales de Astronium lecointei, Dinizia excelsa y Peltogyne paniculata, tres especies arbóreas madereras dominantes en la Selva Nacional del Jamari, Rondônia, Amazonia Brasileña. Para ello, se utilizó el estimador Kernel, con el objetivo de verificar la posible influencia de factores de primer orden en la distribución de las especies. Para el análisis de los patrones e interacciones espaciales de las especies por medio de los factores de segundo orden, se empleó la función K no homogénea. Los análisis univariados revelaron diferentes patrones espaciales dependientes de la escala para las especies. Agregación relacionada a características ecológicas, como preferencia de hábitat y limitación de la dispersión, fue constatada para A. lecointei y P. paniculata. Dinizia excelsa presentó un patrón espacial aleatorio, explicado por características particulares de su establecimiento, como la necesidad de claros debido a sus requisitos lumínicos. Las asociaciones interespecíficas fueron evidenciadas por los análisis bivariados, en que la atracción espacial de las especies resultó de la misma preferencia por micro hábitats y la repulsión fue resultado de la segregación de nichos.

Forage potential of native ecotypes of Paspalum notatum and P. guenoarum

ABSTRACT The Paspalum genus includes several species that are important for livestock in Rio Grande do Sul, such as P. notatum and P. guenoarum, typical of native pastures of the Pampa biome. The aim of this study was to investigate forage production and chemical composition of four ecotypes of these species in relation to the cv. 'Pensacola' (P. notatum). Ecotypes of P. guenoarum (Azulão and Baio) and P. notatum (André da Rocha and Bagual) and the cv. 'Pensacola' were evaluated for two years, during which four cuts/year were made. The work was carried out under field conditions at the Agronomic Experimental Station of the Federal University of Rio Grande do Sul (30°05'S; 51°39'W), in a completely randomized design. P. guenoarum stood out for higher productivity and greater tolerance to cold; the Azulão ecotype showed more autumn production in relation to the other ecotypes. Crude protein content ranged from 14 (Baio) to 15% ('Pensacola'); for neutral detergent fiber, the variation was 68 (Azulão) to 71% ('Pensacola') and for acid detergent fiber there was a variation of 38 ('Pensacola') to 43% (Baio). The data demonstrates the potential of native genotypes for use as cattle feeding in southern Brazil.

Cellulase activity and dissolved organic carbon release from lignocellulose macrophyte-derived in four trophic conditions

Abstract Considering the importance of lignocellulose macrophyte-derived for the energy flux in aquatic ecosystems and the nutrient concentrations as a function of force which influences the decomposition process, this study aims to relate the enzymatic activity and lignocellulose hydrolysis in different trophic statuses. Water samples and two macrophyte species were collected from the littoral zone of a subtropical Brazilian Reservoir. A lignocellulosic matrix was obtained using aqueous extraction of dried plant material (≈40 °C). Incubations for decomposition of the lignocellulosic matrix were prepared using lignocelluloses, inoculums and filtered water simulating different trophic statuses with the same N:P ratio. The particulate organic carbon and dissolved organic carbon (POC and DOC, respectively) were quantified, the cellulase enzymatic activity was measured by releasing reducing sugars and immobilized carbon was analyzed by filtration. During the cellulose degradation indicated by the cellulase activity, the dissolved organic carbon daily rate and enzyme activity increased. It was related to a fast hydrolysable fraction of cellulose that contributed to short-term carbon immobilization (ca. 10 days). After approximately 20 days, the dissolved organic carbon and enzyme activity were inversely correlated suggesting that the respiration of microorganisms was responsible for carbon mineralization. Cellulose was an important resource in low nutrient conditions (oligotrophic). However, the detritus quality played a major role in the lignocelluloses degradation (i.e., enzyme activity) and carbon release.

Germoplasma do gênero paspalum com potencial para produção de forragem / Germplasm of paspalum genus with production potential for foraging

Este estudo foi conduzido na Fazenda Canchim em São Carlos-SP, área física da Embrapa Pecuária Sudeste, objetivando selecionar, com base nas características agronômicas de produtividade de matéria seca e qualidade da forragem, os acessos das espécies do gênero Paspalum indicados por possuir potencialidade para utilização como plantas forrageiras. Foram avaliadas durante 3 anos, 22 gramíneas forrageiras, sendo 19 do gênero Paspalum e três testemunhas: Brachiaria decumbens, Andropogon gayanus cv. Baetí e Panicum maximum cv. Tanzânia-1, submetidos a dois níveis de intensificação: alto (adubação após cada corte e irrigação suplementar) e baixo (somente adubação de reposição anual sem irrigação). O delineamento experimental foi o de blocos casualizados, em esquema de parcelas subdivididas no espaço e no tempo, com duas repetições. As variáveis estudadas foram: produção de massa seca de forragem, digestibilidade in vitro da matéria seca e percentual de proteína bruta na matéria seca. Os acessos responderam ao nível de intensificação, minimizando os efeitos negativos da estacionalidade de produção. Com base nas variáveis estudadas, os acessos selecionados são: BRA-011401 (Paspalum glaucescens); BRA-011681 (P. atratum); BRA009661 (P. atratum) e BRA-019186 (P. regnellii).

This study was carried out in Fazenda Canchim in São Carlos-SP, physical base of Embrapa Southeast Livestock, aiming to select, based on the agronomic characteristics of productivity of dry matter and quality of the forage, the accesses of suitable gender Paspalum for possessing potentiality of use as foraging plants. Were evaluated for 3 years, with 22 forage grasses, being 19 of Paspalum and three more of control species: Brachiaria decumbens, Andropogon gayanus cv. Baetí and Panicum maximum cv. Tanzania, submitted to two intensification levels: high (fertilizer after each cut and supplemental irrigation) and low (only fertilizer of annual replacement without irrigation). The experimental design was of split blocks subdivided in the space and time with two replications. The studied variables were: dry matter production, in vitro dry matter digestibility and crude protein content. The results show that the accesses responded to the intensification level minimizing the negative effect of the stational production. Based on the studied variables, the selected accesses were: BRA-011401 (Paspalum glaucescens); BRA-011681 (P. atratum); BRA009661 (P. atratum) and BRA-019186 (P. regnellii).

Suplementação de novilhos Nelore sob pastejo, no período de transição águas-seca / Supplementation of Nelore steers under grazing during the rainy/dry transition period

Avaliou-se o efeito da suplementação proteica sobre o consumo e o desempenho de novilhos recriados em pastagens de capim-piatã (Brachiaria brizantha cv. Piatã), durante o período de transição águas-seca. Utilizaram-se 20 novilhos Nelore, com peso médio inicial de 260kg, distribuídos ao acaso, em esquema de parcelas subdivididas. Os suplementos foram: sal mineral com ureia (controle) - ofertado ad libitum; sal proteinado - ofertado a 0,2% do peso vivo; suplemento proteico-energético - ofertado a 0,3% do peso vivo; e suplemento proteico-energético - ofertado a 0,5% do peso vivo. A suplementação teve efeito aditivo sobre o consumo de matéria seca total. O consumo médio diário dos suplementos foi de 0,167; 0,597; 0,865 e 1,469kg/animal, sendo observado ganho médio diário de 0,686; 0,761; 0,719 e 0,850kg/animal para os tratamentos controle e suplementados com 0,2; 0,3 e 0,5% do peso vivo, respectivamente. Verificou-se que as estratégias de suplementação avaliadas foram economicamente viáveis e proporcionaram desempenho semelhante sob condições de elevada oferta de forragem, sendo recomendado iniciar a suplementação proteica no período de transição águas-seca.

The effects of proteic supplementation on performance and forage dry matter intake of steers grazing on Brachiaria grass (Brachiaria brizantha cv. Piatã) during the rainy/dry transition period were evaluated. Twenty Nelore steers with an average body weight (BW) of 260kg, were assigned in a split plot design. The treatments were: mineral salt plus urea offered ad libitum (control); proteic supplement offered at 0.2% BW, proteic-energetic supplement offered at 0.3% BW and proteic-energetic supplement offered at 0.5% BW. The supplementation increased total dry matter intake. The average intake of supplements was 0.167; 0.597; 0.865 and 1.469kg/animal/day and the average daily gain (ADG) was 0.686; 0.761; 0.719 and 0.850kg/animal/day, for control, 0.2, 0.3 and 0.5% BW, respectively. It was verified that all strategies of supplementation are economically viable and similar in performance, under high herbage availability conditions. It is suggested that proteic supplementation begin during the rainy/dry transition period, for better animal performance and economic results.

Unusual chromosome numbers in Paspalum L. (Poaceae: Paniceae) from Brazil

Somatic chromosome numbers were determined for 20 new germplasm accessions of Paspalum, belonging to 17 species collected in Brazil. Chromosome number is reported for the first time for P. reduncum (2n = 18), P. cinerascens (2n = 20), P. cordatum (2n = 20), P. filgueirasii (2n = 24), P. ammodes (2n = 36), P. bicilium (2n = 40), P. heterotrichon (2n = 40), and P. burmanii (2n = 48). New cytotypes were confirmed for two germplasm accessions of P. carinatum (2n = 30) and P. trachycoleon (2n = 36), one of P. clavuliferum (2n = 40) and one of P. lanciflorum (2n = 40), indicating variability in these species. The remaining chromosome numbers reported here confirm previous counts. The unexpected chromosome numbers 2n = 18, 24, 36, and 48 in Paspalum species, which are usually shown to be multiples of 10, suggest that much more collection and cytogenetic characterization are necessary to assess the whole chromosomal and genomic multiplicity present in the genus, which seems to be much more diverse than currently thought to be.

Ganho de peso de novilhas em pastagem nativa da Serra do Sudeste do RS submetida ao controle de plantas indesejáveis e intensidades de pastejo / Heifers weight gain on Serra do Sudeste native pasture in RS, submitted to undesirable plants control and grazing intensities

Este trabalho teve como objetivo avaliar o efeito de métodos de controle de espécies indesejáveis e de intensidades de pastejo sobre o desempenho animal em pastagem nativa da Serra do Sudeste do Rio Grande do Sul. Foram utilizados os métodos de controle: roçada de primavera (RP), roçada de outono (RO), controle químico (Q) e um tratamento testemunha (T), todos submetidos a dois níveis de oferta de forragem, médio (8 por cento) e alto (14 por cento), expressos em kg de matéria seca diariamente ofertada para cada 100kg de peso vivo animal. O delineamento experimental empregado foi o de blocos completamente casualizados, num arranjo fatorial com duas repetições. A análise estatística não demonstrou interação entre os fatores estudados, bem como existência de diferença entre os métodos de controle de espécies indesejáveis para as variáveis de produção primária e secundária (P>0,1). Não houve diferença de ganho médio diário entre os níveis de oferta de forragem estudados (P>0,1). Animais submetidos à alta oferta de forragem apresentaram menor perda de peso por unidade de área (P<0,1).

Chromosome numbers and meiotic behavior of some Paspalum accessions

Chromosome number and meiotic behavior were evaluated in 36 Brazilian accessions of the grass Paspalum (which had never previously been analyzed) to determinate which accessions might be useful in interspecific hybridizations. The analysis showed that one accession of Paspalum coryphaeum was diploid (2n = 2x = 20) and one accession of Paspalum conspersum hexaploid (2n = 6x = 60), the remaining 34 accessions being tetraploid (2n = 4x = 40). The pairing configuration was typical for the ploidy level i.e. in the diploid, chromosomes paired as 10 bivalents, in tetraploids as bi-, tri- and quadrivalents, and in hexaploid as 30 bivalents. A low frequency of meiotic abnormalities (less than 10%) was observed in the diploid, hexaploid and some tetraploid accessions, although the majority of tetraploid accessions showed a high frequency of meiotic irregularities. The use of accessions with a low frequency of meiotic abnormalities in breeding programs is discussed

In vivo effect of whole grain flour of finger millet (Eleusine coracana) and kodo millet (Paspalum scrobiculatum) on rat dermal wound healing.

Influence of finger millet and kodo millet on rat dermal wound healing was assessed by making a 4 cm2 (2 x 2 cm) excision wound on the shaven back of rats under ether anesthesia. Finger millet or kodo millet flour (300 mg) as aqueous paste was applied topically once daily for 16 days. The granulation tissue formed on day 4, 8 and 12 was used to estimate some biochemical parameters like protein, DNA, collagen and lipid peroxides. There was significant increase in protein and collagen contents and decrease in lipid peroxides. Biophysical parameters like rate of contraction and number of days for epithelialization were also studied. Rate of contraction was 88-90% in kodo millet and finger millet treated rats in comparison to 75% in untreated rats. The number of days for complete closure of wounds was lower for finger millet (13 days) and kodo millet (14 days) treated rats in comparison to untreated (16 days) rats. The results implicate a possible therapeutical role for finger millet and kodo millet in accelerating the process of wound healing.