Techno-functional properties and antioxidant capacity of the concentrate and protein fractions of Leucaena spp. seeds / Propiedades tecno-funcionales y capacidad antioxidante del concentrado y fracciones proteicas de semillas de Leucaena spp

Introduction: The use of vegetable proteins as ingredients in food systems is based on their functional properties. The water and oil holding capacity, foaming, and emulsifying capacity/stability, and antioxidant assay of the protein fractions - albumins, globulins 7S/11S, glutelins and prolamins - isolated from Leucaena seed were evaluated. Objective: The objective of this study was to evaluate the functional properties and antioxidant capacity of the concentrate and protein fractions of ripe Leucaena spp. seeds. Materials and methods: Ripe Leucaena seeds were collected and evaluated in Oaxaca, Mexico (16°59'21''N 96°43'26''O) during the months of February-April 2021.The protein concentrate was isolated by isoelectric precipitation (pH=9, pH=4). The albumins, globulins, glutelins and prolamins were isolated based on their solubility properties in different extracting solutions. Results: Glutelins constituted the main protein fraction (75.88%). Prolamins were not found. The glutelins fractions showed the highest oil holding capacity (0.93±0.08 mL g-1). The albumins fraction had the highest water holding capacity (2.53±0.15 mL g-1), foaming capacity and foam stability (71.83±1.26 % and 70.00±0.00%, respectively) and antioxidant capacity (18.09±0.88%). The globulins exhibited the highest emulsifying capacity and emulsion stability (56.83±1.76% and 55.67±1.20%, respectively). Conclusions: The concentrate and protein fraction of Leucaena seeds showed different techno-functional and antioxidant properties of interest for the food industry, like those showed by other commercial vegetable proteins(AU)

Introducción: El uso de proteínas vegetales como ingredientes en sistemas alimentarios se basa en sus propiedades funcionales. Se evaluó la capacidad de retención de agua y aceite, la capacidad/estabilidad espumante y emulsionante y el ensayo antioxidante de las fracciones proteicas -albúminas, globulinas 7S/11S, glutelinas y prolaminas- aisladas de las semillas de Leucaena. Objetivo: El objetivo de este estudio fue evaluar las propiedades funcionales y la capacidad antioxidante del concentrado y las fracciones proteicas de las semillas maduras de Leucaena spp. Materiales y métodos: Las semillas maduras de Leucaena fueron recolectadas y evaluadas en Oaxaca, México (16°59'21''N 96°43'26''O) durante los meses de febrero-abril del año 2021. Se usó harina de Leucaena desgrasada para la preparación de las fracciones proteicas. El concentrado proteico se aisló por precipitación isoeléctrica (pH=9, pH=4). Las albúminas, globulinas, glutelinas y prolaminas se aislaron en función de sus propiedades de solubilidad en diferentes soluciones de extracción. Resultados: Las glutelinas constituyeron la principal fracción proteica (75,88%). No se encontraron prolaminas. La fracción de glutelinas mostró la mayor capacidad de retención de aceite (0.93±0,08 mL g-1). La fracción de albúminas presentó la mayor capacidad de retención de agua (2,53±0,15 mL g-1), capacidad espumante y estabilidad de la espuma (71,83±1,26% y 70,00±0,00%, respectivamente) y capacidad antioxidante (18,09±0,88%). Las globulinas mostraron la mayor capacidad emulsionante y estabilidad de la emulsión (56,83±1,76 y 55,67±1,20%, respectivamente). Conclusiones: El concentrado y las fracciones proteicas de las semillas de Leucaena mostraron diferentes propiedades tecno-funcionales y antioxidantes de interés para la industria alimentaria, similares a los reportados por diversas proteínas vegetales comerciales(AU)

Efectividad de hongos micorrizo-arbusculares nativos en suelos con diferentes usos agropecuarios / Native arbuscular mycorrhizal fungi effectiveness in soils with different agricultural uses

RESUMEN Objetivo. Determinar la efectividad de hongos micorrizo-arbusculares (HMA) de suelos con diferentes usos agropecuarios, en el valle medio del río Sinú, Colombia. Materiales y métodos. Bajo condiciones de invernadero se realizó el experimento, donde se utilizó como planta indicadora Leucaena leucocephala, la cual se sembró en materos con suelo de un Andisol (horizonte B) usado como sustrato. Este sustrato, se inoculó separadamente con muestras de siete suelos (horizonte Ap), como fuente de HMA, provenientes del Centro de Investigación Turipaná de Agrosavia. Como controles se incluyeron inoculación con HMA Glomus fasciculatum y uno no-inoculado El efecto de la inoculación micorrizal se evaluó mediante el monitoreo del contenido de P foliar en las plantas de L. leucocephala, en función del tiempo hasta 64 días cuando se determinó la masa seca de su parte aérea y la colonización micorrizal. Resultados. El crecimiento de L. leucocephala y el contenido de P foliar fue significativamente superior cuando el suelo se inoculó con G. fasciculatum, en comparación a aquel observado con los demás tratamientos. De igual forma, la colonización micorrizal fue muy alta en las raíces de L. leucocephala que crecieron en el suelo inoculado con G. fasciculatum e inferior en los otros tratamientos. Conclusiones. Los resultados indican que los HMA nativos de suelos con diferentes usos, provenientes del C.I Turipaná de Agrosavia, exhibieron bajo potencial para desarrollar simbiosis micorrizal, lo que limitó el crecimiento y la concentración de P foliar en la planta hospedera.

ABSTRACT Objective. To determine the effectiveness of mycorrhizal-arbuscular fungi (AMF) of soils with different agricultural uses, in the middle valley of the Sinú river, Colombia. Materials and methods. The experiment was carried out under greenhouse conditions, where Leucaena leucocephala was used as the indicator plant, which was planted in masons with an Andisol soil (horizon B) used as a substrate. This substrate was inoculated separately with samples from seven soils (Ap horizon), as a source of AMF, from the Turipaná Research Center in Agrosavia. As controls we included inoculation with HMA Glomus fasciculatum and one non-inoculated one. The effect of mycorrhizal inoculation was evaluated by monitoring the foliar P content in L. leucocephala plants, as a function of time to 64 days, when the dry mass of its aerial part and mycorrhizal colonization was determined. Results. The growth of L. leucocephala and the foliar P content was significantly higher when the soil was inoculated with G. fasciculatum, in comparison to that observed with the other treatments. Likewise, mycorrhizal colonization was very high in the roots of L. leucocephala that grew in the soil inoculated with G. fasciculatum and lower in the other treatments. Conclusions. The results indicate that the native AMF of soils with different uses, from Turipaná, exhibited low potential to develop mycorrhizal symbiosis, which limited the growth and concentration of leaf P in the host plant.

Effects of Leucaena leucocephala (lamk. ) shoot tips plus young leaf extract containing mimosine on reproductive system of male rats / Efectos de los brotes de Leucaena leucocephala (lamk. ) y del extracto de hojas jóvenes que contiene mimosina en el sistema reproductivo de ratas macho

This study aimed to determine the mimosine level and examine the male reproductive toxicity effects of Leucaena leucocephala (LL) shoot tips plus young leaf extract. Mimosine level in LL extract was determined by thin layer chromatography before administration in animals. Male rats were divided into control and LL (1,500 mg/KgBW) groups (n = 6). After 60 days of experiment, serum sex hormones, sperm quality, and testicular histopathology were assayed and observed. Malondialdehyde (MDA) level and expressions of steroidogenic acute regulatory (StAR) and phosphorylated proteins in testicular lysate were examined by western blotting. Results showed that mimosine levels in LL extract was 17.35 ± 1.12 % of dry weight. LL significantly decreased FSH & LH levels, sperm qualities, and seminiferous tubule diameter compared to the control (p<0.05). Seminiferous tubular atrophies, germ cell sloughing, and degenerations were observed in LL group. In addition, testicular MDA level and StAR protein expression were significantly decreased in LL group. LL extract could increase the expression of a 50 kDa phohorylated protein in testicular lysate. In conclusion, LL extract has mimosine and reproductive toxicity effects on males.

Este trabajo tuvo como objetivo determinar el nivel de mimosina y examinar los efectos de la toxicidad reproductiva de los brotes de Leucaena leucocephala (LL), más el extracto de hojas jóvenes, en ratas macho. El nivel de mimosina en el extracto de LL se determinó mediante cromatografía en capa fina antes de la administración en animales. Las ratas se dividieron en grupos de control y LL (1,500 mg / kgBW) (n = 6). Después de 60 días, se analizaron y observaron las hormonas sexuales séricas, la calidad de los espermatozoides y la histopatología testicular. A través de Western Blot se examinaron el nivel de malondialdehído (MDA), las expresiones de reguladores agudos esteroidogénicos (StAR) y las proteínas fosforiladas en el lisado testicular. Los resultados mostraron que los niveles de mimosina en el extracto de LL fueron 17.35 ± 1.12 % del peso seco. LL disminuyó significativamente los niveles de FSH y LH, la calidad de los espermatozoides y el diámetro de los túbulos seminíferos en comparación con el control (p <0,05). Se observaron atrofias en los túbulos seminíferos, desprendimiento de células germinales y degeneraciones en el grupo LL. Además, el nivel de MDA testicular y la expresión de la proteína StAR se redujeron significativamente en el grupo LL. El extracto de LL podría aumentar la expresión de la proteína fosforilada de 50 kDa en el lisado testicular. En conclusión, el extracto de LL tiene mimosina y efectos de toxicidad reproductiva en los hombres.

Acute effects of mimosine purified from Leucaena leucocephala on male reproductive system of adult mice / Efectos agudos de la mimosina purificada de Leucaena leucocephala en el sistema reproductor masculino de ratones adultos

This study attempted to examine the acute effect of purified minosine extracted from Leucaena leucocephala on male reproductive system. Adults male mice were divided into 4 groups (n =8); control and 3 experimental groups treated with purified mimosine at different doses of 15, 30, and 60 mg/KgBW, respectively for 7 consecutive days. The morphological features and weights of body and reproductive organs including testis, epididymis plus vas deferens, and seminal vesicle were compared among groups. In addition, epididymal sperm concentration and the changes of histopathology of testicular tissues in all groups were observed. The results showed that mimosine in all doses did not affect mice body weights. However, all doses of mimosine could significantly reduce the absolute and relative weights of testis and seminal vesicle but not of epididymis plus vas deferens. Significantly, mimosine at doses of 30, and 60 mg/KgBW could decrease sperm concentration. Moreover, the seminiferous atrophy and degeneration were obviously found in mimosine treated mice as compared to the control. In conclusion, consumption of Leucaena leucocephala edible parts containing mimosine could damage male reproductive organs which may cause acute male subfertility or infertility.

Este estudio intentó examinar el efecto agudo de la mimosina purificada extraída de Leucaena leucocephala en el sistema reproductivo masculino. Se dividieron ratones machos adultos en 4 grupos (n = 8): un grupo control y tres grupos experimentales tratados con mimosina purificada a diferentes dosis de 15, 30 y 60 mg / Kg por peso, respectivamente, durante 7 días consecutivos. Se compararon entre los grupos, las características morfológicas y el peso corporal, los órganos reproductivos, incluyendo los testículos, el epidídimo más conducto deferente y vesícula seminal. Además, se observó la concentración de espermatozoides epididimarios y los cambios de la histopatología de los tejidos testiculares en todos los grupos. Los resultados mostraron que la mimosina no afectó los pesos corporales de los ratones. Sin embargo, todas las dosis de mimosina podrían reducir significativamente los pesos absolutos y relativos de los testículos y las glándulas seminales, pero no así del epidídimo y los conductos deferentes. La mimosina en dosis de 30 y 60 mg / Kg por peso podría disminuir significativamente la concentración de esperma. Además, se observó la atrofia y degeneración seminífera en ratones tratados con mimosina en comparación con el grupo control. En conclusión, el consumo de partes comestibles de Leucaena leucocephala que contienen mimosina podría dañar los órganos reproductivos masculinos, lo que puede causar subfertilidad masculina aguda o infertilidad.

Influencia de la densidad de árboles de Leucaena en la producción lechera y nitrógeno ureico en vacas F1 Gyr x Holstein / Influence of density of Leucaena trees on milk production and urea nitrogen in F1 Gyr x Holstein cows

RESUMEN El objetivo de esta investigación fue evaluar la composición bromatológica, la selectividad animal, el consumo parcial, la producción lechera y la concentración de nitrógeno ureico en sangre y leche en vacas lecheras F1 (Gyr X Holstein) en sistemas silvopastoriles con diferentes densidades de árboles de Leucaena (Leucaena leucocephala). El estudio se realizó en La Hacienda el Chaco, Tolima (Colombia). Los tratamientos fueron: Ti: pastura de Cynodon nlemfluensis sin arboles; T2: C. nlemfluensis + 1264 árboles/ha de L. leucocephala; T3: C. nlemfluensis + 4255 árboles/ha de L. leucocephala y T4: C. nlemfluensis + 9899 árboles/ha de L. leucocephala. Se evaluaron 4 periodos experimentales de 32 días cada uno y se utilizaron 16 vacas lecheras F1 (Gyr X Holstein). Se observaron diferencias (P < 0,05) en el contenido de materia seca entre C. nlemfluensis y L. leucocephala. Además, se observó alta selectividad de las vacas por la gramínea (P < 0,05). El consumo de materia seca total disminuyó con el aumento en la densidad de árboles de L. leucocephala únicamente en el periodo 3 (P < 0,05). A medida que aumentó la densidad de árboles de L. leucocephala los valores de nitrógeno ureico en sangre y leche aumentaron (P < 0,05). La producción lechera no se alteró por los tratamientos. Se concluye que las vacas F1 (Gyr X Holstein) en sistemas silvopastoriles tienen una alta selectividad y consumo parcial de la gramínea, y niveles más altos de nitrógeno ureico en sangre y leche.

ABSTRACT The objective of this research was to evaluate the chemical composition, selectivity, partial intake, milk production and concentration of urea nitrogen in blood and milk in F1 (Gyr x Holstein) dairy cows on silvopastoral systems with different densities of Leucaena leucocephala trees. The study was carried out in the Chaco Farm, Tolima (Colombia). The treatments were: T1: Cynodon nlemfluensis pasture without trees; T2: C. nlemfluensis + 1264 trees/ha of L. leucocephala; T3: C. nlemfluensis + 4255 trees/ha of L. leucocephala and T4: C. nlemfluensis + 9899 trees/ha of L. leucocephala. Four experimental periods of 32 days each were evaluated and 16 F1 (Gyr x Holstein) cows were used. Differences (P < 0.05) were observed in the dry matter content between C. nlemfluensis and L. leucocephala. Further, there was high selectivity of the cows for the grass (P < 0.05). Dry matter intake decreased with the increase in density of L. leucocephala trees in period 3 only (P < 0.05). As the density of L. leucocephala trees increased, the values of urea nitrogen in blood and milk increased (P < 0.05). Milk production was not different among any of the treatments. It is concluded that F1 (Gyr X Holstein) cows in silvopastoral systems show high selectivity and partial intake of grass, and higher levels of blood and milk urea nitrogen.

Intoxicação natural e experimental por Leucaena leucocephala em equinos / Natural and experimental Leucaena leucocephala poisoning in horses

Este trabalho investigou as principais alterações clínicas e dermatopatológicas de equinos intoxicados natural e experimentalmente por Leucaena leucocephala. Os surtos ocorreram nos estados de São Paulo e Goiás, onde seis cavalos após a ingestão de casca e/ou folhas de L. leucocephala apresentaram alopecia, principalmente na crina e cauda. Nesses animais o diagnóstico foi baseado na observação da ingestão da planta e dos sinais clínicos. Nos animais intoxicados experimentalmente, foi realizado o exame clínico, biópsias da pele das regiões de crina, dorso e cauda e foi feita dosagem sérica de tri-iodotironina (T3) e tiroxina (T4). Alopecia da crina e cauda foi o principal sinal clínico observado, seguido de anorexia, emagrecimento e apatia em todos os equinos. Os níveis de T3 e T4 total apresentaram redução significativa (p≤0,05) na terceira semana de ingestão da leucena quando comparado aos níveis basais. As alterações histológicas observadas nas biópsias de pele demonstram acentuada telogenização dos folículos pilosos ao final dos experimentos. Os achados clínico-patológicos em equinos intoxicados são semelhantes aos observados em ruminantes. A intoxicação experimental de equinos por L. leucocephala evidenciou o acentuado declínio dos níveis dos hormônios tireoideanos, sugerindo efeito bociogênico da mimosina e seus compostos derivados, com hipotireoidismo transitório e alopecia devido à acentuada redução da atividade folicular.(AU)

This paper reports the main clinical changes of natural and experimentally poisoning by Leucaena leucocephala in horses. Outbreaks of poisoning occurred in São Paulo and Goiás States, where six horses after ingestion of bark and/or leaves of the plant showed alopecia mainly in mane and tail. The diagnosis was based on the observation of plant intake and clinical signs. In horses experimentally poisoned, clinical examination was performed and skin biopsies were taken from mane, back and tail regions, and triiodothyronine (T3) and thyroxine (T4) serum levels were assayed. Alopecia in mane and tail was the main clinical sign, accompanied by anorexia, weight loss and lethargy in all horses. T3 and total T4 showed significant decrease in serum levels (p≤0.05) in the third week of leucaena intake compared with baseline levels. Marked telogenization of hair follicles at the end of the experiments were observed in skin biopsies. The clinical and pathological findings in poisoned horses are similar to those observed in ruminants. Experimental poisoning of horses by the plant highlights the marked decline in levels of thyroid hormones, suggesting goitrogenic effect of mimosine and its derived compounds, with transient hypothyroidism and alopecia due to accentuated reduction in follicular activity.(AU)

Production and quality of forage under intercropping systems in the Cerrado/Pantanal ecotone / Produção e qualidade da forragem de consórcios no ecótonoCerrado/Pantanal

The aims of this study were to evaluate forage production and nutritional quality of the elephant grass, leucaena and pigeon pea beans, grown in monocrop or in intercropping systems in Cerrado / Pantanal ecotones in both, dry and rainy, seasons. Experimental design was completely randomized with five treatments and five repetitions. The treatments were: elephant grass, leucaena and pigeon pea all of these in monocrop; intercropping elephant grass with Leucaena; intercropping elephant grass with pigeon pea. During the rainy season, it was carried out three cuts at intervals of 60 days, and in the dry season a single cut with 180 days. In the rainy season, the biomass produced of the forages elephant grass, leucaena and pigeon pea corresponded respectively to 72, 64, 76% of the annual production. Under intercropping system, fodder behaves similarly, with the average of 72% of annual production. During this period, the nutritional quality of the forages was also higher than the dry season. In the dry period, there was decreased the production of biomass and a reduction in the proportion of leaves in all the forage, regardless of cultivation system. In both seasons (rainy and dry), the forage grown under intercropping system showed higher dry matter production in relation to monocrop system, with most of this production coming of elephant grass. The intercropping elephant grass with the pigeon pea has the highest production of dry matter, while the intercropping elephant grass with Leucaena has better nutritional quality.

Os objetivos deste trabalho foram avaliar a produção de forragem e a qualidade nutricional do capim elefante, Leucaena e feijão guandu, cultivados de forma solteira ou em sistema de consórcio no ecótono Cerrado/Pantanal, em duas estações do ano (das águas e seca). O delineamento utilizado foi o inteiramente casualizado com cinco tratamentos e cinco repetições. Os tratamentos foram: capim elefante solteiro; Leucaena solteira; feijão gandu solteiro; consórcio capim elefante com Leucaena; consórcio capim elefante com feijão guandu. Na época das chuvas foram realizados três cortes em intervalos de 60 dias e na época da seca um único corte, com 180 dias. Na estação das chuvas, a biomassa produzida das forrageiras capim elefante, Leucaena e feijão guandu corresponderam, respectivamente, a 72, 64, 76% de toda a produção anual. No sistema de consórcio as forrageiras apresentaram um comportamento similar, com média de 72% da produção anual. Neste período a qualidade nutritiva das forrageiras também foi superior a época seca. No período seco, verificou-se menor produção de biomassa e uma redução na proporção de folhas, em todas as forrageiras, independentemente do sistema de cultivo. Em ambos os períodos (águas e seco), as forrageiras cultivadas em sistema de consórcio, apresentaram produção de matéria seca superior às cultivadas solteiras, sendo a maior parte desta produção oriunda do capim elefante. O consorcio do capim elefante com o feijão guandu apresenta a maior produção de matéria seca, enquanto o consórcio do capim elefante com a Leucaena possui melhor qualidade nutricional.

Reproductive behavior of crossbred dairy cows grazing an intensive silvopastoral system under tropical dry forest conditions / Comportamento reprodutivo de vacas leiteiras mestiças pastando um sistema silvipastoril intensivo em condições de floresta tropical seca

It is widely accepted that selection for high milk yield in dairy cows has negatively affected their reproductive performance. After calving, dairy cows experience a nutritional imbalance due to an asynchrony in the occurrence of the lactation and dry matter intake peaks. In the tropics, this situation is exacerbated due to poor quality and/ or availability of the diet. A study was carried out to describe the nutritional and reproductive behavior of two-to-four parturition crossbred cows (Gyr (Bos indicus) x Holstein (Bos taurus)) divided in two groups according to their calving to first service interval (CFSI): Group 1: ≤50 days CFSI, n=7; Group 2: ≥50 days CFSI, n=8. Animals were grazing in an intensive silvopastoral system (ISS) based on Leucaena leucocephala and Cynodon plectostachyus and also received protein, energy and mineral supplementation. Dry matter (DMI) and nutrient intake were individually estimated and correlations between reproductive and nutritional parameters were performed. Additionally, serum progesterone concentration was monitored. Group 2 had greater forage and total DMI and milk production than Group 1 (P<0.05). Hence, Group 2 had greater nutrient intake from forages than Group 1 (P<0.05). Group 1 had a positive nutritional balance and an optimum reproductive performance compared to Group 2, which had a negative energy balance and lengthier days with open intervals (P<0.05). It was corroborated that protein and energy are required in adequate levels, to ensure that uterus undergoes involution correctly and ovarian activity starts soon in the postpartum period.(AU)

É amplamente aceito que a seleção para alta produção de leite em vacas leiteiras tem interferido no seu desempenho reprodutivo. Depois do parto, um extraordinário desafio nutritivo é experimentado pelas vacas leiteiras, devido a uma assincronia entre a ocorrência do pico de lactação e a do pico de consumo de matéria seca. Este estudo foi realizado para descrever o comportamento reprodutivo de vacas mestiças de dois a quatro partos (Gyr (Bos indicus) x Holstein (Bos taurus)), divididos em dois grupos, de acordo com seu intervalo parto ao primeiro serviço (IPPS): grupo 1: ≤ 50 dias IPPS, n = 7; grupo 2: ≥50 IPPS dias, n = 8. Os animais pastaram em um sistema silvipastoril intensivo (SSI), com base em Leucaena leucocephala e Cynodon plectostachyus, e receberam também suplementação de proteína, energia e mineral. Matéria seca (CMS) e ingestão de nutrientes foram estimadas individualmente e correlações entre parâmetros reprodutivos e nutricionais foram realizadas. Além disso, a concentração de progesterona em soro foi monitorizada. Vacas do grupo 2 apresentaram maior ingestão de forragem, de dieta total e de produção total de leite do que vacas do grupo 1 (P<0,05). Dessa forma, vacas do grupo 2 apresentaram maior consumo de nutrientes de forrageiras do que os animais do grupo 1 (P<0,05). Vacas do grupo 1 tinham um equilíbrio nutricional positivo e um ótimo desempenho reprodutivo em relação ao grupo 2, que teve um balanço energético negativo e mais longos intervalos de dias abertos (P<0,05). Foi corroborado que a proteína e a energia são necessárias em níveis adequados, assim o útero sofre involução corretamente e a atividade ovariana começa logo no período pós-parto.(AU)

Study of in vitro fermentation kinetics of mixtures of forages from intensive silvopastoral systems (SSPI) with Leucaena leucocephala in Colombia¤ / Estudio de la cinética fermentativa in vitro de mezclas de forrajes que incluyen Leucaena leucocephala proveniente de sistemas silvopastoriles intensivos (SSPi) en Colombia / Estudo in vitro da cinética fermentativa de misturas de forragens que incluem Leucaena leucocephala a partir de sistemas silvopastoris intensivos (SSPi) na Colômbia

Abstract A study of the in vitro fermentation dynamics of the forages star grass (Cynodon plectostachyus; E), Guinea grass (Megathyrsus maximus; G) and Leucaena leucocephala (L), available in intensive silvopastoral systems (ISS) was carried out. Samples of these forages were harvested in ISS set in tropical dry forest in the Valle del Cauca, Colombia. With these forages, ten mixes or different treatments were generated: E100, G100, L100, E33G66, E66G33, L33E66, L66E33, L33G66, L66G33 and L33E33G33. The shorter lag phase was observed with L100 (7.02 h) and E33G66 (7.11 h), lower (a= 0.05) than that of L33E66 (10.22 h) and G100 (9.85 h). The maximum production of gas (a) ranged between 97.34 and 253 ml/ g substrate for L100 and G100, respectively. The lowest HIP value was obtained with L100 (23.3 hours) and the gas accumulated to that point was 35.08 ml, which coincides with the lower value. The treatments that most accumulated gas were the grasses alone or their mixtures and those with the least accumulated gas included leucaena. Regarding FP, after 24 hours of incubation, the greater values occurred with L100 and mixtures that included leucaena. It is concluded that the inclusion of Leucaena was associated with decreases in the lag phase time and maximum gas production rates and with high values of FP, characteristics that may be associated with more efficient fermentation processes.

Se estudió la dinámica fermentativa in vitro de los forrajes pasto estrella (Cynodon plectostachyus; E), pasto guinea (Megathyrsus maximus; G) y leucaena (Leucaena leucocephala; L), disponibles en sistemas silvopastoriles intensivos (SSPi). Se recolectaron muestras en SSPi establecidos en bosque seco tropical en el Valle del Cauca, Colombia. Se realizaron 10 mezclas o tratamientos con diferentes porcentajes de inclusión: E100, G100, L100, E33G66, E66G33, L33E66, L66E33, L33G66, L66G33 y L33E33G33. El menor tiempo de fase Lag se observó con L100 (7,02 h) y E33G66 (7,11 h), menores (a = 0,05) a L33E66 (10,22 h) y G100 (9,85 h). Las producciones máximas de gas (a) variaron entre 97,34 y 253 ml/g sustrato para L100 y G100, respectivamente. El menor valor de HPI se obtuvo con L100 (23,3 horas) y el gas acumulado a ese punto fue 35,08 ml, que coincide con el valor más bajo. Los tratamientos de mayor acumulación de gas fueron los que incluyeron gramíneas solas o sus mezclas y los de menor acumulación de gas fueron los que incluyeron leucaena. En cuanto al FP, a las 24 horas de incubación los valores más altos se presentaron con L100 y en las mezclas que incluyeron leucaena. Se concluye que la inclusión de leucaena estuvo asociada a disminuciones en el tiempo de fase lag y tasas máximas de producción de gas, así como con altos valores de FP, características que pueden asociarse a mayor eficiencia en los procesos de fermentación.

Resumo Estudou-se a dinâmica fermentativa in vitro das forrageiras do capim estrela (Cynodon plectostachyus; E), capim coloni ão (Megathyrsus maximus; G) e leucaena (Leucaena leucocephala; L), disponíveis em sistemas silvopastoris intensivos (SSPi). Tomaram-se amostras em SSPi estabelecidos em bosque seco tropical no Vale do Cauca, Colômbia. Realizaram-se 10 misturas ou tratamentos com diferentes porcentagens de inclus ão: E100, G100, L100, E33G66, E66G33, L33E66, L66E33, L33G66, L66G33 e L33E33G33. O menor tempo da fase Lag se observou com L100 (7,02 h) e E33G66 (7,11 h), menores (a = 0,05) a L33E66 (10,22 h) e G100 (9,85 h). As produções máximas de gás (a) variaram entre 97,34 e 253 ml/g substrato para L100 e G100, respectivamente. O menor valor de HPI obteve-se com L100 (23,3 horas) e o gás acumulado nesse ponto foi 35,08 ml, que coincide com o menor valor. Os tratamentos de maior acumulação de gás foram os que incluíram gramíneas solas ou suas misturas e os de menor acumulação de gás foram os que incluíram leucaena. Em quanto ao FP, as 24 horas de incubação os valores maiores apresentaram-se com L100 e em misturas que incluíram leucaena. Pode se concluir que a inclus ão de leucaena esteve associada a diminuições no tempo de fase lag e taxas máximas de produção de gás, assim como com altos valores de FP, características que podem-se associar com a maior eficiência nos processos de fermentação.

Antioxidant capacity and acute testicular toxicity of Leucaena leucocephala aqueous shoot tips plus young leaves extracts / Capacidad antioxidante y toxicidad testicular aguda de brotes acuosos con extracto de hojas nuevas de Leucaena leucocephala

This study aimed to determine the antioxidant capacity of the Leucaena leucocephala aqueous shoot tips plus young leaves (LL-spl) extracts among three different fractions (LL-spl 10, 20, and 40 min) and to examine its acute toxicity on male reproductive parameters. The amount of the total phenolics in LL-spl extract was determined using a Folin-Ciocalteu reagent method and its antioxidant capacity was analyzed using 1, 1-diphenyl l-2-picrylhydrazyl radical scavenging and ferric reducing antioxidant powder methods. The LL-spl extract fraction with highest antioxidant capacity was used in animal treating. Male rats were divided into three groups (n= 5); control and groups treated with LL-spl 400 and 600 mg/Kg body weight for consecutive 40 days. The results showed that the LL-spl 40 min fraction possessed the highest antioxidant capacity. In addition, the LL-spl 400 and 600 groups showed no differences in weights of body, testis and epididymis, serum testosterone levels, and expression of testicular steroidogenic acute regulatory (StAR) protein. Significantly, LL-spl extract reduced the weight of seminal vesicle, sperm concentration, and seminiferous diameters compared with control. Moreover, LL-spl extract had adverse effect on testicular histology in inducing of seminiferous atrophy and degeneration including dilated blood vessels in interstitial tissue. It was concluded that although LL-spl extract possessing antioxidant capacity, in short term consumptions, it could be toxic to some male reproductive organs especially damaging testicular tissues.

El objetivo fue determinar la capacidad antioxidante del extracto de brotes acuosos con hojas nuevas de Leucaena leucocephala (LL-spl) en tres fracciones diferentes (LL-SPL 10, 20 y 40 min), además de examinar su toxicidad aguda sobre los parámetros reproductivos masculinos. Se determinó la cantidad de los fenoles totales en el extracto de LL-spl utilizando un método reactivo de Folin-Ciocalteu. La capacidad antioxidante se analizó por medio de 1-difenil-2-picrilhidracilo y/o métodos de reducción férrica de la capacidad antioxidante. La fracción de extracto LL-spl con mayor capacidad antioxidante fue utilizada en el tratamiento de los animales. Ratas macho fueron divididas en tres grupos (n= 5): el control y los grupos tratados con LL-spl 400 y 600 mg/kg peso corporal por 40 días consecutivos. El resultado mostró que la fracción LL-spl 40 min poseía la mayor capacidad antioxidante. Además, los grupos 400 y 600 LL-spl no mostraron diferencias según el peso corporal, testículos y epidídimo, niveles de testosterona y la expresión de proteínas testiculares. El extracto de LL-spl redujo de manera significativa el peso de la vesícula seminal, la concentración de espermatozoides y los diámetros de los túbulos seminíferos en comparación con el control. Por otra parte, el extracto de LL-spl tuvo un efecto adverso sobre la histología testicular por la inducción de atrofia y degeneración de los túbulos seminíferos, incluyendo a vasos sanguíneos dilatados en el tejido intersticial. Si bien el extracto LL-spl posee una capacidad antioxidante, ésta podría ser tóxica en el consumo a corto plazo para algunos órganos reproductores masculinos y especialmente dañino para los tejidos testiculares.

Chemical-bromatological compositon of leucaena hay as function of drying and storage times / Composição químico-bromatológica de feno de leucena em função do tempo de secagem e de armazenamento

The leucaena is a leguminous that has high protein content and digestibility, can be supplied fresh or made into hay. The objective was to verify the influence of dehydration time of leaves and fine stems of leucaena and storage time on their chemical-bromatological characteristics. Cutting the fractions to be haymaking (leaves and stems smaller than one centimeter) was deposited on a plastic canvas for dehydration, being collected samples of the material at 0, 4th, 8th, 24th and 48th hours of dehydration to determine the levels of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), total carbohydrates (TC), not fibrous carbohydrates (NFC), ether extract (EE) and mineral matter (MM). The bales of hay were made using a manual baler and were kept stored in environment shaded, ventilated and protected of rain for 90 days. In that bales also were collected samples monthly to determine if occurred losses in nutritional quality. The dehydration time for 24 hours and storage for 30 days in water and allowed to dry to obtain the best chemical-bromatological composition of leucaena hay. The levels of CP, NDF, EE and MM decrease as function of drying time and storage both during the rainy as in the dry season, while the DM, TC and NFC increased due to these variables for both periods.

A leucena é uma leguminosa que apresenta elevado teor protéico e digestibilidade, podendo ser fornecida fresca ou fenada. O objetivo foi verificar a influência do tempo de desidratação de folhas e caules finos de leucena e do tempo de armazenamento sobre suas características químico-bromatológicas. As frações comestíveis enfardadas (folhas e caules menores que um centímetro) foram depositadas sobre lona de plástico para desidratação, sendo coletadas amostras do material às 0, 4, 8, 24 e 48 horas de desidratação para se determinar os teores de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), carboidratos totais (CT), carboidratos não fibrosos (CNF), extrato etéreo (EE) e matéria mineral. Os fardos de feno foram confeccionados utilizando-se enfardadeira manual e foram mantidos armazenados em ambiente sombreado, ventilado e protegido da chuva por 90 dias. Mensalmente foram retiradas amostras para se determinar possíveis perdas da qualidade nutritiva. O tempo de desidratação por 24 horas e de armazenamento por 30 dias nas águas e na seca permitiram obter a melhor composição químico-bromatológica do feno de leucena. Os teores de PB, FDN e EE decresceram em função do tempo de desidratação e de armazenagem tanto no período das águas quanto no da seca, enquanto os teores de MS, CT e CNF aumentaram em função destas variáveis para ambos os períodos.

Mimosine and cyclophosphamide: a potential new combination therapy used to prevent tumor development

The effects of mimosine (MI), which is an amino acid that is derived from Leucaena leucocephala, were evaluated on the growth of ascitic Ehrlich tumors, and the effects of the combination treatment of MI and cyclophosphamide (CY) on tumor growth were also assessed. Mice were divided into groups that received the following treatments over the course of 20 days: phosphate buffer solution (CO), MI, Ehrlich cells (E), E plus CY (EC), E plus MI (EM) and E plus MI and CY (EMC). No signs of toxicity were detected in the mice from the MI group. The mice from the EMC group showed reductions in body weights when compared with those from the E group. The animals from the EC, EM and EMC groups showed reductions in ascitic volume compared with those from the E group. The mice from the EMC group showed reductions in total cell numbers of ascitic fluid compared with those from the E, EC and EM groups. The combination of MI and CY was the most effective treatment for Ehrlich tumor ascites.

Uso de protetor físico na semeadura direta para recuperação de áreas degradadas / Use of physical protector in tillage for recovery of degraded areas

A semeadura direta apresenta-se como uma técnica viável economicamente e de fácil implantação para recuperação de áreas degradadas, no entanto problemas na emergência e crescimento inicial das plântulas são fatores limitantes para sua aplicação. Portanto, o presente trabalho teve como objetivo avaliar a eficiência do uso de protetor físico na emergência e crescimento inicial de três espécies arbóreas, Anadenanthera colubrina, Leucaena leucocephala e Sena pendula. Para a proteção das espécies foram utilizados copos plásticos de 400 mL com o fundo removido, sendo que, no período de 45 dias foram avaliadas a emergência, sobrevivência e altura das plântulas. Observou-se que, a utilização de protetor físico não foi significativo para a sobrevivência e emergência das espécies estudadas, porém o crescimento inicial em altura das plantas apresentou melhores resultados nas sementes com protetores quando comparadas às sem proteção, para as espécies L. leucocephala e A. colubrina. Pode-se concluir que, dispensa-se o uso de protetor para aumentar a emergência e sobrevivência das espécies em estudo, mas este é indicado quando deseja-se obter um maior incremento em altura.

The direct seeding is presented as an economically viable technique for easy deployment and recovery of degraded areas, however problems in the emergence and early seedling growth are limiting factors for their application. Therefore, this study aimed to evaluate the effectiveness of using physical protector in the emergence and early growth of three tree species, Anadenanthera colubrine, Leucaena leucocephala e Sena pendula. For the protection of the species used were 400 mL plastic cups with the bottom removed, and, within 45 days were examined emergence, survival and seedling height. It was observed that the use of physical protector was not significant for the survival and emergence of the species, but the initial growth of plant height showed the best results with floating seeds when compared to no protection for the species L. leucocephala and A. colubrina. It can be concluded that dismissal is the use of protective emergency and to increase the survival of the species studied, but this is indicated when it is desired to obtain a greater increase in height.

Recuperação e resposta germinativa de sementes de leguminosas passadas pelo trato digestório bovino / Recovery and germination of legume seeds passed through the digestive tract of bovine cattle

A germinação de sementes pode ser influenciada pela passagem através do trato digestório animal, que, nesse caso, poderá atuar como dispersor, dependendo de como as sementes são afetadas. Quando a passagem pelo trato digestório animal não reduz a capacidade germinativa das sementes, o agente dispersor é considerado legítimo. Este trabalho aborda a influência da ingestão de sementes de Leucaena leucocephala (Lam.) de Wit, Cajanus cajan (L.) Huth e Calopogonium mucunoides Desv. por Bos taurus Linnaeus (1758), sobre sua germinação e viabilidade, com o objetivo de avaliar o gado bovino como legítimo agente dispersor dessas espécies utilizadas como forrageiras. Amostras de sementes foram misturadas ao alimento oferecido a três fêmeas de B. taurus, cujas fezes foram recolhidas até 36 horas após a ingestão e submetidas à triagem para recuperação das sementes, as quais foram testadas para germinação e crescimento inicial. Como controle foram usadas sementes intactas não ingeridas. A porcentagem de recuperação de sementes não danificadas variou de 12,3 por cento até cerca de 17,5 por cento. A ingestão pelos animais afetou severamente a capacidade de germinação das sementes de Cajanus cajan, enquanto que em Calopogonium mucunoides a redução da porcentagem de germinação ocorreu em menor escala em comparação com a primeira. No caso de L. leucocephala, a germinação não foi influenciada pelo tratamento, o que no caso pode estar relacionado a uma maior dureza do tegumento em sementes dessa espécie. Em C. mucunoides e L. leucocephala a velocidade de protrusão radicular foi ligeiramente aumentada em sementes tratadas, ao passo que o IVE da primeira foi reduzido. A ingestão também reduziu a taxa de crescimento em altura de plântulas de C. cajan, sendo o efeito menos acentuado em C. mucunoides. Em L. leucocephala, a altura média foi maior em plântulas de sementes tratadas. Os resultados sugerem que o gado bovino não pode ser considerado um legítimo dispersor para L. leucocephala, C. mucunoides e C. cajan.

Seed germination can be influenced by passage through the digestive system of animals, which can act as seed dispersers, depending on how seeds are affected. When passing through the animal digestive tract does not reduce the seeds germination, the dispersal agent is considered legitimate. The effects of ingestion by bovine cattle (Bos Taurus Linnaeus (1758)) on the viability and germination of seeds of the species Leucaena leucocephala (Lam.) de Wit, Cajanus cajan (L.) Huth and Calopogonium mucunoides Desv. was investigated in this study, aiming at evaluating the role of cattle as legitimate dispersers of those forage plants. Seed samples were mixed with the food offered to three B. taurus females, whose feces were collected 36 hours after ingestion, and seeds recovered from the feces were quantified and tested for germination and initial seedling growth. Non-ingested seeds were used as a control. The percentage of undamaged seeds recovered ranged from 12.3 to 17.5 percent. The germination capacity (germinability) of C. cajan was strongly inhibited by the cattle ingestion, whereas the germinability of C. mucunoides was less affected. The germinability of L. leucephala was not influenced by the ingestion probably due to their hard seed coat. The germination rate of C. mucunoides and L. leucocephala seeds was slightly increased by cattle ingestion, whereas the Emergence Rate Index (ERI) was reduced in the former. The ingestion by cattle also caused a decrease in the growth rate of C. cajan and C. mucunoides seedlings, although this inhibitory effect was smaller in C. cajan. The height of L. leucocephala seedlings was increased by ingestion. The results suggest that bovine cattle aren't legitimate seed dispersers of L. leucocephala, C. mucunoides and C. cajan.

Atividade anti-HSV-1 in vitro de galactomanana quimicamente sulfatada de sementes de Leucaena leucocephala / In vitro anti-HSV-1 activity of a chemically sulfated galactomannan from Leucaena leucocephala seeds

Obteve-se uma galactomanana quimicamente sulfatada (LLS-2) a partir de polissacarídeo extraído de sementes de Leucaena leucocephala, a qual apresentou 15.2% de sulfato e grau de derivatização de 0,60, e, seu efeito antiviral sobre a replicação do vírus Herpes simplex tipo 1 (HSV-1) em células Vero foi avaliado pela metodologia de redução do número de unidades formadoras de placas. LLS-2 apresentou 93.7% de inibição da replicação viral à concentração de 2,5 ?g/ml, quando adicionado durante as etapas iniciais de replicação, com um índice de seletividade maior que 1.000, sugerindo que LLS-2 inibe a ligação de HSV-1 às células hospedeiras.

A galactomannan extracted from the seeds of Leucaena leucocephala was sulfated chemically, yielding a polymer (LLS-2) with 15.2% sulfate by weight (degree of sulfation 0.60), and its effect on the replication of Herpes simplex virus 1 (HSV-1) in Vero cells was investigated. When added during infection and early replication, LLS-2 showed 93.7% inhibition of HSV-1 replication at a concentration of 2.5 ?g/mL, according to the reduction in the number of viral plaques, and a selectivity index higher than 1,000, suggesting that it inhibits HSV-1 binding to the host cell.

Comportamiento productivo de conejos alimentados con dietas basadas en follajes tropicales / Perfomance traits of rabbits fed tropical foliage based diets

Se estudió la inclusión de follaje de leucaena (Leucaena leuco-cephala), naranjillo (Trichanchera gigantea) y morera (Morus alba) en proporciones de 10; 20 y 30 por ciento en dietas balanceadas granuladas para conejos. Se distribuyeron en alojamientos individuales 80 conejos Nueva Zelanda × California en etapa de engorde (1124,1 ± 289,7 g de peso vivo) en 10 tratamientos siguiendo un diseño completamente aleatrorizado con arreglo factorial 3 × 3, los factores estuvieron representados por el tipo de forraje y los niveles de inclusión. Adicionalmente, se formuló una dieta testigo que no contenía follaje de prueba, la cual se comparó con los tratamientos dietéticos. La ganancia diaria de peso fue superior (P<0,05) en los animales que recibieron dietas con follaje de leucaena (29,49 ± 6,10) y morera (26,00 ± 6,20), con respecto a naranjillo (21,85 ± 5,62 g/conejo); de manera similar, la conversión alimenticia y la relación beneficio costo de alimentación, fueron mejores (P<0,01) en los animales que recibieron las dietas con leucaena y morera en comparación con los que consumieron la dieta con naranjillo (4,45 ± 1,41; 5,01 ± 1,57 y 5,97 ± 1,74; y 3,28; 2,82 y 2,63 bolívares, respectivamente). El nivel de inclusión y la interacción entre factores no afectaron (P>0,05) las variables estudiadas. En los conejos que recibieron la dieta testigo se observaron valores de 4,21 ± 0,94 para conversión alimenticia y 2,76 ± 0,59 bolívares (Bs) en la relación beneficio costo, los cuales fueron similares (P>0,05) a los encontrados en los demás tratamientos, aunque el crecimiento (31,78 ± 4,54 g/conejo/día) fue mayor (P<0,05) en la dieta testigo. Estos resultados permiten sugerir la incorporación hasta 30 por ciento de estos recursos en dietas balanceadas para conejos de engorde.

The inclusion of Leucaena leucocephala, Trichanchera gigantea and Morus alba foliage in pelleted rabbits diets in proportions of 10, 20 and 30 percent was studied. Eighty New Zealand × California rabbits (1124.1 ± 289.7 g of live weight) were individually allocated in 10 treatments according with a completely randomized design with factorial arrangement 3 × 3, the factors were the forages and the inclusion levels. Additionally, a control diet was formulated that didn’t contain test foliage, which was compared with the dietary treatments. The average dailygain was higher (P<0.01) in the animals that received diets with L. leucocephala (29.49) and M. alba (26.00) foliage, with regard to T. gigantea (21.85 g/rabbit). Similarly the feed conversionand the relationship benefit feeding cost was higher (P<0.01) in the animals that received L. leucocephala and M. alba with regard to T. gigantea (4.75, 5.34 and 6.30, and 3.28, 2.82 and 2.63 Bs, respectively). The inclusion level and the interaction didn’t affect (P>0.05) the studied variables. The rabbits that received the control diet showed 4.21 in feed conversion and 2.76 Bs in the relationship benefit feeding cost, and there were similar (P>0.05) with regard to other treatments; although the average daily gain (31.78 g/rabbit) was higher with the control diet. These results allow to suggest the incorporation until 30 percent of this forages in fattening rabbits diets.

Composición proximal, mineral y contenido de colesterol del músculo Longissimus dorsi de novillos criollo limonero suplementados a pastoreo / Proximate composition, mineral and cholesterol content of the Longissimus dorsi muscle of criollo limonero steers supplemented on pasture

Las muestras de músculo longissimus dorsi fueron obtenidas de 23 novillos Criollo Limonero (CL), que a los 36 meses de edad se distribuyeron aleatoriamente en cada uno de los siguientes tratamientos de suplementación, durante un período de 158 días: T1= Pastoreo (Echinochloa polystachia) no suplementado; T2= Pastoreo más 1.0Kg./animal/día de concentrado al 11 por ciento Proteína Cruda (PC) y T3= Pastoreo más 1 h/día ramoneando Leucaena leucocephala. A las 48 horas postmortem, le fue retirado un bistec del músculo longissimus dorsi para determinar el efecto de la suplementación sobre la composición proximal y mineral (Ca, Mg, Na, K, Fe, Zn, Mn, Cu, y P), y contenido de colesterol. El análisis de varianza por el método de mínimos cuadrados no indicó efectos significativos (P>0,05) de los tratamientos de suplementación sobre las variables estudiadas. Los bajos niveles de lípidos totales y contenido de colesterol de las muestras para todos los tratamientos, incluyendo la suplementación con concentrado, evidenciaron una alta magrez, lo que indica que las carnes de los novillos Criollo Limonero pudieran ser comercializadas como carnes ligeras o bajas en grasas.

Longissimus dorsi samples were obtained from 23 Criollo Limonero (CL) steers, that were subjected to supplementation treatments (at 36 months of age), during 158 d of fattening on pasture, as follows: T1= a non-suplemented (control) group, grazing on Echinochloa polystachia grass; T2= grazing plus 1 Kg/d/head of a concentrate to 11% Crude Protein (CP), and T3= grazing plus 1h/d of pruning an arboreal legume (Leucaena leucocephala). After postmortem, muscles samples were removed from their carcasses to study the effects of supplementation on the proximal (content of protein, moisture, total lipids and ash) and mineral composition (Ca, Mg, Na, K, Fe, Zn, Mn, Cu, and P), cholesterol content. Analysis of variance was conducted by the least squares method. The variance analysis did not reveal significant effect (P>0.05) of the supplementation treatments on the proximal composition, cholesterol and mineral content in the longissimus dorsi muscle. Meat derived from Criollo Limonero steers showed low levels of total lipids and cholesterol, which indicated that meat derived from these animals could be marketed as light meat or low in fat.

Caracterización de diez cultivares forrajeros de Leucaena leucocephala basada en la composición química y la degradabilidad ruminal / Chemical composition and ruminal degradability of ten fodder cultivars of Leucaena leucocephala

Objetivo. Estudiar las variaciones en la composición química y la degradabilidad ruminal dediez cultivares de Leucaena leucocephala Lam. de Wit. mediante el análisis de componentesprincipales (ACP). Materiales y métodos. Se tomaron muestras durante tres años paraevaluar la composición química, los niveles de metabolitos secundarios y la degradabilidadruminal en ovinos. Los datos fueron analizados con el paquete estadístico SPSS y medianteel diagrama tridimensional se obtuvieron las agrupaciones de las accesiones en dependenciade sus características nutritivas. Resultados. Con los primeros tres componentes del ACPse explicó el 85.83 % de la variabilidad. La concentración de proteínas, fracción fibrosa,minerales, polifenoles, fitatos y la degradación ruminal presentaron las mayores fluctuaciones.Las agrupaciones formadas permitieron identificar seis grupos con características químicasdiferentes (G1: elevada cantidad de proteínas, baja proporción de fibra y de metabolitossecundarios y elevada degradación -cv. CNIA-250 y cv. K-28-; G-2: elevado contenido demateria seca, proteínas y fenoles, poca fracción de fibra y taninos y baja degradabilidadruminal -cv. Ipil-Ipil-; G-3: composición nutricional promedio -cv. México-; G-4: bajo contenidode materia seca, fenoles, mimosina y elevada degradación ruminal -cv. Cunningham, cv. 7 ycv. América-; G-5: elevado contenido de materia seca, fenoles y valor nutritivo medio -cv.K-8 y cv. K-67-; G-6: elevado porcentaje de materia seca y taninos, y baja degradabilidad -cv. Perú-). Conclusiones. La biomasa comestible de los cultivares Cunningham, América, 7,México, CNIA-250 y K-28 constituyen las mejores opciones para la alimentación de rumiantes.

Spontaneous poisoning by Leucaena leucocephalai in a goat from Rio de Janeiro State, Brazil

Poisoning of a goat by Leucaena leucocephalai (Leg. Mimosoideae) in the State of Rio de Janeiro, Brazil, is described. Fresh leaves of the plant were ingested as the animal's main meal for at least 4 months before it developed total alopecia. At necropsy the thyroid was moderately enlarged. Histological examination revealed a decrease in the number of hair follicles (empty or in telogenic phase), vacuolation of keratinocytes of the epidermis and hair follicles, and superficial and follicular hyperkeratosis. Myxedema was found between skeletal and cardiac muscles fibers, in the kidneys, and in the submucosa/muscular layer of the digestive tract. The thyroid follicles were enlarged and filled with copious amounts of colloid (colloidal goiter). Although L. leucocephala is common in several tropical regions, natural poisoning by this plant in goats seems to be rare. It is the first report about spontaneous poisoning in goats by L. leucocephala in Brazil.

Este trabalho descreve a intoxicação natural por Leucaena leucocephalai em um caprino, no município de Maricá, RJ. No ano de 1997, o animal ingeriu voluntariamente as folhas da planta fresca como alimentação quase exclusiva, por pelo menos 4 meses, e, aos poucos, foi perdendo os pêlos até tornar-se totalmente alopécico. À necropsia, a tireóide estava moderadamente aumentada. O exame microscópico revelou decréscimo do número de folículos, além de folículos sem pêlos ou em fase telogênica, vacuolização de queratinócitos da epiderme e de folículos e acentuada hiperqueratose superficial e folicular. Havia mixedema entre fibras musculares esqueléticas e cardíacas, no rim e na submucosa, e muscular do trato digestório. Os folículos tireoideanos estavam dilatados e preenchidos por grande quantidade de colóide ("bócio coloidal"). Embora essa planta seja freqüente em várias regiões tropicais, a ocorrência natural dessa intoxicação parece bastante rara e ainda não havia sido descrita em caprinos no Brasil.

Efecto de la suplementación con leucaena (leucaena leucocephala lam. De wit) sobre la degradabilidad ruminal del pasto alemán (echinochloa polystachya h.b.k. Hitch) / Effect of Leucaena Supplementation (Leucaena leucocephala Lam. De Wit) on Ruminal Degradability of Aleman-Grass (Echinochloa polystachya H.B.K. Hitch)

Para evaluar el efecto de la suplementación con Leucaena sobre la degradabilidad de la materia seca (MS) del pasto Alemán (PA), se determinó in situ la degradabilidad potencial (a+b), fracción soluble (a), máxima a 96 h (b), tasa de degradación (c), pH ruminal y nitrógeno amoniacal. Se utilizaron tres machos Criollo Limonero castrados, con 14 días de adaptación a la dieta (F1) y 4 días de incubación (F2). Las dietas fueron: T1: PA + alimento concentrado (AC), T2: PA + Leucaena 2 kg una vez al día y T3, PA + Leucaena 2 kg suministrada 1 kg en la mañana otro en la tarde. Durante F2 las bolsas de nylon se incubaron secuencialmente, a 0; 6; 12; 24; 48; 72 y 96 horas. Se midió el pH del líquido ruminal en F2 a las 0; 3; 6; 9; 12 y 24 h. Se utilizó un diseño en cuadrado latino con tres repeticiones, la degradabilidad ruminal se analizó mediante regresión no lineal. No se encontró diferencia para a, b y c entre los tratamientos, mientras que para la a+b el valor alto (P < 0,05) se obtuvo para T3 (62,91%) en comparación con T1 y T2 (58,31 y 59,17%, respectivamente). El pH ruminal mas alto (P < 0,05) se observó en T3 (6,74), comparado con T1 y T2 (6,66; 6,65; respectivamente). Los valores de nitrógeno ruminal fueron 405,00; 486,14 y 508,25 mg L-1 para T1, T2 y T3, respectivamente. Se concluye que el suministro de L. leucocephala dos veces por día, mejora la degradabilidad del pasto Alemán.

To evaluate the effects of Leucaena supplementation on in situ ruminal dry matter (DM) degradability of Aleman-grass (AG), DM potential degradability (a+b), soluble fraction (a), maximum degradability (DM), degradation rate (c), ruminal pH and ammonia nitrogen, three ruminal cannulated Criollo Limonero steers were fed at 14-day adaptation period (F1) and samples were taken during the following 4-day period (F2). Diets were: T1, Aleman-grass (AG) + concentrate (CO); T2, PA + 2 kg Leucaena once a day and T3, PA + 2 kg Leucaena twice a day. During F2 nylon bags were sequentially incubated on 0; 6; 12; 24; 48; 72 and 96 h, and rumen contents pH were measured on 0; 3; 6; 9; 12 y 24 h post feeding. A Latin Square design with three replications was used and ruminal degradability data was analyzed by nonlinear regression model. No differences between treatments were found for a, b and c. a+b was higher (P < 0.05) on T3 (62.91%) than T1 (58.31%) or T2 (59.17%). Ruminal pH was higher (P < 0.05) in T3 (6.74) than T1 (6.66) and T2 (6.65). Ammonia nitrogen values were 405.00; 486.14 and 508.25 mg L-1 for T1, T2 y T3, respectively. It was conclude that L. leucocephala fed twice a day increases DM degradability of Aleman-grass.