Hepatic and renal lesions in sheep intoxicated with Urochloa hybrid Mulato II in Argentina.

A flock of 48 sheep in Argentina grazing on a pasture of hybrid Urochloa (formerly Brachiaria) Mulato II (Urochloa ruziziensis × Urochloa decumbens × Urochloa brizantha) developed facial dermatitis, severe jaundice, and weakness after brief physical activity. Blood biochemistry of 3 animals revealed azotemia, elevated aspartate aminotransferase activity, and increased direct, indirect, and total bilirubin concentrations. The urine was markedly turbid and contained large concentrations of bile pigments and protein. At autopsy of 2 animals, there was severe jaundice and subcutaneous submandibular edema. The livers were enlarged, intensely yellow, and had a marked acinar pattern. Gallbladders were distended, and the kidneys were diffusely dark in one animal and yellow-green in the other. Microscopically, there was lymphoplasmacytic and histiocytic cholangiohepatitis with abundant crystals in the lumen of bile ducts and in the cytoplasm of macrophages. The proximal and distal convoluted renal tubules had protein casts in their lumens, and crystals were observed in the lumen and epithelial cells. Lectin histochemistry showed strong affinity for Arachis hypogaea agglutinin in hepatic macrophages. In the one sheep that was tested for heavy metals, copper concentrations in the liver and kidney were within the RIs. Despite the immediate change of pasture, morbidity and mortality were 100% within 3 mo. The association between the consumption of this pasture, and the clinical, biochemical, pathology, and lectin histochemistry findings confirmed intoxication with Urochloa hybrid Mulato II. To our knowledge, intoxication by this hybrid of Urochloa has not been reported previously.

Nutritional Quality, Voluntary Intake and Enteric Methane Emissions of Diets Based on Novel Cayman Grass and Its Associations With Two Leucaena Shrub Legumes.

Methane (CH4) emissions from enteric fermentation in cattle are an important source of greenhouse gases, accounting for about 40% of all agricultural emissions. Diet quality plays a fundamental role in determining the magnitude of CH4 emissions. Specifically, the inclusion of feeds with high digestibility and nutritional value have been reported to be a viable option for reducing CH4 emissions and, simultaneously, increase animal productivity. The present study aimed to evaluate the effect of the nutritional composition and voluntary intake of diets based on tropical forages upon CH4 emissions from zebu steers. Five treatments (diets) were evaluated: Cay1: Urochloa hybrid cv. Cayman (harvested after 65 days of regrowth: low quality); Cay2: cv. Cayman harvested after 45 days of regrowth; CayLl: cv. Cayman + Leucaena leucocephala; CayLd: cv. Cayman + Leucaena diversifolia; Hay: Dichantium aristatum hay as a comparator of common naturalized pasture. For each diet representing different levels of intensification (naturalized pasture, improved pasture, and silvopastoral systems), CH4 emissions were measured using the polytunnel technique with four zebu steers housed in individual chambers. The CH4 accumulated was monitored using an infrared multigas analyzer, and the voluntary forage intake of each animal was calculated. Dry matter intake (DMI, % of body weight) ranged between 0.77 and 2.94 among diets offered. Emissions of CH4 per kg of DMI were significantly higher (P < 0.0001) in Cay1 (60.4 g), compared to other treatments. Diets that included Leucaena forage legumes had generally higher crude protein contents and higher DMI. Cay1 and Hay which had low protein content and digestibility had a higher CH4 emission intensity (per unit live weight gain) compared to Cay2, CayLl and CayLd. Our results suggest that grass consumed after a regrowth period of 45 days results in lower CH4 emissions intensities compared to those observed following a regrowth period of 65 days. Diets with Leucaena inclusion showed advantages in nutrient intake that are reflected in greater live weight gains of cattle. Consequently, the intensity of the emissions generated in the legume-based systems were lower suggesting that they are a good option for achieving the emission reduction goals of sustainable tropical cattle production.

Nitrogen requirement of Brachiaria hybrid cv. Ipyporã / Exigência em nitrogênio de Brachiaria hibrida cv. BRS Ipyporã

Ipyporã grass, a Brachiariainterspecific hybrid was developed by crossing a genotype of Brachiaria ruziziensis(syn. Urochloa ruziziensis) and an access of Brachiaria brizantha(syn. Urochloa brizantha), which have different nitrogen requirements. Therefore, the objective with work was to verify the nitrogen requirement of the interspecific hybrid of Brachiaria hybrid cv. Ipyporã. Experiment was carried out in a greenhouse in a randomized block design, with twelve treatments and four replications. Treatments consisted of a 4 x 3 factorial arrangement, with four nitrogen doses (0; 100; 200 and 300 mg/dm³) and three forages (Brachiaria hybrid cv. BRS Ipyporã, Brachiaria humidicolacv. Llanero and Panicum maximum cv. Zuri). Each experimental plot consisted of a 3 dm³ pot with three plants. Three evaluation harvest were done. B. hybrid had greater response to nitrogen fertilization for number of tillers and leaves than the other forages. However, for the total dry mass, B. hybrid was less responsive to nitrogen than P. maximumgrass (high demand) and more responsive than B. humidicola (low demand), which shows that this hybrid has medium nitrogen requirement.(AU)

O capim Ipyporã, um híbrido interespecífico de Brachiaria, foi desenvolvido através do cruzamento de um genótipo de Brachiaria ruziziensis(sin. Urochloa ruziziensis) e um acesso de Brachiaria brizantha(sin. Urochloa brizantha), que possuem diferentes exigências de nitrogênio. O objetivo com este trabalho foi verificar a necessidade de nitrogênio do híbrido interespecífico de Brachiaria hibrida cv. Ipyporã. O experimento foi conduzido em casa de vegetação, em delineamento de blocos ao acaso, com doze tratamentos e quatro repetições. Os tratamentos corresponderam a um fatorial 4x3, sendo quatro doses de nitrogênio (0, 100, 200 e 300 mg/dm3) e três gramíneas forrageiras (B. hibridacv. BRS Ipyporã, B. humidicola cv. Llanero e Panicum maximum cv. Zuri). Cada parcela experimental foi constituída por vaso de 3 dm³ com três plantas. Foram realizados três cortes de avaliação. A B. hibrida Ipyporã obteve maior resposta à adubação nitrogenada para número de perfilhos e de folhas em relação aos demais capins. Entretanto, para a massa seca total, observou-se que a B. hibrida foi menos responsiva ao nitrogênio que o capim P. maximum(alta exigência) e mais responsivo que B. humidicola (baixa exigência), o que mostra que esse híbrido é uma forrageira com média demanda em nitrogênio.(AU)

Nitrogen requirement of Brachiaria hybrid cv. Ipyporã / Exigência em nitrogênio de Brachiaria hibrida cv. BRS Ipyporã

Ipyporã grass, a Brachiariainterspecific hybrid was developed by crossing a genotype of Brachiaria ruziziensis(syn. Urochloa ruziziensis) and an access of Brachiaria brizantha(syn. Urochloa brizantha), which have different nitrogen requirements. Therefore, the objective with work was to verify the nitrogen requirement of the interspecific hybrid of Brachiaria hybrid cv. Ipyporã. Experiment was carried out in a greenhouse in a randomized block design, with twelve treatments and four replications. Treatments consisted of a 4 x 3 factorial arrangement, with four nitrogen doses (0; 100; 200 and 300 mg/dm³) and three forages (Brachiaria hybrid cv. BRS Ipyporã, Brachiaria humidicolacv. Llanero and Panicum maximum cv. Zuri). Each experimental plot consisted of a 3 dm³ pot with three plants. Three evaluation harvest were done. B. hybrid had greater response to nitrogen fertilization for number of tillers and leaves than the other forages. However, for the total dry mass, B. hybrid was less responsive to nitrogen than P. maximumgrass (high demand) and more responsive than B. humidicola (low demand), which shows that this hybrid has medium nitrogen requirement.

O capim Ipyporã, um híbrido interespecífico de Brachiaria, foi desenvolvido através do cruzamento de um genótipo de Brachiaria ruziziensis(sin. Urochloa ruziziensis) e um acesso de Brachiaria brizantha(sin. Urochloa brizantha), que possuem diferentes exigências de nitrogênio. O objetivo com este trabalho foi verificar a necessidade de nitrogênio do híbrido interespecífico de Brachiaria hibrida cv. Ipyporã. O experimento foi conduzido em casa de vegetação, em delineamento de blocos ao acaso, com doze tratamentos e quatro repetições. Os tratamentos corresponderam a um fatorial 4x3, sendo quatro doses de nitrogênio (0, 100, 200 e 300 mg/dm3) e três gramíneas forrageiras (B. hibridacv. BRS Ipyporã, B. humidicola cv. Llanero e Panicum maximum cv. Zuri). Cada parcela experimental foi constituída por vaso de 3 dm³ com três plantas. Foram realizados três cortes de avaliação. A B. hibrida Ipyporã obteve maior resposta à adubação nitrogenada para número de perfilhos e de folhas em relação aos demais capins. Entretanto, para a massa seca total, observou-se que a B. hibrida foi menos responsiva ao nitrogênio que o capim P. maximum(alta exigência) e mais responsivo que B. humidicola (baixa exigência), o que mostra que esse híbrido é uma forrageira com média demanda em nitrogênio.

The effect of different grazing heights on carcass and meat quality characteristics of Nellore cattle fattened in pastures of Convert grass.

Carcass characteristic and meat quality from bulls and Nellore steers (n = 64 total) subjected to different grazing heights (15, 25, 35, and 45 cm) were evaluated isolatedly, under continuous grazing and variable load, in pastures of Convert grass. The experimental period was from May 2015 to June 2017, in an area of 16 ha, divided into 16 paddocks of 1 ha. The experimental design was randomized blocks with four replications. Each paddock was grazed by three animals and regulators, used to adjust grazing heights. The final slaughter weight, hot carcass, and crude protein in the meat of steers were higher when the pastures were managed at 42 cm. When the pasture was managed between 25 and 35 cm in height, greater fat thickness, marbling, muscle:bone and muscle+fat:bone ratio and lower color* of the meat and percentage of bone were found. For the steers, the height of 40 cm provided higher fat thickness and marbling in the meat. The loss during thawing in meat was greater at 28 cm in height. The heights of grazing alter the carcass characteristics and meat of bulls and steers.

Can silicon (Si) fertilization influence the production and nutritional value of Urochloa Convert HD364? / A fertilização por silício (Si) pode influenciar a produção e o valor nutricional da Urochloa Convert HD364?

Tropical soils are highly weathered, acidic, and low in silicon (Si) availability for plants. Si has been considered an essential nutrient for many grasses. Urochloa Convert HD364 is classified as a forage plant that accumulates Si, but the accumulation of this nutrient in the leaf can influence qualitative characteristics, fiber quality, plant architecture, and development of forage. In this study, we aimed to evaluate the production and nutritive value of Urochloa hybrid cultivar Convert HD364 (CIAT 36087) grown from soils collected in the state of Paraná, Brazil. The experiment was carried out in a greenhouse using 8-L plastic pots and three types of soil. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils [Rhodic Acrudox (Ox1), Rhodic Hapludox (Ox2) and Arenic Hapludult (Ult)] and five silicate rates (0, 1, 2, 4 and 6 Mg ha-1 of calcium/magnesium silicate), with four replications. Application of CaSiO3 to the soil increases the concentration of Si in the leaves of Urochloa Convert HD364. The dry matter, crude protein and mineral matter, fiber quality, and digestibility of Urochloa were not influenced by the increase in Si levels in the leaves until 45 days after seeding. Forty-five days after planting, CaSiO3 did not interfere with the growth characteristics and production of Urochloa Convert HD364. There is no evidence that the increased Si levels in the leaf affected the production and nutritive value, especially fiber quality of Urochloa Convert HD364 until 45 days after sedding.(AU)

Os solos tropicais são altamente intemperizados, ácidos e com baixa disponibilidade de silício (Si) para as plantas. O Si tem sido considerado um nutriente essencial para muitas gramíneas. A Urochloa Convert HD364 é classificada como planta forrageira que acumula Si, mas o acúmulo desse nutriente na folha pode influenciar as características qualitativas, qualidade da fibra, arquitetura da planta e no desenvolvimento da forragem. Neste trabalho, objetivou-se avaliar a produção e o valor nutritivo da Urochloa cv. Convert HD364 (CIAT 36087), cultivado em três solos coletados no estado do Paraná, Brasil. O experimento foi conduzido em casa de vegetação com vasos plásticos de 8 L e três tipos de solo. Os tratamentos foram arranjados em blocos casualizados em esquema fatorial 3 × 5: três solos [Latossolo Vermelho distrférrico (Ox1), Latossolo Vermelho eutroférrico (Ox2) e Argisolo Vermelho-Amarelo (Ult)] e cinco doses de silicato (0, 1, 2, 4 e 6 Mg ha- 1 de silicato de cálcio / magnésio), com quatro repetições. A aplicação de CaSiO3 no solo aumenta a concentração de Si nas folhas de Urochloa Convert HD364. A matéria seca, proteína bruta, matéria mineral, qualidade da fibra e digestibilidade da Urochloa Convert HD364 não foram influenciadas pelo aumento nos teores de Si nas folhas até 45 dias após a semeadura. Quarenta e cinco dias após o plantio, o CaSiO3 não interferiu nas características de crescimento e produção do Urochloa Convert HD364. Não há evidências de que o aumento dos níveis de Si na folha tenha afetado a produção e o valor nutritivo, especialmente a qualidade da fibra, de Urochloa Convert HD364 até 45 dias após a semeadura.(AU)

Can silicon (Si) fertilization influence the production and nutritional value of Urochloa Convert HD364? / A fertilização por silício (Si) pode influenciar a produção e o valor nutricional da Urochloa Convert HD364?

Tropical soils are highly weathered, acidic, and low in silicon (Si) availability for plants. Si has been considered an essential nutrient for many grasses. Urochloa Convert HD364 is classified as a forage plant that accumulates Si, but the accumulation of this nutrient in the leaf can influence qualitative characteristics, fiber quality, plant architecture, and development of forage. In this study, we aimed to evaluate the production and nutritive value of Urochloa hybrid cultivar Convert HD364 (CIAT 36087) grown from soils collected in the state of Paraná, Brazil. The experiment was carried out in a greenhouse using 8-L plastic pots and three types of soil. Treatments were arranged in a randomized block design in a 3 × 5 factorial: three soils [Rhodic Acrudox (Ox1), Rhodic Hapludox (Ox2) and Arenic Hapludult (Ult)] and five silicate rates (0, 1, 2, 4 and 6 Mg ha-1 of calcium/magnesium silicate), with four replications. Application of CaSiO3 to the soil increases the concentration of Si in the leaves of Urochloa Convert HD364. The dry matter, crude protein and mineral matter, fiber quality, and digestibility of Urochloa were not influenced by the increase in Si levels in the leaves until 45 days after seeding. Forty-five days after planting, CaSiO3 did not interfere with the growth characteristics and production of Urochloa Convert HD364. There is no evidence that the increased Si levels in the leaf affected the production and nutritive value, especially fiber quality of Urochloa Convert HD364 until 45 days after sedding.

Os solos tropicais são altamente intemperizados, ácidos e com baixa disponibilidade de silício (Si) para as plantas. O Si tem sido considerado um nutriente essencial para muitas gramíneas. A Urochloa Convert HD364 é classificada como planta forrageira que acumula Si, mas o acúmulo desse nutriente na folha pode influenciar as características qualitativas, qualidade da fibra, arquitetura da planta e no desenvolvimento da forragem. Neste trabalho, objetivou-se avaliar a produção e o valor nutritivo da Urochloa cv. Convert HD364 (CIAT 36087), cultivado em três solos coletados no estado do Paraná, Brasil. O experimento foi conduzido em casa de vegetação com vasos plásticos de 8 L e três tipos de solo. Os tratamentos foram arranjados em blocos casualizados em esquema fatorial 3 × 5: três solos [Latossolo Vermelho distrférrico (Ox1), Latossolo Vermelho eutroférrico (Ox2) e Argisolo Vermelho-Amarelo (Ult)] e cinco doses de silicato (0, 1, 2, 4 e 6 Mg ha- 1 de silicato de cálcio / magnésio), com quatro repetições. A aplicação de CaSiO3 no solo aumenta a concentração de Si nas folhas de Urochloa Convert HD364. A matéria seca, proteína bruta, matéria mineral, qualidade da fibra e digestibilidade da Urochloa Convert HD364 não foram influenciadas pelo aumento nos teores de Si nas folhas até 45 dias após a semeadura. Quarenta e cinco dias após o plantio, o CaSiO3 não interferiu nas características de crescimento e produção do Urochloa Convert HD364. Não há evidências de que o aumento dos níveis de Si na folha tenha afetado a produção e o valor nutritivo, especialmente a qualidade da fibra, de Urochloa Convert HD364 até 45 dias após a semeadura.