Distúrbios metabólicos por manejo alimentar inadequado em ruminantes: novos conceitos

In the “top” cattle farming, the metabolic problems are frequent due to the necessity of getting an animal that presents a high performance. One of the main problems found in this type of activity is the extreme concentration of food supply. Among the main metabolic disorders are ruminal acidosis, bloat, ketosis and hepatic lipidosis. The metabolic disorders’ damages are rarely visible because, most of times, these illnesses don’t show clinical signals. There are ways to manipulate the rumen to minimize the metabolic disorders that can be at the animal level, the diet or rumen microorganisms, such as the use of residues and by-products from the agro-industry in the animal feeding. More researches are necessary to completely understand the influence of the nutrition handling on the metabolic disorders.En las llamadas ganaderías “elite” los problemas metabólicos son frecuentes debido a la necesidad de obtener un elevado desempeño animal. Uno de los principales problemas observados en esos sistemas es la elevada oferta de alimentos concentrados. Dentro de los principales desórdenes metabólicos se destacan la acidosis ruminal, timpanismo, cetosis e hígado graso. Los perjuicios ocasionados por estos problemas no son visibles, ya que muchas veces no aparecen síntomas clínicos. Existen formas de manipular el rumen para evitar estos trastornos, a través de la dieta, del animal o de los microorganismos ruminales, como puede ser el uso de ciertos alimentos. Son necesarias más investigaciones sobre la influencia del manejo alimenticio para evitar la incidencia de estos disturbios y poder entenderlos mejor

Glicerina cruda en la dieta de bovinos: efecto sobre los parámetros bioquímicos séricos

El objetivo fue evaluar posibles alteraciones en los valores bioquímicos séricos de bovinos de engorde confinados, recibiendo elevadas concentraciones de glicerina cruda en la dieta. Treinta novillos Nelore fueron utilizados para las colectas de sangre, las cuales se realizaron cada 28 días. Los animales fueron confinados durante 103 días, alimentados con cinco dietas experimentales con 0; 7.5; 15; 22.5 y 30% de glicerina cruda en la materia seca, formuladas para obtener una relación entre forraje: concentrado de 30:70, en la que el ensilaje de maíz fue la fuente forrajera, y el concentrado compuesto por grano de maíz, cascarilla de soya, torta de girasol, glicerina cruda, carbonato de calcio, fosfato bicálcico y sal común. Se utilizó un diseño en bloques al azar, con cinco tratamientos y seis repeticiones, utilizando contrastes ortogonales para determinar los efectos lineal, cuadrático y cúbico de la adición de glicerina. Hubo un efecto lineal de la adición de glicerina sobre las concentraciones de creatina quinasa (P=0.02), cuadrático sobre la de alanina amino transferasa (P=0.009), cúbico sobre la de urea y creatinina (P=0.008 e P=0.002, respectivamente). La adición de glicerina, considerando el tratamiento control, afectó significativamente (P<0.05) las concentraciones de amino transferasa, alanina amino transferasa y creatinina dietas para bovinos tipo carne, con elevadas proporciones de glicerina, ocasionan alteraciones en los parámetros bioquímicos séricos de los animales

Glicerina bruta na dieta de bovinos de corte confinados: efeito sobre o hemograma

Objetivou-se com este estudo avaliar o hemograma de bovinos alimentados com glicerina bruta. Trinta novilhos da raça Nelore foram utilizados para as colheitas de sangue, as quais foram realizadas a cada 28 dias. Os animais foram mantidos confinados durante 103 dias e foram alimentados com cinco dietas contendo 0, 7,5, 15, 22,5 e 30% de glicerina bruta com base na matéria seca, formuladas na proporção volumoso:concentrado de 30:70 sendo a silagem de milho o volumoso e o concentrado composto por milho em grão, casca de soja, farelo de girassol, glicerina, calcário calcítico, fostatobicálcico e sal comum. O delineamento utilizado foi em blocos casualisados com cinco tratamentos. Contrastes ortogonais foram usados para determinar os efeitos linear, quadrático, cúbico e tratamento com glicerina × controle. Não houve efeito dos tratamentos (P>0,05) sobre as concentrações sanguíneas de hemácias, hematócrito, basófilos, eosinófilos, neutrófilos bastonetes e linfócitos, porém houve efeito linear sobre as concentrações de plaquetas, hemoglobina e monócitos (P=0,009, P=0,001 e P=0,043, respectivamente), e efeito cúbico sobre as concentrações de leucócitos totais e neutrófilos segmentados (P=0,008 e P=0,004, respectivamente). Dietas para bovinos de corte, contendo relação volumoso:concentrado 30:70 aditivadas com glicerina bruta, promovem alterações no eritrograma e no leucograma destes animais.The aim of this study was to evaluate the hemogram in cattle fed crude glycerin. 30 Nellore steers, were used for blood sampling, which were done each 28 days. The animals were confined for 103 days and were fed with five diets containing 0, 7.5, 15, 22.5 and 30% crude glycerin based on dry matter, formulated in a forage:concentrate ratio of 30:70. Corn silage was used as forage and the concentrate was composed by corn grain, soybean hulls, sunflower meal, glycerin, limestone, dicalcium phosphate and salt. The experimental design was a randomized block with Five treatments. Orthogonal contrasts were used to determine the linear, quadratic, cubic effects and gliceryn treatments × the control one. There was no treatment effect (P>0,05) on blood concentrations of erythrocytes, hematocrit, basophils, eosinophils, band neutrophils and lymphocytes, but were linearly effect on the concentrations of platelets, hemoglobin and monocytes (P=0.009, P=0.001 and P=0.043, respectivelly), and cubic effect on the concentrations of total leukocytes and segmented neutrophils (P=0.008 and P=0.004, respectivelly). Diets for beef cattle, with forage:concentrate ratio of 30:70 added with crude glycerin promote changes in the erytrhogram and leucogram of these animals.

Performance of the 2007 WHO Algorithm to diagnose Smear-negative Pulmonary Tuberculosis in a HIV prevalent setting

The 2007 WHO algorithm for diagnosis of smear-negative pulmonary tuberculosis (PTB) including Mycobacterium tuberculosis (MTB) culture was evaluated in a HIV prevalent area of Kenya

Sources and management of nitrogen before or after irrigation on the winter wheat and bean production

Studies that demonstrate the effects of sources of nitrogen (N) applied before or after irrigation on the yield of winter crops are limited in literature. In this sense, the objective of this study was to compare the effect of sources of N applied immediately before or after 13 mm irrigation of wheat and bean winter crops. It was used a randomized complete block design, with 4 replicates, in a 5 × 2 + 1 factorial scheme, and 11 treatments consisted of five N sources: urea, polymer-coated urea, urea + ammonium sulfate, ammonium sulfate, and ammonium nitrate and a control treatment (without N fertilization). For wheat, although ammonium nitrate provided great N content in the leaves, the grain yield was lower due to the lodging of the plants; since the application of N either before or after irrigation did not influence the grain yield. Regarding the bean, N fertilization increased productivity, but there were no differences among N sources and, despite the greater N content in the leaves observed with the N supply before irrigation the greatest grain yield was observed when N was applied after the irrigation

The discovery, distribution, and evolution of viruses associated with drosophila melanogaster

Drosophila melanogaster is a valuable invertebrate model for viral infection and antiviral immunity, and is a focus for studies of insect-virus coevolution. Here we use a metagenomic approach to identify more than 20 previously undetected RNA viruses and a DNA virus associated with wild D. melanogaster. These viruses not only include distant relatives of known insect pathogens, but also novel groups of insect-infecting viruses. By sequencing virus-derived small RNAs we show that the viruses represent active infections of Drosophila. We find that the RNA viruses differ in the number and properties of their small RNAs, and we detect both siRNAs and a novel miRNA from the DNA virus. Analysis of small RNAs also allows us to identify putative viral sequences that lack detectable sequence similarity to known viruses. By surveying >2000 individually collected wild adult Drosophila we show that more than 30% of D. melanogaster carry a detectable virus, and more than 6% carry multiple viruses. However, despite a high prevalence of the Wolbachia endosymbiont—which is known to be protective against virus infections in Drosophila—we were unable to detect any relationship between the presence of Wolbachia and the presence of any virus. Using publicly available RNA-seq datasets we show that the community of viruses in Drosophila laboratories is very different from that seen in the wild, but that some of the newly discovered viruses are nevertheless widespread in laboratory lines and are ubiquitous in cell culture. By sequencing viruses from individual wild-collected flies we show that some viruses are shared between D. melanogaster and D. simulans. Our results provide an essential evolutionary and ecological context for host-virus interaction in Drosophila, and the newly reported viral sequences will help develop D. melanogaster further as a model for molecular and evolutionary virus research

Aspectos fundamentales del crecimiento en ovinos

The animal growth is a complex process regulated and affected by several factors. Aspects such as age, genetics, the physiological stage, the nutritional status, calving type, among others, effect the sheep growth. Recent advances in this field have achieved a better understanding of regulation of growth, but without clarifying several points. The compensatory growth is used as a management strategy for profit in animal productions and it is also used in sheep. The objective of this review was to gather information on key concepts of the sheep growth physiology to provide a better understanding of the mechanisms involved in this process.El crecimiento de los animales es un proceso complejo, regulado y afectado por varios factores. Aspectos como la edad, la genética, el tipo de animal, la fase fisiológica, el estado nutricional, tipo de parto, entre otros, influyen en el crecimiento de ovinos. Los avances en este campo han logrado un mejor entendimiento de los procesos que rigen el crecimiento, pero sin aclarar varios puntos. La ganancia compensatoria es utilizada con fines lucrativos en la producción animal y está siendo utilizada en los ovinos. El objetivo de esta revisión fue recopilar información sobre los principales conceptos de la fisiología del crecimiento en el ganado ovino para proporcionar una mejor comprensión de los mecanismos implicados en este proceso

Glicerina bruta em dietas para bovinos da raça Nelore confinados

Objetivou-se neste estudo avaliar a inclusão de glicerina bruta em dietas para bovinos da raça Nelore e seu efeito sobre o comportamento ingestivo, consumo, desempenho, parâmetros sanguíneos, características de carcaça e carne, digestibilidade, degradabilidade, parâmetros ruminais, produção de CH4 e CO2 e da massa microbiana. Cinco dietas experimentais foram testadas: G0 - controle sem adição de glicerina, G7,5 - 7,5% de glicerina na matéria seca da dieta, G15 - 15% de glicerina na matéria seca da dieta, G22,5 - 22,5% de glicerina na matéria seca da dieta e G30 - 30% de glicerina na matéria seca da dieta. No primeiro experimento foram utilizados bovinos (n=30, machos, não castrados, raça Nelore, 277,7kg PC, 18 meses de idade) distribuídos em delineamento em blocos ao acaso. Foram avaliados, durante 103 dias de confinamento, o consumo de MS e de nutrientes, GMD, CA, EA, além do comportamento ingestivo. No segundo experimento foram avaliados os parâmetros sanguíneos dos animais do confinamento e pesos de carcaça quente e fria, rendimento de carcaça, AOL, GSUB, além da composição centesimal, perfil de AG, colesterol e análise sensorial da carne. No terceiro experimento foram avaliadas as digestibilidades da MS e de nutrientes e a degradabilidade ruminal dos ingredientes utilizados. Para as incubações ruminais foram utilzados bovinos (n=5, machos castrados, raça Nelore, 400kg PC, 24 meses de idade) dotados de cânulas ruminais permanentes e distribuídos em delineamento em quadrado latino (5 × 5). No quarto experimento foram avaliados pH, N-NH3, AGCC, produção de CH4 e CO2, além das bactérias sólido-aderidas e bactérias e protozoários líquido associados. A inclusão de até 30% de glicerina deprimi a digestibilidade e degradabilidade da fibra, diminui a produção de CH4 e CO2 e interfere negativamente na produção...The objective of this study was to evaluate the inclusion of crude glycerin in diets for Nellore cattle and its effect on ingestive behavior, intake, performance, blood parameters, characteristics of carcass and meat, digestibility, degradability, ruminal parameters, production of CH4 and CO2 and microbial mass. Five experimental diets were tested: G0 - control without addition of glycerin, G7, 5 - 7.5% glycerin in the diet dry matter, G15 - 15% glycerin in the diet dry matter, G22, 5 - 22.5% glycerin in the diet dry matter and G30 - 30% glycerin in the diet dry matter. In the first experiment bovine (n=30, steers, Nellore, BW 277.7 kg, 18 months old) distributed in a randomized block design were used. It was evaluated during 103 days of feedlot, DM and nutrient intake, ADG, G:F, F:G, and ingestive behavior. The second experiment evaluated the blood parameters of animals in the feedlot, hot and cold carcass weights, LM, SF, and the proximate composition, fatty acid profile, cholesterol and sensory analysis of meat. In the third experiment it was evaluated the dry matter and nutrient digestibility and ingredients degradability. For rumen incubations, cattle (n=5 steers, Nellore, BW 400kg, 24 months old) fitted with permanent ruminal cannulas and distributed in Latin square design (5 × 5) were used. In the fourth experiment it was evaluated pH, N-NH3, SCFA, production of CH4 and CO2, in addition to the particle-associated bacteria and liquid-associated protozoa and bacteria. The inclusion of up to 30% glycerin depresses fiber digestibility and degradability, decreases production of CH4 and CO2 and has negative impact on the production of particle-associated bacteria, and it does not promote changes in performance variables... (Complete abstract click electronic access below)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Use of acids as additives in sugarcane silage

Background: sugarcane silage often becomes a problem for the producers due to its high population of yeast and its high content of soluble carbohydrates. Objective: to evaluate the effect of formic and phosphoric acid on the chemical composition, fermentation characteristics, and digestibility of sugarcane silages. Methods: sugarcane was ensiled in experimental mini-silos. Five treatments were evaluated in the ensilage process (sugarcane added with 0.5 or 1% formic acid and 0.5 or 1% phosphoric acid, and a control treatment without additives). A completely randomized design was used. Results: the dry matter content of silages containing phosphoric acid was lower. Lower values of NDF, ADF, and hemicellulose were observed in the control and formic acid treatments. Conclusions: formic and phosphoric acids promote beneficial changes in the chemical composition of sugar cane silage