Ivan Barbosa Machado Sampaio

Degradabilidade in situ da matéria seca de forrageiras tropicais obtidas em diferentes épocas de corte

The ruminal degradability of 10 tropical forages at three cutting times (21, 42 and 63 days) incubated at 6, 24 and 96 hours using the in situ technique was estimated. The forages were: Andropogon gayanus cv. Planaltina, Brachiaria brizantha (accesses 3401, 3413, 3451 CPAC), Cenchrus ciliaris (accesses 79119, 79146, 79148, 80199 and 81302 CPATSA) and Panicum maximum (3616 CPAC). The accesses of B. brizantha, P. maximum and A. gayanus cv Planaltina presented the highest dry matter degradability values and the accesses of C. ciliaris the lowest. For all forages, increased cutting age led to dry matter reduction. The accesses of B. brizantha 3413 and 3451 presented the best effective degradabilities.

Quantitative analysis of cardiac lesions in chronic canine chagasic cardiomyopathy.

Lesions observed in chronic chagasic cardiopathy frequently produce electrocardiographic alterations and affect cardiac function. Through a computerized morphometrical analysis we quantified the areas occupied by cardiac muscle, connective and adipose tissues in the right atrium of dogs experimentally infected with Trypanosoma cruzi. All of the infected dogs showed chronic myocarditis with variable reduction levels of cardiac muscle, fibrosis and adipose tissue replacement. In the atrial myocardium of dogs infected with Be78 and Be62 cardiac muscle represented 34 and 50%, fibrosis 28 and 32% and adipose tissue 38 and 18%, respectively. The fibrosis observed was both diffuse and focal and mostly intrafascicular, either partially or completely interrupting the path of muscle bundles. Such histological alterations probably contributed to the appearance of electrocardiographic disturbances verified in 10 out 11 dogs which are also common in human chronic chagasic cardiopathy. Fibrosis was the most important microscopic occurrence found since it produces rearrangements of collagen fibers in relation to myocardiocytes which causes changes in anatomical physiognomy and mechanical behavior of the myocardium. These abnormalities can contribute to the appearance of cardiac malfunction, arrythmias and congestive cardiac insufficiency as observed in two of the analyzed dogs. Strain Be78 caused destruction of atrial cardiac muscle higher than that induced by strain Be62.

[Multiple causes of death due to non-communicable diseases: a multidimensional analysis]

This study approaches multiple causes of death to analyze the associations between causes of death from non-communicable diseases, age, and gender in 3,106 death certificates issued in 1998, comprising individuals who were 20 years old or over and resided in Belo Horizonte, Minas Gerais State, Brazil. The multiple cause of death approach, by considering all the diagnoses mentioned in the death certificate, highlights conditions that are underestimated by the underlying-cause approach that has traditionally been used in mortality statistics. Association of causes of death was analyzed using the multidimensional data analysis method with the multiple correspondence factor analysis technique. The results reinforce the usefulness of the multiple causes approach to improve information on mortality and demonstrate important associations, such as hypertension and cerebrovascular diseases, obesity and diabetes or ischemic heart diseases, allowing to plan, prioritize, and reevaluate health actions.

The ecology of horse cyathostomin infective larvae (Nematoda-Cyathostominae) in tropical southeast Brazil

Experimental studies about the recovery, survival and migration to pasture of cyathostomin infective larvae (L(3)) from fresh feces depositions were conducted from February 2005 to March 2007 in a tropical region of southeast Brazil. Grass and feces were collected weekly at 8 a.m., 1 and 5 p.m. and processed by the Baermann technique. Multivariate analysis (principal components method) showed the influence of time and environmental variables on the number of infective larvae recovered from the feces and pasture. In the rainy period (October-March), more infective larvae were recovered on the feces and grass apex. In contrast, in the dry period (April-September), the recovery was higher only on the grass base, as well as the L(3) survival on feces and grass. More larvae were recovered at 8 a.m., except from the grass apex, where the highest recovery was at 1 p.m. Few studies investigating the seasonal transmission of equine cyathostomin have been conducted in South American tropical climates. These results demonstrate that in tropical conditions L(3) are available on feces and pasture throughout the year. Knowledge of climatic influences on the development and survival of L(3) is crucial to designing integrated parasite control programs that provide effective protection while slowing the development of anthelmintic resistance.

Determination of the minimal representative number of microscopic fields to quantify apoptosis in canine lymph nodes

Determinou-se o numero minimo de campos por lâmina para se ter uma amostragem representativa para o estudo de apoptose em linfonodos de caes com cinomose. Um linfonodo traqueobronquico de cao foi colhido e processado segundo tecnica para inclusao em parafina. Seccoes de 5µm foram coradas pelo tricromico de Shorr. Utilizou-se um analisador de imagens para registrar o numero de celulas em apoptose e os indices apoptoticos de 300 campos, na mesma lâmina. Obtiveram-se, entao, valores medios para 10 amostras de 5, 10, 15, 20, 25, 30, 35, 40, 45 e 50 campos ao acaso. Realizou-se o estudo dos desvios-padrao das medias (DP) em relacao ao tamanho da amostra que os originou. Quando as oscilacoes de DP entre amostras consecutivas foram menores que 5%, o ganho em representatividade produzido pelo acrescimo no numero de campos nao se justificou, dispensando amostragens maiores. Desse modo, a analise de 40 campos por lâmina, na pesquisa de indices apoptoticos em linfonodos caninos, e suficientemente representativa, uma vez que apresenta instabilidade aceitavel.

Descarte e congelabilidade do sêmen de touros de raças zebuínas e taurinas em central de inseminação artificial no Brasil

Semen characteristics from 250 Zebu and 144 European bulls were described and compared among season and species. All bulls were selected as donors and during five years were always stationed at an Artificial Insemination Center in Southeast of Brazil, where temperatures were above 19o C in both dry and rainy seasons. Contingency tables and Tukeys test were used to check associations and to compare group means, respectively. Semen from European breeds showed higher swirl, motility and concentration values than those of Zebu breeds (P<0.05). Semen volume was higher for Zebu breeds (P<0.05). There were more discarded ejaculates in the rainy season (P<0.05). A major cause for discarding ejaculates was undesirable physical characteristics for the Zebu and morphological characteristics for the European breeds (P<0.05). Semen freezing ability values for the European breeds were higher.

Efeito da suplementação e do intervalo de pastejo sobre a qualidade da forragem e consumo voluntário de vacas Holandês × Zebu em lactação em pastagem de capim-elefante

Mean daily dry matter intake of elephantgrass (DMI) (Pennisetum purpureum, Schumack) in a rotational grazing with lactating Holstein × Zebu cows was estimated in a trial carried out from February to September. The pasture was divided into paddocks and grazed for three days by 24 cows randomly allotted to four treatments. The treatments consisted on grazing intervals of 30 days, and concentrate (2kg/cow/day) and grazing intervals of 30, 36 or 45 days without concentrate. From February to May the elephantgrass was the only roughage, but from June to September (dry season) the cows were fed on chopped sugarcane plus 1% urea. DMI was estimated monthly using the extrusa in vitro dry matter digestibility (IVDMD) and the fecal output (chromium oxide). The average chemical composition of extrusa was generally similar (P>.05) among grazing intervals (6.1 to 18.2% of CP; 63.5 to 81.4% of NDF; 32.7 to 47.6% of ADF and 43.7 to 72.9% of IVDMD). The CP content of extrusas decreased and the NDF and ADF contents increased (P .05) among grazing intervals. During the dry season cows fed on treatments without concentrate the DMI varied from .39 to 2.2%BW and its contribution to total DM intake decresead from 52% in the first to 43% in the third day of paddock occupation. Sugarcane intake effectively minimized the effects of the low pasture intake in the dry season.

Coeficientes de digestibilidade aparente pelos métodos de indicadores e coleta total de fezes em cães

Foram avaliados comparativamente os metodos de coleta total de fezes (CT) e de indicadores, oxido cromico (Cr2O3), fibra em detergente acido (FDA) e cinzas insoluveis em acido (CIA), para determinacao dos coeficientes de digestibilidade aparente (CDA) da materia seca, proteina bruta, extrativos nao nitrogenados e energia bruta de um alimento comercial para caes. Cinco caes adultos, machos, sem raca definida e com media de peso de 13,84kg receberam diariamente 2g de Cr2O3, divididos em duas porcoes de 1g, administradas por meio de capsulas de gelatina por um periodo de 14 dias. Os sete primeiros dias foram de adaptacao e os sete dias subsequentes de coleta de fezes. Os metodos de CT, de Cr2O3 e de CIA nao apresentaram diferencas entre si (P>0,001) e podem ser utilizados para determinacao dos coeficientes de digestibilidade aparente na especie canina. O indicador FDA apresentou menor indice de recuperacao do que os indicadores CIA e Cr2O3 e seus resultados nao apresentaram equivalencia com os obtidos por outros metodos testados. As medias (+ desvio padrao) dos indices de recuperacao foram 55,1% (+3,7), 93,9% (+ 17,7) e 93,7% (+ 13,3) para FDA, CIA e Cr2O3, respectivamente.

Influência das pontas excessivas de esmalte dentário na digestibilidade e nutrientes de dietas de eqüinos

Para avaliar a influencia das pontas excessivas de esmalte dentario na digestibilidade dos nutrientes de dietas de equinos, utilizaram-se 13 animais alimentados com capim-elefante (Pennisetum purpureum) e racao comercial. Foram analisadas materia seca, proteina bruta, energia bruta, fibra em detergente neutro, fibra em detergente acido, hemicelulose e celulose nas fezes antes e duas semanas apos o desgaste corretivo das pontas excessivas de esmalte. A digestibilidade aumentou (P<0,001) em todas as variaveis estudadas apos o desgaste corretivo.

Efeito do Estádio Vegetativo do Sorgo (Sorghum bicolor, (L.) Moench) sobre a Composição Química da Silagem, Consumo, Produção e Teor de Gordura do Leite para Vacas em lactação, em Comparação à Silagem de Milho (Zea mays (L.))

Este trabalho foi conduzido com o objetivo de avaliar o efeito do estadio de maturacao do sorgo sobre a composicao quimica da silagem, o consumo, a producao e o teor de gordura do leite em vacas holandesas, em comparacao a silagem de milho. O experimento foi realizado na estacao experimental da Empresa Pernambucana de Pesquisa Agropecuaria - IPA, localizada em Sao Bento do Una-PE. Foram utilizadas nove vacas holandesas puras, em fase de lactacao, distribuidas em tres quadrados latinos. Os quadrados foram formados de acordo com a producao de leite e a ordem de lactacao e constavam de tres vacas e tres periodos. Cada periodo teve duracao de 28 dias. Os tratamentos consistiram de: SM - silagem de milho; SSE - silagem de sorgo fase de emborrachamento; SSL - silagem de sorgo grao leitoso. Foram ainda fornecidos 25 Kg de palma forrageira animal/dia e concentrado comercial de acordo com a producao de leite. A silagem de milho propiciou aos animais maior consumo medio de materia seca da silagem e da dieta total. Nao houve efeito significativo do estadio vegetativo do sorgo sobre o consumo de silagem. As producoes de leite total e corrigida para 4% de gordura foram maiores nos animais que consumiram silagem de milho em relacao aos que receberam silagem de sorgo no estadio de grao leitoso, todavia os que ingeriram silagem de sorgo na fase de emborrachamento nao diferiram dos demais. Quanto ao teor de gordura do leite, nao houve diferenca significativa entre as silagens analisadas.