Host specificity of sheep and cattle nematodes in São Paulo state, Brazil

The trial was carried out to investigate parasite host specificity and to analyse the dynamics of infection with nematodes parasitizing sheep and catt:le raised together or separately in São Paulo state, Brazil, and, also to clarify doubts about the systematics of species of the genus Haemonchus on the basis of cytological and morphological studies. Ten steers and 32 ewes were randomly assigned to three paddocks (P), as follows: P1, 5 steers; P2, 5 steers and 16 ewes; and P3, 16 ewes. The animals remained on these paddocks in continuous grazing throughout the trial (1-yr period). Faecal exams and larvae counting on pasture were performed fortnightly. Once a month two tracer lambs were placed in each paddock, while two tracer calves were also placed, but only in the eighth month of the trial. All these animals were slaughtered for worm identification and counting. At the end of the trial, one steer and one ewe from P2, which showed high faecal egg counts, were also slaughtered for the same purpose. Nematodes identified cytogenetically as H. placei presented spicule hooks longer than those identified as H. contortus. The following distribution of parasites in cattle and sheep was observed: Bunostomum phlebotomum, H. similis, Mammomonogamus laryngeus strongly adapted to cattle, H. placei and Cooperia punctata more adapted to cattle than to sheep, Trichostrongylus axel and C. spatulata apparently more adapted to cattle, T. colubriformis strongly adapted to sheep, H. contortus more adapted to sheep than to cattle and C. curticei apparently more adapted to sheep. Cross-infection was shown to occur involving some species, however, with time the animals apparently eliminate the species that are not well adapted to them. Therefore, grazing management systems using cattle and sheep appear to be promising for worm control in southeastern Brazil. (C) 1997 Elsevier B.V. B.V.

Nematódeos de ruminantes em pastagem com diferentes sistemas de pastejo com ovinos e bovinos

O objetivo deste trabalho foi avaliar os efeitos de diferentes sistemas de pastejo, com ovinos e bovinos, sobre a quantidade de larvas no estágio L3 de nematódeos de ruminantes. O delineamento experimental foi inteiramente ao acaso, em arranjo fatorial com quatro sistemas de pastejo e quatro períodos de rotação de pastagem. A duração do experimento foi de 91 dias, com sistema rotacionado (7 dias de ocupação e 21 de descanso), em 8 ha de Panicum maximum cv. Tanzânia. Foram avaliados os sistemas de pastejo: alternado, simultâneo e isolado, com ovinos e com bovinos. Foram utilizados 20 bovinos (mestiços), 30 cordeiros e 15 ovelhas adultas (raça Santa Inês). As amostras do capim, para recuperação e identificação dos nematódeos, foram realizadas semanalmente no pré e pós-pastejo dos piquetes. Na média geral de todos os manejos, a ordem decrescente de número de larvas foi: Haemonchus spp., Trichostrongylus spp., Oesophagostomum spp., Strongyloides spp. e Cooperia spp. Correlações médias foram encontradas entre as quantidades de larvas L3 no pré e pós-pastejo. Com o aumento do número de rotações, houve aumento no grau de contaminação da pastagem pelas larvas, independentemente do sistema adotado. O sistema de pastejo simultâneo foi o que apresentou maior controle da carga parasitária de Haemonchus spp. na pastagem de capim-tanzânia.

Suplementação da dieta de bovinos de corte como estratégia do manejo das pastagens

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Impact of overseeding cool-season annual forages on spring regrowth of tifton 85 bermudagrass

Field observations have shown stand reduction and slow spring regrowth of Tifton. 85 bermudagrass (Cynodon spp.) pastures overseeded with temperate forages for grazing during the cool season. This experiment compared the effect of cool-season management programs, including overseeding and use of different grazing treatments, on productivity of Tifton 85 the following warm season. There were seven treatments: four were bermudagrass overseeded with a cool-season annual forage mixture (two grasses and two legumes) and grazed differentially, and three were bermudagrass controls With differences in amount of residual stubble remaining at beginning of autumn. There was only a slight delay in initiation of Tifton 85 spring regrowth relative to the unseeded controls and no apparent stand loss resulting from overseeding cool-season forages. Late spring and summer Tifton 85 production generally was greater on seeded than non-seeded areas, possibly resulting from the nitrogen (N) release from decaying cool-season legumes. Grazing management of winter species in seeded plots and stubble height of bermudagrass in control plots had no effect on bermudagrass performance. Nutritive value responses generally favored overseeded plots. These data, though from one year, show no negative effect on Tifton 85 bermudagrass performance from overseeding and grazing cool-season annual forages during winter.

Correlações entre características morfogênicas e estruturais em pastos de capim-braquiária

The analysis of both morphogenetic and structural characteristics of pasture allows us to understand the response patterns of the plant to the environment. Thus, this study was conducted to evaluate the associations between the morphogenetic and structural characteristics of Brachiaria decumbens under continuous grazing by cattle. The development of individual tillers in pastures was evaluated under two grazing management strategies during three seasons (winter, spring and summer). Pearson correlations between variables were estimated. The lengths of leaf and stem, number of tillers and leaves per tiller, rates of leaf appearance and elongation of leaf and stem of B. decumbens were positively correlated. There was a negative relationship between appearance and lifespan of leaves (r = -0.89). However, positive correlations between leaf appearance rate and number of tillers (r = 0.64) and between length of stem and leaf senescence rate (r = 0.63) were determined. The B. decumbens modifies its morphogenesis to better adapt to climate and grazing management.

Óleo de Neem: tratamento parasitário em ovinos e desenvolvimento ponderal

Pós-graduação em Ciência Animal - FMVA

Fatores de meio que influenciam o peso à desmama de bovinos da raça Nelore em diferentes regiões geográficas

Pós-graduação em Genética e Melhoramento Animal - FCAV

Uso de fontes lipídicas na recria de bovinos mantidos em pastos de Brachiaria brizantha cv. Xaraés

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Manejo de híbridos de sorgo e cultivares de milheto em sistema de pastejo rotativo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Produção intensiva de cordeiros suffolk em pastagem com ou sem desmama e comportamento seletivo de ovelhas coopworth em pastejo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pastejo alternado de ovinos e bovinos na profilaxia das helmintoses ovinas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Suplementação de novilhas de corte em pastagem de capim-Marandu submetidos à intensidades de pastejo sob lotação contínua

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Puberdade em novilhas Nelore provenientes de duas linhas de seleção para peso

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho de vacas leiteiras em pastejo de alfafa

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Seasonal fluctuation of soil carbon dioxide emission in differently managed pastures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)