24 research outputs found
Prevalence of some common bacterial diseases in commercial poultry farm
Bacterial disease of poultry is one of the major constraints to the expansion of poultry industry. The study was undertaken to investigate some common bacterial diseases in commercial poultry farm. A total of 100 sick and dead chickens (67 broilers, 26 layers and 7 sonali) were collected from different poultry farms which were subjected to postmortem examination for tentative diagnosis. After the post-mortem examination, out of 100 collected dead chickens, bacterial diseases were confirmed 58 %. Among them 52 % of the chickens were diagnosed tentatively to be the case of colibacillosis, 4 % salmonellosis, and 2 % of fowl cholera. In post-mortem examination, some pathological lesions like: omphalitis, fibrinopurulent fluid accumulation in peritoneal cavity, air sacculitis, pericarditis and perihepatitis, extreme congestion and septicemia in intestine for colibacillosis infection; unabsorbed yolk mass, bronze discoloration and friable liver, hemorrhages in spleen, misshaped ova for salmonellosis as well as swollen and hardening of comb, congestion of skin, multiple pin point pale color necrotic lesion on liver, pin point hemorrhage on fat muscle of heart were observed for fowl cholera infection. Hence, this study will definitely help to perceive the prevalence of common bacterial diseases like colibacillosis, salmonellosis and fowl cholera infection in commercial poultry farm
Effect of Non-local Grazing on Dry-land Vegetation Dynamics
Dry-land ecosystem has turned into a matter of grave concern, due to growing
threat of land degradation and bioproductivity-loss. Self-organized vegetation
patterns are a remarkable characteristic of these ecosystems; apart from being
visually captivating, patterns modulate the system-response to increasing
environmental stress. Empirical studies hinted that herbivory is one the key
regulatory mechanism behind pattern formation and overall ecosystem
functioning. However most of the mathematical models have taken a mean-field
strategy to grazing; foraging has been considered to be independent of spatial
distribution of vegetation. To this end, an extended version of the celebrated
plant-water model due to Klausmeier, has been taken as the base here. To
encompass the effect of heterogeneous vegetation distribution on foraging
intensity and subsequent impact on entire ecosystem, grazing is considered here
to depend on spatially weighted average vegetation density, instead of density
at a particular point. Moreover, varying influence of vegetation at any
location over gazing elsewhere, is incorporated by choosing suitable averaging
function. A comprehensive analysis demonstrates that inclusion of spatial
non-locality, alters the understanding of system dynamics significantly. The
grazing ecosystem is found to be more resilient to increasing aridity than it
was anticipated to be in earlier studies on non-local grazing. The
system-response to rising environmental pressure is also observed to vary
depending on the grazer. Obtained results also suggest possibility of
multi-stability due the history-dependence of system-response. Overall, this
work indicates that the spatial heterogeneity in grazing intensity has a
decisive role to play in the functioning of water-limited ecosystems.Comment: 24 pages, 6 figure