Clinicopathological Indications of Resilience of Swamp Buffaloes to Infection with Fasciola gigantica
Fasciolosis caused by Fasciola gigantica is a common disease among livestock such as swamp buffaloes (Bubalus bubalis) in rice-producing areas in humid tropical regions. It causes a significant reduction in meat and milk production, growth rate, fertility and draught power in infected animals (Dargie, 1987). However, the extent to which infection adversely affects the production of infected animals depends on several factors, among which is the breed of susceptible animals. Different breeds of animals and individuals within the same breed manifest varying responses and resilience to infection (Spithill et at., 1999). For instance, differences in response to infection with F. gigantica were seen in Bali, Ongole and buffalo calves in terms of weight gain (E. Wiedosari, personal communication, 1997). This information demonstrates breed differences in response to F. gigantica infection and shows that swamp buffaloes are more resilient than cattle to F. gigantica. The clinicopathological responses of swamp buffaloes naturally infected with F. gigantica were evaluated in this study to determine whether these parameters would indicate resilience to natural infection with parasites.
The impact on production and mechanisms of pathogenesis of trematode infections in cattle and sheep.
Abstract Trematodes can have marked effects on several components of individual animal productivity—particularly growth and wool production, but there is a need for better definition of their effects upon overall flock and herd productivity and of the economic benefits to be derived from their control by chemical, immunological and/or genetic approaches. The reasons for reduced productivity are complex and include reduced appetite coupled with a protein/energy drain arising from increased protein turnover, and in some cases derangements in gastrointestinal function and mineral metabolism are to be anticipated. Knowledge of the effects of trematodes on animal productivity and metabolism lags far behind that of gastrointestinal nematodes and while there is certainly a need for more study of the effects of trematodes per se , there is perhaps an even more pressing need for experimental and field work on mixed infections.
Evaluation and Control of Collapsible Soils
Some compacted soils wetted under certain conditions of compaction and loading may exhibit additional settlement (collapse). To investigate the effect of the soil type, compaction water content, initial dry unit weight and applied pressure at wetting on collapse potential, 138 single‐oedometer tests were conducted on eight different soils. The results indicate that well‐graded soils tend to collapse more than poorly graded ones under similar conditions. Furthermore, collapse potential decreases with an increase in (1) The difference between the sand and clay percentages; (2) compaction water content; and (3) initial dry unit weight, while it increases with pressure at wetting. A multiple regression analysis was performed on the laboratory results to provide a collapse‐predictive model that was substantiated by data reported by several researchers. A chart is presented to estimate (1) The collapse potential of soils under various conditions; and (2) the critical water content beyond which no collapse is ex...