Effects of harmful gases emitted from poultry houses on productive and health performance

Air pollution in the environment in which poultry is raised is one of the most serious problems facing the poultry sector across various aspects of production. Perhaps the most dangerous gas emitted from poultry houses is ammonia. The high concentrations of this gas in the air above the permissible limits (15 ppm) will have disastrous consequences. Ammonia directly affects the health and safety of birds, as it is a cause of ammonia blindness in birds accompanied by many respiratory diseases that destroy production and increase breeding costs. In addition, high concentrations of ammonia (above 20 ppm) contribute to enhancing the infection of birds with Newcastle and the bronchitis virus. In general, the greenhouse gases emitted from poultry houses included four main gases (carbon dioxide, nitrous oxide, methane and hydrogen sulphide). Studies regarding their direct effects on the health and productivity of birds have been insufficient. In the direct form, as the concentrations of greenhouse gases rise to very high limits, they cause suffocation and death., the behaviour of the greenhouse gases in the indirect effect is reflected being a source of nutritional stress and a group of diseases and parasites which lead to a decrease in productivity levels. The intensity and concentrations of gas emissions are directly related to many factors such as geographic location, the season of the year, ventilation technologies, humidity, litter quality, nutritional status and stocking density. The advances in ventilation technologies have played a key role in expelling all harmful gases, especially those that depend on negative pressure. However, greenhouse gases remain a real threat to the poultry industry in particular and to the planet's environment in general.

Technical efficiency analysis of shrimp farms in Andhra Pradesh, India using stochastic frontier approach

Brackishwater aquaculture sector is dominated by the exotic vannamei shrimp farming, which is the economic engine of Indian aquaculture. In 2019-20, exports of 12,89,651 t of Indian marine products fetched foreign exchange worth 246,662.85 crores and farmed shrimps accounted for about two-thirds of the shrimps exported. Shrimp farming is export oriented and market price often fluctuates widely impacting the profitability significantly. We conducted this study to estimate technical efficiency of the shrimp farmers in Nellore District, Andhra Pradesh which tops in shrimp aquaculture in the country. The data were collected through structured questionnaire using personal interview from 80 farmers during COVID 2020 pandemic period. The farm specific technical efficiency varied from 75 to 94% with a mean of 93%. The estimates of the discrepancy parameter ?? indicated that 93% of the difference between the maximum possible output and actual output were due to differences in technical inefficiencies of farmers. Feed and labour are the significant variables compared to other variables. The results indicated that farmers need to be encouraged to apply more feed to increase shrimp production.