Evolution and Neural Network Prediction of CO2 Emissions in Weaned Piglet Farms

This paper aims to study the evolution of CO₂ concentrations and emissions on a conventional farm with weaned piglets between 6.9 and 17.0 kg live weight based on setpoint temperature, outdoor temperature, and ventilation flow. The experimental trial was conducted during one transition cycle. Generally, the ventilation flow increased with the reduction in setpoint temperature throughout the cycle, which caused a reduction in CO₂ concentration and an increase in emissions. The mean CO₂ concentration was 3.12 g m^–3. Emissions of CO₂ had a mean value of 2.21 mg s⁻¹ per animal, which is equivalent to 0.195 mg s⁻¹ kg⁻¹. A potential function was used to describe the interaction between 10 min values of ventilation flow and CO₂ concentrations, whereas a linear function was used to describe the interaction between 10 min values of ventilation flow and CO₂ emissions, with r values of 0.82 and 0.85, respectively. Using such equations allowed for simple and direct quantification of emissions. Furthermore, two prediction models for CO₂ emissions were developed using two neural networks (for 10 min and 60 min predictions), which reached r values of 0.63 and 0.56. These results are limited mainly by the size of the training period, as well as by the differences between the behavior of the series in the training stage and the testing stage.

Effects of Probiotics and Wheat Bran Supplementation of Broiler Diets on the Ammonia Emission from Excreta

Simple Summary

Animal production is the main source of ammonia emission worldwide and all member countries of the European Union must reduce their national emissions. Among nutritional strategies, feeding low protein diets, using more nutritional phases, or using different feed additives can decrease the nitrogen excretion of animals and, in this way, lower the ammonia volatilisation from the manure. Pro- and prebiotics are widely used to improve gut health and to decrease the incidence of diseases. Numerous research findings have been published on the practical effects of pro- and prebiotics, but their impact on the urinary and faecal N excretion in chickens has not been completely clarified yet. In this research, the effects of using lactic acid and butyric acid producing bacterial strains, and wheat bran as a potential prebiotic, was tested with broiler chickens. Both probiotics increased the dry matter content and decreased the urinary N ratio of the excreta, which is positive from an ammonia emission point of view. Wheat bran and its xylan-oligosaccharides decreased both the ammonium -N content and the urinary N ratio. The results proved that beside the well-known nutritional techniques, the feed additives, which modify the gut microbiota and the fermentation in the caeca, can decrease the urinary-N excretion, and in this way lower the ammonia emission of broiler chickens.

Abstract

Ammonia emission is a concern for the poultry industry from both environmental and animal welfare points of view. The objective of this research was to determine whether probiotics or wheat bran supplementation of broiler diets can modify the N composition of the excreta and the dynamics of ammonia volatilisation emission from the manure. A total of 120-day-old Ross 308 broiler chickens were fed six different diets. The treatments included a corn and soybean meal-based control diet (C) and diets containing wheat bran (WB). Both diets were fed alone and with supplementation of a lactic acid (Lactobacillus farciminis, LAB) and a butyric acid (Clostridium butyricum, BAB) producing bacterial strain. Treatment BAB had a significant effect on the dry matter content of the excreta and both probiotics decreased the amount of excreted uric acid. Treatment WB resulted in a significantly lower NH⁺₄-N concentration of excreta and a tendency toward reduced uric acid content. Treatment LAB reduced the urinary N ratio of excreta. Among dietary treatments, WB resulted in the highest urease producing cell numbers in the excreta, but this difference was not significant. Based on our results, similar to pigs, the soluble fibre fraction of poultry diets can also modify the urinary to faecal N ratio of the excreta.

Effects of Season and House Microclimate on Fungal Flora in Air and Broiler Trachea

Fungi are present in abundance in poultry housing. The aim of the study was to assess the effect of season and microclimate parameters in poultry housing on fungal flora in the air and broiler trachea in commercial fattening conditions. The study was conducted in summer and winter. Study results indicated seasonal impact and association between fungal flora composition in housing air and broiler trachea. However, the total fungal count in housing air was significantly higher in summer and in broiler trachea in winter, both significantly correlated with indoor relative humidity and ammonia concentration. There was no significant correlation between outdoor and indoor air temperature, relative humidity and airflow rate, respectively. Study results suggested that environmental determination of fungi should be accompanied by their determination in broilers. In addition, seasonal impact on fungal contamination should be associated with microclimate conditions in the poultry house rather than the season itself. The fungi detected and the results obtained have implications not only for broiler health but also for the health of humans working in such environments.

Factor Influences for Diagnosis and Vaccination of Avian Infectious Bronchitis Virus (Gammacoronavirus) in Chickens

Infectious bronchitis virus (IBV) is a major economic problem in commercial chicken farms with acute multiple-system infection, especially in respiratory and urogenital systems. A live-attenuated and killed vaccine is currently immunized to control IBV infection; however, repeated outbreaks occur in both unvaccinated and vaccinated birds due to the choice of inadequate vaccine candidates and continuous emergence of novel infectious bronchitis (IB) variants and failure of vaccination. However, similar clinical signs were shown in different respiratory diseases that are essential to improving the diagnostic assay to detect IBV infections. Various risk factors involved in the failure of IB vaccination, such as various routes of application of vaccination, the interval between vaccinations, and challenge with various possible immunosuppression of birds are reviewed. The review article also highlights and updates factors affecting the diagnosis of IBV disease in the poultry industry with differential diagnosis to find the nature of infections compared with non-IBV diseases. Therefore, it is essential to monitor the common reasons for failed IBV vaccinations with preventive action, and proper diagnostic facilities for identifying the infective stage, leading to earlier control and reduced economic losses from IBV disease.

Influence of carbon fixation on the mitigation of greenhouse gas emissions from livestock activities in Italy and the achievement of carbon neutrality

Among the greenhouse gas emissions due to livestock activities there is, in addition to rumen methane, that which derives from the fermentation and management of manure from farmed animals. To feed the farmed animals, plants are used that fix carbon and therefore subtract carbon dioxide from the atmosphere. The emissions related to rumen fermentations, those related to manure, management, and spreading of animals of species reared in Italy, as well as manure released by grazing animals were quantified and summed. The emissions due to the respiration of animals were calculated and the carbon dioxide fixed by the main crops of zootechnical interest was calculated and then subtracted from the atmosphere. In addition, the emissions from the cultivation of plant species, attributable to the working of the soil, the production of fertilizers and pesticides, electricity, fuels, and the operation of machines, were also taken into account. The results of this elaboration show that in Italy the CO₂ fixed in the vegetation cultivated to feed animals is about 10% higher than the sum of that emitted by the animals reared and by the entire process that is part of it. It could therefore be argued that the influence of carbon fixation should probably be taken into account to calculate the environmental impact in terms of carbon footprint of agricultural and animal products. In this way, carbon neutrality would be demonstrated, which characterizes the production processes of agricultural products and animal productions unlike other production cycles.

Relation Between Microclimate and Air Quality in the Extensively Reared Turkey House

Good air quality in poultry houses is crucial for animal health and productivity. In these houses, air is generally contaminated with noxious gases and microorganisms, the concentrations of which depend on numerous factors including microclimate. In this case study, the relation between microclimate and air concentrations of noxious gases and microorganisms was investigated in extensively reared turkey house. The study was carried out at a family household in Dalmatia hinterland, Croatia, with 50.3±3.1 turkeys kept in the house during the study period. Air temperature, relative humidity, airflow rate, concentrations of ammonia, carbon dioxide, bacteria and fungi in indoor air were measured three times per month from September to December, in the morning, prior to releasing turkeys out for grazing. Air temperature ranged from 9.73 to 26.98 °C, relative humidity from 63.29% to 75.08%, and airflow rate from 0.11 to 0.17 m/s. Lowest ammonia and carbon dioxide concentrations were measured in September (2.17 ppm and 550 ppm, respectively) and highest in December (4.50 ppm and 900 ppm, respectively). Bacterial and fungal counts were lowest in December (2.51×105CFU/m3and 3.27×103CFU/m3air, respectively) and highest in September (6.85×105CFU/m3and 1.06x105CFU/m3air, respectively). Air temperature and relative humidity showed negative correlation with concentrations of noxious gases and positive correlation with air microorganisms (P<0.05 all).

Air Quality in Alternative Housing Systems may have an Impact on Laying Hen Welfare. Part II-Ammonia

The EU ban on conventional barren cages for laying hens from 2012 has improved many aspects of laying hen welfare. The new housing systems allow for the expression of highly-motivated behaviors. However, the systems available for intensive large-scale egg production (e.g., aviaries, floor housing systems, furnished cages) may cause other welfare challenges. We have reviewed the literature regarding the health, behavior, production characteristics, and welfare of laying hens when exposed to ammonia in their housing environment. Concentrations of ammonia gas are commonly high in aviaries and floor housing systems in which manure is not regularly removed, whereas they are usually lower in furnished cages. High levels are found during the cold season when ventilation flow is often reduced. Ammonia is a pungent gas, and behavioral studies indicate chickens are averse to the gas. High concentrations of gaseous ammonia can have adverse health effects and, when very high, even influence production performance. The most profound effects seen are the occurrence of lesions in the respiratory tract and keratoconjunctivitis. There is also evidence that high ammonia concentrations predispose poultry to respiratory disease and secondary infections. We conclude that there are animal welfare challenges related to high ammonia levels, and that immediate actions are needed. Development of improved systems and management routines for manure removal and ventilation will be important for the reduction of ammonia levels and hence will contribute to safeguarding hen welfare.