Simulation and Validation of the Evaporation of Water from Liquid Manure using Ventilation Exhaust Air: linking of two Simulation Models

Posted in: Environment by admin on January 1, 2003 | No Comments

The pig production needs to be modified into a sustainable system. Handling of the manure and reducing
emissions have to be taken into account in the design of pig facilities, so the called integrated pig facilities are being developed in which the energy in the exhaust air can be used to evaporate water fromliquid manure. The objective of this research was to link an existing dynamic simulation model for indoor climate calculation to a newly developed simulation model for manure evaporation, allowing annualised calculation of evaporation. The physical processes that occur in the liquid manure evaporator were described in a dynamic simulation model. This model was validated with experiments carried out in a laboratory facility. This model underestimated the evaporation with an average of 15
4%. Some explanations were given. Model calculation of the evaporation at annual basis shows that per fattening pig place 0
38 to 0
41m3 liquid manure per year can be evaporated. To increase the evaporation level, thermal energy can be added. The linking of two simulation models was successful. The liquid manure drying simulation model can be used to gain insight in the possibilities of using a manure drying technique under a variety of circumstances, and to design practical installations and to optimise the drying process.

Literature review: the physical properties of compost

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INFLUENCE OF ASH AMENDMENT ON ODOR EMISSIONS AND AEROBIC BIODEGRADATION OF BIOSOLIDS MIXES

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Estimating Ammonia Volatilization from Swine-Effluent Droplets in Sprinkle Irrigation

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TopCross High Oil Corn Production: Select Grain Quality Attributes

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Large Groups for Grower-Finisher Pigs: Impacts on Pig Productivity

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The “large group” concept for pigs is gradually being adopted in North America. Housing grower-finisher pigs in large groups of 50-500 pigs/pen compared to conventional group sizes of 10-40 pigs/pen has the possibility to reduce housing costs and may also simplify some aspects of management. Large group pens prove to be economically attractive to pork producers. However, there is the concern that the social instability of pigs in large groups may lead to poorer growth rates, increased mortality and morbidity, and higher variation in body weights at the end of the production cycle. The goal of this study was to compare production performance of grow-finish pigs housed in large groups (108 pigs/pen) to those housed in conventional groups (18 pigs/pen). It has been suggested that there may be higher levels of undesirable vices such as tail biting, or higher incidence of diseases and mortalities with the formation of pigs into larger groups. However, results from this study do not support this suggestion as similar numbers of pigs were removed from both pen sizes throughout the course of the trial. Pigs housed in the large groups had a lower ADG (2%) than the smaller groups, but there were no significant differences in ADFI and feed efficiency among the two group sizes. Carcass measurements indicated no detrimental effects of either group size. Overall, results indicate that performance in the large groups were not inferior to the smaller groups evaluated in this study.

Electronic sow feeder: A preliminary report

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The housing of gestating sows as proven to be one of the more controversial topics of pig production. Four major group-housing systems are available to replace the conventional gestation stalls, all of which have different management options. The PSC Elstow Research Farm has chosen to use the electronic sow feeder (ESF) system as a group system, and is examining a number of management options within this system. Half of the 600-sow herd is housed in the group housing system with ESF on partially slatted floors while the other half are housed in gestation stalls. The four aspects being compared are productivity and behaviour of gilts and sows of different parities, relative benefits of grouping animals shortly after breeding or after implantation and its interaction with parity, the management of animals in static and large dynamic groups and all electronic sow feeder groups are compared with animals managed in conventional stalls. Preliminary results have shown that younger animals tend to perform better in stalls, while older sows do better in the ESF system. “Add ins” or post implantation animals performed better than those grouped shortly after breeding. Older animals performed better in static programs, while gilts did better in dynamic programs. Overall, the stall system outperformed the ESF; however, this was not the case for the ESF management programs. As this study continues, behavioural and physiological observations will be included.

On-farm monitoring of pig welfare by assessment of housing, management, health records and plasma haptoglobin.

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Poor health records and increased levels of haptogobin have been shown to correlate with a poor environment, but there is limited data regarding variation between individual animals. This study was carried out using 78 farrow-to-finish pig farms spread throughout the yearly seasons. Data on housing and management were collected on each farm visit. Pathological findings and blood samples were taken from each pig at slaughter. Ten blood samples were analyzed for Lawsonia intracellularis (PIA), Mycoplasma hyopneumoniae, salmonella, and haptoglobin values (HAP). Descriptive statistics and analysis of variance were used to analyze the data. Pigs from farms ranking higher in housing (space allowance) and management (sanitation, cleaning, disinfection, climatic control, and breeding protocol) scores showed lower HAP levels and had a lower within farm variability. Pigs infected with PIA or who had lung lesions also had higher HAP levels. Fasting before transport was found to be negatively correlated with lung lesions. HAP levels were lower when pigs with lung lesions were fasted. In conclusion, haptoglobin sampling on the slaughter line was determined to be relevant for integrative welfare assessment of slaughter pigs at the individual level and for longitudinal monitoring at the farm level.

Social discrimination and aggression by laying hens in large groups: from peck orders to social tolerance.

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Laying hens kept in small groups exhibit social behaviour similar to that of their wild ancestors, red jungle fowl, with a dominance hierarchy which is most likely based on establishment fights. In larger groups this system is thought to break-down, and hens may adapt to the new environment with a different social strategy. The present study tested the ability of laying hens living in groups of 10 and 120 to discriminate flockmates from unfamiliar birds. Subjects were presented in test cages with vertical bars, positioned outside the home pens in one of two places. Sixteen subject hens from each group size were presented to their home group (familiar) and a different group of the same size (unfamiliar). Hens in small groups discriminated between familiar and unfamiliar subjects by showing more aggression towards unfamiliar hens. In large groups, the overall level of aggression towards subjects was reduced in that attempted fights were rare, and aggressive outcomes were no different in response to unfamiliar or familiar hens. Certain individual hens in large groups were more likely to approach the subjects showing no evidence that hens have limited ‘territories’ within the pen. Those birds approach and aggressive towards the subjects in large groups were heavier and had larger combs than the subjects. These findings are consistent with idea that in large groups hens become less aggressive and may change their social system to one where dominance is determined through direct assessment and ‘status signalling’ rather than the remembered individual assessment of a small group pecking order.

The effects of feeding method, milk allowance and social factors on milk feeding behaviour and cross-sucking in group housed dairy calves.

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This is a review of factors affecting cross-sucking in group housed calves. Evidence is presented to indicate that cross-sucking is a re-direction of normal sucking behaviour. It is primarily seen when calves are fed milk or milk replacer rather than being allowed to suckle their mother. Prolonging the milk meal by reducing the flow rate (orifice size) in teat buckets reduces the problem of cross-sucking, as does leaving the buckets in the pen after the meal is ended. In large groups of calves, fed via computerized milk feeders, a protective stall for the calf that is drinking is helpful to reduce cross-sucking directed toward the drinking calf. However, both means of reducing cross-sucking in such conditions, reducing flow rate and protecting the drinking calf, reduce the number of calves that can be fed from a feeding station. Additional work is needed on determining the appropriate number of calves that can be fed from a computer controlled station while keeping cross-sucking within an acceptable level.