Autotrophic denitrification and chemical phosphate removal of agro-industrial wastewater by filtration with granular medium

Posted in: Environment by admin on January 1, 2007 | No Comments

Precipitation of Liquid Swine Manure Phosphates Using Magnesium Smelting By-Products

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SOIL AND WATER QUALITY MONITORING TECHINIQUES

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Effect of urinations on the ammonia emission from group-housing systems for sows with straw bedding: Model assessment

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As ammonia is a polluting gas, the Dutch agricultural sector is committed to developing ammonia-emission reducing techniques. Furthermore, to improve animal welfare, Dutch pig farmers are using more straw bedding, especially for group-housed sows. A group-housing system for sows can be considered to have four different emitting surfaces: the slurry in the pits, the concrete surfaces of slats and of solid floors, and the straw bedding. Elsewhere (Groenestein et al., 2006), laboratory measurements of the volatilisation of ammonia from samples of these surfaces in response to the application of a dose of urine have been described and it was concluded that a urine pool on straw emits less ammonia than a urine pool of the same size on a slatted or solid floor. This implies that the spatial distribution of urinations influences the ammonia emissions from the house and that emission could be reduced by manipulating the surface the sows urinate upon. The objective of the study described here was to develop model simulations that estimate the effect of the size of the urine pool, the distribution of urine pools over the different emitting surfaces, and the size of the emitting surfaces. The aim was to assess whether the results of such simulations in combination with knowledge of the urinating behaviour of the sows could be important in designing the sow house to reduce environmental pollution (Bos et al., 2003). The reference data were from a house with a floor comprising 60% straw bedding, 14% drinking area (slatted floor with pit), 3% waiting area (slatted floor with pit) and 23% alley (solid floor). Simulations were performed to elucidate the effect of the distribution of the urinations over the different surfaces, relating this to the size and distribution of the urine pools, and the area of the surfaces urinated upon. The results were compared with emission data from an entire sow house. When the default settings were a urine production of 7 l/d per sow, a urination frequency of 5 times a day per sow, and urinations distributed evenly over the four emitting surfaces the model estimated the ammonia emission from the entire house as 11.7 g/d per sow, and the relative contributions of the straw bed, the drinking area, the waiting area and the alley as, respectively, 27%, 22%, 9% and 42%. By comparison, the actual emission from the house was 8.7 g/d per sow. Increasing the size of the urine pool from 0.14m² to 1.40m² in the model simulations caused ammonia emission initially to increase from 9.7 to 12.1 g/d per sow when the pool volume was 0.47m². If the pool was bigger, emission fell to 10.6 g/d per sow because, though the larger emitting area increases ammonia emission, the increase is outweighed by the reduction in emission caused by successive, superseding urinations on the same spot. If the entire emitting area was assumed to be straw bedding, the calculated emission from the house was 5.8 g/d per sow. Assuming slatted and concrete floors without straw bedding increased the emission to 16.5 g/d per sow. It is concluded that measures to reduce the ammonia emission from the bedded sow house should be aimed at decreasing the emission from the solid floor and/or allowing more urinations on the straw bed. The model is a useful design tool for achieving emission reduction from group-housing systems for sows with straw bedding. Its predictive power would be improved by inputting data on the actual size of the urine pool and urinating behaviour of sows.

A survey of manure management on pig farms in Northern Vietnam

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Reduced Crude Protein Effects on Aerial Emissions from Swine

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The effect of feeding reduced crude protein (CP) diets on air emissions was evaluated using barrows fed over the
course of four feeding phases: G1 (beginning at 24.5 kg BW), G2 (55.3 kg), F1 (87.2 kg), and F2 (111.4 kg). Pigs were offered a control diet (C), a low CP diet (LCP) or an ultra low CP diet (ULCP). Both the LCP and ULCP diets were supplemented with crystalline amino acids to avoid performance loss. It was found that diet had no effect on mass of manure produced; however TKN and NH3-N concentration decreased with decreasing diet CP (79, 67, 57 g kg-1 and 54, 44, and 35 g kg-1, respectively, for C, LCP, and ULCP diets).

Large Group Housing – Learning From Experience

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Conventional management of grow/finish pigs until recently has been to keep one or two litters in each pen in order to minimize aggression. In recent years producers have moved to sorting pigs by sex (for split sex feeding) or weight (in an unsuccessful attempt to reduce variation at marketing). However small group sizes are still retained, usually limited by the number of pigs that could be fed from a 2-4 hole feeder. With larger operations, or those that practice batch farrowing, producers are now able to form groups of several hundred pigs of similar age and gender. Advantages with larger operations are that less penning is used and the need for alleys within the room is eliminated, thus reducing some aspect of capital cost. More importantly, large groups allow us to apply new technology, particularly when it comes to sorting animals not only for market but also for phase feeding programs within each group. There is the potential for handling to be improved through the use of facilities designed for large groups, and anecdotal evidence would suggest that pigs from large groups handle and load better at marketing. However, a number of producers who have adopted large groups, particularly those using auto-sort technology, have experienced unsatisfactory results. This is common whenever new technology is tried, and solutions need to be found to the problems they are experiencing. Most of the concerns about large group sizes in the past were related to the behaviour and stability of the social structure within groups. As group size increased, social problems increased, and many producers feared that aggression, productivity, and general health of the pigs would deteriorate. This was true to a certain point, but research indicates that the nature of the social structure among animals changes in very large groups. Studies have found that aggression following regrouping is similar, when expressed as minutes per pig, in conventional groups of 10-20 and large groups of over 100. Studies have also examined how readily pigs could move into small and large groups. When pigs were added to a small group there was more fighting than when pigs were added to a large group. Large groups also make the use of auto-sort technology affordable. In such a system pigs are required to pass through a scale that directs them into different areas based on their weight. The scales are usually set up so that pigs pass through them on the way to the feeder. However, most problems associated with auto-sort systems involve pigs refusing to pass through the scale or reluctance to do it several times a day. There are two basic approaches to ‘teaching’ pigs to pass through the sorter. The first approach is to force them through to ensure that all animals have passed through the scale to the food court. The second approach involves ‘shaping’ the pigs behaviour, from that of eating in an open pen to being willing to walk through the scale to obtain feed. Some producers allow their pigs to have ready access the food court at all times with the exception of a weekly managed sort. During this time the animals are gradually moved through the scale and sorted into appropriate weight groups for the following week. The pigs are never required to move through the sorter on their own. We are still at an early stage in developing all of the management criteria for these systems, and so it is better to err on the side of the pig rather than attempting to save on equipment and space. Managing grow-finish pigs in large groups has a great deal of potential, particularly if auto-sorters are used to manage a multi-phase feeding program. Producers choosing to adopt large groups for grow-finish pigs should demand a high level of service from their suppliers, and watch for the results of recent research in the producer press.

Impact of piglet birth weight and birth order on growth and the variability in growth

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Sow herd productivity has a major impact on the overall profitability of pork production and Canadian producers have been successful in their efforts over the past several years to increase average litter size. It is well known that piglets born into larger litters are on average smaller. This article examines the relationship of litter size on birth weight and growth, as well as the variability in growth. Data was collected from about 100 farrowings. At birth, the piglets were divided into litter size and also one of 4 birth weight quartiles, 0.80-1.20kg, 1.25-1.45kg, 1.5-1.7kg, and 1.75-2.5kg. Piglets weighing less than 800 grams at birth were excluded from the experiment. It was determined that the light birth weight piglets never completely catch up. While increasing litter size resulted in a decreased mean birth weight by 5 wks post-weaning, the average body weight was similar among litter sizes. The data does not support the hypothesis that larger litters result in more within litter variation. Larger litters were no more variable than small litters and larger litters resulted in more pork produced per sow.

Suitability of three commercially produced pig breeds in Germany for a meat quality program with emphasis on drip loss and eating quality

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The effects of noise level in gestation barns on human hearing loss and swine reproduction.

Posted in: Ontario Pork, Pork Insight Articles by admin on October 13, 2006 | No Comments

Farmers are often exposed to loud noises, studies have shown that they often deal with noises of 89 dB’s for eight hours a day. There has not been an extensive study that looks at the noise effects of working in a pig barn. Studies of pig vocalization have tied it to stress. When pigs are making noise they are not comfortable and there bodies shift there duties from normal activities like productive growth and reproduction to trying to reduce stress. This study sets out to document noise levels in hog barns and to see if their is a connection between noise and reproduction of the sows. 18 group housed barns and 18 crated barns were used in the study. Each barn had a db recorder hung from the ceiling to record noise levels, and historical reproductive statistics were provided by the barns. Swine barns were found to reach levels of uncomfortable noise at least some point in the day and this has an effect on reproduction and worker safety. Wearing hearing protection is one way to help producers avoid risk such as hearing loss. Environmental design of barns and management practices are suggested as one way to reduce the noises made by the sows