Outdoor Pig Research Articles

Porcine brucellosis (Brucella suis)

Porcine brucellosis (Brucella suis)

Screening the Working Environment in Outdoor Pig Systems

This study investigated how well organic growing-fattening pig systems provided a safe and healthy working environment and identified areas where improvements are needed. The study formed part of a larger project aimed at identifying strategies for creating a good animal and working environment and resource-efficient nutrient management in outdoor pig systems. Field studies were carried out at six Swedish farms in two types of outdoor pig systems (mobile and stationary). A method known as WEST (Work Environment Screening Tool) and a modified version of WEST, called WEST-agriculture (WEST-AG), were utilized for screening. Together, the two methods covered six factors of the working environment. The results were expressed in WEST-AG points and WEST points, an economic measure of the risk of impacts on health and productivity expressed as Swedish Krona (SEK) per thousand working hours. The results demonstrated that the risk of injury and ergonomic load during manual feeding and watering was much higher than during semi-automatic feeding and watering at farms with the mobile system. The study also identified other health-risk areas and provided valuable information for further improvement of the working environment in different outdoor pig systems.

ASPECTOS EPIDEMIOLÓGICOS DE UM FOCO DE TUNGÍASE (Tunga penetrans, SIPHONAPTERA) EM UM SISTEMA INTENSIVO DE SUÍNOS CRIADOS AO AR LIVRE

The outdoors intensive-type pig production is characterized by maintaining swine during reproductive, pregnancy and nursing periods on pasture limited by wiring and/or electric fences. The aim of the present report was to describe the epidemiological aspects of an outbreak of Tunga penetrans in an outdoor pig production system. A total of six mature boars, 9 lactating sows, 13 pregnant sows, 9 mating sows, 20 suckling pigs and 34 weaned pigs were clinically examined. None of the boars were infested, while 50% of all sows examined had the parasite lesions, most frequently observed in the breast area, thus resulting in agalactia in lactating sows due to obstruction of the galactophorus channel, with subsequent involution of the mammary gland. In 90% of suckling piglets walking difficulty was observed, caused by the presence of the parasite in the hoofs, with 25% of these animals also showing hock lesions (farm number 1, n = 48). Similar lesions were observed in 100% of 40-47 days old weaned pigs (farm number 2, n = 24) and in 80% of 70 days old weaned pigs (farm number 3, n = 10), all of which had been transferred to finishing units in a confinement system. Therefore we conclude that Tunga penetrans can infest pigs reared or kept outdoors, causing agalactia in lactating sows, and walking disorders in suckling and weaned pigs. KEY-WORDS: Chiggers, agalactia in sows; outdoors pig production.

Outdoor pig fattening at two Swedish organic farms—Spatial and temporal load of nutrients and potential environmental impact

In Sweden, outdoor organic pig production is gaining interest. However, the excretory behaviour of pigs may create plant nutrient hotspots in outdoor areas, increasing the environmental impact. This study examined fluxes and balances of N, P, K, Cu and Zn at pen level, and determined the effects of the excretory behaviour of fattening pigs on nutrient load, manure distribution and N, P, K, Cu and Zn concentration in soil within pens at two farms with different outdoor systems (mobile and stationary). A pen in the mobile system had about 72 pigs ha −1 and in the stationary system about 91 pigs ha −1. The average pen balance in the mobile system was 270 kg N, 60 kg P, 110 kg K, 0.4 kg Cu and 1.3 kg Zn ha −1 and in the stationary system 205 kg N, 57 kg P, 99 kg K, 0.4 kg Cu and 1.5 kg Zn ha −1. The smaller net accumulation of nutrients in the stationary system was due to about 30% of excrement nutrients being excreted indoors. A substantial proportion of nutrients (43–95%) from one pig group was found to be concentrated in an area of arable land representing 4–24% of the total pen area. In the mobile system the major part of the defecating was deposited on the hut, feeding and drinking sub-areas. The manure mapping also revealed pig behaviour of avoiding defecation in certain zones. In the stationary system, the concentration of exchangeable P and K in soil (0–30 cm depth) in areas preferred for excretion was more than four-fold higher and the concentration of mineral-N (0–90 cm depth) was about eight-fold higher than in other areas of the pen by the end of the fattening period. Preferred areas for excretion within the pen were affected both by the present pig groups and by previous pig groups 4 years back in time. In the mobile system, the concentration of mineral-N in soil was about three-fold higher in preferred excretion areas compared with other areas. Neither of the two outdoor systems succeeded in avoiding excessive point loads of N within the pen. The flexibility of the mobile outdoor system has to be further improved so that no harmful point loads of nutrients can occur. In the stationary system, a nutrient management technique for collecting the manure on the preferred excretion areas on arable land needs to be developed.

A serological study on brucellosis in wild boars in Germany

A recent outbreak of brucellosis in an outdoor pig herd, where wild boars were identified as the most probable source of infection, prompted us to conduct a serological study on wild boars from five federal states of Germany. A total of 885 sera were examined using a combination of screening and confirmatory testing, i.e. indirect enzyme-linked immunosorbent assay (ELISA) followed by complement fixation and slow agglutination tests. Seroprevalences of Brucella suis antibodies in the various regions were between 0 and 28.5% in the ELISA. After confirmatory testing, the amount of positive sera was lower and reached only up to 12.1%, dependent on the method. Although wild boars usually harbour B. suis biovar 2, which is less virulent for humans, a zoonotic risk for persons dealing with these animals and their carcasses cannot be ruled out.

Pre-weaning mortality in outdoor pig herds

Pre-weaning mortality in outdoor pig herds

Associations between the proportion of Salmonella seropositive slaughter pigs and the presence of herd level risk factors for introduction and transmission of Salmonella in 34 Danish organic, outdoor (non-organic) and indoor finishing-pig farms

Abstract This paper evaluates the association between herd level risk factors for introduction and transmission of Salmonella in farms with three different production systems: organic, outdoor (non-organic) and indoor finishing-pig farms, and the presence of seropositive animals in the herds. Potential risk factors for Salmonella in the three pig production systems were identified through a literature review, and management information as well as serological data were collected in 34 pig farms: 11 organic farms, 12 outdoor farms, and 11 indoor farms. There were no general differences in the proportion of Salmonella seropositive animals in the organic, outdoor, and indoor pig farms. Correspondence analysis showed that the occurrence of seropositive animals in the herds was mostly associated to the risk of introducing Salmonella in the herds by purchasing and transporting growing pigs. No associations between herd risk factors for transmission and survival of Salmonella and seropositive animals in the herds were found.

Ecological risks of outdoor pig fattening in organic farming and strategies for their reduction—Results of a field experiment in the centre of Germany

Outdoor pig fattening in organic farming has become more popular over the past few years, due to benefits in relation to animal welfare and economical reasons. On the other hand, ecological risks like nutrient accumulation in soils and leaching of nitrate (N) into groundwater have been described and discussed in outdoor pig productions systems. The regulations of the national organic farming associations and the EEC directive limit nutrient inputs by stocking rates adapted to maximum nitrogen (N) loads of 112 and 170 kg ha−1, respectively and maximum phosphorus (P) loads of 43 kg ha−1 according to national regulations. N and P inputs and their distribution were calculated and measured under specific management strategies. In a field experiment at the experimental farm of Kassel University in central Germany with loessial and clayey soils. Ratios of concentrate and feed compositions were evaluated in relation to N and P inputs to soil. Moving of huts and troughs and weekly extended area for grazing were examined for their effects on nutrient distribution. Additionally, soil structure was assessed. The results indicate that with nutrient input and their distribution as a main feature of management, the ecological risks of nutrient accumulation and leaching can be kept on a tolerable level. Most relevant measures to reduce nutrient losses in outdoor pig production are: restrictions in the amount of concentrate offered to the pigs, supply with field fodder, avoidance of fodder loss, optimising the crop rotation to ensure that nutrients in the soil are used efficiently. Available field fodder has to be considered to reduce the ratio of concentrate additionally. Fodder loss should be avoided. Nutrients have to be taken out of the soil by following crops, as a result of integrating outdoor pig fattening into crop rotation. The distribution of N and P was homogenized by moving huts and troughs at short intervals and when paddocks were provided at weekly intervals as strip grazing. Due to the impact of pigs, the infiltration rate at soil surface was reduced at highly frequented areas around troughs and in front of huts, which were 1–10% of the paddocks’ size.

Nitrate leaching and residual soil nitrogen supply following outdoor pig farming

. Large nitrogen (N) inputs to outdoor pig farms in the UK can lead to high nitrate leaching losses and accumulation of surplus N in soil. We investigated the residual effects of three contrasting outdoor pig systems as compared to an arable control on nitrate leaching and soil N supply for subsequent spring cereal crops grown on a sandy loam soil during 1997/98 and 1998/99 harvest seasons. Previously, the pig systems had been stocked for 2 years from October 1995 and were designated current commercial practice (CCP, 25 sows ha−1 on stubble), improved management practice (IMP, 18 sows ha−1 on undersown stubble) and best management practice (BMP, 12 sows ha−1 on established grass). Estimated soil N surpluses by the end of stocking in September 1997 were 576, 398, 265 and 27 kg ha−1 N for the CCP, IMP, BMP and continuous arable control, respectively. Nitrate leaching losses in the first winter were 235, 198, 137 and 38 kg ha−1 N from the former CCP, IMP and BMP systems and the arable control, respectively. These losses from the former pig systems were equivalent to 41–52% of the estimated soil N surpluses. Leaching losses were much smaller in the second winter at 21, 14, 23 and 19 kg ha−1 N, respectively. Cultivation timing had no effect (P>0.05) on leaching losses in year 1, but cultivation in October compared with December increased nitrate leaching by a mean of 14 kg ha−1 N across all treatments in year 2. Leaching losses over the two winters were correlated (P 0.05) for the three previous pig systems and the arable control, and cultivation timing had no effect (P>0.05) on grain yields and crop N offtake. This systems study has shown that nitrate leaching losses during the first winter after outdoor pig farming can be large, with no residual available N benefits to following cereal crops unless that first winter is much drier than average.

Iron Deficiency Anemia in a Neonatal Foal

Journal of Veterinary Internal MedicineVolume 20, Issue 6 p. 1495-1498 Open Access Iron Deficiency Anemia in a Neonatal Foal Kelly A. Fleming, Kelly A. Fleming Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA. Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602; e-mail: [email protected]Search for more papers by this authorMichelle H. Barton, Michelle H. Barton Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA.Search for more papers by this authorKenneth S. Latimer, Kenneth S. Latimer Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA.Search for more papers by this author Kelly A. Fleming, Kelly A. Fleming Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA. Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602; e-mail: [email protected]Search for more papers by this authorMichelle H. Barton, Michelle H. Barton Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA.Search for more papers by this authorKenneth S. Latimer, Kenneth S. Latimer Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA.Search for more papers by this author First published: 05 February 2008 https://doi.org/10.1111/j.1939-1676.2006.tb00773.xCitations: 14 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL References 1 Harvey J., Asquith RL, McNulty PK, et al. Haematology of foals up to 1 year old. Equine Vet J 1984; 16: 347– 353. 2 Bauer J. Normal blood chemistry. In: AM Koterba, ed. Equine Clinical Neonatology. Philadelphia , PA : Lea and Febiger; 1990: 602– 614. 3 Madigan J. Manual Equine Neonatal Medicine, 3rd ed. Woodland , CA : Live Oak; 1997: 367. 4 Grace N., Pearce SG, Firth EC, et al. Concentrations of macro and micro-elements in the milk of pasture-fed thoroughbred mares. Aust Vet J 1999; 77: 177– 180. 5 Guyton A., Hall JE. Textbook of Medical Physiology, 10th ed. Philadelphia , PA : Saunders; 2000: 382– 391. 6 Hillman R., Finch CA. Red Cell Manual, 5th ed. Philadelphia , PA : Davis; 1985. 7 Carley A. Anemia: When is it iron deficiency Ped Nursing 2003; 29: 127– 133. 8 Smith B. Large Animal Internal Medicine, 3rd ed. St Louis , MO : Mosby; 2002: 1063– 1065. 9 Smith JE, Cipriano JE, DeBowes R., et al. Iron deficiency and pseudo-iron deficiency in hospitalized horses. J Am Vet Med Assoc 1986; 188: 285– 287. 10 Brommer H., Van Oldruitenborgh-Oosterbaan MM. Iron deficiency in stabled Dutch warmblood foals. J Vet Intern Med 2001; 15: 482– 485. 11 Harvey J., Asquith RL, Sussman WA, et al. Serum ferritin, serum iron, and erythrocyte values in foals. Am J Vet Res 1987; 48: 1348– 1352. 12 Kohn C., Jacobs RM, Knight D., et al. Microcytosis, hypoferremia, hypoferritemia, and hypertransferrinemia in standardbred foals from birth to 4 months of age. Am J Vet Res 1990; 51: 1198– 1205. 13 Szabo P., Bilkei G. Iron deficiency in outdoor pig production. J Vet Med A Physiol Pathol Clin Med 2002; 49: 390– 391. 14 Geissler PW, Mwaniki DL, Thiong'o F., et al. Geophagy, iron status and anemia among primary school children in Western Kenya. Trop Med Int Health 1998; 3: 529– 536. 15 Gleed PT, Sanson BF. Ingestion of iron in sow's feces by piglets reared in farrowing crates with slotted floors. Br J Nutri 1982; 47: 113– 117. 16 Sharma V., Brannon MA, Carloss EA. Effect of omeprazole on oral iron replacement in patients with iron deficiency anemia. South Med J 2004; 97: 887– 889. 17 Smith J., DeBowes RM, Cipriano JE. Exogenous corticosteroids increase serum iron concentrations in mature horses and ponies. J Am Vet Med Assoc 1986; 188: 1296– 1298. 18 Pearson E., Andreasen CB. Effect of oral administration of excessive iron in adult ponies. J Am Vet Med Assoc 2001; 218: 285– 287. 19 Rooney D. Applied nutrition. In: SM Reed, ed. Equine Internal Medicine, 2nd ed. St Louis , MO : Saunders; 2004: 235– 272. 20 Lumsden H., Valli VE, McSherry BJ, et al. The kinetics of hematopoiesis in the light horse. Am J Vet Res III. The hematological response to hemolytic anemia. Can J Comp Med 1975; 39: 332– 339. Citing Literature Volume20, Issue6November 2006Pages 1495-1498 ReferencesRelatedInformation

Effects of insulation on the temperature within farrowing huts and the weaning weights of piglets reared on a commercial outdoor pig unit

The air temperatures inside uninsulated and insulated huts were recorded on an outdoor pig unit in the south of England between September 1997 and September 1998, and the herd’s production...

Behavior, preference for, and use of alfalfa, tall fescue, white clover, and buffalograss by pregnant gilts in an outdoor production system1

Sustainable outdoor pig production requires vegetation that can maintain ground cover, assimilate manure nutrients, and prevent soil erosion. Two experiments were conducted to evaluate the suitability of four forages: alfalfa (Medicago sativa), tall fescue (Festuca arundinacea), white clover (Trifolium repens), and buffalograss (Buchloe dactyloides) for grazing or ground cover in pastures for pigs. Each forage plot covered 7.5 m2, with nine replicates in a randomized block design. In Exp. 1, eight pregnant gilts had free access to all forages during a 2-d adjustment period. Immediately thereafter, pairs of gilts were assigned randomly to one of each of four blocks of the four forages during a 2-d measurement period. The percentage of ground cover for each forage was visually estimated at 0, 24, and 48 h of study. Behavioral data, including walking, eating, grazing, rooting, drinking, standing, lying, and time spent in hut were video-monitored continuously for 48 h. Initial percentage of ground cover was 100% for all species. By 48 h, percentage of ground cover decreased (P < 0.001) for white clover (11.3 +/- 0.88%) and alfalfa (36.3 +/- 0.88%), but not for tall fescue (98.0 +/- 0.88%) or buffalograss (98.0 +/- 0.88%). Gilts spent more (P < 0.01) time grazing white clover (16.3 +/- 1.97 min/d) and alfalfa (11.2 +/- 1.97) than tall fescue (0.8 +/- 1.97) or buffalograss (0.3 +/- 1.97), and rooted more (P < 0.04) white clover than other forages. In Exp. 2, six gilts from the initial group were put on six blocks of the four forages. Each gilt was assigned randomly to three replicates of each forage, including alfalfa, tall fescue, or buffalograss (white clover was excluded because of damage by gilts during Exp. 1), and gilts grazed single forages for 2 d. After this grazing period, the percentage of ground cover was less (P < 0.01) for alfalfa than for buffalograss or tall fescue (37.5 +/- 0.38, 96.7 +/- 0.39, 96.3 +/- 0.39%, respectively). With access to a single forage, pregnant gilts spent more (P < 0.01) time grazing alfalfa (15.8 +/- 2.36 min/d) than buffalograss (1.5 +/- 2.36) or tall fescue (0.7 +/- 2.37). These gilts clearly preferred grazing white clover and alfalfa, and rooting and eating white clover compared with buffalograss or tall fescue. Rates of ground cover loss were less (P < 0.01) for tall fescue and buffalograss than for the more preferred forages. Less preferred forages could have potential as pasture for swine when the primary objective is ground cover maintenance rather than nutrient supply.

Tail-biting in outdoor pig production

A study was performed in five identical outdoor production units in the same geographic area using growing-finishing pigs of similar genetic makeup, age, diet and feed management. The severity of tail-biting (TS) was scored 1–4. The average group prevalence of bitten tails at slaughter on different farms was between 14.1 ± 2.1% and 20.1 ± 3.0% ( P < 0.05). The odds of a barrow being bitten were 2.9 times higher than those for a gilt. The most frequently recorded score of bitten tails was TS3, indicating moderate wounds with low grade infection. The prevalence of bitten barrows was positively correlated with the percentage of gilts in a group ( r = 0.54, P < 0.001). Pigs with zero TS score had no significantly higher weights at slaughter compared to pigs with a score of TS1. As the TS increased from 1 to 4, weights decreased (TS 1 to TS 2 to 4, P < 0.05). TS 3 and 4 were positively ( P < 0.001) associated with subsequent carcass condemnation. We concluded that outdoor rearing does not prevent tail-biting.

Nitrate leaching and residual soil nitrogen supply following outdoor pig farming

Nitrate leaching and residual soil nitrogen supply following outdoor pig farming

Evaluation of corn cob mix in organic finishing pig nutrition

AbstractTwo consecutive experiments were performed to evaluate corn cob mix (CCM) inclusion in an organic diet. The experiments were performed in an organic barn on nine pens of four pigs (two barrows and two sows) of commercial breeds from 45 kg to slaughter. In the first experiment, an organic concentrate was mixed with organic CCM‐silage to obtain three concentrate:CCM ratios of 1:0, 4:1 and 3:2 (w:w). In the second experiment, three concentrates were produced to obtain diets with equal nutrient levels on a dry matter basis after 0, 200 and 400 g kg−1 CCM inclusion respectively. In all groups of both experiments, meat and carcass traits were comparable with common practice and differences between treatment groups were not seen. Feed conversion ratio on an as‐fed basis was worse with higher CCM levels in the diet, most likely due to the dilution effect by the lower dry matter content of CCM. In the first experiment, pigs on a higher concentrate:CCM ratio showed a higher feed intake, indicating a compensation for the lower energy density of these diets. In the second experiment, the 400 g kg−1 CCM group showed a lower daily dry matter intake (p = 0.048) leading to slower growth (p = 0.015). This indicated a bulk effect of the CCM in this case. In conclusion, lean carcasses with good meat quality can be obtained even in situations where up to 400 g kg−1 organic CCM‐silage is included in a balanced organic pig fattening diet. Moreover, a bulk effect of CCM‐silage can be used in some cases to limit the typically high dry matter intake in outdoor pig fattening, thereby preventing excessive fat accretion. Copyright © 2005 Society of Chemical Industry

Product quality attributes associated with outdoor pig production

Outdoor pig production offers animals increased environmental diversity and behavioural freedom but imposes challenges for breed adaptation, management control, biosecurity, and environmental protection. Each of these issues has potential implications for the real and perceived quality of the product. In most conventional Northern European production systems, only adult and suckling animals are at pasture. However, in traditional Mediterranean systems and in organic production systems, meat animals may be maintained outdoors throughout their lives. Major influences on organoleptic quality of product derive from the choice of breeds most appropriate to outdoor systems, modifications to growth rate, and the increased proportion of forage in the diet. Indirect consequences may also result from both positive and negative influences on physiological stress responses in the pre-slaughter period. Whilst some aspects of animal health and hygiene may be improved in more extensive conditions, exposure to parasites and to contact with wildlife may increase zoonotic infection risk. Perceptual attributes of product quality may be either positively or negatively influenced, depending on the ethical attitudes of consumers and the quality of management and husbandry in outdoor pig units which are visible to the public. The extent to which real and perceived differences in product quality are reflected in changed economic value is more a function of marketing than production system.

Extensive bedded indoor and outdoor pig production systems in USA: current trends and effects on animal care and product quality

The objective of this review paper is to document extensive bedded indoor and outdoor pig production in the United States, which has expanded due to growing niche markets for natural and organic pork. Bedded hoop (tentlike) barns are used for finishing pigs and gestating sows. Seasonal outdoor farrowing and some indoor bedded farrowing systems coupled with group lactation are used also. Most natural pork markets require outdoor or bedded settings, no subtherapeutic antibiotics or growth promotants, no animal by-products in feed, and a family farm production setting. Hoop-fed pigs have more backfat, smaller loin area, and lower carcass yield compared with confinement-fed pigs. Hoop-fed pigs have fewer aberrant behaviors and handle easier than confinement pigs. Health is similar except for an increase in internal parasites in hoop-fed pigs. Pigs in hoops are in larger groups than in confinement. Biosecurity in hoops is more difficult due to incoming bedding and open access. Hoop-fed pig performance varies depending on thermal environment, which is closely related to season and climate. Bedded hoop barns with individual feeding stalls provide an acceptable environment for gestating sows. Overall, product quality differences are relatively minor compared with wide variations in rearing environment for extensively reared pigs.

High diversity of Salmonella serotypes found in an experiment with outdoor pigs

Little is known about the risk of Salmonella infection in outdoor pig production, but seroprevalence data have indicated a higher incidence of Salmonella in outdoor than in conventional indoor production systems. This higher incidence may be due to an increased exposure of the animals to the surrounding environment, including contact with wildlife. In a study on the transmission of Salmonella to outdoor pigs an unexpected high diversity of Salmonella serotypes that are not normally isolated from pigs, like for instance S. Uganda and S. Goldcoast, was detected in faecal and in soil and water samples. However, in a small-scale wildlife survey to elucidate the potential source of the different Salmonella serotypes, the bacterium was not detected in any of a total of 22 rats, mice and shrews nor in 22 birds (mainly crow-birds; Corvidae). The unidentified source of the Salmonella serotypes isolated implies inadequate control possibilities and may therefore pose a problem to outdoor pig production in terms of food safety.

Factors correlated with the presence of rodents on outdoor pig farms in Denmark and suggestions for management strategies

The correlation between farm characteristics and the occurrence and importance of rodent pests on outdoor pig farms in Denmark was explored in an extensive questionnaire survey. Mice occurred on most farms but were only rarely considered a problem, as opposed to rats, which were controlled on more than half of the farms. A series of trapping studies showed a high small-mammal diversity in and around the pigsties. The presence of rats was positively correlated with farm size, the presence of straw stacks near the pigsties and the use of automatic feeders. Rats were considered a problem more often when open drinking basins were used or when feed was stored near the pigsties. The environment of the farm did not play an important role except to some extent the proximity of hedges. Recommendations for preventative rodent management include avoiding conditions indicated previously, frequent mucking out and movement of huts, keeping feed in rodent-proof containers, avoid spillage of fodder, and general cleanliness. Direct control methods include application of rodenticides with proper consideration for the risk of unintended poisoning of production animals, the use of traps, keeping dogs or cats, and possibly shooting.

Appropriateness of nutrient budgets for environmental risk assessment: a case study of outdoor pig production

Outdoor pig production has expanded rapidly in recent years due to economic and market pressures. Recent research has shown that a high degree of heterogeneity in soil nutrient distribution can occur as a result of this agricultural system. This study examined the consequences of dietary manipulation on total excretion and spatial distribution of N and P in soils under outdoor sow production. Small areas of land chosen for excretion received excessive amounts of both N and P. Values equivalent to up to 2861 kg ha −1 of soluble N were observed in preferred areas, up to 90% of this was in organic forms. Within 15 months, applied nutrients were sufficient to saturate the soil profile in preferred areas with respect to P and produce areas that represented a significant environmental risk. Lowering the amount of N and P in the diet has potential to reduce environmental impact but cannot eliminate spatial variability. The use of simple input output nutrient budgeting approaches may underestimate losses of N and P as they cannot account for mineralisation rates of organic nutrients excreted or for P saturation in areas preferentially used for excretion.