Outdoor Pig Production Research Articles

Helminth parasites in pigs: New challenges in pig production and current research highlights

Helminths in pigs have generally received little attention from veterinary parasitologists, despite Ascaris suum, Trichuris suis, and Oesophagostomum sp. being common worldwide. The present paper presents challenges and current research highlights connected with these parasites.In Danish swine herds, new indoor production systems may favour helminth transmission and growing knowledge on pasture survival and infectivity of A. suum and T. suis eggs indicates that they may constitute a serious threat to outdoor pig production. Furthermore, it is now evident that A. suum is zoonotic and the same may be true for T. suis. With these ‘new’ challenges and the economic impact of the infections, further research is warranted. Better understanding of host–parasite relationships and A. suum and T. suis egg ecology may also improve the understanding and control of human A. lumbricoides and T. trichiura infections.The population dynamics of the three parasites are well documented and may be used to study phenomena, such as predisposition and worm aggregation. Furthermore, better methods to recover larvae have provided tools for quantifying parasite transmission. Thus, an on-going study using helminth naïve tracer pigs has surprisingly demonstrated that soil infectivity with A. suum and T. suis increases during the first 2–3 years after pasture contamination.Though all three helminth species stimulate the Th2 arm of the immune system, Oesophagostomum seems weakly immunogenic, perhaps via specific modulation of the host immune system. A. suum and T. suis potently modulate the host immune response, up-regulating Th2 and down-regulating Th1. As a consequence, A. suum may compromise the efficacy of certain bacterial vaccines, whereas T. suis, which establish only short-term in humans, is a favourite candidate for down-regulating autoimmune Th1-related diseases in man.Some basic research findings have offered new possibilities for future sustainable control measures. For example, the heredity of host resistance to A. suum and T. suis is so high that breeding for resistant pigs may be a possibility. Experimental studies have demonstrated that fermentable dietary carbohydrates have an antagonistic effect on Oesophagostomum and to a lesser extent on T. suis and A. suum, whereas egg-destroying microfungi may be used to inactivate the hard-shelled A. suum and T. suis eggs in the environment.Helminth control in Denmark has previously relied solely on anthelmintic treatment in herds with low helminth transmission. When indoor transmission rates increase, or in outdoor herds with high pasture contamination levels, medication may advantageously be combined with sustainable control measures, such as selected pig genomes, bioactive forages, and egg-destroying microfungi.

Breeding for welfare in outdoor pig production: A simulation study

Despite the societal and market attention, to our knowledge, there is no breeding program for outdoor pig production in which improvement in animal welfare is emphasized. In this study, a dam-line selected for an outdoor production system was simulated. The purpose was to investigate the opportunities for improving welfare through traditional selection methods. The genetic gain from simulated breeding programs was compared for three alternative scenarios: 1) a conventional scheme that improves production and reproduction traits (litter size, piglet mortality (PM), mean piglet weight at weaning, weaning-to-mating interval (WMI), average daily gain (ADG) from birth to 20 kg, ADG from 20 to 100 kg, and lean content); 2) extension of the first scenario with welfare considerations including leg condition of sows after first lactation (LEG w) and additional non-market values on PM and WMI; and 3) a breeding program for welfare in which genetic progress of traits important for welfare (mothering ability and sow longevity) was obtained by increasing the non-market values of LEG w, PM and WMI. The simulation showed that, compared with weights found in the literature, greater weights on LEG w, PM and WMI (approximately 3, 2 and 7 times higher, respectively) were required to avoid deterioration of these traits. The improvement of traits important to welfare was realized with a reduction in the genetic gain of production traits. Thus, the implementation of a breeding program for welfare in outdoor production requires other prerequisites than the market value of the genetic progress only.

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.

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.

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

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.

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.

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.

Results of Giltsrearing in Outdoor Production System

The applied technology is an alternative approach to pigkeeping-systems. An outdoor pig production breeding sows are kept at pasture either year-round or in a certain period of the year. The important equipments of outdoor pig production are farrowing or grouping sows inhuts, which protect pigs against the effects of extreme weather, and electric fences, which surround and divide the pasture. Concentrate feed can be fed from the ground or from feeders which are made of steel or timber. One of main advantages of this pig keeping system is the total mobilizable keeping technology.Within the scope of the study we are performing an experiment to make a comparison between coventional system and free range sows keeping technology. Pannonhybrid F1 gilts were used in this experiment, 28 gilts were kept on pasture all day and 28 gilts are kept in conventional, indoor system.In this work the results of gilts-rearing are presentated as a part of our two-years experiment.

Intake of nutrients from pasture by pigs.

The domestic pig evolved from the omnivorous wild boar and has retained many natural foraging behaviour patterns. Although most modem commercial pigs are housed and fed concentrate diets, interest in the potential nutrient contribution from pasture has increased due to growth in outdoor and organic pig production systems. The energy requirements of outdoor pigs are increased by approximately 15% under Northern European conditions as a result of greater climatic energy demand and locomotory activity. The nutritional contribution made by pasture will depend on the availability, nutrient composition, grazing intake and digestive utilisation of herbage. Information on these topics is currently very sparse. Herbage availability is often low due to farm rotational policy or destructive foraging by the pigs. Herbage composition shows large varietal and seasonal differences, but the high fibre content reduces the efficiency of energy utilisation and may impair utilisation of other nutrients. Intake of grazed herbage varies widely between individuals, but is typically approximately 2.0 kg DM/d for dry sows fed restricted concentrate, and approximately 0.1 kg DM/d for growing pigs offered ad libitum concentrate. This intake can contribute 50% of the maintenance energy requirement and a high proportion of the amino acid, mineral and trace element requirements of dry sows, but < 5% of requirements of growing pigs. Whilst the potential to increase nutrient intakes from grazing exists, this process requires better understanding of herbage intake and digestion, and development of better systems for paddock management.

The gradual weaning process in outdoor sows and piglets in relation to nematode infections

In EU organic pig production it is required that the piglets are weaned no earlier than 6 weeks of age. During the lactation period, a gradual weaning process occurs. Outdoor and organic pig production differ markedly from semi-natural and indoor environments, where the gradual weaning process has been studied in detail. The differences include the sows’ opportunity for foraging and the feed availability, and compared to indoor pigs also a greater incidence of gastro-intestinal parasitic infections, which may interfere with feed consumption and utilisation of nutrients. In order to describe the gradual weaning process in an outdoor environment and investigate the possible effects of gastro-intestinal nematode infections on the behaviour during the period relevant for organic pig production, we studied the behaviour of 16 sows and their litters kept in separate paddocks with farrowing huts on days 16, 23, 30 and 44 postpartum and their growth rate and feed consumption during the same period. Half the sows and half of each litter were experimentally infected with Ascaris suum, Oesophagostomum dentatum and Trichuris suis. A gradual weaning process took place. The frequency of nursings declined, the piglets were increasingly responsible for initiating nursings, they increasingly visited a piglet feed trough and ate more solid feed, as lactation progressed (all P≤0.001) The sow terminated 100% of the nursings and neither this nor the duration of the post-massage phase changed during the experimental period. Other behaviours usually considered important in the gradual weaning process were unexpectedly rare, i.e. piglets missing at milk let-down (0% of the litter), piglet massaging the udder between nursings (0.7% of scans), non-nutritive nursings (6.3% of nursings) and nursing in a standing position (one sow). There were only negligible effects of nematode infection on nursing behaviours, behaviours performed between nursings, body weight, weight gain and feed consumption in sows or piglets. The results indicate that infected sows did not have to restrict their allocation of resources to piglets further when infected than that which is part of the normal gradual weaning process. However, the infected sows spent more time in the huts (42% versus 29% of scans, P=0.02) perhaps to preserve energy, whereas their piglets probably did so ( P=0.04) because they wanted to stay close to their mothers.

Enquête séro-épidémiologique sur la toxoplasmose dans les systèmes de production porcine de plein air dans la région du sud du Brésil

L’élevage des porcs à grande échelle en plein air est un phénomène nouveau au Brésil, mais c’est un secteur d’intérêt croissant. Des anticorps spécifiques contre Toxoplasma gondii ont été trouvés chez 86,08 p. 100 des 115 porcs examinés. En utilisant le test d’agglutination modifié, les titres en anticorps suivants ont été relevés : 1:50 (3,47 p. 100), 1:100 (6,08 p. 100), 1:200 (9,56 p. 100), 1:400 (6,95 p. 100), 1:800 (6,95 p. 100), 1:1600 (6,95 p. 100) et 1:3200 (55,65 p. 100). La contamination fécale de l’environnement par des chats ou par la consommation de rongeurs infectés est l’origine la plus probable de la toxoplasmose chez les porcs élevés en plein air. Les résultats indiquent que la toxoplasmose est fréquente chez les porcs élevés à l’air libre dans la région. Les services de santé devraient intensifier leur surveillance ainsi que les contrôles sanitaires afin de réduire le risque de toxoplasmoses en particulier chez les femmes enceintes. Ceci est le premier rapport d’une infection à T. gondii chez des porcs élevés dans un système de production en plein air au Brésil.

The fate of nitrogen in outdoor pig production

There may be a conflict between animal welfare and nitrogen pollution in outdoor pig production. In response to concern about nitrogen being lost to the atmosphere and ground water we quantified spatial variation and temporal dynamics of mineral N, ammonia volatilization, denitrification and nitrate leaching from outdoor pig production at three commercial farms in Denmark. From paddocks containing farrowing sows substantial nitrogen losses were observed, particularly around the feeding areas. Gross ammonia emission rates varied between 0.08 and 1.26 kg N ha–1 d-1 and increased with animal density and N intake. The mean annual loss of ammonia per sow was 4.8 kg N. Denitrification rates averaged 0.52 kg N ha–1 d-1 in autumn following summer grazing with lactating sows, and 0.10 kg N ha–1 d-1 in the following spring. Denitrification losses up to 69 to 114 kg N ha-1 were estimated. Cumulated nitrate leaching during sow grazing and in the following year was 126–276 kg N ha–1. Of the N input in feed to the paddock 44% could be accounted for in piglets, 13% as ammonia volatilization, 8% as denitrification and 16 to 35% as nitrate leaching. The necessary development towards increasing N-use efficiency in outdoor pig production may include changes in management, such as lowering the stock density and reducing the level of dietary N. Also, a more uniform distribution of nutrients in the field may be achieved by manipulating the excretory behavior of the animals

Alternatives to nose-ringing in outdoor sows: the provision of a special rooting area

Nose-ringing is commonly used in outdoor pig production to prevent pasture damage. However, nose-ringing causes acute stress at the time of ringing and inhibition of normal rooting behaviour (Horrellet al.2001). Therefore alternatives to nose-ringing need to be investigated. Previous studies have focused on dietary modification as a way of reducing rooting behaviour and pasture damage (e.g. Braundet al.1998). Although these methods helped to reduce rooting behaviour they were ineffective at decreasing long-term pasture damage. This experiment examined the effectiveness of providing a special, enriched rooting area in an attempt to reduce pasture directed rooting behaviour and consequently reduce overall pasture damage.

Implications of grazing by sows for nitrate leaching from grassland and the succeeding cereal crop

Outdoor pig production may have benefits in terms of animal welfare but could be undesirable in terms of nutrient losses. In paddocks on sandy soil grazed by lactating sows, nitrate leaching was determined using the suction cup technique from the start of grazing in October to after the following barley/pea wholecrop with perennial ryegrass. The inorganic N concentration in soil was uneven after sow grazing, with the highest values found near the feeding area. In contrast to low nitrate leaching in the year of grazing (25–30 kg of N ha–1), losses were considerable in the following autumn and winter. Throughout the measuring period of 18 months, nitrate leaching inside paddocks was on average 320 kg of N ha–1 with the major part near the feeding area. Ten metres from the feeding area, leaching losses were 500 kg of N ha–1 and, at 16 m distance, losses were 330 kg of N ha–1. At 22 and 28 m distance from the feeding area, about 200 kg of N ha–1 was leached and outside paddocks about 100 kg of N ha–1. The combination of a sandy soil with high winter rainfall leads to a large proportion of the N surplus being lost by nitrate leaching near the feeding area. To reduce nitrate leaching, stocking density and the level of dietary nutrient input must be adjusted, and more uniform distribution might be achieved by manipulating the excretory behaviour of the sows.

Análise econômica do Sistema Intensivo de Suínos Criados ao Ar Livre

Foi instalado um Sistema Intensivo de Suínos Criados ao Ar Livre (SISCAL), na Estação Experimental de Pato Branco do Instituto Agronômico do Paraná, com o objetivo de determinar os custos de implantação e produção deste sistema, na região Sudoeste do Paraná. A área do SISCAL foi dimensionada para um plantel de 14 matrizes e um reprodutor, a qual foi dividida em piquetes para separar os animais por estágios fisiológicos (reprodução, gestação e creche). O custo de implantação foi baseado nos custos de mão-de-obra e dos materiais utilizados para instalação do sistema e confecção de alguns equipamentos, como também os custos da construção da fábrica e depósito de ração e dos equipamentos para confecção das rações.O custo total de implantação do SISCAL, excluindo o valor da terra, foi de US$ 6862,80, ou seja, US$ 490,20 por matriz instalada, em julho de 1997. A construção e os equipamentos da fábrica de ração foram os itens mais caros do custo de implantação. O custo total de produção por kg de leitão desmamado produzido foi US$ 0,617, em junho de 1999. Neste período, foi possível obter 18,81% de lucro líquido por kg de leitão produzido.