Intensive Pig Production Systems Research Articles

Amblyomma sculptum (Amblyomma cajennense complex) tick population maintained solely by domestic pigs

In Brazil Amblyomma sculptum from Amblyomma cajennense complex is a tick species with a rather broad distribution encompassing the Cerrado Biome and devastated areas of the Atlantic rainforest. This species is also the major vector to humans of Rickettsia rickettsii, agent of the Brazilian spotted fever. Main primary hosts for the adult stage and frequently associated to high environmental infestation levels are the native capybaras and tapirs and a domestic host, the horse. Recent, however, solely circumstantial evidence, has shown that pigs (Sus scrofa) domestic, feral or exotic (wild boars) as well as wild suidae may maintain A. sculptum populations as well. We herein describe the maintenance of an A. sculptum tick population by domestic pigs for three years when raised in paddocks. Observations herein described occurred in the facilities of an intensive outdoor pig production system within a farm in Uberaba municipality southeast Brazil. Initial evaluation was done upon request due to human tick-bite complains in June 2013. Later tick infestations were evaluated at each of eight consecutive seasons from August 2014 to May 2016. In the first evaluation, 104 nymphs and one female A. sculptum were collected from four pigs and 269 nymphs of A. sculptum and 12 Amblyomma spp larva clusters from the paddocks. Only one A. sculptum nymph was found in each of the surrounding bovine pasture and a nearby riparian forest. Seven Rhipicephalus spp and three Amblyomma spp larva were found in the former as well. Infestations were greatly reduced with elimination of the two most infested paddocks and mowing of vegetation. Still along the inspection of eight consecutive seasons A sculptum ticks were collected overwhelmingly adults from pigs. Thus, observations herein described show that outdoor pig raising may provide both a permissive environment and adequate host allowing for a minimal threshold for the maintenance of A. sculptum populations. Since raising domestic pigs in paddocks to increase animal welfare is an increasing practice, it may indicate a new trend in this parasitism, with yet an unknown effect upon animal and human health.

Agent-based modelling in applied ethology: An exploratory case study of behavioural dynamics in tail biting in pigs

Understanding behavioural dynamics in pigs is important to assess pig welfare in current intensive pig production systems. Agent-based modelling (ABM) is an approach to gain insight into behavioural dynamics in pigs, but its use in applied ethology and animal welfare science has been limited so far. We used ABM in a case study on tail biting behaviour in pigs to explore the use of ABM in gaining more insight into emergent injurious pig behaviour and related welfare issues in intensive production systems. We developed an agent-based model in Netlogo 5.1.0 to simulate tail biting behaviour of pigs housed in conventional pens in groups of 10. Pigs in the model started as neutral pigs (not involved in biting incidents), but could change into a biter, victim, or both biter and victim. Tail biting behaviour could emerge when pigs were unable to fulfil their internal motivation to explore. The effects of a redirected exploratory motivation, behavioural changes in victims and preference to bite a lying pig on tail biting patterns were tested in our model. The simulations with the agent-based model showed that coincidence in development of a redirected exploratory motivation can lead to tail biting behaviour in pigs and can explain the strong variations in incidence of tail biting behaviour observed in conventionally housed pigs. Behavioural changes in victims and preference to bite a lying pig seem to be of minor importance in the causation of tail biting patterns. The behavioural time budget of a pig might be an important factor in predisposing pigs to or preventing them from becoming a tail biter or a victim. ABM showed to be useful in analysing behavioural dynamics and welfare issues. An advantage for ABM in applied ethology is the availability of data from empirical studies.

Income Disparities and the Global Distribution of Intensively Farmed Chicken and Pigs.

The rapid transformation of the livestock sector in recent decades brought concerns on its impact on greenhouse gas emissions, disruptions to nitrogen and phosphorous cycles and on land use change, particularly deforestation for production of feed crops. Animal and human health are increasingly interlinked through emerging infectious diseases, zoonoses, and antimicrobial resistance. In many developing countries, the rapidity of change has also had social impacts with increased risk of marginalisation of smallholder farmers. However, both the impacts and benefits of livestock farming often differ between extensive (backyard farming mostly for home-consumption) and intensive, commercial production systems (larger herd or flock size, higher investments in inputs, a tendency towards market-orientation). A density of 10,000 chickens per km2 has different environmental, epidemiological and societal implications if these birds are raised by 1,000 individual households or in a single industrial unit. Here, we introduce a novel relationship that links the national proportion of extensively raised animals to the gross domestic product (GDP) per capita (in purchasing power parity). This relationship is modelled and used together with the global distribution of rural population to disaggregate existing 10 km resolution global maps of chicken and pig distributions into extensive and intensive systems. Our results highlight countries and regions where extensive and intensive chicken and pig production systems are most important. We discuss the sources of uncertainties, the modelling assumptions and ways in which this approach could be developed to forecast future trajectories of intensification.

Longitudinal gait development and variability of growing pigs reared on three different floor types

Biomechanical investigation into locomotor pathology in commercial pigs is lacking despite this being a major concern for the industry. Different floor types are used in modern, intensive pig production systems at different stages of the pigs’ production cycle. The general perception holds that slatted and/or hard solid concrete surfaces are inferior to soft straw-covered floors regarding healthy musculoskeletal development. Previous studies have compared pigs housed on different floor types using clinical, subjective assessment of leg weakness and lameness. However, reliability studies generally report a low repeatability of clinical lameness scoring. The objective of this study was to quantitatively assess the long-term effect of pen floors, reflected in the biomechanical gait characteristics and associated welfare of the pigs. A cohort of 24 pigs housed on one of three different floor types was followed from 37 to 90 kg average liveweight, with gait analysis (motion capture) starting at 63 kg. The three floor types were fully slatted concrete, partly slatted concrete and deep straw-bedded surfaces, all located within the same building. Pigs underwent five repeated camera-based motion captures, 7 to 10 days apart, during which 3D coordinate data of reflective skin markers attached to leg anatomical landmarks were collected. Pigs walked on the same solid concrete walkway during captures. One-way ANOVA and repeated measures ANOVA were used to analyse the gait data. Results revealed changes over time in the spatiotemporal gait pattern which were similar in magnitude and direction for the pigs from different floor types. Significant increases in elbow joint flexion with age were observed in all pigs (P⩽0.050; +6°). There were few differences between floor groups, except for the step-to-stride ratio in the hind legs being more irregular in pigs housed on partly slatted floors (P=0.012; 3.6 times higher s.d.) compared with those on 5 to 10 cm straw-bedding in all pen areas. As the level of clinical problems was generally low in this cohort, it may be that floors elicit problems only when there is a primary predisposing factor increasing weakness in susceptible tissues.

El extracto leucocitario dializable aumenta la concentración de interferón gamma sérico en cerdos destetados

In most intensive pig production systems piglets are weaned at 3 weeks of age, which creates stress because of feeding changes and hierarchy. This increases ...

Comparison of extensive and intensive pig production systems in Uruguay in terms of ethologic, physiologic and meat quality parameters

The objective of this work is to characterize two contrasting systems of fattening pigs in Uruguay. A total of 96 pigs (average 41.7 kg) were divided into eight groups of 12 animals, representing two production systems: (IN) pigs confined in pens of 12 m2 or (OUT) kept in plots with field shelters and access to pasture. Behavioral observations were performed by scan sampling at 5-minute intervals, three times a day during weeks 6, 8, 10 and 12 of the experiment. Aggressions were also observed at the end of the experimental period. Blood samples were taken for cortisol analysis and other physiological parameters, during growth period and slaughter and meat quality characteristics were assessed after slaughter. Differences were found in carcass characteristics, wherein IN presented a higher dorsal fat. These animals presented an overall lower activity and spent less time resting, with a stable pattern throughout the day. In OUT, pigs usually rested at midday hours, more active in the morning and afternoon. The number of total reciprocal aggressions in the observation period was 4.2±3.7 for IN and 2.3±2.2 for OUT. Cortisol levels and biochemical profile did not show evidence of important problems in the animals. Welfare is not compromised in any of the systems, although higher levels of cortisol and aggressions could be indicating some stress problems in the confinement system. Meat characteristics in OUT were considered better than in IN from a nutritional point of view.

The occurrence of Chlamydiaspp. in pigs with and without clinical disease

BackgroundWithin the genera Chlamydia, the development of refined diagnostic techniques has allowed the identification of four species that are capable of infecting pigs. The epidemiology, clinical, and zoonotic impacts of these species are however largely unknown. The study aimed to investigate the presence of Chlamydia spp. in the intestines of growing pigs and in conjunctival swabs from finisher pigs, and relate the findings to clinical signs.ResultsBy histology, 20 of 48 pigs had intestinal lesions that may be consistent with chlamydial infection. By PCR, forty-six of the pigs were positive whereas two samples were inhibited. Sequencing of 19 DNA extracts identified these as Chlamydia suis. By immunohistochemistry, 32 of 44 samples were positive and a significant relationship was detected between macroscopically visible intestinal lesions and a high degree of infection. By real-time PCR, a significant difference was detected between pigs with and without conjunctivitis when a Ct value of 36 was employed but not when a Ct value of 38 was employed.ConclusionsChlamydia suis was demonstrated in most samples and overall, no correlation to clinical signs was detected. However, a correlation was noted between samples with a high degree of infection and the presence of clinical signs. It is possible, that the intensive pig production systems studied might predispose for the transmission and maintenance of the infection thus increasing the infectious load and the risk for disease in the pig.

Avaliação microbiológica e molecular de líquidos articulares e peri-articulares de suínos

No presente estudo coletaram-se 115 amostras de líquido articular e peri-articular de suínos com suspeita clínica de doença articular oriundos de maternidade (30,43%), creche (44,35%) e crescimento/terminação (25,22%) de Sistemas Intensivos de Produção de Suínos (SIPs) para avaliação microbiológica e molecular. Observaram-se 57 (49,5%) amostras positivas em pelo menos uma das técnicas. No isolamento microbiano, 39,13% das amostras foram positivas, sendo Streptococcus spp. (19,72%), Arcabobacterium pyogenes (18,13%) e Escherichia coli (12,68%) os mais frequentes, havendo também a presença de Candida sp. (2,6%). Na técnica de Reação em Cadeia da Polimerase (PCR), em 20% das amostras foram detectados microrganismos com uma maior ocorrência de Mycoplasma hyosinoviae (34,09%), Erysipelotrix tonsilarum (20,45%) e Haemophilus parasuis (15,90%). Os microrganismos mais frequentemente isolados em animais com artrite, apresentaram distribuição em todas as faixas etárias, entretanto a fase de crescimento/terminação apresentou maior percentual (69%) de amostras positivas. Streptococcus spp. ocorreu em todas as fases sendo o microrganismo mais detectado. M. hyosinoviae foi observado principalmente em animais de creche. Na fase de crescimento/terminação as bactérias predominantes foram A. pyogenes, H. parasuis e E. tonsilarum. Aproximadamente metade dos casos foi negativo o que indica a provável ocorrência de processos degenerativos como a osteocondrose, embora a participação de infecções articulares e peri-articulares possam representar grandes perdas com menor ou maior impacto dependendo da fase de criação. Problemas articulares e/ou peri-articulares de origem infecciosas foram encontrados em todas as propriedades estudadas. O principal agente foi M. hyosynoviae, principalmente na creche, porém não se pode descartar o envolvimento de problemas degenerativos em associação.

Nose-to-nose transmission of Salmonella Typhimurium between weaned pigs

Little attention has been paid to the possibility of transmission of Salmonella in intensive pig production systems through alternate methods, such as airborne or direct nose-to-nose contact. This experimental study tested the hypothesis of nose-to-nose transmission of Salmonella enterica serovars Typhimurium (Trial I) and Agona (Trial II) in weaned pigs using stainless steel/glass isolation cabinets. In each trial, cabinet 1 (control pigs) and cabinet 2 (sentinel pigs) were connected directly to the fan unit. Cabinet 3 (seeded pigs) was not directly linked to the fan, but was arranged to receive a constant unidirectional airflow from cabinet 2 (sentinel pigs) through a 10 cm diameter hole, which also allowed nose-to-nose contact between pigs housed in these two cabinets. Air was taken out of the system through ducts connecting cabinets 1 and 3 to the exhauster. Therefore, direct contact among seeded and sentinel pigs was allowed but possible aerial transference of contaminated particles between those cabinets was prevented. The system was opened 21 days post-inoculation and tissue samples were collected for bacteriological analysis. The recovery of nalidixic acid-resistant Salmonella Typhimurium from sentinel pigs corroborates the hypothesis of nose-to-nose transmission of that pathogen in pigs. However, serovar-related differences might exist regarding the nose-to-nose transmissibility of Salmonella in pigs, since Salmonella Agona was not detected in sentinel pigs (Trial II).

Biosecurity practices on intensive pig production systems in Chile

Chile eradicated classical swine fever (CSF) in April 1998, following a 17-year eradication programme. The authors describe biosecurity levels of pig farms in Chile after the eradication of CSF. A formal survey was administered to 50 large integrated pig farms, which represented almost 60% of the swine population. The main topics on the questionnaire were production, health management, biosecurity, insurance and information about CSF outbreaks in the past. Biosecurity practices were analysed according to the criteria stated by Barcelo and Marco in 1998. A scoring system to measure biosecurity was designed and pig farms were classified according to this score. An adjusted specific measure is discussed as a potential indicator of risk for disease infections. The authors explore associations between biosecurity herd size and insurance policy against CSF.

Influence of salt application on biting by growing-finishing pigs

In intensively kept fattening pigs, biting is a vice complex of fairly common occurrence, of widespread distribution, of some economic importance but of obscure aetiology. It has been suggested that in any one particular outbreak of biting there may be more than one aetiological factor at work and that the behaviour may only occur when the sum of the individual effects of these factors goes beyond a certain critical (undefined) level (Ewbank, 1973). Factors such as: sub-optimal space allowance, temperature control, air movement, nutrients, palatability of feed, access to feed and water, can stimulate this kind of behaviour. Salt (NaCl) is an essential mineral and its rate of inclusion in diets has been implicated in the development and expression of biting behaviour. It is possible that heightened appetite for salt could make pigs particularly attracted to pen-mates with injured tails (Fraser, 1987). Although pigs require only about 0.2% NaCl in the diet for maximum weight gain, NaCl is often provided at 0.5% of the diet for growing pigs, and it has been suggested that an increase to 0.75% or 1% can reduce the incidence of biting. This paper investigates the influence of salt application on biting by growing-finishing pigs under an intensive indoor pig production system. An amount of extra salt was provided to the pigs and behavioural observations (biting, drinking, lying and standing) were recorded.

Food intake and performance of newly-weaned pigs: effect of pairing with an experienced pig

In intensive pig production systems piglets are weaned at between 21 and 28 days of age and it is common for piglets to take a few days to discover and accept solid food as a source of nutrients and this results in a loss of weight (the weaning growth lag). Therefore, if a means could be found to encourage the acceptance of solid food by piglets, benefits in terms of their growth and welfare would ensue. The transmission of information about foods from one animal to another has been demonstrated in the rat (Galef, 1993) and ruminants (Provenza and Balph, 1987) but there have been no studies with pigs at the time of weaning. Therefore, piglets were tested in pairs of experienced and inexperienced animals, with varying degrees of contact, with constant access to food over a period of seven days after weaning of the inexperienced animals.

Effect of three lactation housing systems on sow and piglet performance and behaviour

Confinement of sows in farrowing crates and early weaning of piglets are two major areas of concern in relation to animal welfare in intensive pig production systems. In this project, two alternative lactation systems in which these potential stressors are absent or reduced were evaluated.36 sows and litters were used in an experiment to evaluate, from weekly performance records and observations of behaviour, two alternative strategies for housing and management during lactation in comparison with a conventional current system: (1)Family system (F): Sows were housed throughout in groups of four with voluntary access farrowing pens. Piglets remained with the sows for 12 weeks and a boar was introduced after 3 weeks to induce oestrus.(2)Multisuckling system (M): Sows farrowed in individual crates but were grouped in fours in straw pens after 2 weeks. Piglets remained with the sows for 12 weeks and a boar was introduced after 3 weeks.(3)Conventional commercial system (C). Sows remained in part-slatted, unbedded farrowing crates throughout a four week lactation. Piglets weaned into flat decks and transfered after four weeks into fully slatted grower pens.

Nest site choice by farrowing sows offered cubicles or parallel walls

Freedom of movement and the opportunity to express normal behaviours are important requirements for any housing system which satisfies the welfare codes (MAFF, 1983). Intensive pig production systems generally house farrowing sows in crates to minimise the probability that piglets will be crushed. To satisfy the welfare codes there is, therefore, a need to develop a loose housing system which satisfies a multiplicity of conditions. It must give the sow unrestrained movement, allow nest building activities, provide physical protection and warm environmental conditions for the young piglets. In a previous choice trial sows sited their nests within cubicles rather than a corner or beside a straight wall (Hunt and Petchey, 1989). In another trial they were offered an arrangement of parallel walls spaced 0.55,0.95 or 1.35 m apart, most sows (0.44) chose to farrow between the 0.55 m spaced walls (Petchey, 1991). Sows making this choice (ie 0.55 m spacing) also exhibited more nest building behaviours and built significantly bigger nests (P<0.05). The trial reported here offers sows the preferred sites of the two previous trials.

Dutch free-range pig keeping

The importance of environment, health and welfare nowadays asks for new approaches. Lessons may be learned from experiences elsewhere. In the Netherlands some consumers dislike the intensive pig production systems with little room for movement of the pigs. The pollution problem is considered to be unacceptable. They might also be afraid of harmful effects of additives on their health. A free-range pig keeping system was set up to accommodate these customers. The name of the system is “Scharrelvarkens” and is derived from the Dutch word “Scharrelen” which refers to feed intake behaviour of poultry in free-range conditions. “Varkens” stands for pigs. The free-range production system is according to certain rules. Animals are group housed, partly outdoors and no feed additives are allowed. Details are in the appendix.

Epizootiology of swine fever

Summary In countries with an intensive pig production system, swine fever (SF), where present, may be regarded as one of the economically most important pig diseases. Although reservoirs of virus and pathways of transmission are well understood, field experience has shown that the disease is extremely difficult to eradicate, especially in countries with intensive pig breeding. The virulence of the strains circulating in the field and the measures applied to control the disease determine to a large extent the course of an epizootic. Outbreaks of highly virulent strains are readily recognised. Epizootics caused by low virulent strains are characterised by indistinct signs of disease, slow spread of virus through the herd and the comparatively important role of the 'carrier sow syndrome'. The latter phenomenon may result in the birth of healthy looking but persistently infected and immune-tolerant piglets. This and the occurrence of chronic infections are largely responsible for the perpetuation of the virus in the pig population. The 1982-1985 epizootic of SF in the Netherlands showed an almost equal prevalence of outbreaks in breeding and fattening herds. In proportion to the number of herds in the country, there was in both categories an approximately linear relationship between the risk of infection and the size of the herds. The proportion of affected breeding herds increased as mass vaccination of areas at risk was started earlier in the epizootic. In close-knit communities with large breeding units, man should be regarded as the single most important factor in the herd-to-herd transmission of the virus, whereas in fattening units and in areas with small pig farms, transport and introduction of infected pigs into herds accounts for the majority of outbreaks and for the spread of the disease. Farms visited by persons handling pigs subsequent to contact with an infected herd should, therefore, be included in the epizootiological investigations. Virological and serological methods are indispensable in order to confirm or to rule out the possibility of infection of suspected contacts, especially in outbreaks caused by strains of low virulence. Continuous education of farmers regarding the importance of maintaining precautionary measures against the introduction of contagious diseases and, in the case of an advancing epizootic, special instructions to all people entering piggeries, would contribute greatly to reducing the untraceable pathways of SF spread.