Pig Production Systems Research Articles

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.

Evaluation of smallholder pig production systems in North Vietnam: Pig production management and pig performances

Abstract This study investigated the productive adaptability of pig breeds under different smallholder production conditions in Vietnam, comparing an indigenous with a Vietnamese improved breed. Fieldwork was conducted in four villages with different remoteness in North Vietnam from 2001 to 2002, in 64 households keeping the improved Mong Cai or indigenous Ban as sow breeds and progeny for fattening. Four visits per farm yielded 234 structured interviews. Reproductive performances were derived from 135 litters. Individual weights of pigs (n = 755) were obtained. Data were analysed by regression, linear and generalised linear, especially loglinear models. Two distinct pig production systems were identified, that differed in remoteness, market access, resource availability, distribution of pig breeds and pig production intensity. Higher performances of 1.4 and 1.5 litters year− 1, 8.4 and 8.4 piglets weaned litter− 1, 66.6 and 93.0 kg piglets weaned sow− 1 year− 1, and 136 and 177 g day− 1 ADG were found in two villages near town with semi-intensive production conditions and a high rate of improved Mong Cai sows and MC and LW × MC offspring in the observed population. Lower performances of 1.1 and 1.1 litters year− 1, 4.6 and 5.5 piglets weaned litter− 1, 20.5 and 30.9 kg piglets weaned sow− 1 year− 1, and 66 and 85 g day− 1 ADG were observed in parallel to higher incidences of indigenous Ban pigs away from town under extensive conditions. Total live weight offtake per household per year was higher near town and in one village distant to town. MC and LW × MC remained even under demand-driven conditions below the performance potential reported for improved genotypes. Under resource-driven conditions with a saving-oriented production pattern, the higher-yielding but more demanding Mong Cai might not be an efficient production alternative as a further performance reduction can be assumed. A considerable live weight output was observed under resource-driven conditions and with a higher percentage of crossbred LW × Ban offspring in the population, possibly representing a promising production alternative. Factors influencing the performance expression of pigs, and the suitability of different methods for the assessment of performance parameters on-farm are discussed.

Effect of organic pig production systems on performance and meat quality

The present study was carried out to establish knowledge of consequence for setting up guidelines of importance for production of competitive organic pork of high quality. Performance and meat quality characteristics were compared between three organic pig production systems based on indoor housing with access to an outdoor area and a Danish conventional indoor system including 100% concentrate during the finishing feeding stage. The three organic systems used the following three feeding regimes: 100% organic concentrate according to Danish recommendations, 70% organic concentrate (restricted) plus ad libitum organic barley/pea silage and 70% organic concentrate (restricted) plus ad libitum organic clover grass silage, respectively. With exception of a slightly lower daily gain in organic pigs fed 100% concentrate, no significant difference was found in performance and meat quality characteristics compared with results obtained in the conventional system. In contrast and independent of roughage used, organic pigs raised on 70% concentrate had a significant reduction in daily gain ( P < 0.001) compared with pigs raised on 100% concentrate, despite the fact that no difference in feed conversion rate was seen between the tested production systems. However, the percentage of leanness increased significantly in meat from organic pigs raised on 70% concentrate plus roughage compared with meat from pigs given 100% concentrate. This was reflected in higher yield (weight) of lean cuts and lower yield of cuts with high fat content from pigs fed 70% concentrate plus roughage. In general, organic feeding resulted in a significantly higher content of polyunsaturated fatty acids in the back fat (1.8%), which increased further when restricted feeding plus roughage (4%) was used. Restricted concentrate feeding gave rise to a decrease in tenderness compared with pork from pigs fed 100% concentrate.

Control Panels of Meat Juice Samples for a Salmonella Enzyme-Linked Immunosorbent Assay

In the Danish pig production system, an indirect enzyme-linked immunosorbent assay (ELISA) for detection of antibodies in meat juice is used for Salmonella surveillance. Quality control (QC) of this ELISA was previously based on repeated testing of control serum samples. The purpose of the study reported here was to collect, characterize, and implement a panel of meat juice pools for supplemental internal QC. Muscle samples for extraction of meat juice were collected from slaughter pigs of 5 herds infected with Salmonella spp. and from 4 herds without Salmonella infection. A QC panel with 39 pools of meat juice, yielding ELISA optical density (OD) values covering the full range of expected OD values, was prepared and tested repeatedly to determine mean and SD OD values. Each pool was tested twice on each microtitration plate, and the results were used to determine limits for validity of future tests. This QC panel was included as an internal QC to be tested every month. Besides the QC panel, 2 panels containing 100 samples of meat juice with OD above the positive cut-off value and 100 samples with OD below that value were prepared for quarterly control of the diagnostic sensitivity (DSe) and the diagnostic specificity (DSp) of the ELISA. The inclusion of these panels in the QC system will provide information about drifts in DSe and DSp of the test. The procedures described here can be applied to other tests where meat juice samples are used for testing.

Methods and data for the environmental inventory of contrasting pig production systems

The comparison of the environmental performance of contrasting agricultural production systems using life cycle assessment (LCA) requires very specific data for each production mode, especially for direct emissions on the farm. In a case study of pig production, three contrasting production scenarios were defined: conventional good agricultural practice (GAP), organic agriculture (OA), and red label (RL). An expert panel produced methods for the estimation of emissions for key-processes of these scenarios. Clear differences were obtained for these emissions between the three scenarios. Finally, the summation of the main emissions for the entire life cycle allowed the identification of weak points for each scenario, which can be explained by the differences obtained for the emissions of the key-processes studied.

Use of a serological approach for prediction of Salmonella status in an integrated pig production system

Relevance of a Salmonella serological detection technique was studied from complete results obtained from 9 pigs fattening units. Feces and overshoes were sampled at different periods after starting fattening (2, 3 and 4 months) while caecal contents were taken on the slaughter line. The bacteriological technique used was based on a Diasalm enrichment and a commercial test was used for serology on an average of ten animals per batch. The aim of this work was to establish a correlation between serological results obtained at slaughter (10 samples/batch) and bacteriological results. In this context, two types of logistic regression models were tested by considering alternatively serology and Salmonella detection in caecal contents as the dependent variables. Firstly, beside the fact that all logistic regression models show weak correlations, the first finding was that positive results in overshoes taken at 2 and 3 months are slightly correlated with serological status of herds (odds-ratios of 4.96 and 2.55). Secondly, when batches were characterized as positive on the basis of serological results, the probability of Salmonella recovery in caecal contents was higher than when the batches were considered as negative (odds-ratios comprised between 4.36 and 5.81). A major conclusion is that serology can be used to follow the improvement of an integrated pig production system, but is not the unique solution for assessing risk of Salmonella shedding from specific herds.

Announcing the arrival of enrichment increases play behaviour and reduces weaning-stress-induced behaviours of piglets directly after weaning

Piglets have difficulties with the abrupt changes at weaning associated with conventional pig production systems. Previously, it has been shown in rats that reward and announcement of reward counteracts impact of stress effects. In the present study, it was investigated if announcement of an environmental enrichment, more than enrichment alone, could facilitate play behaviour and reduce weaning-stress-induced behaviours such as increased aggression with subsequent increased injuries and increased social manipulative behaviours (i.e., tail biting, belly nosing, mounting). Twenty-four litters of conventional housed fattening piglets were kept under three different experimental conditions: sound cue (conditioned stimulus, CS) paired with an environmental enrichment (unconditioned stimulus, US) with a maximum delay between the CS and US of 30 s (CS–US paired) in which anticipatory behaviour develops; cue-environmental enrichment unpaired (CS–US unpaired) and no cue and no environmental enrichment (No CS–US). At two weeks of age the so-called ‘anticipation procedure’ started and ended two days after weaning. Growth, play, aggressive, social manipulative, eating and inactive behaviour, and injury rates were measured before and after weaning. Results of this study indicated that announcement of enrichment and not enrichment alone significantly increased play behaviour after weaning. In addition, announcement of enrichment and to a lesser extent enrichment alone decreased aggression before and after weaning and subsequent amount of injuries after weaning. The most important finding of this study is that the effects of an expected enrichment are more pronounced than the effects of enrichment alone. It is therefore suggested that announcing enrichment has an additional effect on the impact of enrichment alone and can be used as a new tool to reduce weaning stress in piglets.

The Effects of Pseuderanthemum palatiferum, a New Medicinal Plant, on Growth Performances and Diarrhea of Piglets

To evaluate the effect of Pseuderanthemum palatiferum, a new medicinal plant, on piglets′ daily weight gain and the effect on piglets with diarrhea, a total of 644 piglets (396 suckling and 248 weaned piglets) were examined using 3 tests for 30 days. Fresh leaves or dried leaf-powder of P. palatiferum were fed daily at different dosages or for different durations to the piglets. The dose of P. palatiferum to both suckling and weaned piglets could improve the following parameters: growth rate became higher; retarded growth, diarrhea and mortality were decreased; and the number and duration of diarrhea cases were decreased. The dosage during 30 days was more effective than that during 7 days and the leafpowder dosage of 0.2 g/kg body weight (BW)/day was more effective than that of 0.1 g/kgBW/day. The effect of the dried leaf-powder was the same as or equivalent to the fresh-leaf. It also kept the piglets in a healthy physiological condition. It is expected that the usage of this plant, especially in the form of leaf-powder, has a high possibility to replace or reduce the amount of antibiotics in pig production systems in future.

Le bien-être animal, un facteur d'évolution des systèmes de production porcine ?

Animal welfare requirements are expected to affect the future development of pig production systems in France. Rules and regulations play a major role in this evolution. This could be in favour of larger farms, better able to sustain their economic burden. The development of alternative production systems should also be in favour of improved animal welfare. However, French consumer demand for this type of production remains very low due to higher prices. On the other hand, simultaneous improvement of animal performance and welfare provides an interesting approach, as the price increase due to the welfare-related cost may be at least partly offset by enhanced animal performance.

Prevalence and Antimicrobial Resistance of Campylobacter in Antimicrobial-Free and Conventional Pig Production Systems

The objectives of this study were to determine and compare the prevalence and antimicrobial resistance of Campylobacter species in swine reared in conventional and antimicrobial-free (ABF) production systems. Campylobacter coli was the predominant species, with 1,459 isolates (99%) in the study. We found significantly higher prevalence of C. coli on the ABF farms (77.3%) than on the conventional farms (27.6%) among pigs at the nursery stage (P < 0.001). At slaughter, we found significantly higher prevalence at the postevisceration than at the preevisceration stage (P < 0.001) in both production systems. The 1,459 C. coli isolates were tested with the agar dilution method for their susceptibility to six antimicrobials: chloramphenicol, ciprofloxacin, erythromycin, gentamicin, nalidixic acid, and tetracycline. Resistance was most prevalent against tetracycline (66.2% of isolates) followed by erythromycin (53.6% of isolates). Frequency of resistance to these two antimicrobials was significantly higher among conventional herds (83.4% for tetracycline and 77% for erythromycin) than among ABF herds (56.2% for tetracycline and 34.5% for erythromycin). Resistance to ciprofloxacin at the MIC (>4 mg/liter) was also found on farms in both systems. Multidrug-resistant C. coli strains were detected in both the conventional (7%) and ABF (4%) herds. This is the first report of ciprofloxacin-resistant strains of C. coli in ABF pigs in the United States. These findings highlight the high prevalence of antimicrobial-resistant C. coli in both conventional and ABF pig production systems and have significant implications for the persistence of antimicrobial-resistant Campylobacter in the pig production environment regardless of levels of antimicrobial use.

A partial-budgeting tool to describe the effect of lactation space and lactation-space management on net revenue in a multi-site production system

Partial budget analysis is an effective production tool to evaluate economic implications of proposed changes to pig production systems. We describe a partial-budgeting tool that estimates the effects of lactation space and lactation-space management on net revenue in a multi-site production system. A partial-budgeting worksheet is linked to an economic model that couples production-system-specific input and prospectively derived research data. A 2600-sow multi-site production system is modeled to illustrate the interactions between lactation-space management, weaning age, and whole-system net revenue. The results of these modeling efforts suggest that inadequate lactation space and poor utilization of lactation space substantially restrict net revenue in multi-site pig production. However, decreasing the number of sows scheduled to farrow each week for the purpose of increasing weaning age may not improve profitability. Quantifying the effects of lactation length on weaned-pig value and subsequent reproductive performance enables a clear understanding of the effects of lactation space and lactation-space management on whole-system net revenue.

Dynamic Simulation Model of Nitrogen Fluxes in Pig Housing and Outdoor Storage Facilities

Many factors in pig production, including genetics, feeding efficiency, feed composition, feed distribution method, environmental control, and waste management, affect the nitrogen content of pig slurry. However, estimating the global impact of these factors on the nitrogen (N) content of daily fresh manure and stored slurry is not easy. Mathematical modelling of certain N fluxes in pig production systems have shown good potential for predicting the impact of some of the aforementioned characteristics on either pig excretion or ammonia volatilisation in buildings and outdoor storage facilities. However, none considered both excretion and ammonia volatilisation over the entire production site. To do this, equations from the literature were used to construct a dynamic simulation model of N fluxes in both batch and continuous production systems. The resulting model allows for prediction of daily concentrations and quantities of N in buildings and storage facilities. Total N concentration in outside slurry tanks can be accurately predicted within an error range of 6·4% for the growing–finishing site and 9·3% for the reproduction site.

Implications of Uncertainty and Variability in the Life Cycle Assessment of Pig Production Systems(7 pp)

Goal, Scope and Background Calculating LCA outcomes implies the use of parameters, models, choices and scenarios which introduce uncertainty, as they imperfectly account for the variability of both human and environmental systems. The analysis of the uncertainty of LCA results, and its reduction by an improved estimation of key parameters and through the improvement of the models used to convert emissions into regional impacts, such as eutrophication, are major issues for LCA.

Molecular epidemiology and diversity ofSalmonellaserovar Typhimurium in pigs using phenotypic and genotypic approaches

For epidemiological investigations of the most common and non-host-adapted Salmonella serotypes, such as Typhimurium, highly discriminatory approaches are essential. In the present study, we evaluated three genotyping methods; amplified fragment length polymorphism (AFLP), pulsed-field gel electrophoresis (PFGE) and repetitive palindromic extragenic-PCR (Rep-PCR) using 40 isolates. AFLP showed the highest discriminatory index (0.939), resolution and throughput. To determine clonality of Salmonella Typhimurium isolates and epidemiological relatedness in different commercial pig production units, we employed AFLP in combination with antimicrobial resistance pattern and phage typing. Salmonella serovar Typhimurium isolates (n=196) obtained from a longitudinal study of 18 pig farms over a 3-year period were studied. Using this approach, 16 distinct clonal types were identified. We found two common multidrug- resistant patterns including AmCmStSuTe and AmKmStSuTe. Two commonly multidrug- resistant phage types that are of known public health importance, DT104 and DT193, were also common. AFLP differentiated distinct clones within DT104, a phage type previously reported to be clonal. Fourteen of the clonal types were unique to one of the two production systems, showing diversity between independent commercial pig production systems located in the same geographical area. Clonal types obtained from nursery farms and corresponding finishing units were, however, similar.

Environmental assessment tools for the evaluation and improvement of European livestock production systems

Different types of assessment tools have been developed in Europe with the purpose of determining the environmental impact of various livestock production systems at farm level. The assessment tools differ in terms of which environmental objectives are included and how indicators are constructed and interpreted. The paper compares typical tools for environmental assessment of livestock production systems, and recommends selected indicators suitable for benchmarking. The assessment tools used very different types of indicators ranging from descriptions of farm management and quantification of input to estimates of emissions of, e.g., nitrate and ammonia. The indicators should be useful in a benchmarking process where farmers may improve their practices through learning from farms with better agri-environmental performance. An example of this is given using data on P-surplus on pig farms. Some indicators used the area of the farm as the basis of the indicator—e.g. nitrogen surplus per hectare—while others were expressed per unit produced, e.g. emission of greenhouse gasses per kilogram milk. The paper demonstrates that a comparison of organic vs. conventional milk production and comparison of three pig production systems give different results, depending on the basis of the indicators (i.e. per hectare or per kilogram product). Indicators linked to environmental objectives with a local or regional geographical target should be area-based—while indicators with a global focus should be product-based. It is argued that the choice of indicators should be linked with the definition of the system boundaries, in the sense that area-based indicators should include emissions on the farm only, whereas product-based indicators should preferably include emissions from production of farm inputs, as well as the inputs on the actual farm. The paper ends with recommendations for choice of agri-environmental indicators taking into account the geographical scale, system boundary and method of interpretation.

Societal expectations of livestock farming in relation to environmental effects in Europe

The potential environmental effects of livestock farming are mainly associated with intensification of poultry, pig and dairy cow production systems. The major impacts are mainly caused by housing of livestock, which can lead to air and water pollution associated with nitrogen and phosphorus emissions and losses from manure. European countries regulate the potential for these types of pollution through a number of mechanisms, which have received wide public acceptance. In grazing systems, nitrogen pollution, associated with the use of nitrogen fertilizer, is also the subject of legislation. Perhaps because of this regulatory approach, surveys of the public have found that human food quality and animal welfare are more important issues than effects on air and water quality when considering livestock systems. Variation in stocking rates of grazing ruminants can change the structure and composition of pastures with potential impacts on biodiversity and the production of methane, a greenhouse gas. In European countries, maximum stocking rates have been set to reduce these impacts. Surveys of the European public have suggested that they are willing to pay for the mitigation of these environmental effects but that they also value strongly the cultural component of grazed livestock systems. There are few underlying concepts about how society views the environmental impacts of livestock systems. These are used to conclude that current attitudes are likely to prevail in the next decade.

A Survey of Pig Production Systems in the Rain Forest of the Pacific Coast of Colombia

A questionnaire-based survey was conducted in small-scale pig farms in the rain forest of the Colombian Pacific coast in order to study aspects of reproduction, nutrition and productivity. A total of 124 farmers was interviewed. They owned, on average, 13.6 pigs, including 2.3 sows, mainly of the Zungo breed. Pigs are reared in extensive systems and are allowed to wander freely in search of food. The sows produce, on average, 9.6 piglets/litter but, owing to poor sanitary conditions, 1.5 are born dead and only 6.3 are weaned alive. Two-thirds of the sows have five litters or more and the boars are also kept for a long time. This leads to high consanguinity rates within the herd and low productivity. Diets are based on maize, banana, tubers (taro, cassava) and fruits (peach palm, among others), and are rich in energy but poor in protein and minerals. The lack of protein and mineral sources appears to be the main limiting factor of these extensive production systems. Tree forages could partially solve the problem but are used by only 2% of the farmers. It is concluded that decreasing inbreeding, better piglet management and provision of balanced diets are areas that require immediate improvement.

Rural income generation through improving crop-based pig production systems in Vietnam: Diagnostics, interventions, and dissemination

Sweetpotato-pig production is an important system that generates income, utilizes unmarketable crops, and provides manure for soil fertility maintenance. This system is widely practiced from Asia to Africa, with many local variations. Within this system, pigs are generally fed a low nutrient-dense diet, yielding low growth rates and low economic efficiency. Our project in Vietnam went through a process of situation analysis, participatory technology development (PTD), and scaling up over a seven-year period to improve sweetpotato-pig production and to disseminate developed technologies. The situation analysis included a series of pig production assessments in several provinces in northern and southern Vietnam, and pig supply-market chain identification was conducted in 13 provinces. The analysis of these studies informed the project of the following: (1) appropriate locations for our activities; (2) seasonal available feedstuff and farmers’ feeding practices; (3) market fluctuation and requirements; and (4) feeding and management improvement needs based on which the subsequent phase of PTD was designed. The PTD involved a limited number of farmers participating in sweetpotato varietal selection, sweetpotato root and vine silage processing, seasonal feeding combination, and pig feeding with balanced crop-feed diet and silage. Six years of multi-location and multi-season sweetpotato selection resulted in a few promising varieties that yielded up to 75% more dry matter and have since been formally released. The most significant results of silage processing and feeding trials include improved growth, higher feeding efficiency, increased year-round local feedstuff, and considerable labor reduction from eliminated cooking and vine cutting. Once these technologies were developed, a farmer-to-farmer training model was designed for scaling up the adoption and impact. Farmer trainers from seven communes in seven provinces received training in these technologies. In turn, they undertook the responsibility of training other farmers on sweetpotato selection, processing, and feeding. An impact study was also administered to monitor and evaluate (M&E) the dissemination process and to document the impact of the new technologies and farmer-to-farmer training model on pig growth and farmer income generation. The results showed that both participating and non-participating farmers have taken up the technologies, although the former demonstrates higher rates of adoption than the latter. The participants also generated more income and saved more labor from the adoption of the technologies. While the scaling up and M&E activities are on-going, the project has since broadened from a sweetpotato-pig system perspective to a pig-cropfeed system perspective based on farmers’ needs. It has included other crop feeds such as cassava and peanut stems in the research portfolio. New technologies based on on-going PTD will continuously be incorporated into the future training curriculum.

Effect of replacing fishmeal with HP 300 on growth performance of piglets from weaning to 28 days post weaning under commercial conditions

The recent ban on animal protein sources as livestock feed has lead to an increased demand for alternative protein sources (Salgado et al., 2001). Soya protein has been suggested as a potential alternative to fishmeal in weaner diets in sustainable pig production systems. However, the digestion of soya products is known to be reduced by the presence of antinutritional factors such as protease inhibitors and lectins (Lallès, 1993). Several methods have been devised to refine soya thereby increasing ileal digestibility’s (Shon et al, 1994). Some of the refined products include isolate soy protein and soybean protein concentrate. The objective of this experiment was to compare the effect of replacing fishmeal (FO) with HP 300 a soya isolate product on growth performance of piglets from weaning to 28 days post weaning under commercial conditions.

Occurrence of mycotoxins in straw used in pig deep litter systems in Australia

Mycotoxins are secondary metabolites produced by fungi under certain stress periods (Smith and Seddon 1998). When ingested, mycotoxins cause insidious losses, ill thrift and reduced disease resistance. Zearalenone is known to cause hyperestrogesium in pigs and hence a reduction in fertility in both sows and boars can occur (Binder 2004). Certain mycotoxins such as zearalenone (ZEA) and deoxinivalenol (DON) are produced by fungi of the fusarium species on crops in the field. Fusarium pseudograminearum (Crown Rot) produces both DON and ZEA in decreasing levels up the tiller of winter cereals (Blaney et al. 1987). Most studies carried out so far analysed the occurrence of mycotoxins in the grain and less is known about the prevalence of mycotoxins in the straw of the crop. Housing of sows during gestation on straw is becoming a favoured production system due to environmental and public perception pressures. The intake of straw by weaners on straw based systems has been found to account for 11.5% of total feed intake (Barneveld et al. 2004), such that there could be a considerable risk for increased ingestion of mycotoxins in animals on straw based systems. The objective of this study was to investigate the occurrence of mycotoxins in straw used for deep litter in Australian deep litter pig production systems.