Indoor Pigs Research Articles

PSV-1 Pasture Does Not Impact Pork Quality of Finishing Hogs

Abstract Sales of certified organic pork continue to increase, and an increasing number of young farmers are looking to rear hogs with organic or other niche labeling claims that require outdoor access. There is limited research available to support pastured pork operations in developing best management practices for rearing pigs in outdoor environments. The goal of this study was to evaluate the impact of housing on swine performance and pork quality and to build best management strategies for raising hogs on pasture. Pigs (n = 50) from the same sire and farrowing cohort were obtained from 10 separate litters. Pigs were grouped into separate treatments according to average body weights (BW) with equal sex rations among both groups: Indoor (n = 25), and Outdoor (n = 25), with 5 hogs per pen within each treatment. The Indoor groups were housed on 7m2 of solid concrete flooring in a ventilation-controlled barn; the Outdoor groups were housed on native grass pasture with pen size being 23m2, and a third shaded with 40% shade cloth. Outdoor pens were rotated to new grass every 14 days to manage soil destruction, while Indoor pigs remained in original pens for the duration of the project. Water access was provided via a nipple drinker system and fed a standard grow-finish ration ad libitum for both groups. All pigs were slaughtered at 26 weeks of age, with the Indoor group averaging BW of 126kg, and the Outdoor group averaging BW of 111kg (P < 0.05). Hot carcass weights were also larger (P < 0.001) of the Indoor group. All pork quality measurements were taken at the 10th rib. Color and marbling scores were not shown to vary between the treatment groups (P ≥ 0.17). Colorimeter values (L*, A*, B*) were similar across treatments as well (P ≥ 0.41). However, loin eye area exhibited a trend with the Outdoor group having a smaller average size (P = 0.07) In addition to this, pH values were also shown to vary at 0h (P = 0.03), 6h (P = 0.01), and 24h (P < 0.01) postmortem, with the Indoor group having the higher ultimate pH. Based on these data, pasture reduced final market size and loin eye area of hogs, but not overall pork quality. Although pH was reduced for the Outdoor group, no values showed a rapid decline in pH that would indicate a PSE pork product. Further, average pH between treatments were within 0.2 at all sampling times. Further research is needed to evaluate efficacy of best management practices to improve efficiency of pig growth rate on pasture and to ensure that pork quality will not be reduced.

Prevalence of Toxoplasma gondii, Hepatitis E Virus, and Salmonella Antibodies in Meat Juice Samples from Pigs at Slaughter in Switzerland

Toxoplasma gondii, hepatitis E virus (HEV), and Salmonella are zoonotic foodborne pathogens that may be transmitted to humans through the consumption of raw or undercooked pork. The aim of this study was to determine the seroprevalence of anti-T. gondii, anti-HEV, and anti-Salmonella antibodies from healthy pigs at slaughter in Switzerland. From August to September 2020, the diaphragm muscle of Swiss fattening pigs was collected in three Swiss abattoirs from 188 farms. Two randomly chosen pig carcasses per farm were selected. On the basis of the slaughter data, we noted the production system and the canton of origin, comparing indoor (n = 120) and free-range (n = 68) farming and regional allocation. The meat juice of these samples was analyzed for pathogen-specific antibodies by using commercial enzyme-linked immunosorbent assay kits. The seroprevalences were 1.3% for T. gondii, 71.8% for the HEV, and 5.3% for Salmonella, respectively. Comparing the origins, the results of many cantons were not meaningful due to the low number of samples. No regional accumulations were found for T. gondii and HEV. The results showed that 2.1% of the farms had least one T. gondii-seropositive animal, 80.3% had at least one HEV-seropositive animal, and 8.5% had at least one Salmonella-seropositive animal, respectively. The seropositivity of T. gondii was higher in free-range pigs than in indoor pigs, whereas anti-Salmonella antibodies were more common in pigs from indoor farming than in outdoor pigs. The seroprevalence of anti-HEV antibodies was similar in free-range and indoor farming pigs. Compared with studies from 2012, the seroprevalence of T. gondii has decreased, whereas the seroprevalence of the HEV has increased and is highly prevalent among fattening pigs in Switzerland. The low seroprevalence of Salmonella has remained stable in recent years.

The impact of livestock farming activity on the quality of surface water.

The most dangerous pollution sources are intensive agricultural activity and livestock farming, whose production waste has a negative impact on soil and water quality. Livestock farming is separated into two systems: indoor (pigs and poultry) and pasture-based (livestock and sheep). Numerous studies aimed at elucidating how different systems affect the environment have been performed. In Lithuania, the biggest environmental problems are caused by 24 farms with more than 5000 pigs, 21 poultry farm with more than 1000 chickens, 2179 cow-cattle farms larger than 50 places, and about 200,000 sheep. We aimed to assess the quality of surface water in the Kaunas region next to the pig and livestock farms. In 2008-2017, seven livestock agricultural companies and seven larger farmers were regarded as potential sources of pollution in the Kaunas region. Half of these sources were pig farms, and the rest were livestock farms. Locations next to potential agricultural pollution sources were chosen to monitor the surface water. The results indicated that although the agricultural areas, number of livestock units, and nitrogen rate per 1ha were similar between the pig and livestock farms, the activity on the pig farms affected the surface water quality more than that on livestock farms. As the number of livestock units (LU) increased on the farms, the pH decreased and the suspended materials, nitrates, and phosphates increased in the surface water. With increasing nitrogen kg/ha, the pH values decreased, thereby yielding more acidic water. The intensity of agricultural activity did not affect the water quality near the livestock farms, except for livestock units (LU), which affected the pH.

Internal Parasites of Pigs and Worm Control Practices in Bamboutos, Western Highlands of Cameroon.

Internal parasites are limiting factors to successful, sustainable livestock production. Knowledge on how they are dealt with is important to prevent resistance to anthelmintics. The aim of this study was to describe the internal parasitism of indoor pigs in Bamboutos Division in Cameroon, as well as the attendant worm control practices. Thus, 324 pigs from 50 small scale farms were sampled for feces which were qualitatively and quantitatively examined for parasite eggs, cysts, or oocysts. Data on worm control practices were also collected. The overall prevalence was 74.7% (95 % Confidence Interval (CI): 69.6–79.3%) and the overall mean egg/oocyst per gram of feces (epg/opg) was 304.1±1218.0. The following parasites were found: Strongylid parasites (58.6%; epg= 105.0±134.7); Coccidia (26.9; opg=517.2± 1862.1); Strongyloides ransomi (25.9%; epg=61.9± 40.8); A. suum (3.7%. epg=50±0); Metastrongylus sp (0.9%; epg=50±0); Trichuris suis (0.9%; epg=50±0); and Macracanthorhynchus hirudinaceus (0.62%; epg=50±0). Single to septuple infestations occurred. The majority of farmers resorted to modern veterinary services (64%) and mostly used conventional drugs (88%). Internal parasitism was associated with the person in charge of animal health, the implementation of a prophylaxis program on the farm, and the annual deworming frequency. The implementation of a prophylaxis program significantly reduced the overall egg/oocyst load while high treatment frequency (more than thrice a year) did not, indicating that prophylaxis measures such as general hygiene must be reinforced in pig herds in the country, and the treatment frequency reduced as much as possible to prevent the selection of anthelmintic resistance.

Effect of feeding restriction on growth and dressing percentages in Mexican hairless pig.

Twenty-four male Mexican hairless pigs, weighing 16 ± 1.12kg, were used to evaluate growth performance and carcass yield in pigs fed 2 (L), 3 (M) and 4 (H) times the Metabolizable Energy (ME) required for maintenance. The pigs were assigned randomly to two experimental rearing systems (indoors and outdoors). They were fed daily according to their respective feeding regimen (FR). The indoor pigs were fed ad libitum with chopped star grass forage (Cynodon nlemfuensis). The outdoor pigs had access during 16h to a paddock of star grass. The pigs were slaughtered when they achieve 70kg of live weight. No significant differences between indoors and outdoors were observed in any of the variables evaluated (P > 0.05). A significant reduction of daily live weight gain (P < 0.05) was observed conforming to FR reductions (0.501, 0.438 and 0.300kg/day for H, M and L, respectively). Days to achieve 70kg of live weight increase (P < 0.05) as FR reduces (110, 124 and 180days for H, M and L, respectively) were recorded. Forage consumption in pigs reared indoors reduces (P < 0.05) conforming to FR increases (0.092, 0.121 and 0.307kgDM/day for H, M and L respectively). Fat carcass yield reduces significantly (P < 0.05) according FR reductions (24.5, 22.8 y 18.9kg, for H, M and L respectively). Also, carcass meat yield was higher (P < 0.05) in pigs from L regimen (25.0kg) than in pigs from M and H regimen (22.0 and 22.8kg, respectively). Results obtained indicate a reduction in daily live weight gain conforming to daily feed intake reductions; however, improvement in carcass meat yield, accompanied with a reduction in carcass fat yield, was observed.

Evaluation of the sensitivity of faecal sampling for detection of monophasic Salmonella Typhimurium and other Salmonella in cattle and pigs.

There has been a rapid rise in the prevalence of cases of monophasic Salmonella Typhimurium (mST) in both humans and farm animals, and it has been found in pigs, cattle and poultry. It is therefore vital to have a good understanding of how to efficiently detect infected farms. The objective of this project was to determine sample type sensitivity in the detection of Salmonella to detect infected groups of animals on both pig (breeder, grower and finisher sites) and cattle (beef and dairy) farms, using data collected from a study investigating farms that were positive for mST, and to explore any variation between different age groups and management practices. A Bayesian approach in the absence of a gold standard was adopted to analyse the individual and pooled faecal sample data collected from each epidemiological group on each of the farms. The sensitivity of pooled sampling depended on the prevalence of infection in the group being sampled, with a higher prevalence leading to higher sensitivity. Pooled sampling was found to be more efficient at detecting positive groups of animals than individual sampling, with the probability of a random sample from a group of animals with 5% prevalence testing positive being equal to 15·5% for immature pigs (3·6% for an individual faecal sample, taking into account the sensitivity and infection prevalence), 7·1% for adult pigs (1·2% for individual sampling), 30% for outdoor cattle (2% for individual sampling) and 34% for indoor cattle (1% for individual sampling). The mean prevalence of each epidemiological group was higher in outdoor farms than indoor for both pigs and cattle (mean within-farm prevalence of 29·4% and 38·7% for outdoor pigs and cattle, respectively, compared to 19·8% and 22·1% for indoor pigs and cattle).

AIRWAY METRICS, ANATOMY AND GROWTH PERFORMANCE OF PIGS REARED INDOORS AND OUTDOORS

While the swine industry has made incredible stride s to improve ventilation, air quality in confinemen t buildings remains an issue. The goal of this study is to char acterize correlation between large airway metrics a nd growth performance in piglets reared indoors and outdoors on pasture. Three experimental trials were conducte d: Trial 1 included three breed types that were strictly raise d indoors, Tamworth X Berkshire, Berkshire X Berkshire and Hereford X Berkshire (n = 4-5 each). Trials 2 and 3 consisted of animals reared in both environments; trial 2 had 28 pigs (n = 14, indoor and n = 14, outdoor) and tr ial 3 had 48 pigs (n = 24, indoor and n = 24, outdo or). For trial 3, body weights were recorded weekly for seven weeks to adjust tracheal measure for body size. Total t racheal and lumen diameters were determined for all animals on trial. Histological evaluations were performed to evaluate potential differences among indoor and out door pig populations. One-way and two-way Analyses of Variance (ANOVA) were performed and LS means with the PDIFF option was used to separate means as applicable. Animals reared indoor shad significantl y larger tracheal diameters and lumens compared to those reared outdoors (p-value<0.05). Outdoor animals had a larger variation of body weights than indoor ani mals; however, no correlation between tracheal measurements and body weights was present. Histological evalu ation of airway sections revealed a 1.4 fold increase in the total population of goblet cells in tracheas of indoor pigs (pvalue<0.0152) versus outdoor pig tracheas. Taken to gether, subtle differences may exist in airways of pigs reared indoors versus outdoors; however, airway distinctio ns do not appear to effect growth performance of pi glets.

In Romania, exposure to Toxoplasma gondii occurs twice as often in swine raised for familial consumption as in hunted wild boar, but occurs rarely, if ever, among fattening pigs raised in confinement

A wide range of swine husbandry practices prevail in Romania: pork for human consumption is derived from hunting wild boar, from household rearing of small numbers of backyard pigs, and from indoor, industrial production of swine raised in confinement indoors. Romania thus represents an instructive place for evaluating the influence of animal management on the exposure risk of the zoonotic parasite, Toxoplasma gondii. The fact that many Romanians eat uncooked or undercooked pork, especially when raised for household consumption, elevates the public health imperative to understand these risks. The aim of the study, therefore, was to evaluate the seroprevalence of T. gondii in pigs and wild boars from Romania. During 2008-2010, we collected 3,595 serum samples from pigs (fattening pigs, sows, backyard pigs) and 150 serum samples from wild boars. The sera were assayed by immunofluorescence antibody test (cutoff, 1:32) for antibodies against T. gondii. The overall seroprevalence of T. gondii infection was 23.1% (829/3,595) in pigs and 16% (24/150) in wild boars. The seroprevalence was significantly higher (p < 0.001) in backyard pigs (30.5%; 783/2,564) than in sows (12.4%; 46/371) or fattening pigs (none of the sera was positive). The management system (indoor pigs versus backyard pigs) represented the most important factor in the epidemiology of T. gondii infection. The proximity of backyard pigs to the definitive host of this parasite (cats), as well as their access to contaminated meat products, elevated their exposure risk well above that of pigs raised in confinement, and even above that of wild boars inhabiting sylvatic environments.

A risk and benefit assessment for visual-only meat inspection of indoor and outdoor pigs in the United Kingdom

The current system of post-mortem meat inspection, using typical macroscopic inspection techniques, is ineffective in identifying the most common foodborne illness hazards, e.g. Salmonella and Campylobacter. Therefore, there is a need to adopt a more appropriate, risk-based approach to meat inspection. One specific example of modifying traditional inspection techniques to represent a more cost-effective approach to meat inspection is the allowance in EC Regulation 854/2004 for pigs that have been reared under controlled housing conditions since weaning to only undergo a visual inspection. However, the definition of controlled housing excludes outdoor pig production, and hence the United Kingdom (UK) has yet to introduce this method of meat inspection into abattoirs because of the associated complications of having a large outdoor UK pig herd. Therefore, in the context of the UK Food Standards Agency's programme of work to modernise meat hygiene inspection, we have conducted a qualitative risk assessment to assess the comparative risks to public and animal health from allowing visual-only inspection of both indoor and outdoor pigs.In order for visual-only inspection to be of higher risk than traditional meat inspection, the sensitivity of detection of a hazard must significantly decrease under visual-only inspection. In addition, for outdoor pigs to pose a greater risk than indoor pigs, the hazard must be more prevalent in the former than the latter. From a large number of hazards originally identified as worthy of investigation, only one (porcine tuberculosis) was considered to be of significant public or animal health risk and would be less likely to be detected through visual-only inspection. Despite higher rates of porcine tuberculosis in outdoor pigs than indoor pigs, the relatively small number of additional heads/carcasses that are infected and would be missed by including outdoor pigs in visual-only meat inspection (compared to traditional meat inspection) would pose a negligible risk to public health and a negligible/very low risk to animal health/welfare. Hence, we concluded that the overall risk from all hazards to public health by transferring to a visual-only inspection method was assessed as negligible for all pigs.

Transfer and uptake of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) into meat and organs of indoor and outdoor reared pigs

This study was designed to investigate how and to what extent PCDD/Fs and PCBs are transmitted from exposure sources to porcine muscle and other tissues derived from pigs. The experimental approach involved two longitudinal studies in which indoor and outdoor pigs were reared to market readiness using typical animal husbandry practices; closely matched samples of soil, feed, bedding, meat, etc. were collected and analysed for PCDD/Fs and PCBs. The total PCDD/F + PCB WHO-TEQs in pig liver were much higher than in meat and kidney samples from the same animals and exceeded the current relevant European Union maximum limits (6 ng PCDD/F-TEQ kg−1 fat). Liver samples were also characterised by much lower PCB contributions to the total TEQ than for the corresponding meat and kidney samples, and by a predominance of many of the hepta- and octa-substituted PCDD/Fs. At ages approaching market readiness, TEQ values in meat samples from outdoor pigs tended to be slightly higher than those from comparable ages in the indoor programme, possibly due to additional intake from soil. Biotransfer factors (BTFs) were derived for each of the 39 PCDD/F and PCB congeners measured. Interpretation of the findings focused particularly on trends in four selected congeners, namely: 2,3,7,8-TCDD, 2,3,4,7,8-PeCDF, PCB 153 and PCB 169. Increases in the BTF for PCB 169 in the pig-rearing programmes were noticed when the diet changed from being dominated by sow's milk to feed. Much higher transfer factors for many of the more heavily chlorinated PCDD/Fs (e.g. 2,3,4,7,8-PeCDF) were found in liver compared with meat or kidney samples from the same animals. Soil consistently accounted for at least 30% of input for many hexa- or higher chlorinated PCDD/Fs, while it rarely representing more than 10% of the total intake.

Selected Swine Viral Pathogens in Indoor Pigs in Spain. Seroprevalence and Farm-Level Characteristics

A serosurvey on porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), Aujeszky's disease virus gE protein (ADV gE), porcine parvovirus (PPV) and porcine circovirus type 2 (PCV2) was carried out in Spanish pig herds. The serosurvey consisted of two studies. First, a retrospective study assessed the proportion of seropositive boar, sow and fattening pig herds and their seroprevalences to PRRSV, SIV, ADV gE and PPV from 2003 to 2005 and to PCV2 from 2000 to 2005. Such information was obtained from routine serologic analyses from two veterinary diagnostic laboratory services. Second, a cross-sectional study in sow and fattening pig herds from 44 farms (without vaccination interferences on serologic analyses) was performed to provide information on seroprevalences and co-seropositivity to PRRSV, SIV, ADV gE and PCV2 (PPV was excluded because of widespread vaccination) and to elucidate their relationships with farm characteristics, management and productive parameters. Similar seroprevalences were observed in both studies, although some variations were obtained, probably because of vaccination schedules, number of tested sera, sampling age and regional variations. Percentage of PRRSV and SIV seropositive herds was over 85% for sows, around 80% for fatteners and around 50% for boar studs. The proportion of ADV gE seropositive sow herds decreased from 41% to 30% between 2003 and 2005, whereas such decrease was from 41% to 33% in fattening pig herds and from 13% to 4% in boar studs PCV2 antibodies were widespread as well as those against PPV; in the latter case, if antibodies were elicited by infection and/or vaccination was not assessed. Concurrent presence of PCV2, PRRSV and SIV antibodies was found in 89% and 66% sow and fattening herds, respectively. No statistical associations were obtained between seroprevalences or co-seropositivity and farm characteristics, management or productive parameters.

Tocopherol content, weight loss and instrumental color analysis of Iberian dry-cured ham as affected by rearing and feeding systems

The effects of rearing (outdoor vs indoor) and feeding systems (acorn and grass vs mixed diets) on ham quality from Duroc x Iberian pigs were studied. Seven groups of 5 females each were used. One group was reared under freerange conditions and fed with acorns and grass (outdoor pigs). Six group were fed mixed diets in confinement (indoor pigs) under a factorial design 3 x 2 with three types of dietary fat: monounsaturated, polyunsaturated and medium (monounsaturated and polyunsaturated) and two levels of α-tocopheryl-acetate. The α-and γ-tocopherol contents were higher (P < 0.05) in hams from outdoor pigs than in hams from indoor pigs. The hams from indoor pigs were lighter than hams from outdoor pigs and redness values were larger in hams from outdoor pigs than in hams from indoor pigs. At 4 days of storage ham samples from outdoor pigs showed a tendency (P < 0.10) to lower weight loss than those from pigs fed a basal level of vitamin E. These results indicate that rearing outdoor and feeding Iberian pigs by acorn and grass increase the α-and γ-tocopherols and improve color and weight losses in dry-cured hams.

Activity behaviour and social interactions of pigs raised outdoors and indoors

Abstract. Activity behaviour and social interactions of pigs in indoor and outdoor systems fed different levels of amino acids were studied on 96 crossbred pigs (Hampshire × Swedish Landrace × Swedish Yorkshire). The pigs were born outdoors and raised indoors in conventional pens or outdoors on pastures and given recommended (R), 7 % lower (R-7) or 14 % lower (R-14) levels of amino acids, in a phase feeding system with a low-energy diet provided ad libitum. Pigs in the outdoor system walked significantly more (p=0.012) and tended to be rooting more (p=0.098) than indoor pigs. Amino acid level did not affect the activity behaviour and social interactions of the pigs. Indoor pigs given diets R-7 and R-14 were drinking significantly more often than indoor pigs receiving the R diet, but had less contact with other pigs (p=0.020 and p=0.002, respectively). For outdoor pigs no such effect of amino acid level was found. Queuing for feed decreased with increasing age of the pigs, both indoors and outdoors (p=0.009). Rooting decreased and sleeping increased with the age of indoor pigs (p=0.014 and p=0.001, respectively), whereas no consistent trend for outdoor pigs was found. Sniffing, nibbling, pushing (p=0.001 for all) and tail manipulation (p=0.002) occurred more often indoors than outdoors. The results show that pigs in an outdoor system are more active and perform more natural behaviours, such as foraging and rooting, than pigs in an indoor system. Furthermore, roughages, such as pasture, and large areas may play an important role in occupying pigs and therefore contribute to less aggressive behaviours.

Analysis of nematode infection levels among indoor pigs in Thika District, Kenya

The infection levels of various species of nematode infection were studied in 35 indoor pig herds in Thika district, Kenya. Faecal samples were collected from 830 pigs of all ages and examined for nematode eggs per gram (EPG) of faeces using a modified McMaster technique. The infection intensity exhibited a binomial distribution with a majority of animals having only a light infection (EPG range = 0-500). The level of nematode infections was associated with the age of pigs. Thus, the highest mean EPG levels of Oesophagostomum spp. was 218 (SE = ±34), Ascaris suum 215 (SE = ±62), Trichuris suis 155(SE = ±66) and Strongyloides ransomi 24(SE = ±6) were found in adults, weaners, porkers and piglets respectively. The widest individual nematode species range of EPG values was found in T. suis (0 - 10,000) and A. suum (0 - 5300) infections. It is possible that the low EPG levels could be due to aggressive helminth control by local farmers. This could increase costs and possibly lead to the emergence of anthelmintic resistance. To reduce these costs, it is recommended that animals should be treated after faecal examination and laboratory determination of the EPG levels.. Kenya Veterinarian Vol. 31 (2) 2007: pp. 54-58

Influence of dietary amino acid level on performance, carcass quality and health of organic pigs reared indoors and outdoors

The influence of dietary amino acids on performance and carcass quality was studied in 192 organic indoor and outdoor pigs given diets with different amino acid levels (recommended amino acid level, 7% and 14% lower) ad libitum in a two-phase feeding system. During phase 2, daily consumption of lysine, methionine+cystine and threonine was higher for outdoor than indoor pigs independent of amino acid level (p=0.002, 0.004 and 0.006, respectively). The outdoor pigs grew faster during phase 2 than the indoor pigs (p=0.001), although feed conversion ratio did not differ (p=0.358). Dressing percentage was higher for outdoor than for indoor pigs (p=0.011) but lean meat content did not differ (p=0.904). The health status of the pigs was evaluated and showed that the incidence of pigs seropositive to erysipelas was higher outdoors. Ascaris suum was present in both production systems, whereas Eimeria sp. only was found among outdoor pigs. The results indicate a discrepancy between pigs housed in different production systems rather than between pigs directed to different dietary amino acid levels. This suggests that growing/finishing pigs fed ad libitum can compensate for dietary amino acid levels lower than the current Swedish recommendations without affecting production results.

Both outdoor and indoor reared piglets respond to antimicrobial supplementation in post-weaning diets regardless of weaning age

Outdoor piglets are reported to eat more readily post-weaning than indoor pigs and show improved post weaning performance (Cox and Cooper, 2001). They are therefore likely to be less reliant on the inclusion of antimicrobial agents in the diet post weaning to enhance performance. Similarly piglets which are older at weaning should also be more resilient and less likely to benefit from antimicrobial agents in the feed. In this experiment we compared piglets reared indoors with those reared outdoors at two different weaning ages to determine whether performance was less dependent on dietary antimicrobial additives in the outdoor-reared older pig.

Microbial diversity in the large intestine of pigs born and reared in different environments

Pigs born outdoors and reared on deep litter (straw) have been reported to experience less of a growth check after weaning and have a higher dressing percentage than counterparts born and reared under conventional (indoor) systems. The reason(s) for this difference is/are presently unknown, but differences in the gut environment might contribute to these observations. PCR-DGGE techniques were used in this study to examine microbial diversity and banding patterns in the large intestine of piglets that were reared under different rearing conditions. Six piglets per treatment were euthanised at weaning (21 days) and at 7 days and 21 days after weaning from two extreme treatments [indoor-born: conventionally-raised after weaning ('Indoor') or outdoor-born, deep-litter raised after weaning ('Outdoor')]. The Shannon diversity index was calculated, and multivariate analysis of banding patterns was performed. Indoor pigs had a more diverse bacterial population at weaning and 21 days after weaning than Outdoor pigs. However at the end of the first week after weaning, outdoor-born and deep-litter pigs had a more diverse microbiota. The Shannon diversity index continued to increase with time after weaning in Outdoor pigs, which did not occur in Indoor pigs. Multivariate analysis of banding patterns showed there was a trend (P = 0.109) for a difference in microbial structure depending on housing type. There was also a significant (P < 0.001) effect of sampling time after weaning and a significant interaction (P < 0.001) between housing and time after weaning.

Performance of Large White x Duroc pigs reared indoors and outdoors: meat and fat quality

During recent years, in order to satisfy consumer’s demand at meat quality and animal welfare, it has become popular to raise pigs outdoors. As reported by various authors this kind of rearing system may affects chemical-physical traits of meat but mainly the adipose tissue, characterised by an higher content of unsaturated fatty acids (Pugliese et al., 2004). The aim of this work is to verify the effect of rearing system on some meat and subcutaneous fat quality traits.For this reason, twelve Large White x Duroc pigs were raised under two different farming system following the organic regulations: six pigs were reared indoors while six pigs were reared outdoors on woodland pastures of 5000 m2. Both group were fed the same diet but, during the months of October and November, the pigs raised outdoors received 1kg/die of chestnuts (Castanea sativa) instead of maize. All animals were slaughtered at the target weight of about 140kg, reached at the age of 12 months for the indoor group and at the age of 13 months for the outdoor group. 24 hours after slaughtering, from all carcasses the left loin (muscle longissimus lumborum) was excised and vacuum packaged. The meat was analysed for the determination of: pHu, colour, water holding capacity (drip loss, water-bath loss and M/T ratio) and shear force on water-bath cooked meat; the subcutaneous fat was analysed for colour and shear force. To verify the effect of the different rearing system, data underwent to variance analysis (SAS, 1995).As regard the main results, the rearing conditions do not affect pHu values (5.43 vs 5.47), in agreement with results of other authors (Lebret et al., 2002; Pugliese et al., 2004). The colour parameters of meat are similar between indoor and outdoor pigs, in spite of the different age and of the attended different content of myoglobin. Shear force on water-bath cooked meat is significantly higher for the outdoors pigs (12.82kg vs 10.94kg) probably due to the higher exercise and to the older age at slaughter. Results of water-holding capacity show that outdoors pigs have a significantly lowest drip loss (2.78% vs 4.86%) and a significantly highest value of water-bath loss (32.36% vs 20.12%); no differences are revealed for the M/T ratio. These contradictory results on water-holding capacity are in agreement with other authors and may be related to the different methodologies used (Pugliese et al., 2004). As regard the quality of subcutaneous fat, it is possible to note that the outdoors pigs show lower value of C* (2.77 vs 4.56) and higher value of H* (58.33 vs 41.01) thus their fat is less coloured and clearer, in agreement with the results of Pugliese et al. (2004). No differences are revealed for shear force parameters: it seems that the consistence of fat is not influenced by rearing system even if it is well known that outdoors pigs have a different fatty acid composition than indoors pigs, mainly in terms of polyunsaturated fatty acid content.In conclusion it seems that the outdoor rearing system, further on influences the consumer perception of quality, effectively modifies some meat and fat quality traits, making interesting an ulterior deepening of this argument.

Performance, carcass and technological meat quality of pigs in indoor and outdoor production systems

This study aimed to compare different production systems, i.e., the combined effect of outdoor and indoor rearing of pigs and organic diets fed ad libitum or restrictively. Furthermore, the suitability of two breed crosses for outdoor rearing was studied. The effects on performance, carcass and technological quality traits were investigated. During two years, 240 pigs of Duroc x Large White (D*LW) and Swedish Landrace x Large White (L*LW) were allocated to three production systems: 1) Pigs kept outdoors, fed an organic diluted diet (20% alfalfa roughage) ad libitum; 2) Pigs kept outdoors, strategically fed a diluted organic diet up to a live weight of approximately 80 kg and thereafter an undiluted organic diet ad libitum; 3) Pigs kept indoors, fed an undiluted organic diet restrictively. For outdoor pigs, strategic feeding increased daily weight gain and backfat thickness, compared with feeding a diluted diet throughout (p≤0.01). L*LW pigs in both outdoor systems grew slower than in the indoor system (p≤0.001), whereas for D*LW pigs only outdoor pigs fed the diluted diet had a slower growth rate. Outdoor pigs had lower dressing percentage than indoor pigs. Glycogen content and L* values in M. longissimus dorsi were higher, whereas b* values were lower in meat from pigs in the indoor system. D*LW pigs had higher water-holding capacity (lower drip, thawing and cooking losses), lower shear force and higher intramuscular fat content compared with L*LW pigs.

Comparison of the performances of Nero Siciliano pigs reared indoors and outdoors: 2. Joints composition, meat and fat traits

A study on the effect of rearing system on tissue composition of principal joints and chemical–physical traits of meat and subcutaneous fat, was carried out on a local pig breed. A total of 78 Nero Siciliano pigs was used; 41 pigs were reared in woods, 37 pigs were reared in pens and fed a commercial diet. Weight at slaughter was 101.9 and 88.2 kg for indoor and outdoor pigs, respectively. Means were estimated at 77 kg of live weight. At ham dissection outdoor-pigs showed higher percentages of lean (58% vs. 55%) and lower subcutaneous fat (31% vs. 34%). In Longissimus lumborum outdoor-pigs showed a higher intramuscular fat percentage (4.3% vs. 3.3%), a lower protein content (22.2% vs. 23.4%), and higher free water (9.6 vs. 7.9 cm 2). Outdoor pigs produced more light ( L *=50 vs. 46.7) and more yellow ( b *=5.84 vs. 4.88) meat. Subcutaneous fat of outdoor pigs showed higher percentages of MUFA (53.3% vs. 47.2%) and lower percentages of PUFA (10.85% vs. 14.45%), no differences were found for n−3 PUFA. Outdoor-pigs had lower atherogenicity (0.48 vs. 0.53) and thrombogenicity (1.03 vs. 1.21) indices.