Lameness and fertility of sows and gilts in randomly selected loose-housed herds in Finland

Deep learning pose detection model for sow locomotion

Lameness affects animal mobility, causing pain and discomfort. Lameness in early stages often goes undetected due to a lack of observation, precision, and reliability. Automated and non-invasive systems offer precision and detection ease and may improve animal welfare. This study was conducted to create a repository of images and videos of sows with different locomotion scores. Our goal is to develop a computer vision model for automatically identifying specific points on the sow's body. The automatic identification and ability to track specific body areas, will allow us to conduct kinematic studies with the aim of facilitating the detection of lameness using deep learning. The video database was collected on a pig farm with a scenario built to allow filming of sows in locomotion with different lameness scores. Two stereo cameras were used to record 2D videos images. Thirteen locomotion experts assessed the videos using the Locomotion Score System developed by Zinpro Corporation. From this annotated repository, computational models were trained and tested using the open-source deep learning-based animal pose tracking framework SLEAP (Social LEAP Estimates Animal Poses). The top-performing models were constructed using the LEAP architecture to accurately track 6 (lateral view) and 10 (dorsal view) skeleton keypoints. The architecture achieved average precisions values of 0.90 and 0.72, average distances of 6.83 and 11.37 in pixel, and similarities of 0.94 and 0.86 for the lateral and dorsal views, respectively. These computational models are proposed as a Precision Livestock Farming tool and method for identifying and estimating postures in pigs automatically and objectively. The 2D video image repository with different pig locomotion scores can be used as a tool for teaching and research. Based on our skeleton keypoint classification results, an automatic system could be developed. This could contribute to the objective assessment of locomotion scores in sows, improving their welfare.

Lameness in Pregnant Sows Alters Placental Stress Response

Pregnant sows from commercial pig farms may experience painful states, such as lameness, an essential indicator in assessing sow welfare. We investigated the effect of lameness during the last third of pregnancy on reproductive performance and placental glucocorticoid concentrations in sows. Periodic locomotion assessments were carried out on two commercial pig farms using a validated 0-5 scoring system (from 0: normal locomotion; to 5: a downer animal). Sows from both farms (N = 511) were grouped based on their average locomotion scores. On Farm 1, 30 sows were selected and grouped as either Not Lame (NL = 16; X¯ = 0-1) or Lame (L = 14; X¯ > 1). On Farm 2, 39 sows were selected and grouped as either Not Lame (G1 = 12; X¯ = 0-1), Moderately Lame (G2 = 13; X¯ = 1.1-2), or Severely Lame (G3 = 14; X¯ ≥ 2.1). Reproductive data (gestation length, litter weight, average piglet weight, litter size, and the number of piglets born alive/mummified/stillborn) were recorded on both farms. Moreover, on Farm 2, piglet intrauterine growth restriction score and the number of piglets dead during the first week were also recorded, and placenta samples were collected to determine their cortisol/cortisone concentrations. A linear mixed model was used to analyze the data. The proportion of lameness in pregnant sows (N = 511) was >40%, and the gestation length tended to decrease with the presence of lameness (p < 0.1) in both farms. G2 sows had a higher placental cortisol/cortisone ratio than G1 and G3 sows (p < 0.01). In conclusion, lameness was high in the sows assessed, which may decrease sow gestation length and reduce placental efficiency in protecting the offspring from the sows' stress response.

Wheatgrass extract has chondroprotective and anti-inflammatory effects on porcine cartilage

Lameness is a commonly observed disorder in sows and negatively impacts both animal welfare and the profitability of the pig sector. The purpose of this study was to determine anti-inflammatory and/or chondroprotective effects of wheatgrass (WG) on porcine cartilage explants stimulated with lipopolysaccharide (LPS). Explants were aseptically prepared from the intercarpal joints of nine market-weight pigs and placed in culture at 37°C for a total of 120 hours. For the final 96 hours, explants were conditioned with an aqueous extract of WG (0, 5 or 15 μg/mL), and for the final 48 hours explants were stimulated with LPS (0 or 10 µg/mL). Media was removed and replaced every 24 hours. Samples from the final 48 hours were analyzed for biomarkers of cartilage inflammation [prostaglandin E2 (PGE2) and nitric oxide (NO)] and cartilage structure [glycosaminoglycan (GAG)], and cartilage explants were stained for an estimate of cell viability. Stimulation of explants with LPS significantly increased media concentrations of PGE2, GAG and NO compared with that from unstimulated explants. LPS stimulation did not significantly affect cell viability. Conditioning of explants with WG (5 μg/mL) significantly reduced LPS-stimulated cartilage release of PGE2, NO, and GAG (5 and 15 μg/mL), without impairing chondrocyte viability. These data provide evidence for a non-cytotoxic chondroprotective and anti-inflammatory effect of WG extract in cartilage and suggest a role of WG in protection against cartilage breakdown, inflammation, and pain associated with osteoarthritis.

Differences in Weight, Hierarchy, and Incidence of Lameness between Two Groups of Adult Pigs Derived from Assisted Reproductive Technologies

The in vitro production (IVP) and subsequent transfer of embryos (ET) to recipient mothers is not yet an established reproductive technology in the pig industry, as it is in cattle. However, that the trade of IVP-cryopreserved pig embryos is expected to start in the next decades. Society and governments are increasingly aware of the repercussions that IVP could have for animal health, welfare, behavior, or food safety, but proven scientific information for this type of animal does not exist, since no colonies of pigs have been created to this end. We created a small one and studied the differences between 16 IVP-derived pigs and 14 pigs derived from artificial insemination (AI), at 3.5 years of age, conceived from the same boar, and housed and fed under the same conditions since they were born. Incidence of lameness, position in the herd hierarchy, weight, adenosine deaminase activity, and hematological and biochemical analytes were compared between the two groups of animals. The results showed that the IVP animals weighed more, occupied higher positions in the herd hierarchy, and had a lower incidence of lameness. Although genetic differences from the maternal line could explain some of these results, it is also possible that the IVP animals developed better adaptative abilities, but more studies with a higher number of animals are necessary to reach consistent conclusions.

A method for labelling lesions for machine learning and some new observations on osteochondrosis in computed tomographic scans of four pig joints

Background

Osteochondrosis is a major cause of leg weakness in pigs. Selection against osteochondrosis is currently based on manual scoring of computed tomographic (CT) scans for the presence of osteochondrosis manifesta lesions. It would be advantageous if osteochondrosis could be diagnosed automatically, through artificial intelligence methods using machine learning. The aim of this study was to describe a method for labelling articular osteochondrosis lesions in CT scans of four pig joints to guide development of future machine learning algorithms, and to report new observations made during the labelling process. The shoulder, elbow, stifle and hock joints were evaluated in CT scans of 201 pigs.

Results

Six thousand two hundred fifty osteochondrosis manifesta and cyst-like lesions were labelled in 201 pigs representing a total volume of 211,721.83 mm³. The per-joint prevalence of osteochondrosis ranged from 64.7% in the hock to 100% in the stifle joint. The lowest number of lesions was found in the hock joint at 208 lesions, and the highest number of lesions was found in the stifle joint at 4306 lesions. The mean volume per lesion ranged from 26.21 mm³ in the shoulder to 42.06 mm³ in the elbow joint. Pigs with the highest number of lesions had small lesions, whereas pigs with few lesions frequently had large lesions, that have the potential to become clinically significant. In the stifle joint, lesion number had a moderate negative correlation with mean lesion volume at r = − 0.54, p < 0.001.

Conclusions

The described labelling method is an important step towards developing a machine learning algorithm that will enable automated diagnosis of osteochondrosis manifesta and cyst-like lesions. Both lesion number and volume should be considered during breeding selection. The apparent inverse relationship between lesion number and volume warrants further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03426-x.

Welfare of pigs on farm

This scientific opinion focuses on the welfare of pigs on farm, and is based on literature and expert opinion. All pig categories were assessed: gilts and dry sows, farrowing and lactating sows, suckling piglets, weaners, rearing pigs and boars. The most relevant husbandry systems used in Europe are described. For each system, highly relevant welfare consequences were identified, as well as related animal-based measures (ABMs), and hazards leading to the welfare consequences. Moreover, measures to prevent or correct the hazards and/or mitigate the welfare consequences are recommended. Recommendations are also provided on quantitative or qualitative criteria to answer specific questions on the welfare of pigs related to tail biting and related to the European Citizen's Initiative 'End the Cage Age'. For example, the AHAW Panel recommends how to mitigate group stress when dry sows and gilts are grouped immediately after weaning or in early pregnancy. Results of a comparative qualitative assessment suggested that long-stemmed or long-cut straw, hay or haylage is the most suitable material for nest-building. A period of time will be needed for staff and animals to adapt to housing lactating sows and their piglets in farrowing pens (as opposed to crates) before achieving stable welfare outcomes. The panel recommends a minimum available space to the lactating sow to ensure piglet welfare (measured by live-born piglet mortality). Among the main risk factors for tail biting are space allowance, types of flooring, air quality, health status and diet composition, while weaning age was not associated directly with tail biting in later life. The relationship between the availability of space and growth rate, lying behaviour and tail biting in rearing pigs is quantified and presented. Finally, the panel suggests a set of ABMs to use at slaughter for monitoring on-farm welfare of cull sows and rearing pigs.

The Effect of Lift Crates on Piglet Survival Rate and Sow Stress Level during Farrowing

In the present study, we aimed to determine the effect of lift farrowing crates on piglet mortality by crushing and on sow welfare. Eighty-four sows were considered in the one-year experiment in three monitoring sessions. In each session, 14 sows were housed in a room with conventional crates (CC), and 14 sows were lodged in a room equipped with lift crates (LC). The sows, of the same genetics, with parity ranging from 2 to 9, were randomly distributed in CC and LC rooms. No primiparous sows were considered in the study to avoid sows unexperienced with the dynamics of lift crates. The numbers of crushed piglets, assessed by the farm’s veterinarian, within 48 h, 72 h, and at weaning (28th day), were recorded. Hair cortisol concentration (HCC) was measured upon entry and exit from farrowing to evaluate stress level variation. Feet diseases and backfat thickness were evaluated to assess sows’ potential diseases induced by lift crates and metabolic problems. The results show that the number of crushed piglets per sow was higher in the CC rooms than in the LC rooms in the first two days after delivery (0.39 vs. 0.15, p < 0.05) and up to weaning (0.50 vs. 0.37; p < 0.05). Mean values of HCC variation in sows during farrowing were significantly different in the two housing systems and higher for the LC sows (0.53 pg/mg vs. 0.22 pg/mg; p < 0.05). No significant differences were detected for backfat variation and feet disease scoring between LC and CC sows. In conclusion, LC sows evidenced an increase in hair cortisol values during farrowing, probably caused by a higher stress status induced by the lift crate, along with the benefit of the higher survival rate of piglets before weaning.

Do Rubber Floor Mats Prevent Lameness in Gestating Sows Housed in Large Groups? A Field Experiment on Three Commercial Farms in France

Lameness and foot disorders are major health and welfare issues in intensive swine production systems. They are exacerbated when sows are housed in large groups on slatted concrete floors during gestation. Our study aimed to assess the effect of rubber mats in the lying area of the gestation pen on lameness and leg health in gestating sows housed in large pens in commercial conditions. The study was conducted on three commercial farms over two successive gestations. A total of 582 Large White × Landrace sows, housed in 10 static groups, were enrolled: 5 groups in pens with rubber mats and 5 groups on slatted concrete floors. Lameness, bursitis, leg injuries, claw growth defects and claw lesions were measured at the beginning, middle and end of each gestation period. The rubber mats decreased the risk of suffering from bursitis, but had no effect on the risk of lameness, leg injuries, claw growth defects or claw lesions. Sows housed on rubber mats were heavily soiled compared with those on slatted concrete floors because the mats were not perforated for slurry evacuation. Locomotion disorders and foot lesions remained prevalent despite the rubber mats in the lying area of the gestation pens, but adding rubber mats in service rooms and farrowing crates may produce better results.

Evolution of welfare indicators of pigs housed in deep bedding systems during growing and finishing phases: assessment of good health principles and housing conditions

The aim of the study was to monitor the evolution of welfare indicators of pigs throughout growing and finishing phases housed in a deep bedding system by principles of good health and housing. In all, 16,500 animals, distributed in 15 facilities, were evaluated over a 4-month period. Three assessments were carried out in each facility by a single evaluator, according to the following time distribution: phase one (75 to 85 days old), phase two (86 to 161 days old), and phase three (162 to 180 days old). Only the parameters related to good health and good housing were considered. Data were analyzed by logistic regression for longitudinal data. Poisson distribution was used on the coughing and sneezing data, with subsequent chi-square analysis. There were no cases of poor body condition, shivering, panting, huddling, tail biting, pumping, twisted snout, rectal prolapse, lameness, and skin conditions. The final evaluations were associated with greater chances of hernia and bursitis, with greater prevalence in males than in females. The prevalence of wound and manure on the body parameters was influenced by the interaction of the evaluation and animal category. The incidence of coughing and the number of animals presenting this symptom gradually increased, becoming considerably higher in the final stage of evaluation. Health-related problems change throughout the production cycle. The evaluation of a broad and reliable view on animal welfare allows for the most appropriate management of production systems using deep bedding.

The in-utero experience of piglets born from sows with lameness shapes their life trajectory

Experiences during gestation can alter the mother's behavior and physiology, thereby potentially affecting the behavioral and physiological development of the offspring. In livestock, one common challenge for pregnant animals is lameness: a multifactorial condition that causes pain, stress, resulting in poor welfare outcomes. Since maternal pain can affect offspring development, we aimed to quantify the behavioral response in 142 piglets born from sows with different degrees of lameness during pregnancy. Gait scores of 22 pregnant group-housed sows were assessed six times at 2-week intervals. Lameness scores varied from 0 (no lameness) to 5 (most severe lameness score). Saliva samples and behavior were assessed in the sows throughout pregnancy. Sows were moved to individual farrowing pens and placental tissue was collected for glucocorticoid assessment. At 28 days of age, piglets were weaned, weighed, and regrouped by body size and sex. Skin lesions were counted for each piglet on days 28, 29, and 30 after birth. During open field and novel object tests on day 30, the vocalization and activity levels were evaluated. Piglet data were grouped by the lameness score of the sows as G1 (without lameness), G2 (moderate lameness), and G3 (severe lameness). Data analysis included ANOVA or Kruskal-Wallis tests and pairwise comparisons which were performed using Tukey and Kramer (Nemenyi) test with Tukey-Dist approximation for independent samples. G2 piglets were heavier than G3 at weaning. G1 piglets had fewer skin lesions at days 28 and 29 than G2 piglets. Moreover, G1 piglets vocalized more than G2 when they were subjected to the combined open field and novel object test. We did not identify differences among sows showing different lameness scores in the concentration of placental or salivary glucocorticoids. Lameness in pregnant sows altered the offspring's weight gain, number of skin lesions and vocalizations, together showing evidence that lameness in sows affect offspring performance and behavior.

Clinical and morphological justification of the treatment of purulonecrotic lesion in deep structures of limb distal segment in pig: case report

ABSTRACT Surgical pathology of the musculoskeletal system, and in particular the diseases of the limb distal segment in pigs are quite common. Their significant spread leads to economic losses due to culling, compulsory slaughter, short-received pig production and pig crop. The purpose of this work was to reveal clinical and morphological features of limb distal segment diseases in pigs and to study the possibility of preserving their health and productivity. The conservative treatment of purulonecrotic lesions in the deep structures of the limb distal segment in pigs is not promising. It is shown that the best way to treat a given pathology is amputation of a sick limb. The technique of carrying out exarticulation of talus shin consists in separation of soft tissues, capsule and ligaments, ligation of vessels, formation of stump. The postoperative recovery period of the animal body is 25 days.

Removal of sows in Spanish breeding herds due to lameness: Incidence, related factors and reproductive performance of removed sows

Lameness is a major reason for sow removal in breeding herds. Increased removal occurrences for lameness decrease reproductive efficiency and increase welfare concerns. Therefore, the objectives of this study were to estimate the incidence rate of removal due to lameness, and to investigate the longevity and reproductive performance of sows removed due to lameness. Poisson regression models were applied to a cohort dataset of 137,907 sows in 134 herds located in Spain. The Wilcoxon rank sum test was used to compare the performance of sows removed due to lameness and their controls in one-to-two matched case-control datasets. Removal due to lameness accounted for 4.3 % of all removed sows, and the incidence rate was 19.6 cases per 1000 sow-years (95 % confidence interval: 15.03, 25.51). The majority (70.4 %) of those removed were farrowed sows, whereas only 29.6 % were serviced sows. In farrowed sows, a higher incidence of removal due to lameness was associated with weeks 4-9 after farrowing, higher parity and winter farrowing (P <  0.01). The removal incidence was 24.7-33.1 times higher in weeks 4-9 after farrowing than during the first week after farrowing (P <  0.01). It was 1.3-1.6 times higher in parity 4-5 than in parity 1, and 1.3 times higher for winter farrowing than for summer farrowing (P <  0.01). In contrast, the factors associated with removal due to lameness with serviced sows were weeks 4-5 after service and being re-serviced (P <  0.01). The service sow removal incidence was 4.7 times higher in weeks 4-5 after servicing than during the first 2 weeks after servicing (P <  0.01). Also, it was 2.2 times higher in re-serviced sows than in first serviced sows (P <  0.01). However, removal in serviced sows was not associated with parity (P =  0.10) or service season (P =  0.39). In the case-control datasets, the sows removed due to lameness had higher weaning-to-first-mating interval (means: 6.5 vs. 5.8 days), fewer piglets born alive (11.7 vs. 12.5 piglets) and lower parity at removal (3.4 vs. 4.9; P <  0.01) than sows removed for other reasons or non-removed sows. However, there was no difference in gilt age at first service between the case and control groups (P =  0.29). We recommend identifying sows showing early signs of lameness and treating them with pain medication until removal. The best time for removal would be at weaning when non-productive sow days start.

Identification of mRNAs Related to Tibial Cartilage Development of Yorkshire Piglets

Cartilage dysplasia is one of the important reasons for the weakness of pig limbs and hooves. Porcine rickets with weak limbs and hooves bring huge economic losses to the pig industry. However, research on the development of pig cartilage is lacking. This study investigated the key genes and molecular mechanisms involved in cartilage development via an RNA-seq technique. Samples of proximal tibia cartilage were collected from three normal piglets with 1 day, 14 days, and 28 days of age, respectively, and then these samples were divided into two comparison groups (1-day vs. 14-day group, 14-day vs. 28-day group). Through the transcriptome analysis, 108 differentially expressed genes (DEGs), such as FORL2, were obtained from 1-day vs. 14-day comparison group, and 3602 DEGs were obtained from 14-day vs. 28-day comparison group, including SOX9, BMP6, and MMP13. The gene ontology (GO) functional and KEGG pathway enrichment revealed that many functions of DEGs were related to bone development. The pathways of DEGs from Day 1 vs. Day 14 were mainly enriched in mineral absorption, but the DEGs of Day 14 vs. Day 28 were enriched in osteoclast differentiation. Then, the expression patterns of six candidate genes were verified via qPCR. In conclusion, candidate genes affecting cartilage development in Yorkshire pigs were obtained by transcriptome analysis, and the clues showed that Day 14 to Day 28 is a more active and extensive period in cartilage developments, which played a key role in revealing the molecular mechanism of pig cartilage development basis, also compensating for vacancies in cartilage research.

The Effect of Group Composition and Mineral Supplementation during Rearing on Measures of Cartilage Condition and Bone Mineral Density in Replacement Gilts

Lameness is a major cause of poor longevity and poor welfare in replacement gilts. The problem is exacerbated by inappropriate housing and diet during the rearing period. Replacement gilts are often reared with male finisher pigs destined for slaughter. If they are not castrated, they perform high levels of potentially injurious sexual and aggressive behaviour. Furthermore, finisher pig diets are not designed to meet the needs of developing gilts and may not supply the necessary minerals to support good limb health. The objective of this study was to evaluate the effect of supplementing the diet of replacement gilts with copper, zinc and manganese and separating them from males during the rearing period on locomotory ability, bone mineral density and cartilage lesion scores. A 2 × 2 factorial design experiment investigated the effect of female-only or mixed-sex rearing, with or without supplementary minerals (Copper, Zinc and Manganese). In total, 384 maternal line gilts were assigned to 32 pens of 12 and were locomotion scored during the rearing period. A sub-sample (n = 102) of gilts were culled at breeding age and the front right limb was removed at slaughter. Areal bone mineral density (aBMD) was measured using dual energy X-ray absorptiometry, after which the limb was dissected to score the condition of the cartilage. The addition of trace minerals to the diet resulted in increased aBMD in the humerus (P < 0.05) compared to the control diet. Rearing gilts in female-only groups reduced the number of cartilage lesions overall (P < 0.05), and on the humeral condyle (P < 0.05). Rearing replacement gilts in female-only groups and with mineral supplementation had benefits for limb health.

Structural characterization of piglet producing farms and their sow removal patterns in Finland

Background

The main objectives of this observational, cross-sectional study were to characterize piglet producing farms in Finland and to investigate how farm profiles are associated with sow culling and mortality.The study was conducted on 43 farms during 2014. A questionnaire survey was administered in-person and supplemented with observations in the housing facilities. Annual removal figures and average monthly sow inventories were retrieved from a centralized animal data recording system (National Swine Registry) administered by the Finnish Food Authority. Multiple correspondence analysis and hierarchical clustering were used to explore the complex underlying data-driven patterns.

Results

Sow removal varied markedly between farms with an overall average culling percentage of 38.0% (95% CI 34.1-42.0) and a relatively high average mortality percentage 9.7% (95% CI 7.9-11.5). We identified three farm clusters, which differed both in their typologies and removal patterns. Cluster 1 included farms with features indicative of a semi-intensive or intensive kind of farming, such as larger herd and room sizes, higher stocking density and more sows per caretaker. Most of the cluster 1 farms exceeded the investigated cut-off levels for culling and mortality. Cluster 2 farms were estimated to have the best animal welfare among the sample farms based on a combination of environmental indicators (e.g. amount of bedding, rooting and nesting materials, space allowance, pen cleanliness) and the lowest level of sow mortality as an animal-based indicator. Cluster 3 farms followed a strategy of a rather non-intensified system based on the predominance of smaller herd size, lower stocking density and less sows per caretaker, combined breeding and gestation rooms and rare use of farrowing induction. This cluster showed the lowest culling levels within the sample.

Conclusions

This study captures the diversity among Finnish sow farms and provides a baseline assessment of their practices and facilities. Our results support the notion that farm typologies are associated with sow culling and mortality. In summary, the control of suboptimal sow removal cannot be based on single improvements only, because of other limitations within the individual farm resources.

Effect of Slat and Gap Width of Slatted Concrete Flooring on Sow Gait Using Kinematics Analysis

The housing of gestating sows in groups requires sound information about the adapted design of the pen floor. Slatted concrete floors are commonly used for effective drainage of manure but can cause feet injuries and lameness. In the present study, kinematics were used to characterize the gait of 12 gilts and 12 lame sows walking in a corridor on slatted concrete floors with different combinations of slat (85, 105 or 125 mm) and gap (19, 22 or 25 mm) widths. The nine experimental floors were tested with slats in the perpendicular and parallel orientation to the direction of animal walk, according to a duplicated lattice design. Gait parameters were quantified using spatial, temporal and angular kinematics for front and rear limbs. Some parameters were significantly affected by the treatments (p < 0.05), but the effects differed between gilts and lame sows and between slat orientations. Gap width had a significant effect on parameters such as back angle, stride length, foot height, and carpal and tarsal joint angle amplitudes. Slat width significantly affected parameters such as foot height, and carpal and tarsal joint angle amplitudes. Comparisons of the different combinations of slat and gap widths revealed that slats with a width of 105-125 mm and gap width of 19-22 mm had the least effect on the gait characteristics of the gilts and sows.

On-Farm Claw Scoring in Sows Using a Novel Mobile Device

Claw lesions and lameness in sows are important problems in the industry as they impair sow welfare and result in economic losses. Available scoring techniques to detect claw lesions are all limited in terms of collecting data during all reproductive phases and recording all claws. The Mobile Claw Scoring Device (MCSD) was designed to address these limitations. After considering different practical situations and a design phase, two prototypes were constructed and tested. Improvements were incorporated into a final aluminium apparatus, consisting of two cameras with light-emitting diode (LED) lights mounted in a two-segment aluminium box and covered with laminated tempered glass plates. The operating system slides underneath the claws and takes video images. This final prototype was optimised and validated in an experiment with 20 hybrid sows, comparing scores for soiled claws using the MCSD against scores for clean claws using the Feet First^© sow chute (as gold standard). Fifty percent of the scores differed between both scoring tools, with mainly medial claw digits deviating, but this seemed biologically irrelevant. The MCSD seems to be an appropriate alternative for on-farm claw scoring and is distinguishable from other claw scoring techniques; however, it needs further optimisation to improve the similarity between the two techniques.

Analysis of influencing factors of boar claw lesion and lameness

This study aimed to investigate the factors affecting boar claw lesions and lameness. A total of 1299 boars were examined for claw lesions and lameness, including 788 boars reared in individual pens with solid concreted floor (IPS) and 511 boars raised in individual stalls with slatted floor (ISS). Flooring type showed significant impacts on all claw lesion types (P < 0.01). Except for swelling ankle, boar age had significant effects on all other claw lesion types (P < 0.01). In addition, only heel overgrowth and erosion, cracked wall horizontal, heel-sole crack, dew claws, and toes were significantly related to boar breeds (P < 0.05). Furthermore, IPS lame boars had higher prevalence of lameness in the hind limb (P < 0.05), whereas in ISS lame boars, there were no significant differences in prevalence of lameness between the fore and hind limbs (P > 0.05). Boar lameness was moderately correlated with swelling ankle (Φ = 0.5571). In conclusion, claw lesions can be influenced by flooring type, boar age and breed, and could serve as a predictor for boar lameness.

Effect of rubber flooring on group-housed sows' gait and claw and skin lesions

This study evaluated the influence of floor type on sow welfare in terms of lameness, claw lesions, and skin lesions. In a 2 × 3 factorial design, we have investigated the effect of rubber coverings on concrete floors and the effect of 3 levels of dietary zinc supplementation on locomotion and claw and skin lesions in group-housed sows. Six groups of 21 ± 4 hybrid sows were monitored during 3 successive reproductive cycles. The sows were group housed from d 28 after insemination (d 0) until 1 wk before expected farrowing date (d 108) in pens with either exposed concrete floors or concrete floors covered with rubber in part of the lying area and the fully slatted area. During each reproductive cycle, locomotion and skin lesions were assessed 4 times (d 28, 50, 108, and 140) and claw lesions were assessed twice (d 50 and 140). Results are given as least squares means ± SE. Locomotion and claw scores were given in millimeters, on analog scales of 150 and 160 mm, respectively. Here, we report on the effect of floor type, which did not interact with dietary zinc concentration ( > 0.10 for all variables). At move to group (d 28) and mid gestation (d 50), no differences between floor treatments were seen in locomotion ( > 0.10). At the end of gestation (d 108), sows housed on rubber flooring scored 9.9 ± 4.1 mm better on gait ( < 0.001). Regarding claw disorders, both parameters "heel overgrowth and erosion" (difference of 4.6 ± 1.8 mm; = 0.01) and "heel-sole crack" (difference of 3.1 ± 1.5 mm; = 0.04) scores were better for sows on rubber flooring at mid gestation (d 50). However, sows on rubber flooring scored worse for "vertical cracks in the wall horn" (difference of 3.4 ± 1.7 mm; = 0.04). At the end of lactation (d 140), both "white line" (difference of 2.9 ± 1 mm; = 0.02) and "claw length" (difference of 4.7 ± 1.4 mm; < 0.001) had better scores on rubber flooring. No differences for skin lesions were observed between floor treatments. The improved scores for gait toward the end of gestation and some types of claw disorders at mid gestation suggest that rubber flooring in group housing has a beneficial effect on the overall leg health of sows. The documented increase in vertical cracks in the wall horn at d 50 requires further investigation.

Risk factors for development of lameness in gestating sows within the first days after moving to group housing

Lameness in sows is an important welfare issue that is affected by housing conditions and is thought to be influenced by hierarchical fights within the first days after mixing sows in groups. A longitudinal study in 15 randomly selected herds was performed to investigate the incidence of sow lameness and possible risk factors within the first days of group housing. Each herd was visited just before and again 3-5 days after the sows were moved to group housing. The floor characteristics and dimensions of the group housing facilities were assessed. Locomotion ability, body condition, skin lesions and degree of faecal soiling were recorded for all sows. Additional information on housing and management was obtained using a questionnaire. Amongst the 810 sows included in the study, the mean lameness incidence was 13.1% (95% confidence interval 10.9-15.6%). Following binomial logistic regression analysis, sows with >10% of the body covered with faeces had an increased risk for development of lameness (odds ratio, OR = 2.33, P = 0.001). An increase in space allowance from 1.7 m² to 3.0 m² (OR = 0.40, P = 0.03) and of herd size from 144 to 750 sows per herd (OR = 0.71, P = 0.02) decreased the risk of development of lameness. Neither the degree of aggression, indicated by skin lesions, nor the floor characteristics influenced the development of lameness. These results indicate that sows can benefit from a larger floor area.

Locomotion Disorders and Skin and Claw Lesions in Gestating Sows Housed in Dynamic versus Static Groups

Lameness and lesions to the skin and claws of sows in group housing are commonly occurring indicators of reduced welfare. Typically, these problems are more common in group housing than in individual housing systems. Group management type (dynamic versus static) and stage of gestation influence the behavior of the animals, which in turn influences the occurrence of these problems. The present study compared prevalence, incidence and mean scores of lameness and skin and claw lesions in static versus dynamic group housed sows at different stages of gestation during three consecutive reproductive cycles. A total of 10 Belgian sow herds were monitored; 5 in which dynamic groups and 5 in which static groups were utilized. All sows were visually assessed for lameness and skin lesions three times per cycle and the claws of the hind limbs were assessed once per cycle. Lameness and claw lesions were assessed using visual analogue scales. Static groups, in comparison with dynamic groups, demonstrated lower lameness scores (P<0.05) and decreased skin lesion prevalence (24.9 vs. 47.3%, P<0.05) at the end of gestation. There was no difference between treatment group regarding claw lesion prevalence with 75.5% of sows demonstrating claw lesions regardless of group management. Prevalences of lameness (22.4 vs. 8.9%, P<0.05) and skin lesions (46.6 vs. 4.4%, P<0.05) were highest during the group-housed phase compared to the individually housed phases. Although the prevalence of lameness and skin lesions did not differ three days after grouping versus at the end of the group-housing phase, their incidence peaked during the first three days after moving from the insemination stalls to the group. In conclusion, the first three days after grouping was the most risky period for lameness incidence, but there was no significant difference between static or dynamic group management.

Impact of group housing of pregnant sows on health

Group housing of sows during gestation is mandatory in the EU since 2013. Compared to housing in individual crates, group housing allows the animals to express normal activity and behavior. The present paper discusses the impact of group housing on health, with emphasis on lameness, aggression and possible spread of infectious diseases. The prevalence of lameness is generally higher in sows housed in group than in sows housed individually. Floor space per sow, group size, pen design and flooring are the main factors of group housing involved in lameness development. Especially floor characteristics are important, and particular attention should be paid to the type, building material and quality of the floor, hygiene and the use of bedding such as straw or rubber mats. Aggression between sows is another critical issue in group housing systems. It occurs predominantly because of competition for access to a limited resource, or to establish a social hierarchy. Key factors to prevent aggression in group housing include gradual familiarization of unfamiliar animals, sufficient space and pen structure during initial mixing, minimizing opportunities for dominant sows to steal food from subordinates, provision of a good quality floor, environmental enrichment and use of straw bedding. Very scarce evidence-based information is available on the relationship between group housing and infectious disease. Compared to individual housing, sows in group housing have more nose-to-nose contact, and they have more oral contact with feces and urine. These factors could contribute to a higher or faster transmission of pathogens, but so far, there is no evidence showing more disease problems in group housing systems. In conclusion, in group housing systems, particular attention should be paid to prevention of lameness and aggression. Management is crucial but also feeding strategies, floor and bedding, and design of housing are very important as relatively minor adjustments may exert major effects on the animals.

Automatic detection of lameness in gestating group-housed sows using positioning and acceleration measurements

Lameness is an important issue in group-housed sows. Automatic detection systems are a beneficial diagnostic tool to support management. The aim of the present study was to evaluate data of a positioning system including acceleration measurements to detect lameness in group-housed sows. Data were acquired at the Futterkamp research farm from May 2012 until April 2013. In the gestation unit, 212 group-housed sows were equipped with an ear sensor to sample position and acceleration per sow and second. Three activity indices were calculated per sow and day: path length walked by a sow during the day (Path), number of squares (25×25 cm) visited during the day (Square) and variance of the acceleration measurement during the day (Acc). In addition, data on lameness treatments of the sows and a weekly lameness score were used as reference systems. To determine the influence of a lameness event, all indices were analysed in a linear random regression model. Test day, parity class and day before treatment had a significant influence on all activity indices (P<0.05). In healthy sows, indices Path and Square increased with increasing parity, whereas variance slightly decreased. The indices Path and Square showed a decreasing trend in a 14-day period before a lameness treatment and to a smaller extent before a lameness score of 2 (severe lameness). For the index acceleration, there was no obvious difference between the lame and non-lame periods. In conclusion, positioning and acceleration measurements with ear sensors can be used to describe the activity pattern of sows. However, improvements in sampling rate and analysis techniques should be made for a practical application as an automatic lameness detection system.

Osteochondrosis, but not lameness, is more frequent among free-range pigs than confined herd-mates

BACKGROUND

Organic pig production is expanding and amongst the objectives of organic farming are enhancing animal health and welfare. However, some studies have reported a higher prevalence of lameness and joint condemnation at slaughter in free-range/organic pigs than in conventionally raised pigs. Organic slaughter pigs have free-range housing in which indoor and outdoor access is compulsory, while in conventional farming the pigs are commonly confined to indoor pens. The present study evaluated the effects of free-range and confined housing on lameness prevalence in a herd of 106 finisher pigs, and whether osteochondrosis and Erysipelothrix rhusiopathiae associated arthritis influences these effects. We also evaluated the association between clinical lameness during the rearing period and joint condemnations at slaughter.

RESULTS

Seventy free-range and 36 confined housed fattener pigs were scored for their gait twice during the rearing period and 848 joints were evaluated post mortem. Osteochondrosis was more frequent among free-range than confined pigs (P < 0.05), and when present it was also more severe (P < 0.001). Pigs with more numerous and more severe osteochondral lesions had their gait affected more than did pigs with fewer such lesions (P < 0.05). Hence it was a paradox that we did not detect more lameness among the free-range pigs than the confined pigs. E. rhusiopathiae associated arthritis was not diagnosed. The association between gait remarks/clinical lameness and joint condemnations at slaughter was not significant.

CONCLUSIONS

The results indicate that free-range housing may have both positive and negative effects on locomotory traits. Free-range pigs may be less clinically affected by osteochondrosis than are confined pigs. One explanation for this effect may be strengthening of joint supportive tissue and pain relief promoted by exercise. Visual gait scoring missed serious joint lesions that probably were harmful to the pigs, and should therefore not be used as a sole indicator of joint/leg health in welfare inspection of pigs. The association between gait scores and joint condemnation appeared to be poor. This study was limited to one herd, and so more and larger studies on the effects of free-range housing on lameness severity and osteochondrosis development in pigs are recommended.

Effect of locomotion score on sows' performances in a feed reward collection test

Sows housed in groups have to move through their pen to fulfil their behavioural and physiological needs such as feeding and resting. In addition to causing pain and discomfort, lameness may restrict the ability of sows to fulfil such needs. The aim of our study was to investigate the extent to which the mobility of sows is affected by different degrees of lameness. Mobility was measured as the sow's willingness or capability to cover distances. Feed-restricted hybrid sows with different gait scores were subjected to a feed reward collection test in which they had to walk distances to obtain subsequent rewards. In all, 29 group-housed sows at similar gestation stage (day 96.6 ± 7 s.d.) were visually recorded for gait and classified as non-lame, mildly lame, moderately lame or severely lame. All sows received 2.6 kg of standard commercial gestation feed per day. The test arena consisted of two feeding locations separated from each other by a Y-shaped middle barrier. Feed rewards were presented at the two feeders in turn, using both light and sound cues to signal the availability of a new feed reward. Sows were individually trained during 5 non-consecutive days for 10 min/day with increasing barrier length (range: 0 to 3.5 m) each day. After training, sows were individually tested once per day on 3 non-consecutive days with the maximum barrier length such that they had to cover 9.3 m to walk from one feeder to the other. The outcome variable was the number of rewards collected in a 15-min time span. Non-lame and mildly lame sows obtained more rewards than moderately lame and severely lame sows (P<0.01). However, no significant difference was found between non-lame and mildly lame sows (P=0.69), nor between moderately lame and severely lame sows (P=1.00). This feed reward collection test indicates that both moderately lame and severely lame sows are limited in their combined ability and willingness to walk, but did not reveal an effect of mild lameness on mobility. These findings suggest that moderately and more severely lame sows, but not mildly lame sows, might suffer from reduced access to valuable resources in group housing systems.

Field study of hind limb claw lesions and claw measures in sows

We investigated the associations of hind limb claw lesions with claw measures and reproductive performance of sows on a commercial breeding farm. We used a five-point scale (score of 0-4) for each hind limb claw region to generate a claw lesion score (CLS). Of 110 sows, 1.8% had no hind claw lesions, and the remaining 98.2% had at least one. The proportions of sows with a CLS of 2 and 3 were 49.1% and 3.6%, respectively. The junction region had the highest frequency of a CLS of ≥ 2 (P < 0.05). The mean toe length was 45.0 ± 0.4 to 46.4 ± 0.4 mm. Sows with the highest CLS of ≥ 2 in the lateral claw had longer sole dimensions than did sows with the highest CLS of ≤ 1 (P < 0.05). There were no significant differences in claw width or height between sows with the highest CLS of ≥ 2 and ≤ 1. There was also no difference in reproductive performance between sows with the highest CLS of ≥ 2 and ≤ 1. In conclusion, most sows had hind claw lesions. The association between CLS and claw measures indicates that the sole length can be used as an indicator of claw lesions.

Herd- and sow-related risk factors for lameness in organic and conventional sow herds

Lameness in sows is an animal welfare problem which also presents an economic challenge to pig producers. Information about the prevalence of herd lameness in organic sows is relatively scarce. The first objective of this study was to establish the prevalence of lameness and to identify risk factors associated with sow lameness in Danish outdoor organic sow herds by analysing the association between risk factors at both sow and herd level using clinical records of lameness. A total of 1850 sows from nine organic herds were included in the study. Second, the study examined differences in the prevalence of sow lameness between outdoor organic and indoor conventional herds. An additional aim here was to identify risk factors associated with clinical records of sow lameness in Danish sow herds by analysing the association between risk factors with lameness at sow and herd level. One thousand and fifty four gestation sows from 44 indoor conventional and nine organic sow herds were included in this study. The nine organic herds were visited twice: once in summer/autumn 2011, and once in winter/spring 2012. In winter/spring 2011, a total of 44 indoor conventional herds were visited. Risk factors included in the study were clinical parameters and factors related to the production system. Sows were examined visually by one of four trained observers. The organic sows were assigned scores for lameness, body condition, hoof length, bursitis, abscesses and leg wounds, while the conventional sows were assigned scores for lameness, body condition and bursitis. A multivariable analysis was carried out by logistic regression with the herd and observer as random effects. The average herd lameness prevalence in gestation and lactation sows in organic herds was 11% in summer/autumn and 4.6% in winter/spring. 'Wounds, bursitis and abscess' on legs (OR=4.7, P<0.001) and body condition score >3 (OR=1.79, P=0.008) were associated with increased risk of lameness in Danish organic sow herds. Season (winter/spring v. summer/autumn) lowered the risk of lameness (OR=0.37, P<0.001). Average prevalence of lameness in gestation sow herds in winter/spring in conventional herds was 24.4%, and in organic herds it was 5.4%. An organic sow had a decreased risk of lameness (OR=0.28, P<0.001) as compared with a conventional sow. Bursitis was associated with increased risk of lameness (OR=2.08, P=0.002) regardless of the production system (i.e. whether the herd was organic or conventional).

Prevalence of lameness and claw lesions during different stages in the reproductive cycle of sows and the impact on reproduction results

Lameness in sows is an emerging disease condition with major effects on animal welfare and economics. Yet the direct impact on reproduction results remains unclear. The present field study investigated the impact of lameness and claw lesions throughout the reproductive cycle on (re)production results of sows. In five farms, a total of 491 group-housed sows were followed up for a period of one reproductive cycle. Sows were assessed for lameness every time they were moved to another area in the farm. Claw lesions were scored at the beginning and at the end of the cycle. Reproduction results included the number of live-born piglets, stillborn piglets, mummified fetuses and crushed piglets, weaning-to-oestrus interval and the presence of sows not showing oestrus post weaning, returning to service and aborting. Sows that left the group were recorded and the reason was noted. A mean prevalence of lameness of 5.9% was found, although it depended on the time in the productive cycle. The highest percentage of lame sows (8.1%) was found when sows were moved from the post-weaning to the gestation stable. No significant associations were found between lameness and reproduction parameters with the exception of the effect on mummified foetuses. Wall cracks, white line lesions, heel lesions and skin lesions did have an effect on farrowing performance. Of all sows, 22% left the group throughout the study, and almost half of these sows were removed from the farm. Lameness was the second most important reason for culling. Sows culled because of lameness were significantly younger compared with sows culled for other reasons (parity: 2.6 ± 1.3 v. 4.0 ± 1.8). In conclusion, the present results indicate that lameness mainly affects farm productivity indirectly through its effect on sow longevity, whereas claw lesions directly affect some reproductive parameters. The high percentage of lame sows in the insemination stable indicate that risk factor studies should not only focus on the gestation stable, but also on housing conditions in the insemination stable.

Risk factors of lameness in sows in England

Lameness in pigs is a major welfare concern and one of the most commonly reported reasons for premature culling of breeding sows. In this study, the prevalence of lameness in sows was estimated using data from 76 pig breeding units in England and risk factors associated with the occurrence of lameness were examined. The prevalence of lameness in sows was 4.5% (farm median 5.0%, range 0-40%), with at least one lame sow being observed at 54% of the 76 farms. Relative risk (RR) of lameness was determined by multivariable Poisson regression analysis. Farms with high producing sows had a lower rate of lame sows than farms with a medium level of production (P=0.01). However, medium levels of production on a farm were associated with higher levels of lameness than farms having the lowest level of production (P=0.02). Farms where the stockman had responsibility for more sows resulted in an increased risk of lameness (P=0.0062). When indoor units were considered, the area of the pen and younger sows (two parities or less) had higher risk of lameness (P=0.001 and P=0.026 respectively). An increased awareness of the risk factors behind lameness is essential in farm management and can be useful when designing housing areas as well as developing future prevention plans for lameness.

Effects of post-partum administration of ketoprofen on sow health and piglet growth

The effect of the non-steroidal anti-inflammatory drug ketoprofen on the post farrowing phase of sows was studied in a randomized, blinded, placebo-controlled trial. Ketoprofen (3mg/kg) was administered intramuscularly to 20 healthy sows for 3 days post-partum (p.p.). The control group (n=20) received a saline placebo. Backfat, number of days of constipation and days before feed refusal were measured. Body condition (BCS) and shoulder sores were scored for 1 week p.p. Changes in BCS, backfat and shoulder sore scores were analysed with ANOVA. Blood was collected on days -1, 0, 5 and 14 with respect to medication. Aspartate aminotransferase (AST), creatinine kinase (CK), haptoglobin and serum amyloid A (SAA) were quantified and analysed with a Mann-Whitney U test. BCS and backfat decreased less following ketoprofen administration than with the placebo (-0.08 ± 0.2 vs. -0.8 ± 0.2, 1.0 ± 0.8mm vs. -2.0 ± 0.9 mm, respectively; P<0.05 for both) during the first 2 weeks of lactation. The shoulder sore score deterioration was milder during days 4-6 p.p. with ketoprofen than placebo (P<0.05). Duration of constipation was shorter with ketoprofen than placebo (5.5 ± 0.3 vs. 6.4 ± 0.3 days p.p.; P<0.05). Incidences of feed refusal occurred later in the ketoprofen group than in the placebos (9.6 ± 0.9 vs. 3.8 ± 0.8 days p.p.; P<0.05). AST and SAA values were higher after ketoprofen administration than placebo on day 5 p.p. (P<0.05). It was concluded that ketoprofen appeared to benefit sows during the first 2 weeks post farrowing, but caused some tissue irritation.

High physiological demands in intensively raised pigs: impact on health and welfare

Genetic selection and better control of the environment of the pigs have resulted in increased production levels concerning both reproduction and growth. Such high performances imply high physiological demands that may deteriorate health and welfare. The aims of this paper are to review the physiological challenges that pigs are facing, to identify possible consequences on health and welfare, to propose ways of detecting and correcting problems whenever possible. At weaning, piglets are submitted to abrupt changes in food supply, housing and social environment. Behavioural changes and efficient adaptations of the digestive tract are critical for their health and welfare. Physiological demands to support these adaptations and risks of failure are inversely related to the age of the pigs. During fattening, modern pigs have high daily weight gain especially of lean tissue as well as elevated feed conversion rate. These high growth performances are suspected to favour stress and disease susceptibility, undesirable behaviours as well as leg weakness, but further experimental data are necessary to validate these effects and find their origin. In reproductive females, high prolificacy generates elevated foetal demands for nutrients and space that are not fully met as shown by an increased number of light piglets having difficulties to adapt successfully to the neonatal life. During lactation, sows with high milk production have high nutrient requirements leading to intense catabolism that may affect their health, welfare and future reproductive abilities.

The interrelationships between clinical signs and their effect on involuntary culling among pregnant sows in group-housing systems

Sows suffering from clinical signs of disease (e.g. lameness, wounds and shoulder ulcers) are often involuntarily culled, affecting the farmer's economy and the welfare of the animals. In order to investigate the interrelationships between clinical signs of individual pregnant group-housed sows, we performed an explanatory factor analysis to identify factors describing the patterns of variation of clinical signs. Moreover, we investigated how these emerging factors affected the probability of a sow to be either (i) euthanized, (ii) suddenly dead, (iii) sent to slaughter due to clinical signs of disease such as claw lesions or wounds or (iv) involuntarily culled (representing a pool of sows that were either euthanized, dead or sent to slaughter due to disease). Data from 2.989 pregnant sows in group-housing systems from 33 sow herds were included in the study. A thorough clinical examination was performed for each sow by using a protocol including 16 different clinical signs. Farmers recorded all cullings and deaths and the reasons for these actions in a 3-month period after the clinical examination. Among the observed sows, 4.2% were involuntarily culled during the 3-month period. From the explanatory factor analysis, we identified three factors describing the underlying structure of the 16 clinical variables. We interpreted the factors as 'pressure marks', 'wounds' and 'lameness' Logistic analyses were performed to investigate the effect of the three factors and the parity number of each sow on the four outcomes: (i) euthanized, (ii) suddenly dead, (iii) sent to slaughter due to clinical signs of disease and (iv) involuntarily culled. The analyses showed that 'lameness' significantly increased the risk of sows to be involuntarily culled (P = 0.016) or sent to slaughter due to clinical signs of disease (P = 0.026). Lameness is generally considered to be an important welfare problem in sows, which could explain the increased risk seen in this study. By contrast, 'pressure marks' and 'wounds' did not have any significant effect on the four outcomes (P > 0.05).

A cross-sectional study of prevalence and risk factors for foot lesions and abnormal posture in lactating sows on commercial farms in England

A cross-sectional study of lactating sows in 71 commercial pig herds in England was carried out to estimate the prevalence of foot lesions and abnormal posture and investigate the associated risks. Observational data were collected on the standing posture, lesions on the hind left foot, and the pen the sow was housed in for 233 sows. The prevalence of foot lesions was 76.8% and 10.8% of lactating sows had abnormal posture. Sows housed on slatted floors during pregnancy had an associated increased risk of heel flaps but a reduced risk of toe erosion, compared with sows housed on solid concrete floors with bedding during pregnancy. There was an increased risk of abnormal posture in lactating sows housed on slatted floors during pregnancy compared with those housed on solid concrete floors with straw bedding during pregnancy. In addition, there was an increased risk of abnormal posture in lactating sows with wounds on the limbs and erosions on the toe and the heel/sole. The positive association between abnormal posture and foot lesions suggests that these lesions might be painful. Housing sows on solid floors during pregnancy might reduce the risk of abnormal posture, and certain foot lesions, in sows during lactation. However, posture is a less sensitive measure of lameness than gait, and the nature of the causal relationship between foot lesions and lameness requires further investigation.

Oral ketoprofen is effective in the treatment of non-infectious lameness in sows

The efficacy of ketoprofen in the treatment of non-infectious lameness in sows was examined in a double-blinded study. Two dose rates of oral ketoprofen were compared to placebo treatment over five consecutive days. Lameness was assessed with a five-grade scoring system prior to and on the last day of the treatment. The rate of treatment success was 54.3% for the ketoprofen 4mg/kg group (n=46), 53.2% for the ketoprofen 2mg/kg group (n=47) and 20.8% for the pigs in the placebo group (n=48). The difference between both ketoprofen groups and the placebo group was significant (P=0.001), but there was no difference between the two ketoprofen groups (P=0.78). Oral ketoprofen was well tolerated and no adverse events were observed. As lameness is a very common problem in sows, oral ketoprofen appeared to be a practical way to alleviate pain and improve the welfare of sows.

Effect of lameness on sow longevity

OBJECTIVE

To analyze the association of lameness and performance variables on sow longevity by use of time-to-event analysis.

DESIGN

Cohort study.

ANIMALS

674 sows from a commercial breeding herd.

PROCEDURES

A lameness assessment was performed on each sow. Data on farrowing performance and longevity were collected for the sows during 3 or fewer parities from the database of the herd during 2005 and 2006. The association of risk factors with sow longevity within 350 days after lameness assessment was analyzed via Cox regression analysis. Pigs per day, total production days, and survival at 350 days after lameness evaluation were compared between lame and nonlame sows.

RESULTS

Numbers of preweaning baby pig deaths, stillborn pigs, and mummified pigs were negatively associated with sow longevity within 350 days after lameness assessment. A higher number of pigs born alive and younger parity of sows were protective. Lame sows had a higher risk (1.710 times as high) of removal from the herd within 350 days after lameness assessment. The number of pigs born alive per day, survival of sows at 350 days, and total number of days in the herd were lower in lame sows.

CONCLUSIONS AND CLINICAL RELEVANCE

Results of this study indicated significant differences in the survivability of lame and nonlame sows in a commercial herd. Parity and farrowing performance variables were factors influencing sow longevity in this herd. Producers need to minimize sow lameness and remove lame sows from a herd early (when treatment is not an option) to minimize economic loss.

Serum haptoglobin concentrations in dairy cattle with lameness due to claw disorders

In cattle, elevated blood serum concentrations of haptoglobin, an acute phase protein, have been demonstrated in association with several diseases, but not with lameness. Serum haptoglobin was measured in 60 Holstein dairy cattle diagnosed with lameness due to four claw disorders, pododermatitis septica (PS; n=41), pododermatitis circumscripta (PC; n=8), interdigital necrobacillosis (IN; n=7), papillomatous digital dermatitis (PDD; n=4). Haptoglobin was measured on day 1 (0-3 days after lameness was observed but before treatment) and on days 3 and 5. A total of 10 healthy cows served as controls (haptoglobin values <1.0 mg/dL). Each of the claw disorders was associated with elevated haptoglobin on day 1 (PS, PC, IN and PDD: 65.9%, 37.5%, 71.4% and 25.0%, respectively). Trimming and antibiotic treatment led to a reduction in the number of PS and IN cows with increased haptoglobin concentrations, respectively (P<0.05), but trimming did not lead to any reduction in cows with PC. The study showed that lameness due to claw disorders can be associated with a systemic acute phase response and elevated serum haptoglobin in dairy cattle. Based on the course of haptoglobin, treatments seemed effective for all claw disorders except for PC.

A cross-sectional study of the prevalence of lameness in finishing pigs, gilts and pregnant sows and associations with limb lesions and floor types on commercial farms in England

The prevalence and risks for abnormal gait in finishing pigs (Sus scrofa), gilts and pregnant sows from a representative cross-section of indoor and outdoor herds in the United Kingdom were investigated. The prevalence of abnormal gait in finishing pigs, maiden gilts, pregnant gilts and pregnant sows from 88 herds was 19.7, 11.8, 14.4 and 16.9%, respectively. In a multivariable analysis of 98 herds, there was an increased risk of abnormal gait in pregnant sows housed on slatted floors compared with pregnant sows housed on solid concrete floors with straw bedding or sows housed outdoors on soil. The lowest prevalence of abnormal gait in finishing pigs occurred in pigs housed outdoors (3.4 vs 19.7% in indoor-housed finishing pigs) however, the difference was not significant because only three farms in the study housed finishing pigs outdoors. In indoor-housed finishing pigs, there was an increased risk of abnormal gait in pigs housed on solid concrete floors with sparse bedding, partly-slatted floors or fully-slatted floors compared with those housed on solid concrete floors with deep bedding in all areas. However, there were no significant associations between floor type and abnormal gait in gilts. There was an increased risk of abnormal gait associated with increasing callus, bursitis and capped hock score on the limbs of finishing pigs. This might have occurred because limb lesions cause discomfort or because lame pigs spend more time lying and this increases the risk of limb lesions developing.