Comparison of injuries in sows housed in gestation stalls versus group pens with electronic sow feeders

OBJECTIVE

To compare the location and severity of injuries in pregnant sows housed in individual gestation stalls with that in pregnant sows housed in dynamic groups in pens with electronic sow feeders.

DESIGN

Prospective study.

ANIMALS

100 pregnant sows of parity 1 to 3 and various body weights.

PROCEDURE

Fifty sows each were randomly allotted to gestation stalls or group pens with electronic sow feeders. Injuries were scored on the basis of location, number, and depth of wounds. Injury scores for sows in both housing systems were compared during a period of 90 days. The influence of factors such as duration of stay in the housing system, parity, and body weight on sow injuries was also examined.

RESULTS

Injury scores were higher in group pens with electronic sow feeders. As body weight increased, injury scores decreased for sows housed in group pens with electronic sow feeders and increased for sows housed in gestation stalls. There was a significant negative association between second parity and total injury scores.

CONCLUSIONS AND CLINICAL RELEVANCE

Modifications in housing system design and management procedures are needed to reduce injuries in pregnant sows.

Lightning injury in an outdoor swine herd

Three pigs, weighing 63 kg-70 kg each, from a group of 8 pigs in an outdoor pen that was struck by lightning were necropsied. All 3 pigs presented with hind limb paralysis. The only lesions identified were multiple fractures of the last (seventh) lumbar vertebral body and first sacral vertebral segment, with dorsal displacement of the sacrum and transection of the distal spinal cord and spinal nerves. Hemorrhages extended from the fracture sites into muscles immediately surrounding the lumbosacral junction and retroperitoneally into the pelvic cavity. These hemorrhages were not clearly visible until the pelvic region was dissected. Lesions commonly found in human lightning-strike victims were not present in these pigs. Because vertebral fractures may be the only lesions and may be grossly subtle in heavily muscled pigs, careful pelvic and vertebral dissection is recommended in cases of suspected lightning strike and electrocution.

[Effects of muscle needle biopsy on parameters of humoral and cellular immunity in pigs]

The shot biopsy is a common experimental technique for the collection of samples to investigate muscle tissue characteristics or to determine meat quality features in pigs. Its application seems to be also possible in interdisciplinary research projects investigating animal stress, behaviour, and welfare. The present study on 12 group-housed pigs (age: 12 weeks, weight: 29.3 kg) shows the influence of this wound-causing technique on different humoral and cell-mediated parameters of the immune system at 1, 3, 5, and 9 days after biopsy compared to the initially investigated levels before. An enhancement of the blood sedimentation rate and both the IgG and the cellular immune response in vivo (leukocytes, lymphocytes) as well as in vitro (ConA) was observed. Furthermore, there were signs of a secondary wound infection 5 days after biopsies were taken possibly caused by mutual oral manipulation of the animals. We conclude that the muscle shot biopsy technique can be used on group-housed pigs as a method to investigate muscle physiological characteristics. The technique, however, induces immunological reactions which may interfere with stress-induced immune reactions.

[Prevalence of herd specific factors and limb disorders, and their associations in intensive swine production]

A longitudinal observational study in 180 pig breeding herds was performed to calculate prevalences of herd specific factors as well as typical limb disorders and to estimate their associations in a 2-step regression analysis. Regarding herd size, genetics, feeding and weight gain herds were distributed almost equal. The population density and the hygiene status were considered proper in most herds. In the farrowing units partially slatted floors of metal or plastic with slats > 9 mm, in the weaning units fully slatted floors of plastic, and in the rearing units fully slatted floors of concrete were most common. Less than 6% of the farms housed their pigs on solid concrete with straw bedding. Herd prevalences of fault floors varied between 18 and 43%. As a herd health problem (morbidity > 25%) claw hematomas and limb abrasions in just 1-week old piglets, overgrown claws and bursa swellings in weaned pigs, and bursa swellings in rearing pigs were wide spread. Leg deformations by osteopathy or arthritis occurred only sporadically. In the risk analysis claw hematomas of piglets were associated with slatted floors, particulary with slats < 10 mm. Abrasions were associated with concrete and rough floor surfaces at all. Overgrown claws and bursa swellings in weaned and in rearing pigs were associated with damaged, slippery or rough floor surfaces. Other associations were not detected. The quality of floor might be more important than the type of housing.

Evaluation of the relationship between injuries and size of gestation stalls relative to size of sows

OBJECTIVE

To determine whether there is a relationship between sow injuries and size of gestation stalls relative to sow size.

DESIGN

Prospective study.

ANIMALS

267 pregnant sows.

PROCEDURE

Sows were randomly selected from 4 swine farms. Sow and stall measurements were obtained, and injuries were scored on the basis of location, number, and depth. Ratios of stall length to sow length and stall width to sow height were calculated.

RESULTS

High injury scores were associated with low ratios of stall length to sow length and stall width to sow height.

CONCLUSIONS AND CLINICAL RELEVANCE

A small increase in stall dimensions could reduce injuries and improve well-being of sows considerably.

[Alterations of the integument of fattening pigs in different housing systems]

Alterations of the integument of fattening pigs were investigated on a total of eleven farms with the following housing systems: "Krieger" system, fully slatted floors, partially slatted floors and kennel housing systems. For this purpose, the alterations of the integument of the animals were visually assessed at different times during fattening. In addition, spot investigations were carried out on three farms with deep litter systems. In the non-littered systems, significantly more changes at the limbs were observed than in the littered systems. The least damages occurred in the deep litter system. Similar as with cattle, soft and deformable lying areas seem to be a prerequisite for the prevention of such alterations. With respect to injuries caused by tailbiting, apart from possibilities of activity, other parameters such as air quality and space availability also play an important role.

The relationship between tail biting in pigs, docking procedure and other management practices

The tail length (docked, tipped or undocked) and tail status (bitten or unbitten) of 27,870 pigs from 450 units was recorded at six UK abattoirs. A farm survey of the final finishing stage was used to investigate the relationship between management practice and tail biting. This showed that docking was the most important factor influencing the probability of being not bitten, with 2.4% of docked and 8.5% of long-tailed pigs being tail-bitten. The following factors reduced the probability of long-tailed pigs being tail-bitten; light straw provision, use of natural ventilation or artificially controlled natural ventilation (ACNV), mixed sex grouping, meal or liquid feeding, and use of double or multi-space feeders. Docked and long-tailed pigs provided with light straw and natural ventilation/ACNV had levels of tail biting of 1.2% and 4.3% respectively; 3.9% of docked pigs with artificial ventilation and no straw were tail-bitten. Long-tailed pigs fed via double or multi-space feeders also had 3.9% of tails bitten.

Risk factors for vulva biting in breeding sows in south-west England

A postal survey was conducted on 410 pig farms in south-west England to investigate the risk factors for vulva biting. The results of the bivariate analyses indicated that group housing, keeping a boar in the same pen and the number of sows per drinker were significantly associated (P < or = 0.05) with vulva biting in service sows. Group housing, group size, keeping a boar in the same pen, straw bedding, electronic sow feeders, feeding once daily, providing water automatically and the number of sows per drinker were significantly associated with vulva biting in dry sows. Vulva biting was also significantly associated with an increased percentage of culled sows and the occurrence of tail biting on the farm. A logistic regression analysis showed that group size and the number of sows per drinker were significant risk factors for vulva biting in service sows, and once a day feeding, group size, the number of sows per drinker and providing water automatically were significant risk factors for dry sows.

Shoulder joint luxation in large animals: 14 cases (1976-1997)

OBJECTIVE

To determine clinical and radiographic findings in and treatment and outcome of large animals with shoulder joint luxations.

DESIGN

Retrospective study.

ANIMALS

5 horses, 3 goats, 1 calf, 1 sheep, 1 Himalayan tahr, 1 pot-bellied pig, 1 reindeer, and 1 white-tailed deer.

PROCEDURE

Medical records and radiographs were reviewed to determine signalment, history, physical examination findings, type of luxation, treatment, and outcome. Owners and referring veterinarians were contracted for follow-up information.

RESULTS

Goats, sexually intact males, and animals < 1 year old were overrepresented, compared with the general hospital population during the study period. Closed reduction was attempted in 3 animals and was successful in 1. Open reduction and internal stabilization was attempted in 4 animals, including 1 in which closed reduction was unsuccessful. Long-term stabilization of the joint was achieved in 3 animals, but overall results were poor because of osteoarthritis and chronic lameness. Three animals were not treated, and 5 were euthanatized because of a poor prognosis.

CLINICAL IMPLICATIONS

Large animals with shoulder joint luxation and concurrent fractures had a poorer prognosis than did those with shoulder joint luxation alone.

Assessment of the injuries sustained by pregnant sows housed in groups using electronic feeders

The incidence of injuries to pregnant sows kept in dynamic groups in a commercial herd was recorded over a period of 18 months. The sows were maintained in a solid-floored building with a straw-bedded lying area allowing 1.7 m2 per sow and fed by means of electronic feeders. Injuries on 12 possible areas of the body were assessed every week, and graded on the scale of 0 to 3 (maximum body score 36). The lesion scores sustained by the sows were very low, with a maximum of 19 and a median of 4. Lesions of the greatest severity constituted only 0.16 per cent of all the recorded injuries. The injuries were not distributed uniformly over the body, most being on the shoulders, flanks and hindquarters, with very few on the head or in the vulval region. The total injury score was related to parity, with sows in parities one, two and three sustaining more injuries than sows in later parities, and it was also related negatively to bodyweight. More agonistic interactions were observed between sows in the lying area and in the vicinity of the feeders than in the dunging area.

Objective scoring of animal handling and stunning practices at slaughter plants

OBJECTIVE

To develop objective methods for monitoring animal welfare at slaughter plants to ensure compliance with the Humane Methods of Slaughter Act.

DESIGN

Survey of existing procedures.

SAMPLE POPULATION

24 federally inspected slaughter plants.

PROCEDURE

6 variables evaluated at each plant were stunning efficacy, insensibility of animals hanging on the bleeding rail, vocalization, electric prod use, number of animals slipping, and number of animals falling.

RESULTS

Of 11 beef plants, only 4 were able to render 95% of cattle insensible with a single shot from a captive-bolt stunner. Personnel at 7 of 11 plants placed the stunning wand correctly on 99% or more of pigs and sheep. At 4 beef plants, percentage of cattle prodded with an electric prod ranged from 5% at a plant at which handlers only prodded cattle that refused to move to 90% at another plant. Use of electric prods at 6 pork plants scored for prod use ranged from 15 to almost 100% of pigs. Percentage of cattle that vocalized during stunning and handling ranged from 1.1% at a plant at which electric prods were only used on cattle that refused to move to 32% at another plant at which electric prods were used on 90% of cattle and a restraint device was inappropriately used to apply excessive pressure.

CLINICAL IMPLICATIONS

To obtain the most accurate assessment of animal welfare at slaughter plants, it is important to score all of the aforementioned variables.

Repair of a mid-diaphyseal femoral fracture in a boar

A simple, oblique fracture of the middle portion of the diaphysis of the right femur was successfully repaired in a 10-month-old 150-kg Berkshire boar, using a 4.5-mm 9-hole broad dynamic compression plate applied to the lateral surface of the bone. A lateral surgical approach provided excellent access to the fragment ends. Intravenous administration of atracurium besylate facilitated traction along the long axis of the bone and fracture reduction. The plate was luted with 5% gentamicin sulfate-impregnated polymethyl methacrylate. Lack of a third trochanter in the porcine species facilitated retraction of the superficial gluteal muscle and provided a smooth plating surface. Full breeding activity by the boar resumed 190 days after surgery without complications. Massive soft tissue in the area over the femur, extensive production of callus, and cautious behavior by the boar contributed to successful fracture repair, indicating that domestic swine may be good surgical candidates for femoral fracture repair.

A field study on group housing of lactating sows with special reference to sow health at weaning

Four farms that group-housed sows from 2 weeks of lactation until weaning (G-farms) and 3 farms that kept the sows individually penned throughout the 5 to 6-week-long lactation period (C-farms), were compared in terms of sow health. All sows were crossbred Swedish Yorkshire x Swedish Landrace. The daily food ration was similar on all farms except during the group-housing period, when G-farm sows were fed ad libitum. Sows were grouped in the breeding section and kept grouped on deep litter in the dry sow section on all farms. Individual health examinations were performed at the time of weaning (+/- 4 days) on 179 G-farm sows and on 167 C-farm sows. Teat- and udder skin wounds occurred less frequently (p < 0.001) in G-farm sows than in C-farm sows. In addition, preweaning atrophy of all mammary glands occurred in 6.6% of the G-farm-sows but not in a single C-farm sow (p < 0.001). This indicates that sow-piglet interactions decrease when sows are group housed. However, these differences did not occur in primiparous sows, suggesting that the relation between the primiparous sow and her litter is not affected. Mastitis frequency was the same in the 2 systems. Moreover, the frequency of locomotor disorders was the same in the 2 groups, and hoof overgrowth was common in both systems. These similarities could be due to the fact that all farms group housed dry sows on deep litter. A strong relation (p < 0.001) between hoof overgrowth and locomotor disorders was evident. Low access to food due to low rank among primiparous group-housed sows was indicated by a lower (p < 0.05) backfat thickness compared with multiparous sows, and a higher (p < 0.001) frequency of skin wounds compared with individually housed primiparous sows.

Housing of pregnant sows in loose and confined systems--a field study 1. Vulva and body lesions, culling reasons and production results

A field study was carried out in 18 herds with loose housing of pregnant sows (loose herds) and in 18 herds with tethered or stalled pregnant sows (confined herds). Three of the loose herds were excluded due to different kind of flooring from the rest of the herds. The remaining 15 herds had partly slatted concrete floors and electronic sow feeding. The frequencies of sows with vulva and body lesions, thin sows as well as the culling reasons and production results were used as animal welfare indicators for the herds. Vulva lesions were found only in the loose herds and the mean prevalence proportion of sows with lesions within these herds was 15.2%. All vulva lesions observed in this study seemed to be caused by biting. The relative risk of vulva lesions was 2.6 times higher in the loose herds with no roughage feeding as compared to loose herds with appetite feeding of roughage. The sows in the loose herds, that had a feeding station with a mechanical hind gate had 1.8 greater risk of vulva lesions than sows in the loose herds that used a feeding station with an electronic gate. The mean prevalence proportion of sows with body lesions was 13.1% in the loose herds and 4.0% in the confined herds. Aggression between sows seemed to be the main cause of body lesions in the loose herds, while decubitus ulcers on the shoulders were the main cause of body lesions in the confined herds. Sows in loose herds that were not fed additional roughage feeding had 1.7 times greater risk of body lesions than sows in herds that used additional roughage feeding. The main culling reasons and production results were similar in the loose and confined herds. This study showed that there were welfare problems both in confined and loose herds, however, with improved management, many of the welfare problems associated with loose housing can be reduced.

Articular fractures of the distal portion of the humerus in Vietnamese pot-bellied pigs: six cases (1988-1992)

Medical records of 6 Vietnamese pot-bellied pigs with articular fractures of the distal portion of the humerus were reviewed. Evaluation of the medical records did not reveal a sex predilection. All fractures were associated with minor traumatic episodes in young pigs. Of 6 fractures involving the humeral condyle, 4 involved the medial portion, 1 involved the lateral portion, and 1 was a Y-shaped fracture. Five of the pigs underwent surgical repair of the fracture, and all 5 did not have signs of lameness at follow-up evaluations (mean, 11 months). Of 4 pigs that had follow-up radiography, all had evidence of mild to moderate degenerative joint disease. Articular fractures of the distal portion of the humerus should be considered as a differential diagnosis in all Vietnamese pot-bellied pigs with forelimb lameness, even if the trauma sustained appeared mild. Surgical repair in Vietnamese pot-bellied pigs is straightforward, and excellent clinical results can be expected.

The effect of claw lesions and claw infections on lameness in loose housing of pregnant sows

During a 12-month period lameness, claw lesions and claw infections were studied in 15 herds with loose housing of pregnant sows on partly slatted concrete floors. Of these herds, 12 herds had concrete slats and 3 herds had plastic slats. The mean prevalence proportion of lame sows in the herds was 13.1%. The risk of lameness increased with increasing claw lesion score and with the presence of claw infections. In the herds with concrete slats, the relative risk of lame sows was 2.4 times higher than in the herds with plastic slats. In the herds with poor floor hygiene, the relative risk of lameness was 2.8 times higher than in the herds with dry and clean floors. The mean prevalence proportion of sows with claw infections at the 3 separate examinations in the 15 herds was 3.8%. Claw infections were more prevalent in herds with dirty floors and in herds with little space per animal (< 2 m2). In the herds with concrete slats, the relative risk of claw infections was 2 times higher than in the herds with plastic slats.

Housing of pregnant sows in loose and confined systems--a field study. 3. The impact of housing factors on claw lesions

The relationship of claw lesions to housing was studied in 36 sow herds. Eighteen herds with loose housing of pregnant sows and 18 herds with confined (stalled or tethered) pregnant sows, were followed over a 12 month period. Fifteen of the loose housing herds had partly slatted concrete floors, while 3 herds had other types of flooring. The mean herd prevalence proportion of sows with major claw lesions in loose housing herds with partly slatted floors was about twice as high as in the herds with confined sows. In the only loose housing herd with deep litter based on straw, the prevalence proportion of sows with major claw lesions was lower than any of the other loose or confined herds. Within herds with loose sows on partly slatted floors, the prevalence proportion of sows with major claw lesions seemed to be higher in the loose housing compartment than in the farrowing compartment. The prevalence proportion of sows with major claw lesions did not differ between loose herds with plastic slats and loose herds with concrete slats.