Tear staining in pigs: a potential tool for welfare assessment on commercial farms.

Tear staining or chromodacryorrhea refers to a dark stain below the inner corner of the eye, caused by porphyrin-pigmented secretion from the Harderian gland. It has been shown to be a consistent indicator of stress in rats and to correlate with social stress and a barren environment in pigs. The current study was, to our knowledge, the first to test it on commercial pig farms as a potential welfare indicator. The study was carried out on three commercial farms in Finland, in connection to a larger study on the effects of different types of manipulable objects on tail and ear biting and other behavioural parameters. Farm A was a fattening farm, on which 768 growing-finishing pigs were studied in 73 pens. Farm B had a fattening unit, in which 656 growing-finishing pigs were studied in 44 pens, and a farrowing unit, in which 29 sows and their litters totalling 303 piglets were studied in 29 pens. Farm C was a piglet-producing farm, on which 167 breeder gilts were studied in 24 pens. Data collection included individual-level scoring of tear staining; scoring of tail and ear damage in the growing-finishing pigs and breeder gilts; a novel object test for the piglets; and a novel person test for the growing-finishing pigs on Farm B and the breeder gilts on Farm C. On Farm A, tear staining was found to correlate with tail damage scores (n=768, rs=0.14, P<0.001) and ear damage scores (n=768, rs=0.16, P<0.001). In the growing-finishing pigs on Farm B, tear staining of the left eye correlated with tail damage (n=656, rs=0.12, P<0.01) and that of the right eye correlated with ear damage (n=656, rs=0.10, P<0.01). On Farm A, tear-staining sores were lower in the treatment with three different types of manipulable objects as compared with controls (mean scores 3.3 and 3.9, respectively, n=31, F29=4.2, P<0.05). In the suckling piglets on Farm B, tear staining correlated with the latency to approach a novel object (n=29, rp=0.41, P<0.05). Although correlations with tail and ear damage were low, it was concluded that tear staining has promising potential as a new, additional welfare indicator for commercial pig farming. Further research is needed on the mechanisms of tear staining.

An ellipsoid farrowing crate: its ergonomical design and effects on pig productivity.

An ellipsoid farrowing crate was designed and compared to the conventional rectangular crate with regard to its effect on sows' production traits. The main features of this crate are its oval horizontal frame and bowed vertical bars. Thirty-two sows farrowed in each system. Those in the ellipsoid crates raised 318 pigs and those in the rectangular crates raised 304. Stillbirth rate was lower in the ellipsoid crates than in the rectangular crates (P < .05). Among pigs born live, no significant difference due to crate was found on the deaths by crushing, infection, and other causes. The overall pigs' weaning rate from total births was also similar in both crates (P > .05). The daily weight gains of pigs for the 1st wk in the ellipsoid crate did not differ from those of pigs in the rectangular crates (P > .05) but were higher for the period from d 7 to d 21 (P < .05). The ellipsoid crate allowed the sow to turn around and have more freedom to move. However, the increase in sow movement did not cause a higher pig crushing rate than that in the traditional crate (P > .05). Behavioral observations also showed that the ellipsoid farrowing crate permitted easier visual and tactile contact of dams with their pigs and offered pigs better access to the sow's teats.

Incidence of foot and skin lesions in nursing piglets and their association with behavioural activities.

A total of 356 piglets from one farm were examined for foot and skin lesions every day for the first 10 days after birth, and then on alternate days until they were weaned. Over a period of 24 days 100 per cent of the piglets examined developed sole bruising, and 49.1 per cent developed sole erosions. Sole bruising lasted for an average of 13 days and sole erosions for seven days. At the beginning of the study, a higher proportion of piglets had mild sole bruising; from three to nine days of age piglets had moderate sole bruising but from days 10 to 20 mild bruising was again observed more frequently. Skin lesions were observed on the carpal aspect of the front limbs; 60.9 per cent of the piglets developed skin abrasions, 70.7 per cent developed healed wounds and 90 per cent developed hairless patches. The skin abrasions lasted on average for six days, the healed wounds for five days and the hairless patches for eight days. Piglets which developed sole bruising and/or sole erosions on the first day of life were significantly heavier than those which did not. Continuous observations of the piglets' behaviour during the first six days of life showed that sole bruising increased as the total time spent in the creep area or lying near the sow on the solid floor increased. During the first three days of life skin abrasions increased as the total time spent lying in the creep area increased. There was a positive correlation between the total time piglets spent suckling and the incidence of carpal skin abrasions between four and six days of age. Piglets with sole bruising, sole erosions or carpal skin abrasions spent less time during the day in 'other' activities such as walking, playing or fighting.

Large quantities of straw at farrowing prevents bruising and increases weight gain in piglets.

Two major welfare issues in current pig production are the lack of nesting material for farrowing sows and poor claw health in suckling piglets. Therefore, a strategic method to supply loose housed sows with large quantities of straw at farrowing has been developed by Swedish piglet-producing farmers. The objective of this cohort study was to estimate the effect of a large quantity of straw (15-20 kg) supplied before farrowing compared to limited daily amounts (0.5-1 kg) on bruising and growth performance in pre-weaning piglets. On each of four commercial piglet-producing farms in south-west Sweden, one batch of sows was studied during two consecutive lactations. At inclusion, sows were randomly assigned to two treatment groups, and sows remaining in the batch during the second lactation switched treatment group. In the STRAW group (n=181 litters) sows were provided with 15-20 kg of chopped straw 2 days prior to expected farrowing. Sows in the CONTROL group (n=182 litters) received 0.5-1 kg of chopped straw on a daily basis plus 2 kg for nest building when the stockperson judged the sow to be about to farrow. Piglets were individually weighed within 36 h after birth, at 3-7 days after birth and at weaning. On day 3-7, limbs and feet were clinically examined for the presence and location of lesions. In conclusion, the provision of 15-20 kg of straw 2 days prior to farrowing effectively prevents the piglets from developing skin abrasions (IRR=0.38) and soft heel/sole erosions (IRR=0.08-0.35). We also conclude that the strategic use of large quantities of straw has a positive effect on weight gain, increasing the expected mean body weight at weaning by 0.33 kg.

Lameness in piglets. Abrasions in nursing piglets and transfer of protection towards infections with Streptococci from sow to offspring.

A group of 175 newborn piglets were monitored with respect to development of abrasions and lameness. Lameness was diagnosed in 10.9% of the piglets. About every second litter was affected and around 75% of these diagnoses took place during the first 3 weeks of life. Skin lesions were present already on day 3. They increased in magnitude until day 10 and thereafter declined. They were generally bilateral and most commonly observed as abrasions over the carpal joints. Hocks, face and tails were affected in a similar way, but at lower magnitudes. Sole bruising was observed in 87% of the piglets on the third day of life, and moderate to severe lesions dominated until day 10. Thereafter the incidence decreased, indicating healing with time. Still 39% of the piglets were affected at day 17. There was a significant positive correlation between skin lesions of carpus and hock within all examination days in selected piglets with known identity (n = 48). Between day 10 and 17 significant positive correlations were found within all examination sites with exception of abdomen and teats. The offspring of sows treated against mastitis expressed more abrasions then piglets delivered by healthy sows and the mortality during the first 17 days postpartum was significantly higher among piglets delivered by sows treated for mastitis. The level of serum antibodies to Streptococcus equisimilis in eight dams decreased during the last month of gestation and a declining maternal immunity to S. equisimilis was demonstrated in all piglets (n = 47) during the first 5 weeks of life. During the first 2 weeks of life somewhat lower median levels of serum antibodies were recorded among the piglets that were treated against arthritis (n = 8).