Effects of stone chewing by outdoor sows on their teeth and stomachs.

Stone chewing is a common behaviour in outdoor sows, but its effects on their teeth and stomachs have not been investigated. Tooth wear and damage was assessed by examining the heads of 58 sows culled from outdoor units and 23 culled from indoor units. Tooth damage was found in 28 per cent of outdoor and 30 per cent of the indoor sows, and tooth wear affected 88 per cent of the outdoor and 91 per cent of the indoor sows. The outdoor sows were more prone to wear on the lower molars and premolars, a pattern of wear associated with stone chewing. The stomachs of 152 outdoor sows and 47 indoor sows were examined. Stones were found in 59 of the outdoor sows but in none of those kept indoors. There was no evidence that the presence of stones damaged the stomach, or that stone chewing affected the health of the sows. The teeth of the outdoor sows were worn, but probably not sufficiently to affect their ability to eat during their relatively short productive lives.

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.

Gastric ulcers in finishing pigs: their prevalence and failure to influence growth rate.

In an abattoir survey the stomachs of 1242 pigs from 15 farms were examined. Ulceration of the pars oesophagea was present in 22.95 per cent with a range from 4.7 to 57.4 per cent. The ulcers were graded mild in 9.5 per cent and severe in 13.4 per cent of the stomachs. Bile staining and hyperkeratinisation of the pars were significantly more common in stomachs with ulcers than in those without (P < 0.001), although the difference between the hyperkeratinisation in cases with severe ulcers and cases without ulcers was not significant. The daily liveweight gains of 208 males and 150 females from two units with a high prevalence of ulcers were calculated from their weaning weights at about five weeks of age and their slaughter weights at around 90 kg. At the abattoir their stomachs were examined for the presence of ulcers of the pars. The daily liveweight gain of the males was significantly greater than that of the females (P < 0.001), but the presence of mild or severe ulcers had no influence on the rate of gain of the pigs from either unit. The prevalence of ulcers in the males and females was 57.2 and 49.3 per cent, respectively, but the difference was not significant.

Abattoir observations of the weights of stomachs and their contents in pigs slaughtered at known times after their last feed.

From 15 farms, 1242 pigs (range per farm 12-169) were sent for slaughter at known times after their last feed. The time of feeding, quantity and type of last feed, time of loading, time in transit, distance travelled, time in lairage and time of slaughter, were recorded. The mean +/- SD stomach weight and wet stomach contents weight were 0.68 +/- 0.12 and 0.55 +/- 0.45 kg, respectively. There were 148 stomachs (11.9%) with wet contents weights > 1 kg, nine > 2 kg but < 3 kg, and one weighed 3.04 kg. The means and ranges for times from last feed to loading interval, time in transport, and time in lairage were 13.6 (0-40), 3.1 (0.75-6.0) and 4.1 (2.1-12.5) h, respectively. The mean and range for distance travelled was 193.1 (43-320) km. Ten stomachs were collected at random from a further load of pigs from one farm. They had been fed 0.64 kg dry pellets and were slaughtered 18.5 h later. The mean and range for wet stomach contents weight was 0.87 kg (0.24-1.33). Samples were dehydrated and the mean calculated stomach dry matter content for the 10 pigs was 127.4 +/- 69.1 g.

Pig welfare and carcase quality: a comparison of the influence of slaughter handling systems at two abattoirs.

Pigs from four farms (two producing 'easy' and two 'difficult to handle' pigs) were slaughtered at two abattoirs, each with two slaughter handling systems, so that 25 pigs of each behavioural type were slaughtered by all four handling systems on each day; there were 16 replicates (3200 pigs) in total. The pigs at abattoir X were electrically stunned, either in a floor pen holding five pigs or in a race-restrainer. At abattoir Y the pigs were stunned either in a floor pen holding five pigs or in a dip-lift carbon dioxide stunner. The following measurements were made: hot carcase weight and backfat thickness at P2, degree of rigor mortis 35 minutes post mortem, skin blemish, pH and muscle reflectance in the m longissimus dorsi at 60 minutes and 18 hours post mortem, and pH and muscle reflectance in the m adductor at 18 hours post mortem. At abattoir X, the pigs slaughtered in the race-restrainer had heavier carcases (74.0 kg vs 73.0 kg, P < 0.05), developed rigor mortis more rapidly (8.1 mm vs 7.3 mm, P < 0.01), had more skin blemish (2.8 vs 2.7, P < 0.01), paler m longissimus dorsi muscles after one hour (15.7 vs 13.9, P < 0.01) and 18 hours (27.8 vs 26.6, P < 0.05), and paler m adductor muscles (24.5 vs 22.7, P < 0.001) after 18 hours. At abattoir Y, the pigs handled through the floor pen system had more skin blemish (2.7 vs 2.6, P < 0.05) and a tendency to develop rigor mortis more quickly (6.11 vs 5.32, P = 0.089).(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of the beta-agonist salbutamol on claw horn lesions and walking soundness in finishing pigs.

The effects of feeding the beta-adrenergic agonist salbutamol to pigs at levels between 0.5 and 5.0 mg/kg feed for different periods were studied in six experiments. The feet and ability to walk of pigs weighing 30 to 100 kg were examined at intervals. False sand-crack, white-line and heel erosion lesions were classified as mild or severe, and corns and wall haemorrhages were also recorded. At each examination the pig was given a grade for the overall severity of its foot lesions. Salbutamol fed at 1.0 to 5.0 mg/kg feed, for as little as 21 to 28 days, increased the frequency (P < 0.05 to 0.001) and often the severity (P < 0.05) of the foot lesions, the higher doses tending to produce more severe lesions, and the overall foot grades deteriorated (P < 0.001). The effects on both sexes were similar. No changes were observed when 0.5 mg/kg was fed for 56 days. Despite the severity of many of the foot lesions, the pigs became lame in only one experiment. Electron microscopy indicated that salbutamol was interfering with horn production, but light microscopy revealed no changes in skin sections. These findings suggested that salbutamol was not directly affecting the function of keratinocytes. Supplementing the diet of the pigs with biotin and methionine did not delay, or prevent, the effects of salbutamol.

Effects of abattoir and slaughter handling systems on stress indicators in pig blood.

Pigs from four farms were slaughtered at two abattoirs, each with two slaughter handling systems. Pigs at abattoir X were electrically stunned, either in a floor pen holding five pigs or in a race-restrainer. At abattoir Y pigs were stunned either in a floor pen holding five pigs or in a dip-lift carbon dioxide stunner. At exsanguination, 96 blood samples (24/farm) were collected from pigs slaughtered through each slaughter handling system (384 samples in total). Serum samples were analysed for cortisol, creatine phosphokinase (CPK) lactate dehydrogenase (LDH) and LDH-isoenzymes. There were no significant differences between the systems at abattoir X. At abattoir Y, pigs slaughtered through the floor pen system had higher levels of LDH-5 (39.84 +/- 1.39 per cent of total LDH vs 34.76 +/- 1.21 per cent, P < 0.05) indicating greater skeletal muscle damage in the floor pen. Pigs at abattoir Y had higher mean serum levels of CPK than pigs at abattoir X (3.63 log10 U/litre vs 3.41 log10 U/litre, 0.03 sed, P < 0.001), higher total LDH activities (1269.5 U/litre vs 922.8 U/litre, P < 0.001) and higher cortisol concentrations (1.70 log10 ng/ml vs 1.51 log10 ng/ml, P < 0.001). These differences suggested that the levels of physical and psychological stress were higher at abattoir Y.

Influence of supplementary iron in late pregnancy on the performance of sows and litters.

On eight farms alternate sows and gilts within three weeks of their expected farrowing date were injected intramuscularly in the neck with 8 ml of an iron (gleptoferron) preparation containing 200 mg iron/ml, or kept as uninjected controls. Data from 513 iron-injected and 488 control animals were used in the analysis of results. Small, but not statistically significant, improvements were observed in the numbers of piglets born alive and dead/litter, the birth weights and weaning weights at three weeks, the numbers of piglets fostered on and off/litter, piglet mortality, the number weaned/litter and the weaning to service interval. The condition scores of the iron-injected sows were marginally below those of the controls at weaning, but their condition scores at farrowing had also been slightly below those of the controls. A summation of these trends would suggest an overall benefit of approximately 0.45 pigs/sow/year in favour of the iron-injected sows.

Rate of claw horn growth and wear in biotin-supplemented and non-supplemented pigs.

The growth and wear rate of claw horn was measured in 42 commercial hybrid pigs. Half received a ration supplemented with 1 mg d-biotin/kg food daily, while the others acted as controls. The start weights of three replicates of 10 pigs averaged 25 kg and their mean finishing weight was 85 kg. Twelve pigs averaged 18 kg at the start and 118 kg at the end of the experiment. No differences in horn growth and wear rates were found between the biotin-supplemented pigs and the controls, or between the front and hind claws, although horn growth and wear both decreased with age. Claw horn grew at an average of 10 mm/28 days in the pigs taken from 25 to 85 kg bodyweight and at 11 mm/28 days in the pigs taken from 18 to 118 kg. The mean rate of wear of claw horn was 6 mm/28 days.