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Biomedical subjects

S N Brown

Publications and source records attributed to S N Brown.

At least 55 records · Page 3Linked to original sources
PubMed1995

Effects on sheep of transport by road for up to 24 hours.

Five groups of 20 slaughter sheep of approximately 37.9 kg liveweight were transported by road for either three, nine, 15, 18 or 24 hours and three groups were not transported, one of them being deprived of food and water for 24 hours. Before and after transport the liveweight and various blood variables were measured and heart rate and behavioural observations were recorded from subsets of the animals. With increased journey time there was a decrease in liveweight and an increase in the plasma levels of free fatty acids, beta-hydroxybutyrate and urea; however, the changes over 24 hours were similar to those in the group deprived of food and water. In the transported sheep, the heart rate and levels of plasma cortisol and glucose were increased by the stresses of loading and the initial stages of the journey, but after nine hours the sheep appeared, to some extent, to have adapted. They were able to lie down and did not appear to be physically stressed. Measurements of plasma osmolality, total plasma protein and albumin did not indicate that the sheep had become severely dehydrated after 24 hours of transport but upon their return, feeding and drinking activity was greater than that observed before the journey.

Adaptation, Physiological↗
PubMed1995

Effects on cattle of transport by road for up to 15 hours.

Twenty-four castrated male cattle aged between 12 and 18 months were transported by road for five, 10 or 15 hours, over distances of 286, 536 and 738 km. Half the animals were of Hereford x Friesian breeding and half of 'continental' type. The animals transported for five hours lost 4.6 per cent of their bodyweight, those transported for 10 hours lost 6.5 per cent and those transported for 15 hours lost 7.0 per cent; recovery to pre-transport values took five days. There was little evidence from changes in blood composition that a 15-hour journey was more stressful than a 10-hour journey. The cortisol concentrations were increased by the stresses of loading and the first part of the journey but then recovered as the journey continued. Creatine phosphokinase (CPK) activities increased progressively with the longer journeys and CPK, urea, albumin and osmolality levels recovered more slowly after the longer journeys. Increases in free fatty acids, beta-hydroxybutyrate and urea concentrations and the continued increase in urea levels after the end of the journeys suggested that the animals' normal pattern of feeding was disrupted. Increases in albumin, total plasma protein and osmolality indicated slight dehydration during transit which was quickly rectified by access to water. The two breed types responded similarly to transport, except that the increases in CPK were greater in the continental breeds, possibly as a result of their greater muscularity or greater sensitivity to stress. Based on the physiological measurements made and the subjective observations of behaviour a 15-hour transport period under good conditions is not unacceptable from the viewpoint of animal welfare.

Animal Husbandry↗
PubMed1994

A survey of mortality in slaughter pigs during transport and lairage.

Of 2.9 million pigs transported to seven slaughter plants in 1991 and 1992, 1781 (0.061 per cent) died in transit and 314 (0.011 per cent) died subsequently in the lairage. Overall mortality for both years was 0.072 per cent and mortality in 1992 was 0.066 per cent. There was little seasonal variation in the number of pigs dying in lairage, but more pigs died in transit in months when the weather was hotter. The relationship with temperature was curvilinear; above about 15 to 17 degrees C the detrimental effect of high temperatures was far more serious. In 1992, the year for which complete data were available, average mortality in the seven plants ranged from 0.045 to 0.093 per cent, but this variation was not related to the size of the plant. The number of pigs which died in lairage, rather than in transit, ranged from 4 to 21 per cent of all deaths in the different plants, and the average was 15 per cent. The variation might be related to differences in average lairage times or to the policies of individual plants with regard to moribund pigs. The survey provided no evidence that the mortality among transported pigs has increased over the last 20 years.

Abattoirs↗
PubMed1994

Long distance transport of export lambs.

Two commercial lorry consignments of 500 sheep were followed from the United Kingdom to their destinations in southern France, one journey of 800 miles taking 18 hours and the other of 950 miles taking 24 hours. Measurements were made of liveweight and skinfold thickness, and blood samples were taken from 100 sheep in each consignment, two days before departure and again immediately after the journeys. The results from each consignment were similar. High levels of plasma beta-hydroxybutyrate, free fatty acids and urea, both before and after the journeys, indicated that the animals were in a catabolic state. Before the journey this was probably as a result of their marketing through livestock auctions. After the journey the animals showed evidence of dehydration, indicated by increased levels of plasma total protein and albumin, and increases in plasma osmolality and skinfold thickness. The behaviour of the sheep after the journeys indicated that they were all alert and physically fit; they showed great interest in any food that was available and were only secondarily interested in drinking, and then resting.

Age Factors↗
PubMed1993

Long distance transport of lambs and the time needed for subsequent recovery.

The effects of nine and 14 hours of road transport and the subsequent recovery in lairage of 392 hill lambs were studied in August and November. The gathering and the handling of the lambs were stressful, both physically and psychologically, and the journey imposed further psychological and metabolic stress. The levels of noise in the trailer were high (90db[A]). There were no measurable differences between the responses of the lambs transported for nine or 14 hours and there appeared to be three stages in their recovery after transport. After the first 24 hours of lairage changes in the blood components usually associated with short term stress and dehydration had recovered; after 96 hours there had been a well defined recovery of liveweight and the levels of most of the metabolites measured appeared to have stabilised and after 144 hours the lambs had recovered almost completely, most of the creatine phosphokinase had been cleared from the plasma and their plasma protein levels had stabilised.

Animals↗
PubMed1992

Time in lairage needed by pigs to recover from the stress of transport.

Two experiments were carried out in which a total of 602 pigs were slaughtered after being held in lairage for periods ranging from less than one hour to 21 hours. In the first experiment the pigs were handled under ideal conditions and slaughtered at the University of Bristol slaughterhouse; in the second the pigs were killed at a commercial plant. Blood samples collected at exsanguination were analysed for indices of stress. There were no consistent effects of time in lairage on the levels of lactate and creatine phosphokinase. Plasma cortisol and beta-endorphin levels were reduced by lairage for three hours or more in the first experiment and cortisol was reduced by lairage for two hours or more in the second; beta-endorphin was not measured in the second experiment. A period of rest in lairage allowed the pigs to recover from transport and the associated handling and the recovery appeared to be complete within two to three hours.

Animals↗
PubMed1992

Influence of width and bends on the ease of movement of pigs along races.

Pigs could be moved along a race 120 cm wide more quickly than along a race 45 cm wide. The presence of a bend with an angle of 45 degrees slowed their progress by about 10 per cent, a bend of 90 degrees or 120 degrees slowed them by 19 per cent and a 180 degrees bend slowed them by 44 per cent. There was little evidence of any interaction between the effects of width and angle of bend; the effect of a sharp bend could not be compensated for by increased width. The pigs became accustomed to the races and moved more quickly in later runs.

Animal Husbandry↗
PubMed1992

Longer journeys to processing plants are associated with higher mortality in broiler chickens.

1. The number of broilers recorded as dead on arrival (DOA) in 1113 journeys to a poultry processing plant was related to the length of the journeys. The average journey time was 3.3 h and the maximum recorded was 9 h. 2. Overall, 0.194% of 3.2 million birds were DOA. Mortality was higher for journeys which took longer. For journeys lasting less than 4 h the incidence of dead birds was 0.156%; for longer journeys the incidence was 0.283%. 3. There was some evidence that it was time of journey, rather than distance travelled, that was more important in determining mortality.

Animals↗
PubMed1991

Effect of the angle of slope on the ease with which pigs negotiate loading ramps.

In experiments to investigate the time taken by pigs to negotiate ramps with different slopes it was found that they ascended with greater facility than they descended. Between 0 degrees and 20 degrees, the slope appeared to have little effect on the time taken to ascend or descend. Above 20 degrees the time taken to ascend increased linearly. The relationship between the time taken to descend and the slope above 20 degrees was biphasic with times increasing substantially above 35 degrees. There were also differences between the times taken on different days but no evidence of habituation. Pigs took longer to climb steeper ramps with wider spaces between cleats but there was no significant effect on the time taken to descend.

Animals↗
PubMed1990

The effects of the beta-adrenergic agonist salbutamol on meat quality in pigs.

The beta-adrenergic agonist Salbutamol was administered to pigs at 3 ppm in the feed between weaning and slaughter at 85 kg. Growth rate was not affected by Salbutamol. Treated pigs had a higher dressing percentage (2.6%) and produced carcasses that were less fat (17%) and had longissimus (LD) muscles of larger (11%) cross-sectional area. They also had smaller livers that contained less glycogen. The thinner backfat in treated animals was less firm and tended to separate from the underlying lean. However, these changes were attributable solely to the reduced fatness and there was no direct effect of Salbutamol. There were no differences in pH 45 min postmortem, percentage drip loss during storage or reflectance value of the LD between the two groups, indicating no greater propensity for Salbutamol-treated pigs to develop pale, soft, exudative muscle. However, treated pigs had higher final pH values in the muscles; this was reflected in slightly reduced hue and saturation values. These results suggest that the propensity of the pigs to develop dark, firm, dry meat was slightly increased. Salbutamol-treated pigs produced LD muscles that were slightly tougher (22%), had reduced concentration of heme pigments in the muscle, reduced plasma glucose and increased plasma creatine phosphokinase activity. Salbutamol improved lean meat yield but slightly increased the potential to produce dark, firm, dry meat and reduced tenderness.

Adipose Tissue↗
PubMed1990

Interactions between the beta-adrenergic agonist salbutamol and genotype on meat quality in pigs.

Salbutamol (2.7 ppm) fed to pigs between weaning and slaughter increased ADG (5%), dressing percentage (2%) and cross-sectional area of the longissimus (LD) muscle (14%). In fatter, White-line-sired pigs, but not in leaner, Meat-line-sired animals, it reduced backfat thickness (25%). Liver weight and glycogen concentration also were decreased. In neither genotype were there effects of Salbutamol on pH45, drip loss or reflectance value of the LD, but ultimate pH was elevated in semimembranosus (SM), adductor (AD) and supraspinatus (SS) muscles, resulting in reduced color saturation values. Total muscle heme pigment concentrations were reduced by 10 (SS) to 19% (LD and SM) and the intramuscular fat concentration of the AD, but not the LD, was reduced by 21%. Treated pigs had LD and SM muscles that when measured instrumentally were 15 and 8% tougher, respectively, after cooking, but the texture of the SS was not significantly altered by treatment. Salbutamol increased plasma lactate and creatine phosphokinase (CPK) concentrations. Compared with White-line-sired animals, Meat-line-sired pigs had a higher dressing percentage (2%) and LD muscles with larger cross-sectional area (13%). They also had higher circulating CPK levels.

Adipose Tissue↗
PubMed1988

Variable effect of toxic shock toxins from different sources on neutrophil function in vitro.

Toxic shock syndrome toxins (TSST) are 23-30 kD proteins that have been isolated from incubation media of strains of Staphylococcus aureus cultured from patients with toxic shock syndrome (TSS). Injection of TSST into animals produces many of the symptoms that characterize TSS including shock, fever, and multiple organ failure. We found that addition of increasing concentrations of TSST-1-VP1035-16A, but not TSST-PEC, TSST-SEC, staphylococcal enterotoxin A or B, progressively decreased human neutrophil bactericidal activity against S. aureus, 502A in vitro. TSST-1-VP1035-16A, but not the other toxins, also decreased superoxide anion and hydrogen peroxide concentrations in mixtures containing neutrophils and phorbol myristate acetate (PMA) in vitro. The results indicate that various preparations of TSST have different effects on neutrophil function in vitro and, accordingly, may have different effects in other in vitro and in vivo models of TSS.

Bacterial Toxins↗
PubMed1988

Depletion of glycogen reserves in fasting broiler chickens.

1. Male broiler chickens were killed at various times up to 36 h after withdrawal of food; hepatic and muscle glycogen concentrations and pH were compared with those of control birds given continuous access to food and water. 2. Liver glycogen was reduced to negligible concentrations (less than 1 mg/g) within 6 h of food deprivation and the initial pH was elevated. 3. Withdrawal of food had no effect on glycogen concentrations in the m. pectoralis superficialis (PS) but reduced them in the m. biceps femoris (BF); the reduction was significant after 12 h. Ultimate pH was elevated by fasting in the BF, but not the PS.

Animals↗