Biomedical subjects

S N Brown

Publications and source records attributed to S N Brown.

59 records · Page 4Linked to original sources

PubMedDate not supplied

An examination of potential indices of fasting time in commercially slaughtered sheep.

A total of 215 market lambs was slaughtered either directly off grass or after 12, 24, 36, 48 or 72 h from food withdrawal. They had access to water at all times. Half the animals were given a moderate exercise and were subjected to venepuncture about 0.5 h before slaughter. Samples of blood were collected at exsanguination and samples of liver and muscle subsequently removed during carcass dressing. Blood packed cell volume and the concentrations of plasma glucose, lactate, free fatty acids, beta-hydroxybutyrate and total protein, and glycogen in liver and muscle, were examined as potential indices of fasting time. Fasting caused significant changes in all parameters but only beta-hydroxybutyrate increased progressively with longer food-withdrawal times and was unaffected by exercise or the stress of venepuncture. The pattern of response to fasting could be described by an equation of the Gompertz form. Sex of animal did not affect fasting responses but origin of blood (venepuncture or at exsanguination) influenced absolute levels of all the measured blood components except total plasma protein.

Abattoirs↗

PubMedDate not supplied

Variation in behavioural indices of fearfulness and fatigue in transported broilers.

Several behavioural measures were used to determine fearfulness and fatigue in broiler chickens subjected to fasting and/or transportation. There was considerable variability between four replicates, although measures within replicates were acceptably consistent. There was no uniform effect of fasting or transport on behaviour. The most cogent results were obtained by monitoring post-journey behaviour. In the few hours after transport, fasted and transported birds stood more than control birds which could be explained by increased food-searching behaviour and/or arousal. It is argued that the high variability between replicates indicates that considerable efforts must be made to control environmental variables in studies of behaviour after transporting chickens.

Animals↗

PubMedDate not supplied

The depletion of glycogen stores and indices of dehydration in transported broilers.

Broilers were either not transported or were transported for 2, 4 or 6 hours after having been subjected to food withdrawal times of less than one hour or of ten hours. The birds were then slaughtered using normal commercial practices. The longer period of food deprivation reduced liver weight and glycogen content, and circulating glucose concentrations. It also elevated the ultimate pH value (pHu) in the biceps muscle and by implication, therefore, reduced its glycogen content. With longer journey times, liver weight and glycogen content decreased. Transport had an inconsistent effect on glycogen concentration in the pectoral muscle but progressively reduced its pHu. In contrast, pHu in the biceps progressively increased, by implication because transport depleted muscle glycogen levels. Birds transported further had higher concentrations of total protein in their plasma which, though this was not significant, also had a higher osmolality. This suggests that transported birds became dehydrated. Additionally, the depletion of body glycogen stores might be associated with the perception of fatigue.

Animals↗

PubMedDate not supplied

Response of broilers to deprivation of food and water for 24 hours.

In order to provide information on the state of hydration of broilers during marketing, 7-week-old Ross broilers of mixed sex were kept at 17 or 23 degrees C and deprived of food, or food and water, for 24 h. Measurements were made of live weight, carcass weight, muscle moisture, packed cell volume, plasma glucose, corticosterone, total protein, osmolality and sodium. There was a decrease in live weight, carcass weight, plasma glucose and plasma total protein, and an increase in packed cell volume and corticosterone, in birds deprived of food, or food and water. Muscle moisture increased in birds deprived of food and decreased in birds deprived of food and water. Osmolality decreased in birds deprived of food, the decrease being greater in birds at 23 degrees C. Plasma sodium levels were higher in birds kept at 23 degrees C and increased only in birds deprived of food and water at 23 degrees C.

Animals↗

PubMedDate not supplied

Time spent by broiler chickens in transit to processing plants.

The minimum distance transported, the journey time and the total marketing time were estimated for 5819 journeys in which 19.3 million broilers were transported to four processing plants. The average distance travelled was 33.5 km, the average journey plus unloading time was 2.7 hours and the average total marketing time, from the start of loading to the completion of unloading, was 3.6 hours. The maximum recorded journey plus unloading time was 12.1 hours and the maximum recorded total marketing time was 12.8 hours. There was considerable variation between plants, those with smaller annual throughputs tending to have longer average times. In 46 per cent of journeys the birds were unloaded within three hours of the start of loading, in 78 per cent within five hours and in 94 per cent within seven hours of the start of loading.

Animal Welfare↗