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Biomedical subjects

D M Broom

Publications and source records attributed to D M Broom.

At least 19 recordsLinked to original sources

Effects of vehicle movements during transport on the stress responses and meat quality of sheep.

Two groups of 26 lambs were transported for 15 hours either on smooth highways or on rougher secondary roads. Nine of the animals in each group were monitored for heart rate and the plasma levels of cortisol, creatine kinase and lactate dehydrogenase, before the journey began, after four, eight and 12 hours and at slaughter. The pH of the meat was measured 45 minutes and 24 hours postmortem and its colour was assessed 24 hours postmortem. The lambs transported on smooth roads had a lower heart rate and lower plasma cortisol concentrations after eight and 12 hours than the lambs transported on rougher roads. Twenty-four hours after slaughter the pH of the meat of the lambs transported on smooth roads was lower than that of the lambs transported on rougher roads.

Animals↗

Timing and causes of piglet mortality in alternative and conventional farrowing systems.

The causes and timing of piglet mortality were studied in different farrowing systems. In the first experiment 198 litters were recorded in three systems, two of which allowed the sows to move freely, and the third restricted them in conventional crates. More piglets were weaned from the conventional crates than from the open systems and they grew more quickly. More than half the liveborn mortality occurred during the first four days after parturition. In the open systems, 17 per cent and 14 per cent of the piglets born alive were crushed, compared with only 8 per cent in the crates. In the second experiment, 29 sows and litters were studied in detail in a communal pen system during the first seven days of lactation. Three-quarters of the liveborn mortality was due to crushing. The total number of piglets dying per litter, including stillbirths, was significantly associated with the total litter size and the sow's parity. The percentage liveborn mortality was significantly associated with the parity and body length of the sows and with the within-litter variation in the birth weight of the piglets. Individual birth weight was closely associated with percentage survival. Only 28 per cent of piglets weighing less than 1.1 kg at birth survived to seven days.

Animal Husbandry↗

The relationships between social behaviour of dairy cows and the occurrence of lameness in three herds.

It is well known that lameness in cattle has a multifactorial causation, however it is still not clear why some individuals are more susceptible to foot lesions in the same environment. Behaviour is thought to play an important role. The aim of this study was to assess the relationships between social and individual behaviour and the incidence of lameness in three dairy herds. Low-ranking cows spent less time lying and more time standing still and standing half in the cubicles than middle- and high-ranking cows. As time spent standing half in the cubicle increased, the number of soft tissue lesions increased and as total time standing increased the number of cases of lameness increased. The survival rate to lameness for low-ranking cows was significantly lower than for middle- or high-ranking individuals.

Animals↗

The behaviour of sheep with sheep scab, Psoroptes ovis infestation.

Methods of behavioural data collection as applied to the study of sheep scab are described. The behaviour of a number of marked animals within an affected flock was recorded using an event recorder. Focal sampled data were analysed for duration and frequency of the observed behaviours. In addition, the flock was observed at intervals and the instantaneous behaviour of each animal recorded. These data were compared with similar observational data from the same flock recorded at intervals during post-treatment recovery. Sheep scab resulted in pathological behaviours of rubbing, scratching and biting at the lesion, and these resulted in interruption of the normal behaviours, grazing, cudding and idling, but did not result in reduced levels of these behaviours. Infested sheep showed stereotypic mouthing behaviour, initiated by rubbing or scratching, or in some cases without any external stimulus. No stereotypic behaviour was seen in animals after treatment. The implications of the behavioural data for the welfare of the sheep is discussed.

Analysis of Variance↗

Effects of simulated lairage conditions on the physiology and behaviour of pigs.

The responses of pigs to being driven and mixed together in lairage were investigated. Five groups of six and five groups of seven 70 kg pigs were transported for 40 minutes on a lorry and then subjected to one of the following treatments: two groups were driven down a passage; four groups (A to D) were mixed together for one hour (A and B together, and C and D together); and, four groups were driven down the passage and then mixed ('combined treatment'). The pigs' behaviour was recorded, skin damage was scored and saliva samples were taken for analysis of cortisol. The initial journey increased the pigs' salivary concentration of cortisol. Their behaviour while being driven was not correlated with the concentrations of cortisol after they were driven and cortisol concentrations did not increase relative to post-transport levels. The frequency and duration of fighting when they were mixed were positively correlated with their level of aggression in the home pen and with the increase in concentrations of cortisol when they were mixed. One hour after they had been mixed, the concentrations of cortisol had decreased relative to post-transport levels. After the combined treatment, the correlations observed for the mixing treatment were absent, and the concentrations of cortisol increased relative to post-transport levels. Skin damage was greatest after the groups of pigs were mixed. The responses observed indicate that the combined effects of driving and mixing, which are very common in lairage, were greater than the effects of driving or mixing alone.

Aggression↗

Effects of quarantine on cats and their owners.

The effects of quarantine on 16 cats and their owners were assessed by means of four questionnaires completed by the owners at the beginning of their cat's stay in quarantine, three months later, and two weeks and three months after the cats left quarantine. Changes in body condition were evident in two-thirds of the cats during and at the end of quarantine but not three months later. Mid-way through quarantine, the owners considered their cats were less attached to them, less relaxed, more excitable, more aggressive, more nervous and less playful than before quarantine. When they left quarantine the cats were friendlier, more affectionate and more timid, and three months later they were more affectionate, more nervous and more vocal than before quarantine. When they left quarantine and three months later the cats spent more time with their owners than before quarantine. Most owners visited their cats once or twice a month; the location of the cattery and the limited opening hours restricted the number of visits they made.

Animals↗

Welfare of cats in a quarantine cattery.

The welfare of seven domestic cats housed singly in a quarantine cattery was studied for six months. Behavioural data were obtained with cameras and by time-lapse video recording, and cortisol to creatinine ratios were measured in urine samples collected from litter trays. It took five weeks for the cats to show evidence of adaptation to their new environment. They spent most of the first two weeks concealed in a house on the floor of their cage. As they adapted, they spent less time hiding and more time higher in the cage. The cats were inactive for approximately 90 per cent of the time observed, and they received little human contact. Compared with the first day, the cats' cortisol to creatinine ratios were significantly lower from their second month in quarantine.

Animal Welfare↗

Effects of lavender straw on stress and travel sickness in pigs.

OBJECTIVE: To observe pigs during road journeys in order to establish whether lavender straw was likely to decrease stress and incidence of travel sickness. SUBJECTS: Forty 70-kg Large White pigs were transported by road for 2 hours, 20 animals each day, over a 2-day period. DESIGN: On day 1, ample wheat straw was provided as bedding such that the floor of the vehicle was entirely covered (straw condition). On day 2, lavender straw was provided as bedding (lavender condition). During the journey, direct behavioral observations of the individually marked pigs were made by scanning every 10 minutes for incidence of standing and lying along with the less severe symptoms of travel sickness (foaming at the mouth and repetitive chomping). Incidences of retching and vomiting were noted as they occurred. A general activity index was also scored every 10 minutes (5 = high activity, 1 = low activity). Saliva samples were taken from each animal at different stages of the journey for analysis of cortisol. RESULTS: Pigs stood more when in the straw condition, but were more active when standing in the lavender condition. Symptoms of travel sickness appeared to be less acute in the lavender condition, with more animals exhibiting the less severe symptom, foaming and chomping (a total of 3 in straw compared with 6 in lavender), but fewer animals showing the more severe symptoms of retching and vomiting (in straw, 3 retched, 6 vomited; in lavender 0 retched, 3 vomited). A total of 6 animals retched or vomited in the straw condition but only 3 in the lavender. There was a significant difference in mean concentrations of cortisol between conditions but this was due to a difference in mean baseline concentrations between groups. CONCLUSION: Addition of lavender straw appeared to decrease incidence and severity of travel sickness but not overall levels of stress (as measured by concentrations of salivary cortisol).

Animals↗

Investigations into the preferences of laboratory rats for nest-boxes and nesting materials.

Nest-boxes and nesting materials were considered potentially useful items with which to enhance the environment of rats housed in standard laboratory cages. This study was carried out to determine whether such items are actually used by rats, and if so, what features are important in their design. Laboratory rats were allowed to choose between four commercially available nest-boxes. Nest-boxes were preferred to other parts of the cage but the nest-box most frequently selected was not suitable for routine laboratory use. Accordingly a new nest-box was designed, incorporating features apparently attractive to the animals. This was a simple structure of opaque perspex, consisting of a roof and three walls. Similarly, rats were exposed to six commercially available nesting materials and those consisting of long paper strips were most preferred.

Animals↗

Operant studies to determine the strength of preference in laboratory rats for nest-boxes and nesting materials.

Previous work has shown that laboratory rats preferred to use nest-boxes and nesting materials rather than empty parts of the cage. In preference tests, they chose opaque or semi-opaque nest-boxes and long strips of soft paper nesting material. Choice tests to demonstrate a preference between nest-boxes and nesting material were not possible because nesting materials were carried into the nest-boxes. Furthermore, preference tests did not show how important these items were to the animals. Accordingly, operant tests were conducted, in which the rats had to lift a weighted door in order to gain access to an empty cage, or one containing a nest-box, nesting material or both items. By progressively increasing the weight of the door in subsequent trials, it was shown that the rats would carry out more work to reach a nest-box, with or without nesting material, than to reach an empty cage.

Animals↗

Hormonal and physiological effects of a 15 hour road journey in sheep: comparison with the responses to loading, handling and penning in the absence of transport.

A controlled study was carried out to investigate the physiological effects of road transport on sheep. Animals (n = 10; body weight 38.9 +/- 1.3 kg), previously with catheters in their jugular veins, were rounded up and loaded onto a vehicle where they were held in a communal pen with eight other lambs. Blood samples were taken at 30 min intervals during the next 15 h while the vehicle remained stationary or was driven a distance of 548 miles (876 km). Measurements were made of plasma concentrations of cortisol, prolactin, creatine phosphokinase and lactase dehydrogenase isozymes and also of plasma osmolality, haematocrit and body weight; heart rate was also recorded in one animal. Loading and the start of driving produced large increases in cortisol and prolactin concentrations. Heart rate also increased whereas osmolality and haematocrit decreased. The major changes in hormone release occurred in the first 3 h period while, during the remaining 12 h, the stimulatory effect of transport was present but small. Body weight loss was similar under both stationary and driven conditions.

Animal Welfare↗

The use of a novel operant test to determine the strength of preference for flooring in laboratory rats.

A previous study showed that laboratory rats preferred to dwell on a solid floor rather than a grid one, particularly when resting (Manser et al. 1995). The strengths of this preference was investigated in an operant trial using a novel test apparatus, which consisted of a grid-floored cage and a solid-floored cage, joined via a central box containing a barrier whose weight was adjustable. Trials in which rats had to lift the barrier in order to explore the whole apparatus were alternated with those in which the rats were confined on the grid floor and then had to lift the barrier in order to reach the solid floor. The latter trials were carried out at the beginning of the light period when the rats were seeking a resting place. In both trials, the weight of the barrier was progressively increased for each rat, until a maximum weight was found which it would lift either to explore its environment (weight A) or to reach the solid floor (weight B). No significant differences were found between weights A and B, showing that rats would work as hard to reach a solid floor to rest on as they would to explore a novel environment. The apparatus used could with some modifications, be appropriate for use in other operant studies in laboratory rats.

Animals↗

Influences of type of anaesthesia on cortisol, beta-endorphin and heart rate in pigs.

Two experiments were carried out using a total of 20 growing pigs of approximately 20 kg in order to investigate the effect of different types of anaesthesia (metomidate versus ketamine) on plasma levels of cortisol and beta-endorphin on the heart rate. The animals were housed individually within a zone of thermal neutrality. Feed and water were available ad libitum. After becoming accustomed to human contact (being approached and touched), a catheter was implanted in the jugular vein, exteriorized in the neck region. This operation was performed under halothane anaesthesia. After recovery, hourly blood samples were taken over a 27 hour period, and cortisol and beta-endorphin concentrations were measured in the sample plasma. After this reference period, half of the animals were anaesthetized with metomidate, the other half with ketamine, and blood samples were taken at regular intervals. During a second experiment the heart rate was monitored after being anaesthetized as described before. An influence of the type of anaesthesia was observed on the plasma concentration of cortisol, but no effect was observed with respect to the beta-endorphin concentration. A fivefold increase of cortisol concentration was observed after injection with ketamine, while a twofold increase was observed after injection with metomidate. This finding suggests a suppressive effect of metomidate on the plasma cortisol levels. A fivefold increase was also observed for the beta-endorphin concentration after injection with either ketamine or metomidate. The increase in the heart rate was related to the awakening activity, which was more difficult after the ketamine injection.

Anesthesia↗

An investigation into the effects of solid or grid cage flooring on the welfare of laboratory rats.

The welfare of laboratory rats housed on either solid or grid floors was investigated in several ways. No differences were found in body weight gain, food consumption or water consumption amongst rats housed in either condition. When handling was standardized between the 2 groups, there was no correlation between flooring and docility. Preference testing revealed that rats chose to dwell on solid floors rather than grids, regardless of previous housing experience. This preference for solid floors was particularly marked (88%) when the animals were resting and much less marked during activity (55.4%). Since the rats were observed to spend 70 to 75% of their time resting, it was concluded that their welfare was likely to be improved by housing them on solid floors.

Animal Husbandry↗