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Biomedical subjects

D M Broom

Publications and source records attributed to D M Broom.

At least 37 records · Page 2Linked to original sources
PubMed1996

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↗
PubMed1996

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↗
PubMed1995

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↗
PubMed1993

Effect of bone strength on the frequency of broken bones in hens.

Bird weight, breaking strength of humerus and tibiotarsus and the number of bones broken during culling were recorded for four breeds of end-of-lay hens housed in battery cages. The probability of a bone being broken increased with bird weight and decreased with increasing bone strength. Bone strength increased with bird weight within each breed but the increase in strength was not great enough to prevent the extra damage suffered by heavier birds. There were differences in tibiotarsal strength between the four breeds of bird but overall no breed was more likely to suffer from broken bones than another. The rate of increase of bone strength with weight was similar between breeds and between humerus and tibiotarsus. The results show that differences in bone strength due to the type of housing system in which birds are kept are great enough to affect the ease with which bones are broken during bird handling during removal from cages at the end of lay.

Animals↗
PubMed1991

Animal welfare: concepts and measurement.

The term "welfare" refers to the state of an individual in relation to its environment, and this can be measured. Both failure to cope with the environment and difficulty in coping are indicators of poor welfare. Suffering and poor welfare often occur together, but welfare can be poor without suffering and welfare should not be defined solely in terms of subjective experiences. The situations that result in poor welfare are reviewed in this study with special reference to those in which an individual lacks control over interactions with its environment. The indicators of poor welfare include the following: reduced life expectancy, impaired growth, impaired reproduction, body damage, disease, immunosuppression, adrenal activity, behavior anomalies, and self-narcotization. The uses of measures of responsiveness, stereotypies, and animal preferences in welfare assessment are discussed. The need to make direct measurement of poor welfare as well as to use sophisticated studies of animal preferences is emphasized.

Adaptation, Psychological↗
PubMed1990

Limb bone strength and movement in laying hens from different housing systems.

Walking and bouts of wing movement performed by 61-week-old ISA brown laying hens which had been taken from one batch of eggs and then kept in three different housing systems which allowed a gradation in spatial freedom, were recorded. After slaughter the breaking strengths of the humerus and tibia of birds from each system were measured. Birds from battery cages exhibited the fewest limb movements and had the weakest bones, their humeri having only 54 per cent of the strength of those of birds from a perchery. Birds from the Elson terrace system were heavier and had a stronger tibia than cage birds. Compared with perchery birds, terrace birds had weaker humeri and also performed fewer wing movements. The results indicate that the amount of movement possible for laying hens in battery cages was insufficient to avoid levels of osteopenia and consequent bone fragility much greater than in birds kept in the perchery and Elson terrace systems.

Animal Feed↗
PubMed1987

The veterinary relevance of farm animal ethology.

The world expects veterinary knowledge to encompass all aspects of the lives of animals. These include their management and welfare, not just their diseases. Modern research into behaviour is relevant to practical veterinary work, such as animal handling and disease diagnosis, and also to general management and welfare. Hence, all veterinary courses should include instruction in behaviour and those involved in veterinary work should be aware of new developments in the subject.

Animal Husbandry↗
PubMed1983

Cow-calf and sow-piglet behaviour in relation to colostrum ingestion.

The declines in both production of immunoglobulin (lg) by mothers and absorption efficiency by young make it desirable for calves to ingest an adequate amount of colostrum by 6-12 h and piglets to do so by 4-8 h. In cattle, suckling attempts may be delayed by weakness of the cow or calf due to difficult calving, injury, deformities or disease. The incidence of attacking or avoiding calves is greater among heifers than among older cows and rejection is occasionally a serious problem. Amongst dairy cattle, the major factor leading to inadequate colostrum intake is difficulty in finding a teat or suckling from it because the udder is pendulous and the teats are fat. Calves of cows with pendulous udders, and this included most older cows, failed to suck within 6 h and obtained inadequate lg levels unless put to the teat. Absorption of lg may be more efficient if the mother is present. Some attacking of piglets by gilts is common and injuries to piglets due to sow attacks may be a serious problem. Injuries, deformities, general weakness or becoming trapped in part of the farrowing pen reduce the chances that a piglet will suckle adequately. Agalactia and competition for teats result in some piglets in larger litters failing to suckle. Fighting for colostrum producing teats peaks 2 h after the birth of the first piglet so later born piglets must obtain less of the lg produced if farrowing is prolonged. Group farrowing and group calving increase the chances that some piglets or calves will fail to obtain adequate colostrum.

Animal Population Groups↗
PubMed1979

The period between birth and first suckling in dairy calves.

The period between birth and first suckling was recorded for 82 dairy calves. 11 per cent of heifers' calves and 46 per cent of cows' calves had not suckled by 6 h after birth. All calves, whether suckling spontaneously or put to the teat at 6 hr, had adequate 48 h total serum immunoglobulin levels.

Animals↗
PubMedDate not supplied

Interactions between cattle and badgers at pasture with reference to bovine tuberculosis transmission.

The normal behaviour of badgers, as described here, would not result in direct transmission of tuberculosis from badgers to cattle via air expired by badgers or via bodily contact. All activities of wild badgers in cattle fields at three different sites were observed at night for a total of 359 h. In addition, all activities of pairs of wild caught badgers were observed in a 0.5 ha enclosure with an artificial sett on 20 nights when cattle were present. Badger foraging in cattle fields was infrequent during dry conditions and variable at other times. Clover fields were preferred to grass pastures in two autumnal studies and under dry conditions the badgers did not prefer to forage on short pasture. Badgers consistently avoided close contact with cattle by changing routes from sett to foraging site and by foraging much less in areas of fields occupied by cattle. When foraging they preferred to remain at least 10-15 m from cattle and they avoided compact groups of cattle more than individuals. Some cattle would move towards badgers, especially if they were carrying out unusual behaviour, but badgers fled rapidly from every approach. In all potential encounters badgers were able to keep at least 2-3 m from approaching cattle. Badgers in the artificial sett delayed entering the enclosure if cattle were within 15 m of the entrance. When cattle were managed on a strip-grazing (rotational) system the whole area which they occupied was avoided by the badgers. However, badgers came closer to individual cattle and foraged in areas grazed by the cattle more if the cattle were set-stocked. If cattle are managed so that they are concentrated in a small area (rotational) system the risk of disease transmission is minimized because they are less likely to encounter badgers or their fresh products than are cattle managed on a large area (set-stocked) system.

Animals↗