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Biomedical subjects

E Lambooij

Publications and source records attributed to E Lambooij.

25 records · Page 2Linked to original sources

Impedance recordings to determine change in extracellular volume in the brain following cardiac arrest in broiler chickens.

The present study describes a method to determine the onset and development of brain damage in broiler chickens. Exsanguination disrupts the brain metabolism and causes the brain to become ischemic. Energy-requiring systems in the cell membrane fail, which results in an ionic shift over the membrane, accompanied by a water influx into the cell. This cellular edema decreases the extracellular volume of brain tissue. In mammals, this brain damage has been measured by recording brain impedance. We adapted this approach for use with poultry. Five to six-week-old commercial broilers were equipped with impedance recording electrodes in the striatum area of the brain. Cardiac arrest was induced by means of an intravenous injection of MgCl2 and brain impedance was recorded for 30 min. The resulting curves showed a high similarity to those obtained in rats. No effects of 12 h antemortem feed deprivation on the size and rate of change in brain impedance could be found. Both in anesthetized and conscious birds, a change in brain impedance was found. We conclude that brain impedance can be used to determine the development of ischemic brain damage in broiler chickens.

Animals↗

Effects of regular moving and handling on the behavioral and physiological responses of pigs to preslaughter treatment and consequences for subsequent meat quality.

The effects of regular moving and handling during the finishing period on behavioral and physiological responses of pigs during preslaughter treatment and consequences for meat quality were studied. From the age of 10 wk onward, 144 pigs were housed in groups of four (two gilts and two castrates) and subjected to one of the following treatments. The Environment treatment allowed pigs to move freely for 8 min outside their home pen. Then the pigs were transported in a box for 2 min, and after which they were returned to their home pen. In the Handling treatment, an experimenter remained for 3 min in the pen, and whenever a pig made contact, it was gently stroked. The experimenter then walked for an additional 1 min, without attempting to pat or stroke any pigs but subsequently held each pig in a tight grip for about 5 s. This entire procedure was then repeated. A Control treatment was also included, in which the pigs were subjected to no treatment. The Environment and Handling treatments were applied twice a week at the age of 15, 17, 19, 21, and 23 wk. At 25 wk of age, pigs were transported to the abattoir. They were held unmixed in the truck and in lairage and were manually stunned. The stockmen needed significantly less time to move Environment pigs out of their pen and into the transport box. There were no differences between treatments in salivary cortisol concentrations before or after transport. Environment and Handling pigs had paler meat than Control pigs. Glycogen content at 1 h after death and water-holding capacity were lower in Environment pigs than in Control pigs, but this did not lead to a higher incidence of PSE meat. We conclude that the pigs that had experience with leaving their home pen and some of the transport conditions were much easier to handle at loading. Pigs that are easier to move are less likely to be subjected to rough handling, which implies improved welfare, and the workload for personnel at the time of marketing is reduced. Differences in meat quality due to treatment were slight.

Abattoirs↗

Effects of injecting electronic transponders into the auricle of pigs.

Electronic transponders (3 x 18 mm) were injected into the base of the auricle of 69 10-day-old pigs, 111 four-week-old pigs and 24 six-month-old pigs, to examine the procedure of injection in the auricle, the tissue reaction and the ease of removal from the carcase. The injection was difficult in the 10-day-old pigs, but was easier at four weeks. One of the 204 transponders were lost and five of them appeared to be broken. Only one gilt showed some exudate around the transponder. The transponders could easily be removed when the pigs were slaughtered by cutting off the ear. The position of the transponder was significantly (P < 0.05) more ventral in the animals injected at 10 days old than in those injected at four weeks. The mean thickness of the connective tissue capsule around the transponders increased at first (P < 0.1) and then decreased when they were injected into 10-day-old pigs but decreased (P < 0.1) from shortly after injection in the pigs injected at four weeks old. After five months, the capsule in the animals injected at 10 days old was on average significantly (P < 0.01) thinner than in those injected at four weeks.

Animal Identification Systems↗

Electronic identification with injectable transponders in pig production: results of a field trail on commercial farms and slaughterhouses concerning injectability and retrievability.

A nationwide electronic system for the identification of all pigs is a means to achieve a tighter control of livestock and meat in the Netherlands. In order to examine the use of electronic identification transponders, two field trails were performed. Transponders supplied by three separate companies were tested on pigs on commercial farms. In phase 1, each device was examined on separate farms and in phase 2, the three devices were tested on each farm. A total of 3,436 and 5,947 transponders from the different suppliers were injected in the base of the ear at weaning in phase 1 and 2 on seven and five farms, respectively. The following aspects were examined: technical labour for injection and reading, readability of the transponders, impact on tissues at the injection site, and retrieval of the transponder after slaughter. After instruction the farmer was well able to inject a transponder in a restrained piglet. The results show that in phases 1 and 2 1.6% to 7.3% of the transponders were unreadable at retrieval in the slaughter line, which is significantly (p < 0.05) higher than the required maximum loss of 1%. The 1.6% failure rate in phase 1 involved transponders from a single supplier. Loss of identification was associated with rejection after injection, expulsion during inflammation and technical failure. Three weeks after injection on average 0.6% of the piglets had an observable inflammation and at the time of retrieval pus was found around, on average, 1.2% of the transponders. An average of between 37% and 88% of the transponders were retrieved in the slaughter line from the base of the ear in phases 1 and 2. The other transponders were retrieved medial or caudal to this position. This positional variation meant that it was not consistently possible to remove the transponder from the carcass within the required 4 second time period. It was concluded that the systems should be improved before recommending their introduction on a large scale, because the variation in readability and location is too high.

Abattoirs↗

[Stunning of slaughtering animals on the farm].

Recent changes in the Inspection Regulations have made it possible for practising veterinarians to stun and bleed animals on the farm. The Health and Welfare Law stipulates, amongst other things, that it is not permissible to put the welfare of the animal to disadvantage. Mechanical methods are the most suitable for use on farms, and of these methods the humane (cattle) killer is clearly to be preferred. The humane killer should be placed frontally, where the imaginary lines between the eyes and ears cross, or occipitally above the brain. A firearms license is needed. As many practising veterinarians are not experienced in the stunning and bleeding of animals, it is advised that these actions be left to emergency butchers.

Animals↗

Subcutaneous tissue reaction to polyethylene terephtalate-covered electronic identification transponders in pigs.

Polyethylene terephtalate-covered identification transponders were injected in 4 week old piglets to examine clinically and histologically the reaction in the surrounding tissue after 4, 7 and 21 days and 6 months. Inflammatory signs at the injection site were clinically noticed from 2 days onwards and gradually decreased after day 3. A second series of inflammatory events occured in some animals around day 7. Swelling was observed thereafter in a few animals. In the pigs slaughtered at day 4, all samples showed a layer of exudate and debris surrounding the transponder. Afterwards a fibrous capsule developed. The mean thickness of reactive tissue decreased significantly (p < 0.01) between days 4 and 7 and days 14 and 21, and remained unchanged between day 21 and 6 months. The mean (+/- s.e.) capsule thickness was 0.32 +/- 0.12 mm after 6 months. It is concluded that PET-covered transponders are encapsulated in fibrous connective tissue within 3 weeks after injection at the base of the ear. After 6 months the capsule around the transponder revealed no or only minor signs of inflammation.

Animal Identification Systems↗