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Biomedical subjects

L J Wilkins

Publications and source records attributed to L J Wilkins.

7 recordsLinked to original sources
PubMed1992

Survival rate and carcase downgrading after the stunning of broilers with carbon dioxide-argon mixtures.

As chickens may rapidly regain consciousness after gas stunning, the effects of a two minute exposure to a carbon dioxide-argon mixture on survival rate were investigated. Broilers were stunned in batches of 10 per transport crate with a mixture of 10, 20 or 30 per cent carbon dioxide in argon with 5 per cent residual oxygen. The birds were exposed to the gaseous atmosphere for two minutes. A control group of birds was electrically stunned (120 mA for four seconds; 50Hz sinusoidal waveform). In addition, the incidence of carcase downgrading conditions after stunning with 20 per cent or 30 per cent carbon dioxide in argon with 5 per cent residual oxygen was compared with the incidence after electrical stunning. The results showed that stunning with 10 and 20 per cent carbon dioxide in argon with 5 per cent residual oxygen resulted in survival rates of 24 and 1 per cent, respectively. Stunning with 30 per cent carbon dioxide in argon with 5 per cent residual oxygen resulted in the death of all the broilers. Electrical stunning resulted in a significantly (P less than 0.001) larger number of broilers with breast muscle haemorrhaging and broken furculum and coracoid bones, whereas stunning with gas mixtures resulted in a significantly (P less than 0.001) higher incidence of broilers with damaged wing bones. Electrical stunning of broilers resulted in a significantly higher pH in the breast muscles 20 minutes post mortem than stunning with carbon dioxide-argon mixtures.(ABSTRACT TRUNCATED AT 250 WORDS)

Abattoirs↗
PubMed1991

Effect of husbandry system on broken bones and bone strength in hens.

The effects of rearing system, forced moulting and three different layer housing systems on broken bones and bone strength, were examined in hens at the end of lay. Weak bones and broken bones were more common in battery hens which had been reared to point of lay on deep litter rather than in cages. The incidence of old breaks was greater in perchery birds (14 per cent) than in tiered terrace birds (5 per cent), and there was also a difference between their incidence in two types of perchery design (17 per cent and 11 per cent). Moulting was associated with a transient decline in bone strength, followed by an increase in strength during the second lay.

Animal Husbandry↗
PubMed1990

The role of electrical stunning, bleeding and plucking efficiency on the downgrading of chicken carcases.

This study examined the effects of inducing a cardiac arrest at electrical stunning, in combination with impaired bleeding and severe plucking, on the incidence of haemorrhages and broken bones in chicken carcases. It was concluded that with the possible exception of breast muscle haemorrhages none of the downgrading conditions were attributable solely to electrical stunning. Poor neck cutting, too severe plucking and flapping of the wings before death also played a part.

Abattoirs↗
PubMed1989

Beta-adrenergic responsiveness in stress-sensitive and stress-resistant pigs.

This study investigated whether enhanced metabolic responsiveness to beta-adrenergic stimulation might explain the liability of the stress-sensitive pig to develop an acidosis during stressful situations. Blood lactate, pH, PCO2 and heart rate response to an intravenous infusion of isoprenaline were examined in three lines of pentobarbitone anaesthetized, atropinized pigs. The lines were Pietrain X Hampshire which had been selected over eight generations for a positive reaction to the halothane test (stress-sensitive); Pietrain X Hampshire which had been selected over eight generations for no reaction to the halothane test (stress-resistant) and British Landrace which had been selected over four generations for a positive halothane reaction (stress-sensitive). The metabolic responses to isoprenaline were greater in the stress-sensitive Pietrain X Hampshire line than the stress-resistant line. The stress-sensitive Landrace pigs, however, had smaller changes in pH and PCO2 in response to isoprenaline than the stress-resistant Pietrain X Hampshire pigs. This inconsistent trend across the three lines led to the conclusion that enhanced beta-adrenergic responsiveness was not the likely cause of stress sensitivity.

Animals↗
PubMedDate not supplied

Effect of electrical stunning frequency on ventricular fibrillation, downgrading and broken bones in broilers, hens and quails.

The effect of stunning current frequency on the incidence of ventricular fibrillation was determined in broilers and hens. When a pulsed unipolar square wave (DC) was used the incidence of ventricular fibrillation decreased as the frequency was increased beyond 125 Hz. When a sinusoidal AC was used, 50 Hz killed some of the birds whereas at the corresponding r.m.s. currents no birds experienced a ventricular fibrillation with 1500 Hz. In quail, it was found that between 45 and 110 mA (50 Hz) all birds experienced a ventricular fibrillation. The effect of 50, 200 and 350 Hz square wave DC on carcass downgrading was examined in broilers, and there were no differences between the groups. It was concluded that there were few advantages from using high frequency stunning currents in poultry.

Abattoirs↗