The vocal expression of feeding motivation and frustration in the domestic laying hen

Posted in: Welfare by admin on January 1, 2000 | No Comments

Thwarting of feeding behaviour in the laying hen results in an increase in stereotyped pacing, displacement preening, and the gakel-all (a call consists of a whining, elongated note, followed by a variable number of short notes). These behaviours therefore reflect the frustration arousal caused by the thwarting of feeding behaviour. This raises the question whether the level of frustration also varies with the intensity of the motivation to perform the thwarted behaviour. This study investigated the relationship between the intensity of the motivation and level of frustration on the one hand and the gakel-call on the other hand. In experiment 1, the strength of the motivation to feed was varied by thwarting hens in their feeding behaviour in an operant procedure after different durations of food deprivation (0, 8, 23, 47 h). Trend analysis showed that with increasing hunger state, an increasing number of gakel-calls was given. No effect of treatments on temporal characteristics of the gakel-call was found. In experiment 2, the level of frustration was varied by reducing or increasing the duration of access to food for food-deprived hens compared to the duration of access during training. It was assumed that a shorter duration of access to food compared to training would elicit frustration, which in turn would affect the performance of behaviours indicative of thwarting. However, we found neither a relation between the number of gake-calls nor the temporal features of the gakel-call and the duration of access to food. Possibly, the differences between treatments were not large enough to induce differences in frustration level. Also, other factors that might have influenced the motivation are discussed.

Pathophysiology of bit control in the horse.

Posted in: Welfare by admin on January 1, 1999 | No Comments

Responses of piglets to early separation from the sow.

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Behavioural effects of social mixing at different stocking densities in prepubertal lambs.

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Domestic animals' fear of humans and its effect on their welfare

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This review paper examines the issue of animal’s fear of humans and how it affects welfare. Sections include: the relationship between fear of humans and productivity; effect of aversive handling on fear and productivity; effect of gentle handling on fear and productivity; physiological effects of handling; effect of the stockperson on fear and productivity; effect of stockpersons’ attitudes; animals’ ability to discriminate stockpersons; and, solutions to fear of human problems. Differences among species are identified and discussed, including the sensory systems used and their ability to distinguish between people.

Clinical, biochemical, and hygiene assessment of stabled horses provided continuous or intermittent access to drinking water.

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The effects of weaning at 7, 14 and 28 days on piglet behaviour.

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Quantification of the pain and distress responses to castration in young lambs.

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Adrenocorticotropic hormone and cortisol in calves after corticotropin-releasing hormone

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One technique used to assess chronic stress in animals is to determine how responsive they are to a corticotropin-releasing hormone (CRH) or an adrenocorticotropic hormone (ACTH) challenge. This is a physiological means of mimicking a severe stress. Animals that have been chronically stressed should have the capacity to respond to such challenges with a larger release of the stress hormone cortisol. This study examined the dose of CRH needed for such a test and the time frame over which a response should be measured. The study was done with 12-wk old calves. Calves were injected with varying doses of CRH and their responses in terms of ACTH and cortisol were assessed over the next 5 hours. The cortisol concentrations between 20 and 90 min post-injection was predictive of the total release of cortisol following treatment. It is suggested that a challenge test should include several samples during that period of time.

Prevalence of severe welfare problems in horses that arrive at slaughter plants.

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