Voerbeperking en stress bij vleeskuikenmoederdieren (BDG.4896)
Project nummer:
bdg4896
Omschrijving van het onderzoek
Feed intake motivation of broiler parentstock reared under feed restriction is so strong during most of the juvenile phase that physiological and behavioural evidence of stress is present in all flocks. A definitive solution to this welfare problem should be sought in changing selection and breeding plans. On the short run relief can only be expected to come from husbandry adaptation, notably nutrition, feeding systems and management, based upon a better understanding of feed intake behaviour and its causative physiological backgrounds. For breeding purposes the definition of unwanted changes in this background, due to correlated response to selection, is essential as well. The project presented here is based on earlier studies with the objective to quantify feed intake motivation and stress in severely restricted juvenile female broiler parents, in comparison with ad libitum fed controls.
First, the so-called 'hungertest', that measures compensatory feed intake, and (physiological) stress parameters in broiler breeder females are further refined (objective 1).
After this new feeding and management systems can be judged with respect to the improvement of broiler breeder welfare. The effect of a more 'natural' feed intake pattern on broiler breeder welfare will also be studied. As a control, not only ad libitum fed female broiler parentstock will be used but also different breeds of broiler parentstock that are not so severly selected for food intake, e.g. parentstock that is used in organic farming systems (objective 2).
Finally, indicators of stress and hunger will be measured in different breeds, so that each breed can be judged based on their welfare (objective 3).
Resultaten van het onderzoek
First experiments revealed that physiological parameters can be used to measure stress in female broiler parentstock, but that it is difficult to separate metabolic and stress effects on the physiology. Behaviour, like stereotypic pecking and the level of activity, seems to be the most reliable indicator of chronic stress in broiler breeders. In addition, plasma corticosterone responses to acute stress seem to be an indicator of chronic stress, whereas baseline corticosterone concentrations, baseline body temperature and heart rate seem to reflect both stress effects as well as metabolic effects.
Special attention has been paid to the measurement of 'hunger'. The 'hungertest' is refined and can be used in future experiments to test new feeding systems or management systems.
In cooperation with the Research Institute for Applied Animal Husbandry, the effect of distribution of the food in the litter by using a so-called 'spinfeeder', and the effect of feeding several meals a day was determined. It turned out that distribution of food in the litter stimulates food searching behaviour in the litter whereas stereotyped object pecking is almost absent. There was little effect of meal feeding on behaviour of broiler breeders. Broiler breeders fed two meals a day instead of one meal were less active during the day. With respect to broiler breeder welfare, distribution of food in the litter seems to have positive effects because the birds are more active resulting in less health problems, and stereotyped pecking is almost absent in these birds.
Publications
- De Jong, I.C., D.A. Ehlhardt, S. van Voorst, J.H. van Middelkoop, H.J. Blokhuis. 2000. Effect of feeding system on behaviour and physiological indices of stress in restricted fed broiler breeders. Proceedings of the 21st World's Poultry Congress, Montral, Canada.
- De Jong, I.C., A. van Voorst, D.A. Ehlhardt, H.J. Blokhuis, 2001. Physiological differences between ad libitum and restricted fed broiler breeders: effects of stress or metabolism? In: Proceedings of the 6th European Symposium on Poultry Welfare, Switzerland.
- De Jong, I.C., A. van Voorst, J.H.F. Erkens, D.A. Ehlhardt, H.J. Blokhuis. Determination of the circadian rhythm in plasma corticosterone and catecholamine concentrations in growing broiler breeders using intravenous cannulation. Physiology and Behaviour: accepted for publication.
- Ehlhardt, D.A., A. Van Voorst, E.W. Ruesink, H.J. Blokhuis. Measuring hunger in restricted fed broiler parentstock pullets. Proceedings of the 21st World's Poultry Congress, Montral, Canada.
- Van der Haar, J., J.H. van Middelkoop, I.C. de Jong, A. van Voorst. 2000. Anders en vaker: op zoek naar goede voedering voor opfokvleeskuikenouderdieren. Pluimveehouderij 30: 8-10.
Gebruikers
De volgende bedrijven/organisaties zijn betrokken bij het project:
Nutreco
Epi Ross Poultry Breeders
Nederlandse Organisatie van Pluimveehouders
Storteboom BV
Projectleider
Dr. ir. H.J. Blokhuis
ID-Lelystad
Research Group Animal Welfare
Division of Animal Sciences
Postbus 65
8200 AB Lelystad
Onderzoeker:
Dr. ir. I.C. de Jong
i.c.dejong@id.wag-ur.nl
Status van het project
| Gestart | : 01-01-2000
|
| Einddatum | : 01-12-2002
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Trefwoorden
Fysiologie, gedrag, honger, stress, vleeskuikenouderdieren, welzijn.
Behaviour, broiler breeders, hunger, physiology, stress, welfare.
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