Brain alterations, their impact on behavior and breeding strategy in Crested Ducks (Anas platyrhynchos f. d.)

作者：Mehlhorn Julia^*; Rehkaemper G

来源：Archiv fur Geflugelkunde, 2010, 74(3): 203-209.

• Crested Duck
• locomotion incoordination
• brain composition
• intracranial fat body
• righting test
• breeding strategy
• cerebellum

Crested Ducks (CR) are widely bred by poultry fanciers and are in focus of animal welfare activists, because they show occasionally intracranial fat bodies, incoordination of locomotion and high pre- and postnatal mortality. Here, it is shown that 24 of 26 CR bear such a fat body, but with a high variability in size (0.3% to 41% of total brain volume). A large fat body could hold responsible for motor incoordination, thus fat body size seems to be a decisive factor. A behavioural test helps to identify CR bearing a problematical fat body. Therefore, ducks were put on their back and time required to stand up was measured. The appropriateness of this test has been proven in a special breeding program. To investigate the influence of fat bodies on brain composition, an allometrically comparison of 26 CR brains with those of three uncrested duck breeds was done.
Ten CR exhibited suboptimal motor coordination. CR with motor incoordination showed significantly larger fat bodies and needed significantly more time in the test than "normal" CR. Total brain volume was significantly larger in CR, but brain volume minus fat body was significantly smaller compared to reference breeds. Cerebellum, apical hyperpallium, tegmentum and olfactory bulb were significantly reduced in CR. Obviously, the behavioural deficits cannot be explained by the existence of a fat body but by functionally suboptimal cerebella and tegmenta. The relationship between fat body and reduced structures was discussed.
A breeding experiment with test selected ducks resulted in increased hatching rate, decreased number of (un-hatched) ducklings with skull malformations and as well decreased number of (hatched) ducks with malformations or motor incoordination. Thus, this study could be conducive to overcome the criticism of animal welfare activists without eliminating this old and traditional breed.

• 出版日期2010-7