Cannibalism has become a serious problem in the poultry industry especially in ducks. Understanding
and controlling cannibalism is a crucial to duck production and welfare. Cannibalism causes detrimental effects on
welfare, physiology, and immunology resulting in abnormalities and impaired production performance of ducks.
Furthermore, the negative impact of cannibalism on ducks welfare has recently attracted increasing public
awareness and concern. Much information has been published on the effects of cannibalism on production
performance and physiological responses in ducks. In contrast, our knowledge of basic mechanisms associated to
the reported effects, as well as related to duck welfare exposed to cannibalism is in fact scarce. Several managerial
strategies have been conducted to counteract the deleterious effects of cannibalism in poultry, including bill
trimming. Bill trimming is used as a method of reducing the damage to feathers and skin caused by injurious
pecking in ducks. However, bill trimming also causes some welfare issues as trimming the beak results in pain and
sensory loss. This review presents the deleterious effects of beak trimming on beak morphology and structure,
physiological conditions, and production performance of ducks.