Review: feed withdrawal and non feed withdrawal moult

Abstract

Moulting is a natural phenomenon in birds. Temperature variation and photoperiodic changes induce circadian and circannual rhythms, manifested by changes in the neural and endocrine systems, ultimately causing physiological processes resulting in a moult. The concept of induced moulting by feed deprivation arose during the early part of the 20th century as a solution to economic challenges of decreased egg production in commercial layer flocks toward the end of the first laying cycle as they approached the moult phase. Efficiency of feed removal programs in enhancing post moult productivity and economical feasibility insured a gain in popularity by the 1930′s. In 2003, more than 75% of all flocks were moulted in the U.S. However, moulting with feed withdrawal caused risk to the health of birds by impairing the immune system and increasing susceptibility to various pathogens, especially Salmonella enteritidis (SE). During the 1980s, increased incidence of gastroenteritis due to SE was linked to forced moulting. The importance of challenges for conventional forced moulting was realized and animal activists, welfare organizations, researchers, consumers, and producers realized that alternative moulting methods were necessary. Ultimately, the United Egg Producers Scientific Advisory Committee, having dealt with the issue of feed withdrawal for moulting since the early 1990′s, amended the Animal Husbandry Guidelines for U.S. Egg Laying Flocks to specify the use of non feed withdrawal moult methods after January 1, 2006. Furthermore, moulting hens would have to be fed nutritionally adequate and palatable food suitable for non-egg producing hens. Though metals or hormones are efficient moult inducers, results of studies showed that they had disadvantages like residual effects and physiological alterations, respectively. Diets supplemented with low nutritious feed ingredients are safe and demonstrate promising outcomes. Unconventional feedstuffs such as coconut meal and cumin seed meal are successfully used in layer and non feed removal moults in Asian and Middle Eastern countries. In the western U.S. (especially in California), local ingredients like safflower meal and tomato pomace are promising alternatives.

Keywords::

• feed withdrawal diets
• moulting
• non feed removal diets
• safflower meal
• tomato pomace