Dietary Inositol Reduces Fearfulness and Avoidance in Laying Hens
Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK S7N 5A8, Canada
AB Vista, Marlborough, SN8 4AN, UK
Author to whom correspondence should be addressed.
Received: 8 October 2019 / Revised: 1 November 2019 / Accepted: 5 November 2019 / Published: 8 November 2019
Brain inositol is known to affect memory, and the incidence of depression, anxiety, and obsessive-compulsive disorder in mammals. Phytate, a naturally occurring inositol ester in plants, binds other nutrients, making them unavailable for digestion. The addition of phytase, the enzyme capable of hydrolyzing phytate, to diets increases the release of both inositol and nutrients for absorption in the chicken digestive tract. In this study, we assessed how dietary phytase or pure inositol affected laying hen behaviour, fearfulness, aggression, and stress levels. To increase the probability of seeing effects, hens were not beak treated and were fed two balanced protein levels differing in digestible amino acid sufficiency. Inositol did not affect stress levels, as measured by heterophil-to-lymphocyte ratio, or the number of hen comb or skin lesions. However, regardless of the source, pure inositol or phytase derived inositol reduced the number of feathers in the vent area, suggesting an increase in feather pecking. Pure inositol reduced fearfulness in laying hens, but phytase-derived inositol did not.