Diet change could prevent overeating
Scientists at the University of Edinburgh have conducted a study which could improve poultry welfare, through the development of new diets.
Poultry farmers often have to restrict the food intake of chickens, as some birds are insensitive to feelings of fullness and can overeat, affecting productivity.
Researchers say they have identified how the genetic make-up of a chicken can affect signals sent from the stomach to the brain, telling the animal when it is full.
The study, which was carried out by the Roslin Institute at the university, focused on a protein called cholecystokinin (CCK), which has a key role in sending signals linked to fullness from the gut to the brain.
Research involved cross-breeding a fast-growing meat production strain of chicken, with a relatively slow-growing chicken. The researchers examined how the protein was processed in both types of chicken and the new cross-breed.
Researchers found that some birds were better equipped to recognise the protein, and those birds were more effective in triggering signals of feeling full. Findings also showed that reduced levels of the protein that recognises the fullness signal, also affected the chicken's natural body weight.
"The findings shed greater light on food intake in birds and help us understand why some breeds - in general the faster growing types of chickens - are more insensitive to feelings of fullness than others."
These findings, which have been published in the American Journal of Physiology, Endocrinology and Metabolism, support the theory that when poultry were domesticated thousands of years ago and bred for increased size, their appetites changed. This study could also help to inform research into appetite regulation in other animals.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
