When provided a choice, broilers may innately select diets for long-term survival rather than economic benefits. In a Virginia Tech study, intense selection for growth and feed efficiency to market weight did not rule out the chickens’ ability to discriminate among diets, according to geneticist Paul Siegel, who made a presentation at the Midwest Poultry Convention last month.
Breeders have emphasized enhanced feed efficiency in the development of commercial meat and egg poultry, he noted.
“There has been criticism in some quarters that these highly selected chickens have difficulty in making dietary choices unless the diets are deficient in specific nutrients. We wished to test this thesis and took broilers from three genetic stocks known to differ in growth potential and fed them either a single diet or a choice of two diets that differed in protein and energy.”
The choice diets were formulated so that when mixed in specific proportions they provided a single diet with recommended levels of protein and energy to enhance growth and feed efficiency (both weight/feed consumed).Broilers fed the single diet were heaver with enhanced feed efficiency and more breast meat and less fat than those provided choice diets. There was no difference between groups in immunocompetence as measured by response to sheep red blood antigen.
Breeders have emphasized enhanced feed efficiency in the development of commercial meat and egg poultry.