Influence of Body Composition, Methionine Deficiency or Toxicity and Ambient Temperature on Feed Intake in the Chick

Abstract
Three studies were conducted to investigate the effect of methionine deficiency or toxicity, initial body composition and temperature on voluntary food consumption and body weight gain of chicks. Either a deficiency or an excess of methionine depressed both the amount of food consumed and body weight gain. Chicks maintained at a low temperature, regardless of their initial body composition, were able to increase both their consumption of a low methionine diet and their weight gain. Obese chicks consumed significantly less food than their nonobese counterparts, regardless of the ambient temperature or the methionine content of the diet. Similarly, the growth rate of the obese chicks was lower than that of the nonobese ones fed the same diet. Obese chicks fed an adequate methionine diet tended to consume nearly normal amounts of food, gain weight, lose their body fat and return to a normal body composition within approximately 2 weeks. The body composition appeared to exert an important role in regulating the voluntary food intake of the chick.