title: Effect of a low protein diet on the energy metabolism of growing chickens.
abstract: Two slaughter experiments were carried out to determine whether the protein content of the diet has an influence upon the efficiency of utilization of ME in fast growing chickens. A normal-protein diet (NPD, 204 g CP/kg DM: 14.7 MJ ME/kg DM) based on soybean meal as the sole source of protein was given at four different levels of intake (ad libitum or restricted at about 90, 65 and 40% ad lib) to 10-d-old animals for 2 weeks. In a parallel experiment the chickens were fed ad libitum a low protein diet (LPD, 66 g CP/kg DM: 15.0 MJ ME/kg DM) based on soybean meal. The intake of metabolizable energy ranged from 1675 to 777 and 1770 to 832 kJ/kgW0.75 per day for NPD and LPD treatments, respectively. Mean values of energy retention, gross efficiency of energy utilization and energy retained as protein were significantly (P < .05) lower and heat production (expressed as both kJ/kgW0.75 per day and kJ/kg body protein content0.75 per day) was significantly higher (P < .05) for the chickens fed on LPD. These findings support the concept of dietary-induced thermogenesis in response to reductions in dietary protein concentration. It is concluded that the increased heat production found in the birds fed on the low-protein diet can be explained by both an increase in energy requirements for maintenance (MEm) and a sharp decrease in the efficiency of utilization of ME of growth (k(g)).
authors.affiliation: Estación Experimental del Zaidin, Department of Animal Nutrition, Granada, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Nieto
authors.forename: J F
authors.initials: JF
authors.lastname: Aguilera
authors.forename: I
authors.initials: I
authors.lastname: Fernández-Fígares
authors.forename: C
authors.initials: C
authors.lastname: Prieto
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D002645:Chickens / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D018753:Diet, Protein-Restricted / Q000662:veterinary*; D004044:Dietary Proteins / Q000494:pharmacology*; D004435:Eating / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D008297:Male; D012044:Regression Analysis; D015430:Weight Gain / Q000502:physiology
chemical_list: D004044:Dietary Proteins