Free availability of high-energy foods led to energy over-ingestion and protein under-ingestion in choice-fed broilers

Abstract

The objective of this study was to compare energy and protein content of the diet selected by choice-fed broilers with thatof broilers fed a balanced diet. One hundred and eighty 1-day-old male broilers were randomly assigned in groups of 10to one of three experimental treatments (n = 6). Control broilers were fed a standard balanced diet, whereas choice-fedbroilers were fed three foods which were more concentrated (Choice C+ treatment) or less concentrated (Choice C?treatment) in protein, carbohydrate or fat. We evaluated food intake behavior, nutrient intake, and performance param-eters of broilers from 2 to 7 weeks of age. Choice C+ broilers showed enhanced preference for the high-fat food, whichled to higher energy intake and lower protein intake than those of control broilers at 2 to 4 weeks of age. Body weight,weight gain and feed conversion efficiency were negatively affected by diet selection of Choice C+ broilers. Choice C?broilers selected a balanced diet, and showed performance parameters similar to those of control broilers. Our results supported the hypothesis that free availability of high-energy foods bias ingestive behavior of choice-fed broilers toward selecting a diet with higher energy and lower protein than needed for normal growth.