New Ileal Digestibility Assay

A series of experiments were conducted at the University of Illinois to develop a precision-fed ileal digestibility assay for amino acids using 3-wk-old broiler chicks. Day-old Ross x Ross 708 broiler chicks were fed a standard corn-soybean meal starter diet until 21 d of age. In the first experiment, feed was removed and excreta were collected at 2, 4, 6, 8, 10, 12, and 14 h after feed withdrawal. Results indicated that 8 h of feed withdrawal was sufficient to empty the ileum of feed residues. In a subsequent experiment, chicks were fasted overnight for 10 h and then tube-fed various amounts (from 6 to 15 g) of a corn-soybean meal mixture (60:40). Ileal digesta were collected at various times between 3 and 7 h postfeeding. Results indicated that ileal amino acid digestibilities can easily be determined in 3-wk-old broiler chicks when using a precision-fed assay. The assay involves fasting chicks for at least 8 h before tube-feeding, precision-feeding approximately ten grams of feed and collecting ileal contents at approximately 4 hours postfeeding.

E. J. Kim, P. L. Utterback and C. M. Parsons. 2011. Development of a precision-fed ileal amino acid digestibility assay using 3-week-old broiler chicks. Poultry Sci. (90):396-401.