EVALUATION OF PROTEIN AND ENERGY QUALITY OF RENDERED SPENT HEN MEALS

This study evaluated three spent hen meals (SHM) that were produced in commercial rendering plants. The levels (percentage) of selected nutr ients (mean and range) in the meals were: CP, 64 (56 to 71); ash, 16 ( 12 to 18); lysine, 4.0 (3.6 to 4.3); methionine, 1.3 (1.2 to 1.4); cys tine, 1.1 (0.8 to 1.5). Protein efficiency ratios (PER; weight gain pe r unit of protein intake) were determined in chicks fed 10% CP diets c ontaining a SHM as the only source of dietary protein. The PER values for the SHM averaged 1.6 but varied from 1.1 to 2.2. An experiment was conducted using New Hampshire x Columbian chicks during the 7 to 20 d age period to determine the effect of substitution with either 7.5 or 15% of a SHM to a 21.5% CP corn-soybean meal diet. When substituted a t 7.5%, growth performance was not affected by two of the SHM but was depressed by the other one. Growth performance was decreased by all SH M when substituted at 15% of the diet. True amino acid digestibility a nd TMEn of the SHM were determined using the precision-fed cecectomize d rooster assay in which four roosters were crop-intubated with 30 g o f a SHM and excreta were collected for 48 h. True amino acid digestibi lity varied among SHM (P less than or equal to 0.05) and digestibility of cystine was substantially lower than digestibility of the other am ino acids. Mean TME, (kilocalories per gram of DM) of the SHM was 3.00 3 but varied by 44% among samples. The results of this study indicated that SHM has substantial nutritional value for poultry but the nutrit ional quality may vary greatly among samples.