title: Evaluation of protein and energy quality of rendered spent hen meals.
abstract: This study evaluated three spent hen meals (SHM) that were produced in commercial rendering plants. The levels (percentage) of selected nutrients (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); cystine, 1.1 (0.8 to 1.5). Protein efficiency ratios (PER; weight gain per unit of protein intake) were determined in chicks fed 10% CP diets containing 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 at 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 SHM when substituted at 15% of the diet. True amino acid digestibility and TMEn of the SHM were determined using the precision-fed cecectomized rooster assay in which four roosters were crop-intubated with 30 g of a SHM and excreta were collected for 48 h. True amino acid digestibility varied among SHM (P < or = 0.05) and digestibility of cystine was substantially lower than digestibility of the other amino acids. Mean TMEn (kilocalories per gram of DM) of the SHM was 3.003 but varied by 44% among samples. The results of this study indicated that SHM has substantial nutritional value for poultry but the nutritional quality may vary greatly among samples.
authors.affiliation: Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
authors.forename: M W
authors.initials: MW
authors.lastname: Douglas
authors.forename: M L
authors.initials: ML
authors.lastname: Johnson
authors.forename: C M
authors.initials: CM
authors.lastname: Parsons
mesh_terms: D000375:Aging / Q000502:physiology; D000821:Animal Feed / Q000032:analysis / Q000592:standards*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000254:growth & development* / Q000378:metabolism / Q000502:physiology; D003545:Cysteine / Q000032:analysis / Q000378:metabolism; D004032:Diet / Q000592:standards / Q000662:veterinary*; D004044:Dietary Proteins / Q000378:metabolism / Q000494:pharmacology* / Q000592:standards; D004063:Digestion / Q000502:physiology; D002149:Energy Intake / Q000502:physiology*; D008239:Lysine / Q000032:analysis / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000032:analysis / Q000378:metabolism; D009753:Nutritive Value
chemical_list: D004044:Dietary Proteins; D008715:Methionine; D008239:Lysine; D003545:Cysteine