Comparison of methods for the effective evaluation of the energy content of poultry byproduct meal for beagles

Lay Summary The scale of the global pet food market is expanding daily, but there are relatively few evaluations that have been performed on many of the common ingredients in pet food recently. This study compares direct, difference, and regression methods of evaluating the effects of the energy values of poultry byproduct meal (PBM), which is commonly used in beagle foods. Beagles were fed five diets containing different proportions of PBM, and the effects on diet quality were compared. The direct evaluation method enabled relatively accurate assessment of the energy value of PBM but could cause diarrhea in the test dogs. Different proportions of PBM significantly affected the results, and the difference method identified feed with 30% poultry meal as optimal. The regression method effectively determined the digestible energy and metabolizable energy values of the various tested levels of PBM. The difference method performed best in evaluating the energy values of beagle feed, and a diet consisting of 30% PBM was determined to be optimal. The ratio of poultry byproduct meal (PBM) added to pet food for beagles significantly affects dogs' digestion, absorption, and energy utilization. The difference method of evaluating the energy value of PBM in beagle food is effective, and it is recommended for use in evaluating protein sources in dog food. The objectives of this study were to compare the energy values of poultry byproduct meal (PBM) as feed for adult beagle dogs using the direct, difference, and regression methods to examine dogs' nitrogen metabolism, energy utilization, gaseous metabolism, and body health. Five groups of six 12 mo old female beagles with an average body weight of 9.67 +/- 0.52 kg were tested in a 5 x 6 incomplete Latin square design, with six repetitions in each group. Five experimental diets were tested consisting of 100% PBM; three substitution diets containing either 15%, 30%, or 45% PBM (termed 15PBM, 30PBM, and 45PBM, respectively); and a basal diet (included 6.90% PBM). Each experimental period lasted for 10 d, comprising 4 d of dietary acclimation followed by 6 d of testing (including 3 d feeding period and 3 d fasting period), during which the heat production (HP) was determined and feces and urine were collected. Results showed that, in the feeding state, the nitrogen intake, urinary nitrogen, apparent nitrogen digestibility, retained nitrogen, andHP increased significantly (P < 0.05) as the PBM level increased. The net protein utilization, biological value of protein, and total apparent digestibility of amino acids did not differ between the 30PBM and 45PBM diets (P > 0.05). The O-2 consumption and CO2 production of beagles during the fasting period were not influenced by the PBM level (P > 0.05). The digestible energy and metabolizable energy values of the PBM estimated by the regression method were 20.16 and 18.18 MJ/kg dry matter (DM), respectively, and did not differ from those determined by the direct method (P > 0.05). The fecal DM percentages and fecal PBM scores were significantly higher in the PBM diet than in the difference method groups (P < 0.05). The direct method group had a significantly higher fecal score (4.63) than the other groups (P < 0.05), The fecal score of the 45PBM diet (3.50) was significantly higher than the 30PBM diet (2.90; P < 0.05). In summary, the direct and difference methods of determining the effective energy value of PBM for beagles, produce significantly different results. Under the conditions of this test, the best proportion of PBM in beagle feed for optimum energy provision is 30%.