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

Abstract

The objectives of this study were to compare the energy values of poultry by-product 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-month-old female beagles with an average body weight of 9.67 ± 0.52 kg were tested in a 5×6 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 days, comprising 4 days of dietary acclimation followed by 6 days of testing (including 3 day feeding period and 3 day 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, and heat production (HP) 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 O2 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 MJ/kg 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 dry matter 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 method and difference method 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%.

Evaluation of Effective Energy Values of Six Protein Ingredients Fed to Beagles and Predictive Energy Equations for Protein Feedstuff

“…The CP content of BD of 26.10% and the fecal score of 2.47 in this study were similar to those reported by El-Wahab et al of 22.00% and 2.39, respectively [83]. The crude protein content of the remaining test diets in the present study was all above 30%, and their fecal scores were higher than BD, which supports a positive correlation between canine fecal scores and dietary protein content [20,43].…”

“…The THP and HI of beagles were determined using the following equations [41]: where VO 2 was O 2 consumption, and VCO 2 was CO 2 production. To account for the effect of body weight on energy metabolism and respiration between animals, the data were converted to metabolic weight [20].…”

“…2 The difference between measured and estimated ME. 3 Predicted ME using NRC [20] equation. The NRC-recommended equation is ME (kcal/100 g) = (5.7CP + 9.4EE + 4.1 Carbohydrate) × (91.2 − 1.43CF)/100 − 1.04CP.…”

“…The difference method is more suitable for determining the nutrient digestibility and the effective energy value of single ingredients in vivo [29][30][31][32]. A 30% substitution ratio in the difference method in vivo has been shown to effectively assess the energy content of poultry by-product meal for beagles in our previous study [20]. Traditional protein sources in pet foods include poultry by-product meal, fish meal (FM), meat and bone meal (MBM), corn gluten meal (CGM), and soybean meal (SBM) [33][34][35].…”

“…Knowledge of the energy values and digestibility of ingredients is important to correctly balance pet food [ 19 , 20 ]. Current research on the effective energy value of pet food typically recommends the modified Atwater equation or predictive equations based primarily on fixed energy values and digestibility coefficients associated with the chemical composition of diets to estimate the metabolizable energy (ME) content of pet foods [ 20 , 21 , 22 , 23 ]. However, the equations do not apply to all ingredients and may overestimate the food energy of animals [ 24 , 25 ].…”