Meat and bone meal (MBM) is one animal by-product used in pets. This study purposed to provide information on MBM including either coarsely (MBMc) or finely (MBMf) ground with regard to diet digestibility and fecal characteristics in dogs. Three different levels of MBM (6%, 12% and 24%) of each grinding form (MBM6, MBM12 and MBM24) were added to a basic diet. Six Beagle dogs (body weight 16.7 kg ± 0.42) participated in a Latin Square experiment. Each trial began with the animals adapting to the food for a five-day period, followed by five days of fecal collection. The feed particle size had no effect on the apparent digestibility of organic matter, crude protein and crude fat. The fecal score was significantly affected by the particle size × level interaction among treatments (p < 0.0001). It was noted that the different particle sizes or levels of MBM as main effects had no significant effect on the fecal fatty acid concentrations. These findings suggest that using coarse or fine grinding even including MBM up to 24% in dog diets does not affect the apparent digestibility of protein nor fecal quality negatively in our experimental study.

Animal by-product meals show large variability in diet digestibility. This study aimed to provide information on including bone protein meal (BPM) or feather meal (FM) in extruded dog diets with regard to digestibility and fecal characteristics in two trials. In the first trial, compared to the control (BPM0), 6, 12, and 24% of the basic diets were replaced by BPM (BPM6, BPM12, and BPM24, respectively). In the second trial, in comparison to the control (FM0), 5, 10, and 20% of the basic diets were replaced by FM (FM5, FM10, and FM20, respectively). In both trials, six Beagle dogs (BW 17.3±2.14 and 18.1±2.04 kg for trials 1 and 2, respectively) participated in a crossover experiment design. Five days were used as wash-out before each experimental period for each trial. The fecal consistency scores were based on a 5-point scale (1 = very hard, 2 = solid, well formed “optimum”, and 5 = watery diarrhea). In the first trial, results showed that the apparent digestibility of dry matter, crude protein, and crude fat was significantly lower for dogs fed BPM6 compared to those fed BPM24. There was a lower number of dogs with a fecal consistency score value > 2 (16.7%) among those fed BPM6 (median = 2, Interquartile range (IQR) = 0) compared to those fed BPM24 (83.3%). The fecal dry matter content was significantly (p < 0.05) the highest (39.4%±2.15) for dogs fed BPM6. In the second trial, the data revealed that dogs fed FM0 had significantly (p < 0.05) the highest organic matter digestibility (87.2%±1.05), while dogs fed FM20 had significantly (p < 0.05) the lowest crude fat digestibility (95.0%±0.95). Inclusion of FM at 10% or 20% in the diet decreased fecal dry matter significantly (29.0%±2.10 and 27.9%±2.46, respectively) compared to those animals offered FM0 (31.1%±2.56). Among those dogs fed FM0 and FM5, there was a lower significant number of dogs with a fecal score value > 2 (16.7% and 16.7%, respectively; p < 0.05). While the fecal score was significantly a higher (median = 4, IQR = 0) for dogs fed FM20. Including FM at any level in the diet resulted in significantly higher levels of iso-butyric and iso-valeric acids compared to FM0. These findings in both trials suggest that apparent crude protein digestibility was not affected when diets containing BPM up to 24% and FM up to 20% were offered, but fecal quality was reduced.