Digestibility of raw soybeans in extruded diets for dogs determined by different methods

Abstract

The objective was to evaluate the coefficients of total tract apparent digestibility (CTTAD) and metabolisable energy (ME) of raw soybeans (RSB) in extruded diets for dogs by three methods (difference, regression and substitution). We also evaluated the urease and trypsin inhibitor (TI) activity, CTTAD, ME and faecal characteristics of adult dogs fed diets containing increasing RSB levels. Six dogs, distributed in a 6 Â 6 Latin square design, were fed extruded diets containing 0, 60, 120, 180, 240 or 300 g of RSB/kg. Urease and TI were reduced in all diets after extrusion (p < .01), but TI was not completely inactivated. The inclusion of RSB linearly reduced (p < .01) the digestibility of dry matter (DM), organic matter and crude protein (CP) and linearly increased (p < .05) the digestibility of fat and gross energy and the ME of diets. The CTTAD of DM, CP and fat, and ME of RSB, predicted by the substitution method were: 0.767, 0.758, 0.960 and 20.7 MJ/ kg, respectively. The dietary inclusion of RSB reduced faecal DM content and promoted a quadratic increase (p < .01) of pH and ammonia. Increasing RSB in diet reduced CTTAD estimate errors (p < .05). When 300 g of RSB were added per kg of diet, CTTAD of RSB estimated by the three methods did not differ (p>.05). The three methods can be used to determine RSB digestibility. Diet extrusion may not be able to completely deactivate the protease inhibitors present in the RSB. HIGHLIGHTS Extrusion may not be able to deactivate protease inhibitors of raw soybeans. Raw soybeans reduce nutrient digestibility of extruded diets in dogs. The substitution method is recommended to evaluate digestibility of raw soybeans.

Nutrient Digestibility of a Vegetarian Diet with or without the Supplementation of Feather Meal and Either Corn Meal, Fermented Rye or Rye and Its Effect on Fecal Quality in Dogs

“…Besides the general influence of the raw materials used and the processing, there are other factors influencing the digestibility of a diet. Several antinutritional factors in ingredients of vegetable origin could influence the digestibility [ 50 , 51 ]. Among others, in particular the high amounts of non-starch-polysaccharides of rye have an impact, particularly on the prececal digestibility in monogastric species [ 52 ].…”

Evaluation of Soybean Ingredients in Pet Foods Applications: Systematic Review

“…There were two cat digestibility experiments studying mixed-breed cats [9] and shorthair cats [10], and [9] contained studies on both dogs and cats. There were 40 dog studies with various breeds of dogs: purpose-bred dogs [11], mongrel dogs [12][13][14], mix-breed dogs [15], Spitz dogs [16,17], beagles [4,9,[18][19][20][21][22][23], Labradors [24], hound dogs [25,26], and a mix of breeds including Labrador, American Pit Bull Terrier, Weimaraner, Border Collie, Dachshund, and Great Dane [27]. The remaining three studies examined only processing of pet food or the analysis of soybean phytoestrogen concentration (soybean isoflavones) in dog foods, with no experimental animals used.…”

“…As we compared the nutrient digestibility data when different inclusion levels of soybean protein ingredients were fed to dogs, the DM and CP ATTD increased in some studies [18,26] with the increase of soybean ingredients in formulas; however, those digestibilities decreased in a greater number of studies [4,12,22,34,36] as the soybean inclusion level increased. The inclusion level above which the decrease in nutrient digestibility began varied by studies (14%, [36]; linear decrease, [12]; 48%, [22]; linear decrease, [4]; 5%, [34]). Marx et al (2015) studied the effects of soybean oil as a fat source at different levels in dry extruded dog food [27].…”

“…Soybeans contain antinutritional factors including trypsin inhibitors, urease [4], and oligosaccharides (raffinose and stachyose) [5], which may limit their use in pet food. However, most dry pet foods are produced using an extrusion process, and the heat processing deactivates most protease inhibitors [6].…”

Perspective Chapter: Technological Strategies to Increase Insect Consumption – Transformation of Commodities Meal and Oil into Food/Functional Ingredients

“…Vitamin B12 is only found in foods of animal origin [17]. Several of these characteristics are not present in plant sources [18][19][20][21]. In addition, projections indicate that the price of animal-derived meat and meals will increase steadily [22].…”