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Composition, digestibility and nutritive value of cereals for dogs

Authors:
  • Equine College, Finland, Ypäjä

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Most dry dog foods are based on cereals, but very little published information and few comparative studies are available on the nutritive value of various cereals in dogs. To determine the apparent nutrient digestibilities and feed values of five different autoclave-processed and ground cereals: oat groats, barley, wheat, corn and rice, a digestibility trial was carried out on twelve adult huskies ac-cording to a 6 × 4 cyclic changeover design. Total tract organic matter (OM), crude carbohydrate and gross energy (GE) digestibilities were higher in rice than in all the other cereals. Apparent crude protein (CP) and acid hydrolyzed fat digestibilities of rice (80% and 94%, respectively) were as good as for oat groats (81% and 93%). However, oat groats had higher OM, CP and GE digestibilities than barley, wheat and corn. The amount of digestible crude protein (118 g kg -1 DM) was higher in oat groats than in the other cereals. Digestible energy contents (MJ kg -1 DM) of oat groats, rice, corn, wheat and barley were 17.1, 16.0, 15.7, 15.6 and 15.5, respectively. The quantity of excreted wet faeces increased and the percentage of dry matter (DM) in faeces decreased when oat groats, barley, wheat or corn were supplemented to the basal diet, in contrast to rice, which had the opposite effect on wet faeces excretion. Oat groats are good substitutes for rice or other cereals in dry dog foods.
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... A study on dogs in which rye was added at 20%, as-is, to a basic diet found no differences in ATTD of crude protein or crude fat [54]. Dog foods containing other cereals have been observed to vary in digestibility of nutrients depending on carbohydrate source [55], with digestibility decreasing with increasing ber inclusion [56]. The difference in ATTD between diets in our study may also have been due to the rye meal being more coarsely ground than the wheat meal. ...
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Background Rye intake has been associated with beneficial effects on health in human interventions, possibly due to soluble dietary fiber in rye. In dogs, few studies have explored the effects on health of dietary fiber in general, and rye fiber in particular. The aim of this study was to investigate how inclusion of rye, compared with wheat, influenced fecal microbiota composition, short chain fatty acids (SCFA) and apparent total tract digestibility (ATTD) in dogs. Six male Beagle dogs (mean age 4.6 years, SEM 0.95 years; mean body weight 14.6 kg, SEM 0.32 kg) were fed three experimental diets, each for 21 days, including an adaptation period of six days. The diets were as similar as possible regarding energy and protein, but had different carbohydrate sources (refined wheat (W), whole grain rye (R), or an equal mixture of both (RW)) comprising 50% of total weight on a dry matter (DM) basis. The diets were baked and titanium dioxide was added for ATTD determination. Fecal samples were collected before and in the end of each experimental period. Fecal microbiota was analyzed by sequencing 16S rRNA gene amplicons and fecal SCFA by high-performance liquid chromatography. Crude protein, crude fat, neutral detergent fiber, and gross energy (GE) in food and feces were analyzed and ATTD of each was determined. Univariate and multivariate statistical methods were applied in data evaluation. Results: Microbiota composition, in feces, differed depending on diet (P=0.002), with samples collected after consumption of the R diet differing from baseline. This was primarily because of a shift in proportion of Prevotella, which increased significantly after consumption of the R diet (P<0.001). No significant differences were found for SCFA, but there was a tendency (P<0.06) for higher molar proportions of acetic acid following consumption of the R diet. The ATTD of crude protein, crude fat, neutral detergent fiber, and GE was lower after consumption of the R diet compared with the other diets (P<0.05). Conclusions: Consumption of the R diet, but not RW or W diets, was associated with specific shifts in microbial community composition and function, but also with lower ATTD.
... With use of the difference method, three studies with adult dogs have determined the digestibility of crude protein in extruded (14), whole-ground (15) or autoclaved (16) wheat. The apparent, totaltract, crude-protein digestibilities were 83, 81 and 78% of intake. ...
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... Although dogs and cats have no absolute dietary requirement for carbohydrates, most pet food manufacturers take advantage of their capacity of digesting them, and employ variable amounts of cereals, such as corn, rice, wheat, barley or sorghum, as well as cereal byproducts as a cheap source of energy, proteins, fiber and other nutrients, such as thiamine and niacin (FEDIAF, 2018c;Leung et al., 2006). The proportion of these cereals in the feed formulation can be up to 70%, although it is usual to be between 30 and 50% (Kempe et al., 2004). ...
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