Influence of protein concentration and quality in a canned diet on urine composition, apparent nutrient digestibility and energy supply in adult cats

Abstract

BackgroundProtein concentration and quality in cat food can vary considerably, and the impact on feline urine composition and nutrient supply is of high practical relevance. In the present study, 6 canned diets with varying protein concentrations and qualities were fed to 10 healthy adult cats. Protein quality in the diet differed depending on the amount of collagen-rich ingredients. Hydroxyproline concentrations were 2.56–4.45 g/kg dry matter in the high quality and 3.76–9.44 g/kg dry matter in the low quality diets. Protein levels were 36.2, 43.3 and 54.9% in the high quality and 36.7, 45.0 and 56.1% in the low quality groups. Each diet was fed for 6 weeks, using a randomized cross-over design. In the last 2 weeks of each feeding period, urine and faeces of the cats were collected.ResultsRenal calcium (Ca), oxalate (Ox) and citrate excretion were unaffected by the dietary protein concentration, possibly mediated by a high urine volume (24.2–34.2 ml/kg bodyweight (BW)/day) in all groups. However, renal Ox excretion was lower when the high quality diets were fed (P = 0.013). Urinary relative supersaturation (RSS) with calcium oxalate (CaOx) was low in general, but reduced in the high quality groups (P = 0.031). Urinary RSS values for magnesium ammonium phosphate (MAP) were high (2.64–5.00) among all groups. Apparent digestibility of crude protein and most minerals was unaffected by the different diets. Feed intake was higher in the low quality groups (P = 0.026), but BW of the cats did not differ depending on dietary protein quality. BW of the cats increased with increasing dietary protein concentrations (P = 0.003).ConclusionIn conclusion, a high protein canned diet might not be a specific risk factor for CaOx urolith formation in cats. In contrast, all diets resulted in high RSS MAP values, which might be critical concerning MAP crystallization. Protein quality had a minor, but significant impact on urine composition, necessitating further research on this subject. A lower energy supply when feeding a low protein quality can be assumed. Changes in BW were only small and require a careful interpretation.Electronic supplementary materialThe online version of this article (10.1186/s12917-018-1517-x) contains supplementary material, which is available to authorized users.

Effects of crude protein and sodium intake on water turnover in cats fed extruded diets

“…A low urine volume may result in an increased solute concentration to excrete minerals and metabolic end products, with a possible decrease in the urination frequency, factors that, together, are suspected to favour the formation of crystals and calculi (Bartges & Kirk, 2006;Bargets & Callens, 2015). This relationship, however, is not fully established due the several causative factors that are suggested for this condition (Bartges & Callens, 2015;Bartges et al, 1999), as many other dietary factors also influence the urine volume, pH and chemical composition (Zentek & Schulz, 2004; Bartges & Kirk, 2012;Jeremias et al, 2013;Mendonça et al, 2018;Paßlack, Brenten, Neumann, & Zentek, 2014;Paßlack, Kohn, Doherr, & Zentek, 2018;Stevenson & Rutgers, 2006).…”

Amino acid nutrition and metabolism in domestic cats and dogs

“…In adult cats, the apparent digestibilities of CP were 91%–94%, 87%–88%, or 89%–90%, respectively, in a meat (a mixture of beef and mutton)-based diet containing 22% cornstarch, 14.3% corn, or 14.3% wheat grains, and were not affected by fine grinding or cooking [ 31 ]. Likewise, the apparent digestibilities of CP by healthy adult cats did not differ between two diets containing 36%–55% high-quality proteins (a high proportion of meat) and 37%–56% low-quality proteins (a low proportion of meat) (i.e., 89%–90% versus 88%–91%, respectively) [ 45 ], but most likely did not reflect the true digestibilities of the proteins due to microbial AA metabolism in the large intestine. However, the apparent digestibility of dietary CP was decreased in cats fed raw corn starch and raw potato starch compared with cooked foods [ 46 ].…”

Abrupt Dietary Change and Gradual Dietary Transition Impact Diarrheal Symptoms, Fecal Fermentation Characteristics, Microbiota, and Metabolic Profile in Healthy Puppies

“…It is well-known that feeding different diets to dogs and cats at different life stages is necessary to meet their nutrient requirements [ 1 ]. In other species, dietary changes often induce changes in nutrient digestion, absorption, growth performance, and the gut microbiota (GM) due to different dietary compositions [ 2 , 3 , 4 , 5 ]. A sudden dietary change often results in diarrhea in pets, but the underlying mechanism remains unknown [ 6 ].…”