Effects of six carbohydrate sources on diet digestibility and postprandial glucose and insulin responses in cats1

Abstract

The effects of diets with different starch sources on the total tract apparent digestibility and glucose and insulin responses in cats were investigated. Six experimental diets consisting of 35% starch were extruded, each containing one of the following ingredients: cassava flour, brewers rice, corn, sorghum, peas, or lentils. The experiment was carried out on 36 cats with 6 replications per diet in a completely randomized block design. The brewers rice diet offered greater DM, OM, and GE digestibility than the sorghum, corn, lentil, and pea diets (P < 0.05). For starch digestibility, the brewers rice diet had greater values (98.6%) than the sorghum (93.9%), lentil (95.2%), and pea (96.3%) diets (P < 0.05); however, starch digestibility was >93% for all the diets, proving that despite the low carbohydrate content of carnivorous diets, cats can efficiently digest this nutrient when it is properly processed into kibble. Mean and maximum glucose concentration and area under the glucose curve were greater for the corn-based diet than the cassava flour, sorghum, lentil, and pea diets (P < 0.05). The corn-based diets led to greater values for the mean glucose incremental concentration (10.2 mg/dL), maximum glucose incremental concentration (24.8 mg/dL), and area under the incremental glucose curve (185.5 mg.dL(-1).h(-1)) than the lentil diet (2.9 mg/dL, 3.1 mg/dL, and -40.4 mg.dL(-1).h(-1), respectively; P < 0.05). When compared with baseline values, only the corn diet stimulated an increase in the glucose response, occurring at 4 and 10 h postmeal (P < 0.05). The corn-based diet resulted in greater values for maximum incremental insulin concentration and area under the incremental insulin curve than the lentil-based diet (P < 0.05). However, plasma insulin concentrations rose in relation to the basal values for cats fed corn, sorghum, pea, and brewers rice diets (P < 0.05). Variations in diet digestibility and postprandial response can be explained by differences in the chemical composition of the starch source, including fiber content and granule structure, and also differences in the chemical compositions of the diets. The data suggest that starch has less of an effect on the cat postprandial glucose and insulin responses than on those of dogs and humans. This can be explained by the metabolic peculiarities of felines, which may slow and prolong starch digestion and absorption, leading to the delayed, less pronounced effects on their blood responses.

Substitution of wheat bran by corn gluten feed without steep water in cats feed

“…As to corn fibre, as in the present study, GUEVARA et al (2008) reported no differences in the weight of faeces from dogs that received a diet supplemented with this ingredient compared to animals fed with control diet. However, the moisture content of faeces from animals fed with corn fibre was less than that in the other animals' faeces, unlike what was observed in the present study, in which the median moisture content (66.3%) was slightly higher in the faeces, resulting in a faecal score below the desired value (score 3 according to de-OLIVEIRA et al, 2008). This result can be explained by the higher content of insoluble fibre in the diet, which in turn promoted increased water retention in the faeces.…”

“…The material collected was weighed, placed in plastic bags and stored in a freezer at -20ºC. Prior to collection, the faecal score was assessed according to the scale proposed by de-OLIVEIRA et al (2008), in which 1 corresponds to watery faeces and 5 to hard, dry and well-formed faeces. At the end of the experiment, faeces were thawed and faecal samples from each animal were homogenized and stored in a forced air oven at 65°C for 72 hours.…”

Replacing wheat bran by corn gluten feed without steep water in complete dog food

“…The complete foods were extruded, subsequently ground and then provided to the dogs with an added water ratio of 2:1 (water:food) in two daily meals at 8:00 am and 5:00 pm. The faeces samples were collected immediately after defaecation to determine their physicochemical characteristics using the following measurements: a consistency score according to de-Oliveira et al (2008), weight, pH (determined directly in the faeces using a 0.01 accuracy digital pH metre (model Q400A, QUIMIS, Diadema, SP, Brazil), buffer capacity (BC) (Zeyner et al 2004) and ammonia nitrogen (Preston 1995).…”

“…The differences in the solubility and fermentability of these fibres can provide different physiological benefits and affect faecal characteristics (de-Oliveira et al 2008;Calabr o et al 2012). Several outcomes were evaluated to determine the physicochemical characteristics of faeces, such as faecal production (Kawauchi et al 2011), faecal score (Laflamme et al 2011), pH (de-Oliveira et al 2008, buffering capacity (BC) (Zeyner et al 2004) and ammonia nitrogen (Brito et al 2010).…”

Influence of various carbohydrate sources on postprandial glucose, insulin and NEFA concentrations in obese cats

“…be important contributing factors influencing postprandial hyperglycemia in cats (de-Oliveira et al 2008). Therefore, the objective of this study was to investigate and evaluate whether different carbohydrate sources (corn starch, glucose, maltose, and trehalose) can influence the degree of induced hyperglycemia and postprandial glucose parameters [postprandial serum glucose, insulin and non-esterified fatty acid (NEFA) concentrations] in obese cats.…”