Alternativas nutricionais para prevenir a formação de bolas de pêlos em gatos

Abstract

The grooming habit is common in cats, so the intake of hair is inevitable. In this way, the formation of hairballs occurs naturally in this species and may eventually cause gastrointestinal disorders such as vomiting, dyschisis, constipation and intestinal obstruction. Currently the main ways to prevent this problem are the association of animal management and the increase of fiber content in the diet. This study aimed to evaluate the inclusion of an insoluble fiber, associated or not to a complex of proteases containing keratinase, to prevent the formation of hairballs in cats, observing the effects of the enzymatic complex on the digestibility and apparent metabolizable energy of the diet and fecal characteristics. The study was divided into two stages: pre-experiment and experiment. The pre-experimental phase was carried out with the purpose of evaluating the in vitro enzymatic activity of four commercial enzymes and selecting the one with the highest performance to perform the experiment with the animals. The activity of the enzyme chosen on the hair was also evaluated and its best performance conditions (concentration, pH, temperature and hydrolysis time) were determined. The experiment was conducted in randomized blocks (2 blocks x 4 diets x 3 replications per block), each lasting 57 d. The experimental diets consisted of: control (Co), low addition of insoluble fiber and without enzyme; Control with enzyme (Coenz); High Fiber (HF): with addition of 14.8% of sugarcane fiber and without enzyme; High Fiber with enzyme (HFenz). The metabolizable energy of feed was estimated according to its bromatological composition and the amount supplied was calculated individually according to the energy requirements for cats in maintenance. The consumption of each animal was measured daily. For each diet, it was determined the in vitro digestibility coefficients, the apparent digestibility (CDA) of the nutrients and the metabolizable energy (ME) through the total collection of feces, without collection of urine. For quantification of hairballs, the animals' feces were collected in four moments (at days -2 to 0; 15 to 17; 31 to 33 and 47 to 49). During the tricobezoars' collection and the in vivo digestibility test, the feces were collected, evaluated through the fecal score and weighed. The daily fecal production was calculated. In the in vitro test, the enzyme showed enzymatic activity over the hair in high concentrations. The temperature and pH of the enzyme showed the best activity were at 55ºC and 8, respectively. The dry matter's consumption was higher (P = 0.005) for diets containing high addition of sugarcane fiber. The ME intake did not differ (P = 0.068) between treatments. The enzyme's inclusion had no effect on the CDA of nutrients, gross energy (GE) and ME. The addition of high level of sugarcane fiber reduced (P<0.05) the CDA of all nutrients, GE and ME. The feces' production increased (P<0.05) with the inclusion of fibers. The fecal score did not differ between diets (P = 0.236). The feces's DM was the same (P = 0.918) for all diets. The addition of insoluble fiber and enzyme, separately, did not reduce the total mean number of excreted hairballs. However, when they were associated, a reduction in the total mean number of excreted hairballs was observed (P = 0.0344). There was no association between the size of excreted hairballs in relation to treatments (P = 0.3763).