João Paulo Fernandes Santos

Increasing levels of zeolite and Yucca schidigera in diets for adult cats

The effect of the additives Yucca schidigera (YSC) and zeolite (clinoptilolite) on digestibility, fecal texture and odor, blood parameters and urine pH of domesticated felines was evaluated. The experiment was conducted in a randomized block design, with twenty-one cats, in two periods, distributed in seven treatments: moist commercial feed (control); control + 125, 250 and 375 ppm YSC; and control + 0.5; 0.75 and 1.0 % zeolite. No differences were observed between the diets regarding apparent digestibility coefficients of nutrient, energy, urine pH or blood parameters. However, levels of 0.5 and 0.75% zeolite were effective both in reducing odor (R2 = 96.39) and for fecal texture (R2 = 99.63), showing a quadratic pattern for these variables. Levels of 125 and 375 ppm YSC were also efficient in reducing fecal odor; however they did not adjust to regression. Levels of 0.5% and 0.75% zeolite significantly reduce odor of feces and increase fecal texture when added to commercial feed for cats.

Efeitos do extrato da parede de levedura na digestibilidade, no escore fecal e na palatabilidade de dietas para gatos

Para avaliar o efeito do extrato seco da parede de levedura (EPL) sobre a digestibilidade, o escore fecal e a palatabilidade de dietas para gatos, foram realizados tres ensaios experimentais. No primeiro, 20 animais adultos foram distribuidos ao acaso em quatro tratamentos: dieta comercial umida (controle) e dieta-controle + 0,2, ou dieta-controle + 0,4 ou dieta-controle + 0,6% de EPL na materia seca. No segundo, utilizaram-se alimento seco e as mesmas proporcoes com o mesmo delineamento do primeiro experimento. No ensaio 3, de palatabilidade, 20 gatos adultos receberam simultaneamente dieta comercial umida sem e com a inclusao de 0,4% de EPL. No experimento 1, nao foram observadas diferencas quanto a digestibilidade da materia seca, proteina bruta, extrato etereo, materia orgânica e energia bruta, assim como no escore fecal; no segundo, houve aumento linear (P<0,46) no coeficiente de digestibilidade da materia seca, e, no terceiro, observou-se efeito negativo da inclusao de 0,4% sobre a palatabilidade da dieta (P<0,004). Conclui-se que a inclusao de EPL em dietas umidas nao influi na digestibilidade, mas pode comprometer a palatabilidade, e que em dietas secas ha melhora da digestibilidade da materia seca.

Acidifying and yeast extract in diets for adults cats

This study evaluated the effects of adding an acidifying agent based on phosphoric acid (A), a yeast extract from a specific strain (Saccharomyces cerevisiae) (Y) and the combination of these two additives in food for adult cats. A test was conducted with 24 animals (mean 3.5 years old), mixed breed, weighing 3.72 ± 0.74 kg, kept in individual metabolic cages and distributed in a completely randomized design with a 2 × 2 factorial design (with or without A 0.6% of dry matter, with or without Y 1.5% of dry matter) totalling four treatments and six replicates of each condition. The experimental period was 15 days. The A or the Y reduced (P< 0.01) the dry matter intake, but the effect was not observed when they were associated. The association improved (P<0.05) the digestibility of dry matter and ashes. The A reduced urine pH (P=0.05) regardless of the presence of the Y. There was no effect (P>0.09) on other parameters evaluated. Results of this study show that the isolated use of 0.6% A or 1.5% Y in diets for cats is not recommended. However, the association of these two additives was beneficial in increasing nutrient digestibility.

Urinary acidifier in diet with high excess base for adult cats

Maintaining the pH of urine in the ideal range (6.2 - 6.4) is of great importance for health promotion in the lower urinary tract of cats. In the economic and standard feed sector this is a major concern, given that the animal urine tends to be alkaline after food consumption of those commercial segments, which predispose to the formation of struvite urolith. Therefore, this study aimed to study the effects of increasing levels of urinary acidifiers (0.0%, 0.3%, 0.6% and 0.9%, on a dry matter base) in feed with high excess base over the acid-basic balance in the organism, apparent digestibility coefficients of nutrients, urinary pH, hydro-electrolyte balance in cats, as well as the adequacy of equations proposed in the literature to estimate the urinary pH. Twenty-four adult cats, males and females were distributed in a completely randomized design, consisting of six animals per treatment. The dry matter content of urine presented a quadratic behavior (p 0.05). The equations proposed in the literature, which use excess of base in feed to estimate urinary pH, overestimated the pH values found in this study.

Inclusion of Yucca schidigera and zeolite in dog feed: influence on mineral excretion

This study aimed to evaluate the effects of adding Yucca schidigera and zeolite (Clinoptilolite) to feed (super premium and standard) for adult dogs on the apparent indigestibility coefficient of minerals. In the first assessment, 21 dogs were used, with average weight of 12.5kg±1.46 in seven treatments in two periods (super premium diet referred to as control and control with the addition of 125, 250, 375ppm Yucca schidigera and 0.5%, 0.75% and 1.0% zeolite). The second assessment was conducted with standard feed, using 21 experimental plots distributed in three treatments (standard diet referred to as control and control with the addition of 375ppm of Yucca schidigera and 1.0% zeolite). The additives did not affect the acceptability of feed and fecal characteristics in both assessments (P>0.05). With the exception of calcium, no minerals were affected by the inclusion of additives (P>0.05) in the experiment with super premium feed. In the assessment with standard feed, calcium as phosphorus and magnesium presented decreased excretion (P<0.05) with the inclusion of additives. It is possible to conclude that the inclusion of additives in the tested concentrations may interfere with the excretion of some minerals in the diet.

Efeitos da parede de levedura em dieta úmida na microbiota fecal, na produção de gás e na morfologia intestinal de gatos adultos

The aim of this study is to evaluate the effects of yeast extract (EPL) in the moist diet on the fecal microbiotal, gas production and intestinal morphology of adult cats. Twenty adult cats from both sexes were randomly assigned to four treatments: 1) moist commercial diet (control); 2) control + 0,2% yeast extract dry matter; 3) control + 0,4%; and 4) control + 0,6%. Fecal microbiology and intestinal morphology were performed by radiographic, ultrasound, colonoscopy and intestinal biopsy exams for histology. There were no significant differences (P>0,05) for lactic acid bacteria counts and clostridium-reductor, gas area in the bowel (radiographic), wall thickness of the colon (ultrasound) and colonocytes count/globet cells (histology). Through colonoscopy, changes in characteristics of the intestinal mucosa in animals receiving treatment 4 were noticed. It is concluded that the addition of up to 0.6% EPL had no effect on the parameters evaluated, but further studies are needed to understand the action mechanisms and additive effects for domestic cats.

Abnormal carbohydrate metabolism in a canine model for muscular dystrophy

The canine golden retriever muscular dystrophy (GRMD) model is the best animal model for studying Duchenne muscular dystrophy in humans. Considering the importance of glucose metabolism in the muscles, the existence of metabolic and endocrine alterations in a wide range of muscular dystrophies, and the pre-existing relationship between blood insulin concentration and muscular atrophy, the present study aimed to evaluate the postprandial glucose and insulin response in GRMD dogs. A total of eighteen golden retriever dogs were randomly distributed into three experimental groups: healthy/control (G1), female GRMD carriers (G2), and male dogs affected by GRMD (G3). Higher plasma resting glucose levels (P = 0·0047) were seen in G2 and G3 compared with G1, as was the case for minimum (P = <0·0001), mean (P = 0·0002) and maximum (P = 0·0359) glucose values for G3 compared with G1. Fructosamine concentrations were in accordance with reference values found in the literature for dogs. Insulin levels were lower in G3 compared with G1 (P = 0·0065); however, there was no evidence of insulin resistance according to the homeostasis model assessment index values obtained. As for the evaluation of postprandial responses, fluctuations of glucose (P = 0·0007) and insulin (P = 0·0149) were observed in G1 and G2, while in G3 the values remained constant. The results allowed us to identify metabolic changes related to carbohydrate metabolism in GRMD dogs, highlighting the importance of adequate food management for these animals.

Inclusion of Yucca schidigera extract in diets with different protein levels for dogs

This study evaluated the effects of inclusion of Yucca schidigera extract (YSE) in two diets with different levels of crude protein (CP) for dogs on facal odour, nutrient digestibility, ammonia concentration in feces and hematological and serum biochemical profiles. Twenty adults Beagles were used, distributed in a randomized block design in a 2 × 4 factorial design (two diets, 25% and 34% CP, and four YSE levels: 0, 250, 500 and 750 mg/kg) with five replicates, obtained during two experimental periods. The fecal odour reduced (P < 0.05) when 500 mg/kg of YSE was used in diets with higher CP. The inclusion of YSE reduced (P < 0.05) fecal ammonia, and the inclusion of 250 and 500 mg/kg YSE reduced intestinal gas. The inclusion of 750 mg/kg YSE increased the mean corpuscular hemoglobin (MCH), alanine aminotransferase (ALT) activity and tended to increase the serum cholesterol concentration, regardless of the protein level of the diets. There was no effect on the digestibility of nutrients, fecal consistency, nitrogen balance and thickness of the intestinal wall. The inclusion of 500 mg/kg YSE is effective in reducing fecal odour in dogs receiving diets with 34% of CP. Regardless of the protein content, YSE reduces fecal ammonia, but may cause adverse effects if included at higher doses.