Addition of chromium propionate in dog food: metabolic, immunological, and oxidative effects

Chromium is a trace element essential in metabolising carbohydrates, lipids, and proteins and is involved in other biological functions. Therefore, this study determined whether chromium propionate supplementation in dogs improves haematologic, metabolic, immune/inflammatory, and antioxidant biomarkers. A commercial product (Labex® Chromium) containing 0.4% chromium was used at 500 g/ton of food, which provided an additional calculated amount of 2 mg of chromium per kg of food. We used ten beagles divided into two treatments: the chromium group (supplemented with 0.380 mg of chromium/dog/day; T-CHR) and the control group comprised dogs fed a basal diet (no chromium supplementation). The experiment included two periods of 28 days, with an interval of 15 days, i.e. the dogs in the control group in the first period were in the chromium group in the second period (all dogs underwent all treatments in a crossover design). Dogs supplemented with chromium had higher serum mineral levels on days 14 and 28 (P ≤ 0.001). The group in the chromium group showed significantly higher numbers of total leukocytes and lymphocytes and concentrations of total protein, globulin, thio-proteins, and catalase activity in blood than the control group. Serum urea concentrations and TBARS (lipid peroxidation) were lower (P ≤ 0.05) in the chromium group. Tendencies towards lower concentrations of reactive oxygen species were observed on day 28 in the T-CHR group (P = 0.10). Chromium supplementation increased the concentration of cytokines in serum (tumour necrosis factor-alpha [TNF-α], IFN-γ, and IL-10) and C-reactive protein (P ≤ 0.05). Dogs in the chromium group had higher gamma globulin concentrations than controls (P ≤ 0.001). These findings suggest that supplementation with chromium propionate (2 mg/kg) in food positivity modulates metabolic, antioxidant, and immune indicators in dogs.

Practical diet with total replacement of fishmeal by soybean meal for Nile tilapia: growth performance and health effects

Abstract This study aimed to evaluate the growth performance and animal health in juveniles of Nile tilapia (Oreochromis niloticus) fed a practical diet with total replacement of fishmeal (FM) by soybean meal, as well the effect on survival, following pathogenic challenge with Aeromonas hydrophila. Two hundred juveniles of Nile tilapia were stored in 8 tanks (800 L). The experiment consisted of two treatments: a commercial diet formulated with FM (control) and a practical diet with total replacement of FM by soybean meal (SM). The variables of water quality, zootechnical and hematological parameters were measured. In addition, at the end of the experiment, the fish were submitted to a challenge with A. hydrophila. Higher cost per kg of fish was obtained in the control treatment (with FM). N retention was higher in fish fed a diet without FM, while hematological, immunological parameters and survival after the experimental challenge did not differ between treatments. It is possible to reduce dietary costs by replacing FM with SM without affecting growth performance or animal health, in addition to benefiting the environment by reducing the excretion of N in water.

Dieta prática com substituição total da farinha de peixe por farelo de soja para tilápia-do-nilo: desempenho de crescimento e efeitos na saúde

Resumo O objetivo deste estudo foi avaliar o desempenho de crescimento e saúde em juvenis de tilápia-do-nilo (Oreochromis niloticus) alimentados com dieta prática com substituição total da farinha de peixe (FP) por farelo de soja (FS), bem como o efeito na sobrevivência, após desafio patogênico com Aeromonas hydrophila. Duzentos juvenis de tilápia-do-nilo foram alojados em 8 tanques (800 L). O experimento consistiu de dois tratamentos: dieta comercial formulada com FP (controle) e dieta prática com substituição total do FP pelo FS. Foram mensuradas as variáveis de qualidade da água, parâmetros zootécnicos e hematológicos. Além disso, ao final do experimento, os peixes foram submetidos a um desafio com A. hydrophila. Maior custo por kg de peixe foi obtido no tratamento controle (com FP). A retenção de N foi maior nos peixes alimentados com dieta sem FP, enquanto os parâmetros hematológicos, imunológicos e a sobrevivência após o desafio experimental não diferiram entre os tratamentos. É possível reduzir os custos dietéticos substituindo a FP pelo FS sem afetar o desempenho do crescimento e a saúde do animal, além de beneficiar o meio ambiente ao reduzir a excreção de N na água.