No abstract

The biomass productivity and nutrient composition of microalgae, such as Chlorella vulgaris, depend on the cultivation process and the nutrient content of growth media. Thus, in this study aimed to investigate the biomass productivity of C. vulgaris cultivated in fish and dairy cattle wastewaters. Thirty wastewater samples (2.5 L) were collected from system of production. Microalgae were cultivated in Erlenmeyer flasks containing 10 mL of microalgae and 1,790 mL of wastewater under constant light of 5,000 lux for 16 days at 25 ± 2.0 °C. Wastewater samples differed in composition. Biomass productivity was 47 % higher (P<0.0001) in dairy cattle than in fish wastewater, reaching 67.61 g m?3 day?1 (dry matter basis, DM) when compared by Student’s t-test (P<0.05). Cultivation media also had an effect on biomass chemical composition. The C. vulgaris grown in dairy cattle wastewater was higher in crude protein and ash contents (359.6 g kg?1 DM and 230.4 g kg?1 DM, respectively), whereas microalgae grown in fish wastewater had higher nitrogen-free extract content (347.8 g kg?1 DM). Crude fat content did not vary greatly (mean of 313.15 g kg?1 DM). The pH (8.0 – 8.7) and ammonia concentration (0.07 to 0.4 mg L?1) in fish wastewater was stable throughout the 16-day experimental period. In dairy wastewater, pH increased up (6.3 to 8.9) to the fourth day and remained constant thereafter, and ammonia concentration increased up (24.3 to 28.7 mg L?1) to the eighth day and then it declined (2.1 mg L?1). The C. vulgaris was successfully grown in both wastewaters, but productivity was higher in dairy cattle wastewater.

Grooming is a natural hygienic behaviour of cats that favours the formation of hairballs. Increased fibre concentration in the diets is a strategy to minimize hairball formation, but it is not fully effective. Because cat hair is formed mostly by keratin, the addition of keratinases in the diets might be an alternative for hairball control. Thus, the objective was to evaluate the effect of the combined use of sugarcane fibre and a protease complex to reduce the hairball excretion in cats. Twenty‐four adult cats were divided into four treatment groups (n = 6 per treatment) in a 2 × 2 factorial arrangement. Treatments were as follows: control diet (Control; containing low concentration of insoluble fibre, 5.34% of total dietary fibre), control diet plus enzyme (Co‐e), high‐fibre diet (HF; containing high amounts of insoluble fibre, 17.8% of total dietary fibre), and HF diet plus enzyme (HF‐e). Proteases from Bacillus licheniformis PWD‐1 were administered orally (5 mg/day) as gastro‐resistant capsules. Total collection of faeces was carried out to determine the number of excreted hairballs and the coefficient of total tract apparent digestibilities (CTTAD) of the diets. Separate addition of insoluble fibre (HF; p = .5947) or enzyme complex (Co‐e; p = .3633) had no effect on the hairballs excreted in the faeces. However, the combined use of insoluble fibre and enzymes (HF‐e) reduced (p = .0344) the total number of hairballs excreted. The size distribution of hairballs (small, medium, or large) was not affected by treatments (p = .3763). The CTTAD of crude protein was not affected by protease addition (p = .781) but was reduced by HF and HF‐e treatments. Sugarcane fibre associated to keratinolytic enzymes reduces the hairball excretion in cats. This strategy can be adopted for this purpose; however, methods for faecal hairball quantification must be improved. If you have not already completed a Copyright Transfer Agreement, please log on to Wiley Author Serivices, https://authorservices.wiley.com/bauthor/, sign‐in and complete the License Agreement form"

O objetivo foi avaliar o rendimento, a qualidade física e bromatológica de ração peletizada para coelhos após processamento e reprocessamento. Uma ração basal para coelhos foi fabricada, peletizada e peneirada, visando eliminar os finos gerados. Na sequência, esses finos foram integralmente reprocessados na peletizadora, para obtenção de nova ração oriunda de resíduo do peneiramento. O delineamento experimental foi inteiramente casualizado, com dois tratamentos (ração processada uma ou duas vezes) e seis repetições. De posse das duas rações obtidas após o peneiramento, ambas foram