Although fumonisins are identified as responsible for alterations in weight gain, little information is available on their effects on expression of growth-related genes, especially for Nile tilapia (Oreochromis niloticus) fingerlings. In this study, Nile tilapia fingerlings were treated with increasing levels of fumonisin B₁ (FB₁) and fumonisin B₂ (FB₂) (diets of 0, 20, 40, and 60 mg/kg) to evaluate their effects on weight gain (WG), feed intake (FI), feed efficiency (FE), growth hormone receptor (GHR) and insulin growth factor 1 (IGF-1) mRNA expression in liver of this fish. All variables were evaluated at 15 and 30 days of treatment. Diet containing 0 mg fumonisin/kg was used as control treatment. Treatment with 20, 40, and 60 mg fumonisin/kg of diet significantly reduced WG (P<0.0001) and FE (P<0.0001), while GHR and IGF-1 mRNA expression was reduced both at 15 and 30 days of treatment. Feed intake was not affected by diets in any of the evaluated periods. These results indicate that fumonisins (FB₁ + FB₂) affect the growth of Nile tilapia fingerlings through mechanisms that involve reduction of GHR and IGF-1 expression.

Chemical composition and physicochemical and mechanical parameters of New Zealand White rabbit tanned skin were evaluated. Skin samples from 70-d-old males, in natura and semi-finished, were collected for evaluation. The in natura treatment comprise skins without any processing, while semi-finished treatment comprise skins after soaking, fleshing, liming, de-liming, purging, degreasing, pickling, tanning, neutralising, re-tanning and dyeing, followed by oiling, drying, stretching and softening. After tanning, samples from the dorsal and flank regions were removed for tensile and physicochemical testing in the longitudinal and transverse directions. A split plot design was used with plot treatments (leather regions: R1=dorsal and R2=flank) and subplots directions (S1=longitudinal and S2=transversal), using 10 examples per treatment. At the end of processing, the leather analysis revealed low moisture (31.76%), protein (46.48%) and fat content (24.95%), and a high ash content (8.58%). Leather presented a pH of 4.9 and contained 2.0% chromium oxide, 25.5% extractable substances in dichloromethane, and these characteristics were coupled with a higher tensile strength (10.84 N/mm2) in the dorsal region. However, samples in the same region proved to have higher elasticity (64.57%) in the longitudinal direction, although there was no difference in the progressive tearing analysis (21.07-23.50 N/mm). Overall, our analyses suggest that, in this case, the tanned leather product does not have sufficient resistance for application in clothing production.