Effect of dietary supplementation with insect fats on growth performance,digestive efficiency and health of rabbits

Background: The present work aimed at evaluating the effect of the dietary replacement of soybean oil(S) by two types of insect fats extracted from black soldier fly larvae(H, Hermetia il ucens L.) and yel ow mealworm larvae(T, Tenebrio molitor L.) on growth performance, nutrient digestibility, blood parameters, intestinal morphology and health of growing rabbits.Methods: At weaning, 200 crossbred rabbits(36 days old) were allotted to five dietary treatments(40 rabbits/group): a control diet(C) containing 1.5% of soybean oil and four experimental diets where soybean oil was partially(50%) or totally(100%) substituted by H(H50 and H100) or T(T50 and T100) fats. Total tract digestibility was evaluated on 12 rabbits per treatment. The growth trial lasted 41 d and, at slaughtering(78 days old), blood samples were collected from 15 rabbits per treatment, morphometric analyses were performed on duodenum, jejunum and ileum mucosa,and samples of liver, spleen and kidney were submitted to histological evaluation.Results: No difference was observed between the control and the experimental groups fed insect fats in terms of performance, morbidity, mortality and blood variables. The addition of H and T fats did not influence apparent digestibility coefficients of dry matter, protein, ether extract, fibre fractions and gross energy. Gut morphometric indices and organ histopathology were not affected by dietary inclusion of H and T fats.Conclusions: H and T fats are suitable sources of lipid in rabbit diets to replace soybean oil without any detrimental effect on growth performance, apparent digestibility, gut mucosa traits and health.

Assessment of chicken breast shelf life based on bench-top and portable near-infrared spectroscopy tools coupled with chemometrics

Objectives:Near-infra red(NIR)spectroscopy is a rapid technique able to assess meat quality even if its capability to determine the shelf life of chicken fresh cuts is still debated,especially for portable devices.The aim of the study was to compare bench-top and portable NIR instruments in discriminating between four chicken breast refrigeration times(RT),coupled with multivariate classifier models.Materials and Methods:Ninety-six samples were analysed by both NIR tools at 2,6,10 and 14 days post mortem.NIR data were subsequently submitted to partial least squares discriminant analysis(PLS-DA)and canonical discriminant analysis(CDA).The latter was preceded by double feature selection based on Boruta and Stepwise procedures.Results:PLS-DA sorted moderate separation of RT theses,while shelf life assessment was more accurate on application of Stepwise-CDA.Bench-top tool had better performance than portable one,probably because it captured more informative spectral data as shown by the variable importance in projection(VIP)and restricted pool of Stepwise-CDA predictive scores(SPS).Conclusions:NIR tools coupled with a multivariate model provide deep insight into the physicochemical processes occurring during storage.Spectroscopy showed reliable effectiveness to recognise a 7-day shelf life threshold of breasts,suitable for routine at-line application for screening of meat quality.