Results 2021

Abstract - The apparent dry matter digestibility of diets for rabbits was measured in vivo and in vitro with the Ankom DaisyII Incubator. Four diets were tested: low fiber (LF), LF + 5% of pregerminated fenugreek seeds (PGFS) (LF5), LF + 10% PGFS (LF10), and high fiber (HF). For the ADMDvv, feces samples were collected from 56 White New-Zealand x Californian rabbits fed the 4 diets; animals were randomly allocated into 4 groups and housed in individual cages. For the in vitro trial, 3 methods were tested: fecal inoculum (FA) with Kansans State buffer; fecal inoculum with artificial saliva (FB); and multienzyme (ENZ). Fecal inocula were collected at slaughtering from the distal colon of rabbits fed ad libitum the LF diet. For FA and FB methods, the digestibility was measured at 36 and 48 hours. The in vitro methods ranked the apparent dry matter digestibility of diets in the same order as in vivo, but ENZ values were always higher than FA and FB at 36 and 48 hours. The prediction equations of in vivo digestibility with the ENZ method showed higher coefficient of determination (R2 = 0.69) and lower SE (0.190) than FA and FB; also, reproducibility was higher with ENZ (CV = 3.1 %). In conclusion, different methods can be applied to the Ankom DaisyII Incubator to study the digestibility in rabbits. In our trial, the better reproducibility was observed with the multienzyme method than FA and FB were probably related to the variability of inocula. 

Abstract - During the last ten years, the worldwide interest in using insects as food and feed has surged. Edible insects fall within the category of novel foods, i.e., the category of food not consumed in significant amounts in the European Union before 15 May 1997 (the date of entry into force of Regulation (EC) No. 258/1997, later repealed by Regulation (EU) No. 2283/2015). One of the most promising insect species to be raised for food is the house cricket (Acheta domesticus). In this study, the rearing of a stock of house crickets was studied over a period of four months. The microbiological quality of the farm was studied using swabs on the surface of the rearing boxes to analyze the trend over time of different populations of microorganisms (total aerobic mesophilic microbiota, Lactobacillus spp., enterococci, Staphylococcus spp., Enterobacteriaceae, total coliforms, Pseudomonas

spp. and molds). The presence of four antimicrobial resistance genes (aph, blaZ, sul1, and tetM) was investigated by polymerase chain reaction. A production scheme was also developed in order to obtain a cricket-based flour, which was analyzed for its microbiological and chemical-centesimal profile. The results obtained in this study demonstrate that the contamination increases with time and that a proper management of the farming system for insects is of the utmost importance, as it is for conventional farm animals such as ungulates, poultry, and rabbits. The old-fashioned adage “all full, all empty” for the farming system summarizes the need for proper cleaning and disinfection of the structures at the end of each production cycle.

Abstract - Fresh mechanically deboned meat (MDM) is usually claimed as high-quality ingredient on dry pet food recipes and this aspect may positively influence consumer choice. It is important to determine the scientifically sustainability of this claim and to assess the microbiological safety of MDM inclusion in dry pet food. Objectives were: 1) to evaluate the effect of inclusion of MDM in dry dog food on fatty acid profile and in vivo and in vitro digestibility, proposing a new system (DaisyII Incubator) to measure the in vitro digestibility for dogs; 2) to compare palatability of dry dog food containing MDM with dry dog food in which meat by-products (MBP) are the only animal protein sources; 3) to determine, whether or not, the inclusion of that ingredient changes the microbiology and the storage quality. Results indicated that MDM product was characterized by significant higher nutritional value in terms of fatty acids profile, in vitro digestibility (HV-IVD method) and lower palatability than the MBP product. Microbiological risk assessment showed no microbiological hazards for either product. After 6-months storage, the total mesophilic bacterial count ranged between 1.77 and 2.09 log CFU/g feed, while polyamine values were higher in the MDM (0.37 g/kg) than in the MBP (0.27 g/kg). The DaisyII Incubator was found to be a valid instrument for studying in vitro digestibility also for dogs, providing data simply, quickly, with less variability and costs than in vivo trials. In conclusion, MDM inclusion in dry dog food is microbiologically safe and it can improve its nutritional quality, at the expense of a reduced palatability. The higher polyamine levels fount in MDM-enriched petfood after 6-months storage, however, may represent a possible hazard, and further studies are still warranted.