2022, Kowalska, Joanna, Homska, Natalia, Hoffmann, Lilianna, Rawski, Mateusz, Czyżak-Runowska, Grażyna, Konieczny, Piotr, Kierończyk, Bartosz, Mazurkiewicz, Jan

Abstract The aim of this study was to evaluate the effects of carrot pomaces dried at two temperatures as a feed component on growth performance, environmental sustainability, and meat quality in common carp (Cyprinus carpio). Three diets were developed: a control without pomace (CON); CPL with 15.5% carrot pomace dried at 40°C and CPH with 23.6% carrot pomace dried at 120°C. A total of 240 two-year-old common carp (average body weight of individual: 1025 g) were randomly distributed into 12 tanks, four per treatment, including 20 fish per tank. The experiment was performed using an outdoor open flow aquaculture system. The growth trial lasted 60 days, after which fish samples were taken for analysis of meat quality parameters. There were no significant differences between groups in terms of the final body weight, protein efficiency ratio, or survival rate. However, in terms of weight gain, specific growth rate, and feed conversion ratio, fish fed the CPH diet exhibited significant worsening. Moreover, the fillets of fish from the CPH group exhibited a darker coloration compared to the CON diet. It is concluded that high temperature drying of carrot pomace added to carp diet negatively affected fish quality. It should be also emphasized that inclusion of the both carrot pomaces tested in this study significantly increased the usage of fish meal per kilogram of fish body weight gain. These results showed a reduced efficacy of using carrot pomace in practical and sustainable common carp nutrition.

2022, Homska, Natalia, Kowalska, Joanna, Bogucka, Joanna, Ziółkowska, Ewa, Rawski, Mateusz, Kierończyk, Bartosz, Mazurkiewicz, Jan

The ide (Leuciscus idus) is a native European species of rheophilic cyprinid fish whose wild population status is dependent on conservation efforts, particularly regular restocking. This study aimed to evaluate the effects of including insect meals as a component in the diet of ide juveniles on their growth performance, feed utilization, and nutriphysiological status. Four diets were formulated: three with insect meals, HI–with 20% Hermetia illucens meal, TM–with 20% Tenebrio molitor meal, and ZM–with 20% Zophobas morio meal, and the control group diet, CON–fish meal with no insect component. The effects of the various diets on the efficiency of rearing ide juveniles were assessed based on fish growth parameters, feed utilization parameters, somatic indices, and intestinal and hepatopancreatic histomorphology. The highest increase in fish weight gain and the protein efficiency ratio was observed in the HI and TM groups, while the lowest values were observed in the CON and ZM groups. Comparable results were noted for the feed conversion ratio, which was most favorable in the HI and TM groups and increased in the ZM group. The use of black soldier fly and mealworm larval meal in the diets of ide juveniles had a positive effect on rearing results and overall fish health.

2022, Mazurkiewicz, Jan, Wiśniewski, Marcin, Rawski, Mateusz, Florczyk, Krzysztof, Banaszak, Jan, Homska, Natalia, Kowalska, Joanna, Zakęś, Zdzisław, Demska-Zakęś, Krystyna

2022, Kowalska, Joanna, Rawski, Mateusz, Homska, Natalia, Mikołajczak, Zuzanna, Kierończyk, Bartosz, Świątkiewicz, Sylwester, Wachowiak, Roksana, Hetmańczyk, Katarzyna, Mazurkiewicz, Jan

Abstract Insect meals are sustainable alternative protein sources in animal nutrition. However, the data on their application in petfood and ornamental fish nutrition are scarce. Thus the present study was undertaken to assess their usability in guppy (Poecilia reticulata) diets. The first experiment aimed to investigate the attractiveness of select insect meals for guppies, and the second evaluated superworm (Zophobas morio) meal monodiet effects. The first experiment (free-choice feeding test) lasted five days. Fish were given a choice between four attractants: fish meal, black soldier fly (Hermetia illuces) meal (HI), Madagascar cockroach (Gromphadorhina portentosa) meal (MC), and superworm (Zophobas morio) meal (ZM). The preliminary part of the study showed that the most frequently chosen attractant throughout the entire free-choice feeding test period was ZM. Based on the obtained results, the second part of the study was designed as a growth test with the use of a ZM monodiet compared to commercial feed. The experiment lasted 90 days, and 150 guppy fry were used. The fish were randomly divided into two groups (CON – commercial feed, ZM – Zophobas morio meal). No effects of dietary treatment were found in terms of survival rate, fish body length, or fish body length gain. The present study shows that ZM was the most preferred attractant and that a monodiet based on insect meal can be successfully applied in guppy fry nutrition.