The aim of this study was to determine the influence of dietary supplementation with propolis and bee pollen on the intestinal morphology and absorptive surface areas of chickens. Two hundred day-old Ross 308 chickens (100 male and 100 female) were equally allocated into five groups. Throughout the whole study, the control group of chickens was fed with a basal diet, while the experimental groups of chickens were fed with the same diet supplemented with propolis and bee pollen: P1 = 0.25 g of propolis/kg + 20 g of bee pollen/kg; P2 = 0.5 g of propolis/kg; P3 = 1.0 g of propolis/kg; P4 = 20 g of bee pollen/kg. The duodenal villi of chickens from all experimental groups were significantly higher and wider (p < 0.001), while their duodenal villi crypts were significantly deeper (p < 0.001) in comparison with these parameters in chickens from the control group. The villus height to crypt depth ratio, as well as the absorptive surface areas of broiler chickens, were significantly increased (p < 0.001) in experimental groups of chickens in comparison with the control group. These findings suggest that dietary supplementation with propolis and bee pollen has a beneficial effect on broilers chickens’ intestinal morphophysiology.

Simple SummaryToday, there are increased demands for consumers to use natural products as alternative additives in broiler feeding. In this study, we evaluated the effects of propolis and bee pollen as potential new additives on liver pathology in broilers. The results of this study showed that supplementation of broilers with propolis and/or bee pollen has a strong protective effect on liver pathology. Thus, these natural agents can be used as alternative additives in modern broiler production. Such an approach will enable the production of chicken meat enriched with bioactive substances from propolis and/or bee pollen, such as flavonoids, that have been proven beneficial for human health.AbstractOne of the major problems in intensive breeding of chickens is liver damage. The objective of this study was to determine the influence of dietary supplementation with propolis and bee pollen on liver pathology in broiler chickens. The study was conducted on 200 Ross 308 chickens equally distributed by sex that were divided into five groups. Throughout the whole study, the control group of chickens was fed with a basal diet, while the experimental groups of chickens were fed with the same diet further supplemented with propolis and bee pollen, each supplement given separately or in combination in a certain proportion. The study showed that the clusters of lymphocytes in the hepatocytes, the vacuolar degeneration and necrosis of the liver parenchyma, the bile ductule hyperplasia, and the various forms of pathological changes in the liver arteries and veins were more frequent in liver tissue samples of the control group compared to liver tissue samples of all the experimental groups (p < 0.001). The study further showed that all the previously mentioned histopathological lesions of liver tissue were always more extensive in the liver tissue samples of the control group than in the liver tissue samples of all the experimental groups (p < 0.001). The supplementation of broiler chickens with propolis and/or bee pollen has a strong protective effect on liver pathology in broiler chickens.

The aim of this study was to determine the effect of propolis and bee pollen on selected biochemical blood parameters in broiler chickens. This experimental study was conducted on 200 Ross 308 chickens of equally distributed sex, which were divided into five groups (a control group and four experimental groups). Throughout the whole study the control group of chickens was fed the control feed mixture while the feed mixture that was fed to the experimental groups of chickens contained additives (propolis and/or bee pollen, each supplemented separately or in combination in a certain proportion). The results obtained by this study are: significantly lower blood glucose, cholesterol and calcium levels (P < 0.001), as well as significantly lower triglycerides levels (P = 0.002), but also significantly higher sodium and chloride (P < 0.001), phosphorus (P = 0.004) and globulins levels (P = 0.027) in chickens of the experimental groups compared to the chickens of the control group on the 21st day of fattening. Furthermore, this study has found significantly lower blood glucose (P = 0.033) levels and significantly higher levels of total proteins and globulins (P = 0.003), as well as albumins (P = 0.040) in chickens of the experimental groups compared to the chickens of the control group on the 42nd day of fattening. It can be concluded that the application of propolis and bee pollen as additives in broiler feeds enables the production of more vital and healthier animals, which significantly improves the fattening of chickens.

Across the world, as well as in Croatia, there is a continuous increase in the consumption of chicken meat, and attempts are being made in modern poultry production to improve its quality as much as possible by using various natural additives. The aim of this study was to determine the influence of dietary supplementation with propolis and bee pollen on the quality of chicken meat. In order to determine this effect, the carcass body weight of slaughtered chickens and carcass yield were determined, as well as the average pH1 and pH2 of chicken breast muscle, drip loss values, and skin color and chicken breast muscle color expressed as values of L* (lightness), a* (redness), and b* (yellowness). The study was conducted on 200 Ross 308 chickens, divided into five groups. Throughout the study, the control group of chickens was fed with a basal diet, while the experimental groups of chickens were fed with the basal diet supplemented with propolis and bee pollen, each supplement given separately or in combination in specific proportions. At the end of the experiment (42nd day), 10 chickens from each group were slaughtered for the analyses mentioned above. The carcass yield values were significantly higher (P = 0.038) and the drip loss values were significantly lower (P = 0.003) in the experimental groups in comparison to the control group. In addition, there was a statistically significant difference in b* skin color (P = 0.017) and b* chicken breast muscle color (P<0.001) between the groups of chickens. The study showed that dietary supplementation with propolis and bee pollen has a significant positive effect on the quality of chicken meat.

Background Following the increased internet use due to the COVID-19 pandemic there have been concerns regarding an elevated risk of developing internet addiction (IA). University students are especially prone to develop IA and risk factors for its development in this population during pandemics are not fully investigated nor understood. This study aimed to identify possible risk factors of IA in the studied population during the ongoing pandemic and to compare it with risk factors in pre-pandemic time. Methods In April 2016 and April 2022 a validated, anonymous questionnaire that contained questions regarding demographic data, as well as Young's Internet Addiction Test, was self-administered to a cross-faculty representative student sample of the University of Osijek, Croatia. Results The study included 1602 university students median age of 21 years (interquartile range 20-22), 34.5% males, and 65.5% females. There was no statistically significant difference in the median age between the two student samples (p = 0.234). The main reason for internet use (social networking and entertainment and online gaming) was considered the significant risk factor for IA in a studied population in pre-pandemic time (the year 2016) and pandemic time (the year 2022) (p &lt; 0.001). In pre-pandemic time the IA was more frequent in males (p = 0.046) while the difference in IA prevalence between sexes did not exist during pandemics (p = 0.160). During pandemics, the students who did not work during their study had higher proportions of IA (p = 0.021) while there was no difference in IA prevalence among students regarding their working status during the study in pre-pandemic time (p = 0.251). Conclusions During the COVID-19 pandemic working status of students has been recognized as the new risk factor for IA in the Croatian university students population. Further studies are needed to identify other possible risk factors for IA in the studied population during pandemics. Key messages