This investigation aimed to assess the appetite response changes of olive flounder to starving and re-feeding conditions. Three different feeding groups (2 weeks feeding, fed; 2 weeks starving, starved; and 1 week starving and 1 week feeding, re-fed) were established to examine the changes in appetite-related genes for each group. The weight gain of the fish was highest for the fed group and lowest for the starving group. Based on the daily feed intake (DFI) and cumulative feed intake (CFI), overall food intake was found to increase in the re-fed group more than in the fed group from week 1 to week 2 of the experiment. Hypocretin neuropeptide precursor (HCRT) and galanin receptor 1 (GAL-R1) mRNA expression in the brain of olive flounder were decreased in the starved group. Corticotropin-releasing hormone (CRH) was decreased in all experimental groups, except for the fed group. However, overall leptin concentrations in the plasma did not change across groups. Considering the differences between this study and previous studies on starving and feeding, various factors (except the production and expression mechanisms of appetite-related factors in response to starving) are likely acting on the appetite responses of the fish. In this study, a 1-week re-feeding period induced substantial effects on appetite response when compared to a 2-week feeding period. These findings show that even if re-feeding is performed after starving, the unbalance caused by the re-feeding can affect various physiological changes in fish by feed intake efficiency.

This study investigated the changes in appetite and behavior of cattle and pigs after foot-and-mouth disease (FMD) vaccination. This study involved ten calves and ten pigs, each divided into two groups of five animals. One group of each animal was vaccinated with an FMD vaccine (FMD-V), and the other group was used as a non-treated control (CON). Each animal’s appetite and behavior were observed before vaccination and for seven days post-vaccination. In the FMD-V groups, appetite and behavior scores during the seven days post-vaccination were significantly decreased compared to those in the CON groups. The only exception was the seventh day post-vaccination in the swine behavior scores.

The objective of this study was to investigate the effects of soy hydrolysate fractions on appetite suppression and ghrelin releasing. In a short-term experiment, the cumulative food intake and serum ghrelin level were decreased significantly (p<0.05) during a 4-hr period after the interperitoneal injection of soy hydrolysate fractions (0.5, 1 g/㎏ BW), following a 12-hr period of food deprivation. In a long-term experiment, food efficiency ratio (FER) was also reduced significantly (p<0.05), when soy hydrolysate fractions (0.5, 1% in drinking water) were given orally for 8 wks. Therefore, we found that soy hydrolysate fractions affected food intake through appetite and ghrelin releasing in short-term and long-term experiments. In conclusion, this study indicated that soy hydrolysate fractions would diminish the sensation of hunger by reducing the secretion of orexigenic factors such as ghrelin that send satiety signals to the brain, terminating food intake.

The purpose of this study was to measure the effects of food neophobia, nausea, and learned food aversion on food rejection and appetite. A total of 250 questionnaires were completed. Path analytic model was used to measure the relationships between variables. Results of the study demonstrated that the path analysis result for the data also indicated excellent model fit. The effects of food neophobia on nausea and food rejection were statistically significant. The effect of food neophobia on learned food aversion and appetite was not statistically significant. As expected, nausea had a significant effects on learned food aversion and appetite. Moreover, nausea played a perfect mediating role in the relationship between food neophobia and appetite. Nausea played a perfect mediating role in the relationship between food neophobia and learned food aversion. Learned food aversion played a partial mediating role in the relationship between nausea and appetite. Learned food aversion did not play a mediating role in the relationship between food neophobia and appetite. In conclusion, based on path analyses, a model was proposed of interrelations between variables. It should be noted that the original model was modified and should, preferably, be validated in future research.