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A review on fish in vitro digestion studies
55-63Views:4(1) Background: In vitro experiments in fish have been developed to search for dietary substitutes of fish meal in aquafeeds by measuring the digestibility of various feedstuffs by simply simulating the conditions of the stomach or portions of the digestive tract. In vitro digestion studies involving mainly commercial fish species have been conducted to determine the digestibility of conventional and alternative ingredients in fish diets using diverse digestion models. However, there remains a significant knowledge gap, particularly regarding the enzyme functionality, digestion mechanisms in many fish species, and the factors influencing enzymatic activity. This review article is focused on the importance of the use of different enzyme sources in the in vitro digestion model to predict protein hydrolysis.;(2) Methods: For this review, a comprehensive analysis of articles was conducted to gain insights into diverse enzyme interactions and feed evaluation assessments, from the nutritional science and biotechnology sector.; (3) Results: A total of 36 peer-review papers, which include original, and review articles were selected.; (4) Conclusions: In vitro digestion studies offer a valuable tool for evaluating the digestibility of conventional and alternative feed ingredients, helping to identify sustainable dietary substitutes for fish meal while reducing dependence on live animal trials.
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Evaluation of the optimal temperature for digestive protease function in the hybrid catfish Clarias gariepinus × Heterobranchus longifilis
65-70Views:12(1) Background: Water temperature is a key determinant of fish digestion. In vitro methods provide a reliable approach to assess enzyme activity, which is especially important in carnivorous catfish with protein-rich diets. Although the hybrid catfish Clarias gariepinus × Heterobranchus longifilis is widely farmed in Hungary, its optimal temperature for maximizing digestibility remains under investigation.; (2) Methods: Fish were reared at 23 ºC, 25 ºC, and 27 ºC, and stomach and proximal intestine content samples were collected, and it was determined the protease activity (3) Results: No statistically significant differences were observed in enzyme efficiency, crude protease activity (p > 0.05). Despite not significant differences, the stomach and intestinal, protease activity tended to be higher at 25 °C (3.41 ± 0.16 U/mL), and, while in the intestines was higher at 27 °C (2.03 ± 0.27 U/mL). Stomach activity was higher at 27 ºC, at 27 °C (2.03 ± 0.27 U/mL, respectively. (4) Conclusions: Stomach protease activity tended to be higher at 25 °C, while intestinal activity was highest at 25–27 °C. These results may indicate a better starting digestion that supports feed digestion.
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Effect of different n-6/n-3 fatty acid proportion oil sources on reproduction performance and fatty acid profile of milk in modern genotype sows - Pleminary results: Preliminary results
121-128Views:265This study was conducted to investigate the effects of supplemental n-6 and n-3 fatty acids on sow’s milk fatty acid composition during the lactation period and on reproductive efficiency of sows in the subsequent gestation period. Data were collected on a total of 213 DanBred sows (108 control and 105 experimental) representing parity of 2–7, respectively. Control and experimental sows were placed in the same housing conditions during lactation and gestation period. Control group received 6.3 g of sunflower oil (SO) per kg feed as n-6 fatty acid supplementation, whilst experimental animals received the same amount of fish oil (FO) as n-3 fatty acid source. Diets were corn meal-extracted soybean meal based. The experiment was conducted in one replication as being a part of a longer and more comprehensive trial. It was found that the consumed long-chain polyunsaturated fatty acids (LC-PUFAs) appeared in the sow’s milk and changed its fatty acid profile. With this alteration, the n-6/n-3 ratio of experimental (FO) sows’ milk were narrower than in SO group (SO: 13.82 vs. FO: 5.89). The benefits of n-3 fatty acids supplementation were evident for the subsequent reproduction cycle, when experimental sows heated more reliable and earlier than control (weaning to oestrus interval: SO: 5.86 vs. FO: 4.48 days). Only 2.33% of experimental sows (FO) did not heat within 7 days after weaning, but this was 12.36% in the control group (SO). The present study requires further research to evaluate the effect of n-3 fatty acids on maintenance of pregnancy and improved subsequent litter size.