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Impact of chronic heat stress on digestibility of nutrients and performance of meat type ducks
51-55Views:318The aim of the study is to determine the effect of vitamin and mineral supplement under permanently high environmental temperature (30±1 °C) on the digestibility of nutrients, performance and furthermore the composition of duck meat in the growing period. A total of four hundred mixed sex 14 days old Cherry Valley type hybrid ducks were used for the study. Two experimental diets were formulated in the study (control and vitamin E, C and zinc supplemented diet). Based on the results the following conclusions were drown: the antioxidant defence system plays an important role in the reduction of heat stress generated lipid peroxidation process. Feed additives which have direct or indirect antioxidant effects can reduce the negative effects of heat stress on the ducks performance and meat composition. Digestibility of nutrients (Dry Matter, Crude Protein, Crude Fat) was not affected by antioxidant supplementation under chronic heat stress (30±1 °C). The performance was affected significantly by Vitamin C and E and zinc supplementation under heat stress (P<0.05). In the treated group the daily weight gain (dWG) increased and the feed conversion ratio (FCR) was improved significantly (P<0.05). The energy and protein conversion was decreased also significantly (P<0.05).
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Phosphorus (from Different Phosphorus Sources) Utilisation in Piglets, and the Effect of the Addition of Phytase into the Feedstuff
30-36Views:170The experiments were carried out in a 2x2 factorial treatments with three replicates, and were completed with 32P phosphorus metabolism measurement. Hungarian Large White x Dutch Landrace growing pigs with 15–18 kg starting live weight were involved in the experiment.
The experimental scheme was the following:
Diet consisted of maize and extracted soybean meal. Both components have high phytase content and low phytase activity. 1/a animals received their P-supply according to their needs and 1/b animals got 10% less than their actual P-need in the first part of the experiment.
In the second part of the experiment both groups (2/a, 2/b) received identical P-supply and 500FTU/kg P supplementation. Apart from P- and phytase-supplementation, the piglets’ diet was identical.
Total P digestibility was 52% without phytase supplementation, which increases by 4% when P was added according to need and by 12% increase of decreased P-supply. Digestibility of nutrients somewhat increased as effect of phytase supplementation. According to the results of 32P experiments, inorganic P digestibility of MCP was 82–90.8%, which decreases to 73.4–87.2% in case of phytase supplementation.
Parallel with tendency, native P digestibility of the diet was 31.5–32.2%, which increased to 42.5–54.5% in the case of phytase supplementation.
Results support the that inorganic P input can be decreased by phytase supplementation and as a consequence P output, the concept and environmental pollution can at the some time be decreased. -
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 lysine-metabolized energy ratio on performance of meat-type geese
39-42Views:456The aim of the experiment was to determine, how the different ratios of the digestibility lysine/ metabolized energy (0.82, 0.87, 0.91 g DLYS/MJ AMEn) of the feed influence the performance of geese. There were 150 goslings (3 treatments, 5 cages/treatments, 10 birds/cages). The experiment has started and finished at the age of 3 and 9 weeks, respectively.
The results of the experiment showed, the different ratios of DLYS/AMEn (0.82, 0.87, 0.91 g DLYS/MJ AMEn) did not influence the performance of young geese. Better growth performances were found for the 0.91 g DLYS/AMEn feed (feed intake, body weight gain, feed and energy conversion rate). This treatment coincided with high feeding costs. Based on these results we need more models and farm experiments to prove this tendency.