• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.84-92
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• 1999

The rumen microbial ecosystem is coming to be recognized as a rich alternative source of genes for industrially useful enzymes. Recent advances in biotechnology are enabling development of novel strategies for effective delivery and enhancement of these gene products. One particularly promising avenue for industrial application of rumen enzymes is as feed supplements for nonruminant and ruminant animal diets. Increasing competition in the livestock industry has forced producers to cut costs by adopting new technologies aimed at increasing production efficiency. Cellulases, xylanases, ${\beta}$-glucanases, pectinases, and phytases have been shown to increase the efficiency of feedstuff utilization (e.g., degradation of cellulose, xylan and ${\beta}$-glucan) and to decrease pollutants (e.g., phytic acid). These enzymes enhance the availability of feed components to the animal and eliminate some of their naturally occurring antinutritional effects. In the past, the cost and inconvenience of enzyme production and delivery has hampered widespread application of this promising technology. Over the last decade, however, advances in recombinant DNA technology have significantly improved microbial production systems. Novel strategies for delivery and enhancement of genes and gene products from the rumen include expression of seed proteins, oleosin proteins in canola and transgenic animals secreting digestive enzymes from the pancreas. Thus, the biotechnological framework is in place to achieve substantial improvements in animal production through enzyme supplementation. On the other hand, the rumen ecosystem provides ongoing enrichment and natural selection of microbes adapted to specific conditions, and represents a virtually untapped resource of novel products such as enzymes, detoxificants and antibiotics.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.12
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• pp.1736-1743
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• 2014

This study was designed to test the effects of dietary distillers dried grain (DDG) level on the growth performance, feed utilization, body composition and antioxidant activity of juvenile red seabream (Pagrus major). Six isonitrogenous and isocaloric diets were formulated to contain 0%, 5%, 10%, 15%, 20%, and 25% DDG from rice (designated as DDG0, DDG5, DDG10, DDG15, DDG20, and DDG25), respectively. Juvenile red seabream averaging $10.1{\pm}0.05g$ were randomly distributed into 400-L tanks in a flow through systems. Three replicate groups of fish were fed one of the experimental diets to visual satiation two times a day for 10 weeks. Survival, weight gain, feed efficiency, protein efficiency ratio and hepatosomatic index of fish were not affected by dietary DDG levels (p>0.05). Proximate and amino acid composition of whole body in juvenile red seabream were not affected by dietary DDG levels (p>0.05). Plasma content of total protein, glucose, cholesterol, glutamic-pyruvic transaminase, phospholipid and triglyceride were not affected by dietary DDG levels (p>0.05). 1, 1-Diphenyl-2-picryl-hydrazyl radical and alkyl radical scavenging activities in plasma and liver of fish were not affected by dietary DDG levels (p>0.05). The results of this experiment suggest that DDG has the potential to replace plant origin ingredients such as wheat flour and corn gluten meal and could be used up to 25% in diet without incurring negative effects on the growth performance of juvenile red seabream.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.3
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• pp.317-322
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• 2016

This study was carried out to investigate the effects of various dietary lipid sources on the growth performance, body composition, and fatty acid profiles of juvenile fancy carp (Cyprinus carpio var. koi). Three replicate groups of fish (initial mean body weight, 15.1±0.18 g) were fed one of five experimental diets containing fish oil (SLO), soybean oil (SO), linseed oil (LO), lard (LA), or a mixture of SLO, SO, and LO (Mix) for 8 weeks. Fish fed the LA diet gained less weight than did fish fed the LO diet. The feed efficiency and protein efficiency ratio of fish fed the LA and Mix diets were lower than those of fish fed the SO and LO diets. The body lipid content of fish fed the SO diet was lower than those of the other groups. Whole-body fatty acid compositions reflected the fatty acid compositions of dietary lipid sources. Fish fed the SO diet had high concentrations of linoleic acid and arachidonic acid, whereas fish fed the LO diet were rich in linolenic acid. Fish fed the SLO diet had significantly higher levels of eicosapentaenoic acid and docosahexaenoic acid compared with fish fed the SO, LO, and LA diets. The results of this study suggest that SO or LO could be used as a replacement for SLO in the diets of juvenile fancy carp without any negative effects on growth and feed utilization when the dietary essential fatty acid requirements are satisfied for juvenile fancy carp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.557-561
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• 2010

This feeding experiment was conducted to investigate the effects of dietary inclusion of some additives on growth performance, hematological parameter and fatty acid composition of growing flounder. Triplicate groups of fish (average weight 120 g) were fed one of five diets containing 5% kelp meal (Ke), 10% krill meal (Kr), 1% garlic powder (Ga), 1% citrus meal (Ci) or control diet (Con) without supplementation for 15 weeks. After the feeding experiment, survival was not significantly different among the groups fed the different diets. Weight gain of fish fed the Ci diet was significantly higher than that of fish fed the Kr diet, but not significantly different from Con, Ke and Ga treatments. Feed efficiency and protein efficiency ratio of fish fed the Ga diet were significantly higher than those of fish fed the other diets. Total protein, glucose, GOT, GPT and total cholesterol contents in the plasma were not affected by the dietary additives. Composition of C20:4n-6 in the dorsal muscle of fish fed the Con diet was significantly higher than that of fish fed the other diets. The results of this study suggest that the dietary inclusion of garlic meal at 1% may improve feed utilization of growing flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.3
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• pp.310-314
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• 2013

This study investigated the utilization of beef tallow and dextrin as non-protein energy sources in the diet of juvenile far eastern catfish Silurus asotus. Three replicated groups of juveniles (initial mean weight of 3.6 g) were fed diets containing high levels of beef tallow or dextrin for six weeks. The final mean weight of fish fed on a 17% lipid diet with a high level of beef tallow was significantly higher than that of fish fed on a 9% lipid diet with a high level of dextrin (P=0.04). No significant differences were observed in the feed efficiency and protein efficiency ratio of fish fed on the experimental diets. Crude lipid content and the C18:0, C18:1n-9 and C18:2n-6 contents of whole-body fish were significantly affected by diet (P<0.05). The results of this study suggest that beef tallow is better than dextrin as a non-protein energy source for improving the growth of juvenile far eastern catfish, and that beef tallow could be economically used as an ingredient in practical feed.

• Animal Bioscience
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• v.36 no.6
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• pp.920-928
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• 2023

Objective: Angora rabbits fed a low-protein diet exhibit decreased hair production performance. This study was set out to evaluate the effects of methionine on hair properties and nitrogen metabolism in Angora rabbits fed a low-protein diet and to investigate the gene expression related to hair follicle development to determine the possible molecular mechanism of methionine effects on hair follicle development. Methods: An experiment was conducted to investigate the effects of DL-methionine addition on a low-protein diet on hair development in Angora rabbits. Angora rabbits were divided into 5 groups: fed a normal diet (control), fed a low-protein diet (LP), or fed an LP supplemented with 0.2%, 0.4%, or 0.6% DL-methionine (Met). Results: The results showed that rabbits in the LP group had lower wool yield than the control rabbits, but the addition of 0.4% to 0.6% Met to LP attenuated these effects (p<0.05). Dietary addition of 0.4% to 0.6% Met to LP increased the apparent nitrogen digestibility, nitrogen utilization rate, and feed efficiency (p<0.05). Feeding LP decreased the insulin-like growth factor 1 (IGF1), keratin-associated protein (KAP) 3.1, and KAP 6.1 mRNA levels compared with the control, but the addition of 0.4% Met in LP attenuated these effects (p<0.05). Relative to the LP or control group, dietary addition of 0.4% Met increased versican mRNA levels. Conclusion: In conclusion, the addition of Met to LP could improves wool production performance and feed efficiency and reduce nitrogen emissions in Angora rabbits. Met can promote hair follicle development, which may be associated with IGF1, KAP, and the versican signaling.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.4
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• pp.599-605
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• 1989

A comparison of the ARC metabolizable energy system and the NRC net energy system was made with special reference to growing steers. Two simulation models, one based on the ARC and other on the NRC system, were constructed to examine differences between the energy systems. The average daily live-weight gains predicted from both models for growing steers were compared under various conditions in which equal feeding levels and metabolizabilities were assumed. The two simulation models yielded similar results with very high energy intake with high quality feed. Difference between the two systems became larger as feeding conditions deviated from the above. The ARC system generally predicted higher daily live-weight gains than the NRC system. This appeared to be due to the higher efficiency of utilization of metabolizable energy ($k_m$ and $k_f$) and basal metabolism (F), and lower energy value of growth (EVG) in the ARC system.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.554-557
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• 1999

Hatchery waste including infertile eggs, dead embryos in shell, dead or low grade chicks was cooked at $100^{\circ}C$ for 15 minutes and then oven dried and ground. Hatchery waste meal (HWM) thus prepared contained 44.25% protein, 4,573 kcal/kg gross energy, 3,600 kcal/kg metabolizable energy, 30% ether extract, 1.9% fibre, 14% ash, 9.8% nitrogen free extract, 7.26% Ca, 0.84%P, 1.86% lysine and 0.66% methionine with no Salmonella and E. coli. In biological evaluation trial, significantly higher weight gain was observed in ration containing 12% HWM compared with that containing similar amount of fish meal. Protein efficiency ratio on the two rations was 3.96 vs 2.85; protein digestibility, 86.02 vs 71.9; net protein utilization, 64.9 vs 42.37 and biological value, 75.37 vs 58.84, respectively, indicating better balance of amino acids in HWM compared with fish meal. Growth performance trial on broiler chicks also revealed better weight gain and feed efficiency on ration containing 12% HWM than that containing similar level of fish meal.

• Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.172-177
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• 2002

This study was conducted to investigate the utilization of Sargassum meal in the diet on juvenile ayu (Plecoglossus altivelis) reared in seawater. White fish meal and wheat flour were used as the dietary protein and carbohydrate sources in the control diet. Wheat flour in the control diet was replaced with $5\%$ and $10\%$ Sargassum meal. Three replicate groups of fish average weighing 4.0 g were fed one of three isonitrogenous$(45\%)$ and isocaloric (14.5 MJ /kg diet) diets for 7 weeks. Survival of all groups were above $80\%$. Weight gain, feed efficiency and protein efficiency ratio were not significantly affected by dietary Sargassum meal levels (P>0.05). There were no significant differences (P>0.05) in moisture, crude protein, crude lipid, crude ash and fatty acid compositions of whole-body fish among groups. It is concluded that Sargassum meal could be used as a dietary additive or alternative low-cost dietary ingredient up to $10\%$ for juvenile ayu reared in seawater.

• Journal of Nutrition and Health
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• v.22 no.6
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• pp.447-456
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• 1989

This study was performed to investigate nutritional effect and the utilization possibility of rapeseed oil which could replace the imported edible oils and oil crops. The proximate compositions of a recommendable cultivar(Mokpo Dangyo 19) and a native kind(Asahi) and the characteristics of these rapeseed oils were analyzed. The animal experiment of these rapeseed oils was carried out during 8 weeks of growing periods after weanling. Forty male weanling Sprague-Dawley rats were randomly assigned to 3 diet groups of Dangyo 19 oil, Asahi oil and commercial Soybean oil. Mokpo Dangyo 19 variety contained more lipids than Asahi variety by 8% and there was no difference in physiochemical characteristics between Dangyo 19 oil and Asahi oil except that erucic acid was contained little in Dangyo 19 oil but 50% in Asahi oil. Body weight gain, FER(Feed efficiency ratio) and PER(Protein efficiency ratio) of rats fed Dangyo 19 oil were higher than those of rats fed Asahi oil and organ weights such as liver, kidney and epididymal fat pads weights of rats fed Dangyo 19 oil were significantly higher(P<0.05) thanthose of rats fed Asahi oil. the apparent digistibility of total diet and total lipid were higher in rats fed the diets containing Dangyo 19 oil than Asahi oil. The content of total lipid in heart in heart were not significantly different with dietary oil kinds. The content of total lipid in liver increased with age in all rapeseed oil groups.