• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.296-308
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• 1996

Proteolytic enzymes responsible for post-mortem degradation of the fish tissues have been studied in regard with screening the proteases distributed in the fish body by reacting with the specific synthesized substrates. Activities of cathepsin L, B, H, G, and D like enzymes were detected in the muscle crude protease from the both kind of fish, dark fleshed fish (anchovy, Engraulis japonica, and gizzard-shad, Clupanodo punctatus) and white fleshed fish (seabass, Lateolabrax japonicus, and sole, Pleuronichthys cornutus), however, those of chymotrypsin, trypsin, pepsin, and peptidase like enzymes were observed 3n the viscera crude pretense from the fish. Proteolytic activities of the muscle crude protease at pH 6.0 were similar to those of the viscera crude protease at pH 8.0, but, those of the viscera crude protease at pH 8.0 were about 2 times higher than those at pH 6.0. The muscle and viscera crude protease from anchovy showed the strongest proteolytic activity among the four fish crude proteases and the proteolytic activity of the viscera crude protease was approximately 100 times higher than that of the muscle crude protease, which suggest that viscera proteases were more contributed on the development of post-mortem changes than muscle proteases. With the degradation patterns on SDS-polyacrylamide gel electrophoresis against yellowtail myofibrillar proteins, the muscle and viscera crude protease of the four fishes were primary responsible for the degradation of myosin heavy chain, and myosin light chain and actin, respectively.

• Korean Journal of Poultry Science
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• v.47 no.4
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• pp.275-283
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• 2020

This experiment was conducted to investigate the effect of the addition of enzymes and microorganisms to broiler feed on productivity, carcass characteristics, intestinal microflora, and feces odor. A total of one-hundred eighty 180 chicks (Ross 308) were randomly assigned to 5 treatments with 3 replications each having 12 birds per pen. The experimental group was divided into 0.1% EZ group (0.1% metallo-protease added to the feed), 0.2% EZ group (0.2% metallo-protease added to the feed), M group (2.0% Bacillus veleznesis CE 100 added to the feed), and MW group (2.0% Bacillus veleznesis CE 100 added to the feed and drinking water). In the results, final body weight, body weight gain, the feed conversion ratio, protein efficiency, and energy efficiency were not significantly different among all treatments in across all periods. Carcass weight, proventriculus, gizzard, heart, small intestine, cecum, and rectum weight were not significantly different among all of the treatments. However the liver weight was significantly higher in the 0.1% EZ group than in the control, M and MW groups (P< 0.05). E. coli was significantly lower in MW than in the control and M (P<0.05), and it was significantly higher in the M than 0.2% EZ and MW (P<0.05). H2S emissions in feces was not significantly different among all treatments, but NH3 emissions was were significantly higher in 0.1% EZ than in MW (P<0.05). In conclusion, the addition of 0.1% of metallo-protease was effective in the development of the liver of broilers.

• Korean Journal of Poultry Science
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• v.29 no.4
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• pp.237-241
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• 2002

To observe the effect of Induced molting on the recovery patterns of abdominal fat, visceral organs, and muscle tissues in spent laying hens after induced molting, three hundred sixty 77-wk-old, Babcock White hens were divided into 36 experimental units of 10 hens each and subjected to molt induction for seven wk. The post-molt production phase was spread over 84 to 126 wks of age. Thirty-six birds were randomly slaughtered and dressed at the pre-molt, 5% egg production, Peak, and end Phases of e99 Production. The body weight, abdominal fat, relative weight and length of visceral organs were measured. Proximate compositions of breast and thigh muscles were analyzed at each stage. The body weight was found to be minimal at the 5% egg Production stage, but increased as the egg Production increased for the rest of production. The pattern of abdominal fat change was very similar to that of body weight. The relative weight of the liver decreased to the lowest at the start of Post molting stage, but Peaked at the end Phase of egg Production (P<0.05). However, he heart and gizzard were observed to reach their maximum weight at the 5% egg Production (P<0.05), whereas they were, similar to those of the pre-molt phase for the rest of the production stages. Both intestine and reproductive tracts were found o be significantly smaller at 5% egg Production than at the other stages; however, their sizes increased gradually, reaching leak at the end Phase of e99 Production (P<0.05). Fat contents in breast and thigh muscles decreased significantly to the lowest at the start of the Post-molt stage, but increased to the highest at the end Phase of e99 Production (P<0.05). Thus, he Present study indicated that the molting process reduced body weight by decreasing the weights of abdominal fat and other visceral organs. Molting also influenced the breast and thigh muscle composition by decreasing fat content.

• Korean Journal of Poultry Science
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• v.51 no.2
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• pp.107-116
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• 2024

The study was conducted to examine age-related development of digestive organs, intestinal microvilli hydrolase, and hepatic antioxidant enzyme in Korean native chicks (KNC) aged from 0-d to 28-d of post-hatching. Body weight did not significantly increase from 0-d to 3-d-old, but after that remarkably increased from 3-d to 28-d-old (P<0.05). The relative weight (g/100 g of BW) of the proventriculus, gizzard, and liver was significantly higher at 3- and 7-d-old chicks than that of the other ages. The relative weight of the intestine, mucosal tissues, and pancreas was markedly developed at the ages of 3-, 14-, and (or) 21-d-old chicks (P<0.05). In the small intestine, the specific activities of maltase and sucrose were significantly higher at 14-d-old compared with the other ages (P<0.05). Leucine aminopeptidase activity showed a constant level from 0- to 28-d-old without significance. The specific activity of alkaline phosphatase was significantly higher at 0-d-old compared with the other ages (P<0.05). In the liver, the specific activities of superoxide dismutase, glutathione peroxidase, and glutathione S-transferase were shown to be lowest at 0-d-old, but they continued to increase as the age increased. The lipid peroxidation was significantly high at the age of 21-d (P<0.05), after that its level decreased at 28-d old. In conclusion, the KNC rapidly developed digestive organs and intestinal microvilli hydrolase activity from 3- to 14-d-old after hatching. Hepatic antioxidant enzyme activity continued to increase as the age increased after hatching, resulting in 28-d-old chicks showing the highest antioxidant enzyme activity in the KNC.