Dietary supplementation with high lev- els of zinc oxide （ZnO） is an effective method to prevent diarrhea and promote growth in weaned pig- lets. However, the mechanisms behind these beneficial effects are not well ...Dietary supplementation with high lev- els of zinc oxide （ZnO） is an effective method to prevent diarrhea and promote growth in weaned pig- lets. However, the mechanisms behind these beneficial effects are not well understood. Recent advances in this field indicated that the effects of ZnO on piglet growth are achieved through multiple regulatory path- ways rather than a single pathway. This review focu- ses on recent advances in the effects of high level ZnO on： 1 ） Zn status in weaned piglets; 2 ） intestinal microbe flora regulation; 3 ） intestinal structure and function;4） ion secretion in the intestine epithelium;5） intestinal immunology; and 6） secretion of brain-in- testine peptides. ZnO appears to regulate the intestinal microflora and decreases the release of histamine to prevent diarrhea. ZnO also increases the expression of intestinal insulin-like growth factor-1 （ IGF-1 ） and the IGF-1 receptor to ameliorate intestinal injury associat- ed with weaning, and mediates secretion of brain-gut peptides to stimulate food intake, to promote the growth of piglets. Better understanding of the underly-1 ing mechanisms should inspire us to supplement the diet for weaned piglets with ZnO and investigate new approaches to prevent diarrhea and enhance growth.展开更多
ABSTRACT： Three trials were conducted to analyze a multi-enzyme compound produced by Aspergillus sulphureus in solid-state fermentation （SSF） as a po- tential feed additive. The results of the first trial showed th...ABSTRACT： Three trials were conducted to analyze a multi-enzyme compound produced by Aspergillus sulphureus in solid-state fermentation （SSF） as a po- tential feed additive. The results of the first trial showed that there were at least 5 non-starch polysac- charide enzymes： xylanase, 13-ghicanase, pectinase, mannase and carboxy methyl cellulase （CMCase） contained in the compound. Xylanase and fl-glucanase showed good activities at pH 2.5-7.0, which were in the range of 649-1046 U/g and 444-648 U/g, respec- tively. Pectinase showed good activity in acidic solu- tion （pH 2.5-3.0）,which ranged from 195 to 917 U/g. Mannase showed high activity of 235-298 U/g at pH 3.5-4.5 and the activity of CMCase was relatively constant at pH 2.5-7.0, which was in the range of 38.2-78.6 U/g. The second trial was aimed to test the stability of the enzymes in gastric liquor （pH 2.6） of finishing pigs and Na2 HPO4-gastric liquor （ pH 5.5 ）.After 6 h incubation at 40℃ in gastric liquor,the re- tained activity of xylanase, 13-glucanase, pectinase, mannase and CMCase was 26.3% ,65.0% ,71.0%, 74.8% and 85.6%, respectively. While after 6 h in- cubation at 40℃ in Na2I-IPO4-gastric liquor, the re- tained activity of xylanase, [3-glucanase, pectinase, mannase and CMCase was 87.9% ,91.1% ,92.3%, 95.0%, and 97.5%, respectively. The third trial was carried out in a jejunum liquor （ pH 5.8,200 mL）, which contained 0.2 g of the multi-enzyme compound and 10 g of soybean hull or wheat bran, respectively. After 8 h incubation at 40℃, 18.7% of soybean hull and 20.1% of wheat bran could be degraded to solu- ble saccharide, respectively. Compared with the tradi- tional methods for feed enzyme testing which involve feeding animals for 1-3 months, enzyme assay in this way was relatively convenient.展开更多
基金Supported by National Natural Science Foundation of China(30571343)
文摘Dietary supplementation with high lev- els of zinc oxide （ZnO） is an effective method to prevent diarrhea and promote growth in weaned pig- lets. However, the mechanisms behind these beneficial effects are not well understood. Recent advances in this field indicated that the effects of ZnO on piglet growth are achieved through multiple regulatory path- ways rather than a single pathway. This review focu- ses on recent advances in the effects of high level ZnO on： 1 ） Zn status in weaned piglets; 2 ） intestinal microbe flora regulation; 3 ） intestinal structure and function;4） ion secretion in the intestine epithelium;5） intestinal immunology; and 6） secretion of brain-in- testine peptides. ZnO appears to regulate the intestinal microflora and decreases the release of histamine to prevent diarrhea. ZnO also increases the expression of intestinal insulin-like growth factor-1 （ IGF-1 ） and the IGF-1 receptor to ameliorate intestinal injury associat- ed with weaning, and mediates secretion of brain-gut peptides to stimulate food intake, to promote the growth of piglets. Better understanding of the underly-1 ing mechanisms should inspire us to supplement the diet for weaned piglets with ZnO and investigate new approaches to prevent diarrhea and enhance growth.
基金supported by New Century Excellent Talent in University (NCET-07-0807)the National High Technology Research and Development Program of China (2007AA100601)the Projectof State Key Laboratory of Animal Nutrition(2004DA125184(team)0806)
文摘ABSTRACT： Three trials were conducted to analyze a multi-enzyme compound produced by Aspergillus sulphureus in solid-state fermentation （SSF） as a po- tential feed additive. The results of the first trial showed that there were at least 5 non-starch polysac- charide enzymes： xylanase, 13-ghicanase, pectinase, mannase and carboxy methyl cellulase （CMCase） contained in the compound. Xylanase and fl-glucanase showed good activities at pH 2.5-7.0, which were in the range of 649-1046 U/g and 444-648 U/g, respec- tively. Pectinase showed good activity in acidic solu- tion （pH 2.5-3.0）,which ranged from 195 to 917 U/g. Mannase showed high activity of 235-298 U/g at pH 3.5-4.5 and the activity of CMCase was relatively constant at pH 2.5-7.0, which was in the range of 38.2-78.6 U/g. The second trial was aimed to test the stability of the enzymes in gastric liquor （pH 2.6） of finishing pigs and Na2 HPO4-gastric liquor （ pH 5.5 ）.After 6 h incubation at 40℃ in gastric liquor,the re- tained activity of xylanase, 13-glucanase, pectinase, mannase and CMCase was 26.3% ,65.0% ,71.0%, 74.8% and 85.6%, respectively. While after 6 h in- cubation at 40℃ in Na2I-IPO4-gastric liquor, the re- tained activity of xylanase, [3-glucanase, pectinase, mannase and CMCase was 87.9% ,91.1% ,92.3%, 95.0%, and 97.5%, respectively. The third trial was carried out in a jejunum liquor （ pH 5.8,200 mL）, which contained 0.2 g of the multi-enzyme compound and 10 g of soybean hull or wheat bran, respectively. After 8 h incubation at 40℃, 18.7% of soybean hull and 20.1% of wheat bran could be degraded to solu- ble saccharide, respectively. Compared with the tradi- tional methods for feed enzyme testing which involve feeding animals for 1-3 months, enzyme assay in this way was relatively convenient.
