Title Page
Contents
ABSTRACT 9
Ⅰ. Introduction 11
Ⅱ. Materials and Methods 14
2.1. In vitro Experiments of Probiotic Acceptability 14
2.1.1. Culture of Paenibacillus konkukensis 14
2.1.2. Digestive enzyme activity 14
2.1.3. Antimicrobial activity 16
2.2. Laying hen experiment 18
2.2.1. Experimental animals, diets, and design 18
2.2.2. Laying performance 21
2.2.3. Egg quality 21
2.2.4. Blood biochemical characteristics 22
2.2.5. Organ characteristics 22
2.2.6. Tibia characteristics 23
2.2.7. Intestinal histomorphology 23
2.2.8. Next generation sequencing of microbiota 24
2.3. Statistical analysis 25
Ⅲ. Results and Discussion 26
3.1 In vitro experiments of probiotic acceptability 26
3.1.1. Digestive enzyme activity 26
3.1.2. Antimicrobial activity 29
3.2. Laying hen experiment 31
3.2.1. Laying performance 31
3.2.2. Egg quality 34
3.2.3. Blood biochemical characteristics 36
3.2.4. Organ characteristics 39
3.2.5. Tibia characteristics 42
3.2.6. Intestinal histomorphology 44
3.2.7. Next generation sequencing of microbiota 47
Ⅳ. Conclusion 55
References 56
Appendix 68
Abstract (in Korean) 70
Table 1. The pathogen used antimicrobial activity assay 17
Table 2. Ingredients and chemical compositions of the basal diet 20
Table 3. Digestive enzyme activity of Paenibacillus konkukensis on agar plate assay 27
Table 4. Antimicrobial activities of Paenibacillus konkukensis against poultry pathogens 30
Table 5. Effect of supplementation of Paenibacillus konkukensis on laying performance in laying hens 33
Table 6. Effect of supplementation of Paenibacillus konkukensis on egg quality in laying hens 35
Table 7. Effect of supplementation of Paenibacillus konkukensis on blood biochemical characteristics in laying hens 38
Table 8. Effect of supplementation of Paenibacillus konkukensis on organ characteristics in laying hens 41
Table 9. Effect of supplementation of Paenibacillus konkukensis on tibia characteristics in laying hens 43
Table 10. Effect of supplementation of Paenibacillus konkukensis on intestinal histomorphology in laying hens 45
Table 11. Alpha diversity indexes of laying hen cecal contents 51
Figure 1. Digestive enzyme activity of 10 x concentrated supernatant of Paenibacillus konkukensis on agar plate assay. 28
Figure 2. Effect of supplementation of Paenibacillus konkukensis on villus height and crypt depth in laying hens. Con: (A), (E); PK 0.1%: (B), (F); PK 0.3%: (C), (G); PK 0.5%: (D), (H). 46
Figure 3. Rarefaction curve (Chao 1) of laying hen cecal microbiota. 50
Figure 4. The similarity of the bacterial community in cecal contents. (A) Principal coordinate analysis (PCoA) plot based on the weighted UniFrac... 52
Figure 5. Microbiota in the relative abundance at phylum levels. 53
Figure 6. Microbiota in the relative abundance at family levels. 54