본 연구는 산란계에 대한 유산균 배양물의 첨가가 생산성, 계란 품질 및 소화기관내 미생물 변화 및 영양소 이용성에 미치는 영향을 구명하고자 산란계 480수를 공시하여 8주간 사양시험을 실시하였다. 첨가된 유산균 배양물은 육계 맹장에서 채취한 L. reuteri avlbro2 배양물이었으며 첨가수준은 0.1, 0.2, $0.4\%$였다. 산란율은 $0.2\%$ 첨가구가 무첨가구에 비하여 유의적인 증가를 보였으며(P<0.05), 난중은 모든 유산균 배양물 첨가구가 무거운 것으로 나타났다(P<0.05). 1일 산란량 역시 유산균 배양물 첨가구가 무첨가보다 향상되는 것으로 나타났다(P<0.05). 사료섭취량은 유산균 배양물 첨가구가 낮은 것으로 나타났고, 사료요구율은 모든 첨가구가 유의하게 개선되는 결과를 보였다(P<0.05). 계란의 중량등급별 분포에서 유산균 배양물 급여구가 무첨가에 비하여 왕란과 특란의 비율이 향상되고 대란의 비율이 감소하는 것으로 나타났다. 영양소 이용율에서 LR $0.4\%$첨가구가 건물 및 조단백질 이용율이 무첨가 대비 유의하게 향상되었으며(P<0.05), 조지방 및 조회분 소화율은 처리간 유의성은 인정되지 않았다. 난각 강도와 난각 두께 및 Haugh unit, 난황색은 처리간 차이가 없는 것으로 나타났다. 회장과 맹장 내용물의 미생물 변화에서 유산균 배양물 급여구에서 유산균의 수가 유의하게 증가하는 것으로 나타났으며(P<0.05), E. coli와 Salmonella는 처 리간 차이가 없는 것으로 나타났다. 이상과 같은 결과에서 산란계에 대한 유산균 배양물의 첨가 급여는 산란율과 난중, 산란량이 증가하고 사료효을이 개선되었으며 영양소 소화율의 증진 및 장내 유익균의 수가 증가하는 효과가 있음을 알 수 있다.
A feeding trial was conducted to investigate the influence of feeding Lactobacillus reuteri culture (LR) on productive performance, intestinal microflora and availability in laying hens. Four hundred and eighty, Isa-Brown layers, 49 weeks of age, were fed diets supplemented with LR at the level of 0 (control), 0.1, 0.2, and $0.4\%$ of the diets for eight weeks. Egg production and egg weight were measured daily. Feed intake was weighed every two weeks. Egg quality was measured three times at the start, mid-term, and end of the experiment. Intestinal microflora were examined for Lactobacillus spp., E. coli and Salmonella at the end of the experiment. Overall egg production was the highest in $0.2\%$ LR (P<0.05), but that of $0.1\%$ or $0.4\%$ LR treatments did not significantly differ from that of control. Egg weight was significantly higher in LR feeding group than the control (P<0.05). Daily egg mass was significantly higher in $0.2\%$ and $0.4\%$ LR treatments compared to the control and $0.1\%$ LR (P<0.05). The number of jumbo and extra large eggs were increased in LR supplemented groups, especially in $0.1\%$ LR. Feed intake of layers fed LR supplemented diets tended to be lower than the control. However, feed conversion ratio significantly improved in LR supplemented groups (P<0.05). Availability of dry matter and crude protein improved significantly in $0.4\%$ LR treatment (P<0.05). But, those of ether extract and crude ash were not significantly different among treatments. Eggshell breaking strength and eggshell thickness were not significantly influenced by LR supplementation, and Haugh unit and yolk index were also similar to the control. Total number of Lactobacillus spp. in ileum and cecum fed LR supplemented diets were significantly higher than those of the control (P<0.05). There were no significant differences in intestinal E. coli and Salmonella in all treatments. Therefore, it is concluded that dietary supplementation of Lactobacillus reuteri culture can improve the laying performance, feed efficiency and intestinal Lactobacillus.
