Effects of Dietary Acidifier() and Essential Oil() on the Performance, Nutrient Metabolizability, Small Intestinal Microflora and Immune Response in Broiler Chicks

An experiment was conducted to investigate the effects of dietary acidifier($Lactacid^(R)$) and essential oil($Immunocin^(R)$) on the performance, nutrient metabolizability, small intestinal microflora, IgG level and leukocytes and erythrocytes in broiler chickens. Five hundred males and 500 females broiler chickens($Ross^(R)$) were divided into 20 pens of 50 chickens(25 birds in each sex). Five pens were assigned to each of four dietary treatments: control, diets containing antibiotics(Bacitracin methylene disalicilate), acidifier($Lactacid^(R)$) and essential oil($Immunocin^(R)$) dietary treatments. Birds were fed experimental diets ad libitum 5 wks. Weight gain, feed intake, and feed conversion rate were significantly affected by dietary treatment(P<0.05). Overall weight gain($0{\sim}5$ wks) of $Lactacid^(R)$ treatment was significantly lower than the others. Feed intake was highest(P<0.05) in the control followed by antibiotics, $Lactacid^(R)\;and\;Immunocin^(R)$ treatment. Feed conversion rate of $Immunocin^(R)$ treatment was lowest(P<0.05) followed by antibiotics, $Lactacid^(R)$ treatment and the control. Production indices of $Immunocin^(R)$ and antibiotics treatments were significantly higher than those of the control and $Lactacid^(R)$ treatment(P<0.05). $Immunocin^(R)$ treatment was the highest and antibiotics was lowest in serum IgG level. The number of leukocytes and stress index(neutrophil/lymphocytes) tended to be lower in $Immunocin^(R)$ treatment than others. There were no significant differences in erythrocytes among the treatments. The cfu of E. coli was significantly lower in $Immunocin^(R)$ and antibiotics treatments than $Lactacid^(R)$ treatment and the control. Metabolizability of crude protein was significantly lower in the control than $Lactacid^(R)\;and\;Immunocin^(R)$ treatment while that of NFE was significantly lower in $Immunocin^(R)\;than\;Lactacid^(R)$ and antibiotics treatments. It was concluded that essential oil product $Immunocin^(R)$ is as effective as antibiotics in improving feed conversion efficiency and production index while $Lactacid^(R)$ is not.

유기산제제 ()와 Essential Oil()이 육계의 생산성과 영양소 이용율, 소장내 미생물 균총 및 면역 체계에 미치는 영향

본 실험은 항생제 $BMD^(R)$ premix(Bacitracin methylene disalicylate), 유기산 복합제인 $Lactacid^(R)$((주) 은진인터내셔날) 그리고 essential oil 제품인 $Immunocin^(R)$((주) 은진인터내셔날) 이 육계에 미치는 영향을 비교 평가하기 위하여 생산성, 영양소 이용율, 혈액 성상, ND titer, IgG, 그리고 장내 미생물 균총 등을 조사하기 위해 실시하였다. 사양 시험은 육계 ($Ross^(R)$종) 1,000수 (암 수 각각 500수)를 공시하여 4처리 5반복, 반복당 암 수 동수로 50수씩을 floor pen(가로: 2.0m, 세로: 2.4m) 에 완전임의 배치하였다. 사양시험 기간은 35일, 시험 기간 동안 물과 사료를 자유 채식시켰고 24시간 점등하였다. 시험구는 대조구, $BMD^(R)$ premix(Bacitracin methylene disalicylate 2.5%) 0.1 % 첨가구, $Lactacid^(R)$ 0.5% 첨가구, 그리고 $Immunocin^(R)$ 0.1% 첨가구등 4첨가구를 두었다. 생산성에서 essential oil 복합제 $Immunocin^(R)$ 0.1% 첨가구가 $BMD^(R)$ 25ppm 첨가한 항생제구와 동일한 수준의 생산성 개선 효과를 보였는데 (P<0.05) 특히 사료 요구율이 유의하게 향상되었다(P<0.05). 그러나 유기산 복합제인 $Lactacid^(R)$ 0.5% 첨가구는 항생제구보다 생산성 개선 효과가 없었다. IgG 농도는 $Immunocin^(R)$구가 첨가구들 중에서 가장 높았으며(P<0.05) 혈액의 leukocytes 와 stress index는 $Immunocin^(R)$ 첨가구가 낮은 경향을 나타냈다. 장내 미생물의 Cl. perfringens 수는 첨가구간에는 유의차가 없었으며 E. coli 수는 항생제구와 $Immunocin^(R)$ 구가 가장 적었다(P<0.05). 영양소 이용 율에 있어서 조단백질은 $Lactacid^(R)$ 구와 $Immunocin^(R)$ 구 높았다(P< 0.05). NFE 이용율은 생산성 개선 효과는 없었으나 $Lactacid^(R)$ 구가 가장 높았다(P<0.05). 결론적으로 essential oil 제제인 $Immunocin^(R)$을 육계 사료의 첨가제로 사용시 항생제와 같은 수준의 생산성 개선 효과를 보였으나 유기산제제인 $Lactacid^(R)$는 대조구와 차이가 없었다.