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.
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.
