Abstract
This study was conducted to evaluate the effect of iron reinforcing agent on the performance in laying hens for seven weeks. One hundred ninety eight 30-wk-old Brown Tetran layers were assigned to 9 treatments: control containing 45 mg Fe from iron sulfate per kg diet (FE-45), FE-90 (control multiplied two times), FE-180 (control multiplied four times), YM-45 containing 45mg Fe from yeast mutant, YM-90 (YM-45 multiplied two times), YM-180 (YM-45 multiplied four times), YF-45 containing 45mg Fe from ferritin containing yeast, YF-90 (YF-45 multiplied two times), YF-180 (YF-45 multiplied four times) in the experiment. Each treatment had four replications of 6 birds each. In the average egg production, the YF-180 was highest and the FE-45 (the control) was lowest; the YM-180, YF-90, and YF-180 were significantly (P<0.05) higher than the control. In the comparisons of egg weight and egg mass, the YF-180 was significantly higher (P<0.05) than the FE-90 or the control. In the FCR, the YM-90 was highest and the YF-45 was lowest. There was no significant difference between the control and YM-90 although the YF-45 was significantly (P<0.05) lower in FCR than the control. In the eggshell thickness, the YF-180 was the thickest and the FE-90 was the thinnest; the YF-45 or the YF-180 was significantly thicker (P<0.05) than the control. In the eggshell strength, the YF-45 was the strongest and the YM-45 was the weakest; the YM-90, YF-45, and YF-180 were significantly stronger (P<0.05) than the control. In the cholesterol level of egg yolk, the control (FE-45) was the highest and the YF-45 was the lowest; there was a significantly different (P<0.05) between these two treatments. In conclusion, in case of adding organic iron to feed for layers, it gives improvement on performance of layers and develop chemical composition of eggs.
본 연구의 목적은 철 강화제가 첨가된 사료를 산란계에 적용하여 생산성 및 계란의 화학적 조성에 미치는 영향을 평가하고자 실시하였다. 사양시험은 30주령 갈색 테트란 산란계 198수를 공시하였으며, 시험사료는 NRC(1994)의 산란계 영양소 요구량에 맞추어 기초사료를 배합하고, 황산 제 1철(FeSO$_4$$.$ 7$H_2O$: FE)을 사용하여 사양표준 권장량인 Fe 45 mg/kg을 첨가한 대조구 (FE-45), Fe 90mg/kg 첨가한 처리구 \circled2 (FE-90), Fe 180mg/kg 첨가한 처리구 \circled3 (FE-180), Saccharomyces cerevisiae R100 (yeast mutant ; YM, 철 함량 200mg/kg)을 대조구의 철 함량 기준으로 45mg/kg 첨가한 처리구 \circled4 (YM-45), 90mg/kg 첨가한 처리구 \circled5 (YM-90), 180mg/kg 첨가한 처리구 \circled6 (YM-180), Saccharomyces cerevisiae 2805-a7 TYFHLAG-1 (ferritin containing yeast ; YF, 철 함량 500mg/kg)을 대조구의 철 함량 기준으로 45mg/kg 첨가한 처리각 \circled7 (YF-45), 90mg/kg 첨가한 처리구 \circled8 (YF-90) 및 180mg/kg 첨가한 처리구 \circled9 (YF-180)로 한 총 9처리구 4반복, 반복당 6수씩 임의배치하여 7주간 사양시험을 수행하여 다음과 같은 결과를 얻을 수 있었다. 산란율은 YF-180 처리구가 가장 높았으며, 대조구(FE-45)가 가장 낮게 나타나 처리구간의 유의차를 보였다 (P<0.05). 난중과 산란량은 YF-180 처리구에서 FE-90 처리구 및 대조구(FE-45)와 비교하여 유의적으로 높게 평가되었다(P<0.05). 사료요구율은 YM-90 처리구가 가장 높았고, YF-45 처리구가 가장 낮았으며, 처리구간에도 유의차를 보였다 (P<0.05). 난각두께는 YF-180 처리구가 가장 두꺼웠으며, FE-90 처리구에서 가장 얇게 나타나 처리구간의 유의차를 보였다(P<0.05). 난각 강도는 YM-45 처리구가 가장 강했으며, YM-45 처리구가 가장 약해서 처리구간의 유의차를 보였다(P<0.05). 난황 cholesterol은 대조구(FE-45)가 가장 높았으며, YF-45 처리구가 가장 낮게 나타나 처리구간의 유의적 차이를 보였다(P<0.05). 결론적으로, 유기철을 산란계용 사료에 첨가하였을 경우, 산란계의 생산성을 향상시키며, 계란의 화학적 조성을 개선시키는 것으로 사료된다.