Abstract
This study was carried out to evaluate effect of dietary green tea by-products (GTB) on laying performance and quality of eggs in hens. A total of 96 laying hens (22-week-old) "Tetran Brown" were allotted to four dietary treatments, which containing 0, 2, 4 and 6% green tea-by products. The results showed that the egg production increased (P<0.05) in layers fed diets containing 4% or 6% green tea-by products compared to the layers fed control no GTB. Egg weight and egg mass in layers fed diets containing 2% green tea by-products significantly decreased compared to those in the other groups (P<0.05). The feed intake was lower in layers fed diets containing 2% and 6% green tea by-products. The feed conversion ratio was lower (P<0.05) in layers fed diets containing 4% or 6% green tea by-product supplementation respectively. The egg shell thickness was no significantly different between layers fed the control and green tea by-product diets (P>0.05). The egg yolk cholesterol tended to decrease when layers fed diets containing green tea by-products, although the differences were not significant (P>0.05). The linolenic and docosahexaenoic (DHA) acid contents in egg yolk significantly increased in layers fed diets containing different levels green tea by-products compared to those fed control diet (P<0.05). These results suggest that inclusion of green tea by-products in layer diets is suitable for hens without negative effects on egg composition.
본 연구는 산란계에서 사료내 녹차 가공부산물을 첨가하여 난 생산성과 난 성분에 미치는 영향과 녹차 부산물의 최적 첨가수준을 알아보고자 연구하였다. 공시동물은 갈색 테트란 산란계 22주령 총 96수를 이용하였다. 녹차 부산물을 첨가를 각각 0%, 2%, 4% 및 6% 수준으로 4처리 4반복 반복당 6수로 완전임의 배치하였으며, 사료급여와 물은 자유 채식토록 하였고 나머지는 일반 관행에 따랐다. 실험 결과로 산란율은 4% 첨가구와 6% 첨가구가 각각 90.37%와 86.87%로 대조구 79.62%보다 높게 나타났으며, 통계적 유의차를 보였다(P<0.05). 난중, 산란량 및 사료섭취량은 2% 첨가구가 59.68, 45.37 및 117.13 g으로 대조구와 다른 처리구보다 낮은 경향을 보였다 (p.0.05). 난각의 두께는 대조구가 397.50$\mu\textrm{m}$로 가장 두꺼웠지만 처리구간 통계적 유의차를 보이지 않았다 (P>0.05). 4주와 8주때 측정한 난황 콜레스테롤 함량은 녹차 가공부산물의 첨가수준이 증가할수록 낮아지는 경향을 보였으나 처리간 통계적 유의성은 없었다(P>0.05). 계란의 난황내 지방산 함량은 linolenic acid와 docosahexaenoic acid (DHA)가 대조구보다 녹차 가공 부산물을 첨가한 처리구에서 증가하는 경향을 보였다.