Abstract
This study was conducted to investigate the effects of dietary conjugated linoleic acid (CLA) and oil containing unsaturated fatty acid supplementation on egg production and quality in laying hens. Two hundred-eighty eight, 36 week old ISA brown commercial layer, were employed in a 5 week feeding trial. Dietary treatments are 1) BO (basal diet + 1% soybean oil + 1% oat), 2) BS (basal diet + 1% safflower oil + 1% oat), 3) BF (basal diet + 1% free fatty acid + 1% oat), 4) CD (basal diet + 1% CLA containing diglyceride + 1% oat), 5) CT (basal diet + 1% CLA containing triglyceride + 1% oat) and 6) CP (basal diet + 1% CLA by-product + 1% soybean oil). For overall period, hen-day egg production was not significant among treatments (P>0.05). Egg shell breaking strength at 3 weeks in CP treatment was significantly lower than BS, BF, CD and CT treatments (P<0.05) and that at 4 weeks in BO and CP treatments was significantly lower than others (P<0.05). Egg shell thickness at 3 and 4 weeks in CP treatment was significantly lower than BS, BF, CD and CT treatments (P<0.05). Egg weight at 3 and 4 weeks in CP treatment was significantly lower than others (P<0.05). Yolk height at 4 weeks in BF and CT treatments was significantly highest compared to BO, CD and CP treatments (P<0.05) and among BO, CD and CP treatments, that in BO and CD treatments was significantly higher than CP treatment (P<0.05). At 4 weeks, yolk color in CP treatment was significantly higher than BO and BS treatments (P<0.05). Haugh unit at 3 and 4 weeks in BO and CP treatments was significantly lower than others (P<0.05). In conclusion, supplementing CLA and oil containing unsaturated fatty acid for laying hens improved egg shell breaking strength, egg shell thickness, egg weight, yolk height, yolk color and haugh unit.
본 시험은 산란계 사료내 conjugated linoleic acid(CLA)와 불포화지방산 함유 oil의 첨가가 산란율과 계란 품질에 미치는 영향을 알아보고자 실시하였다. 시험 동물은 36주령 ISA Brown 갈색계 288수를 공시하였으며, 사양 시험은 5주간 실시하였다. 시험 설계는 1) BO(basal diet + 1% soybean oil + 1% oat), 2) BS(basal diet + 1% safflower oil + 1% oat), 3) BF (basal diet + 1% free fatty acid + 1% oat), 4) CD(basal diet + 1% CLA containing diglyceride + 1% oat), 5) CT(basal diet + 1% CLA containing triglyceride + 1% oat), 6) CP(basal diet + 1% CLA by-product + 1% soybean oil)로 6개 처리를 하여 처리당 8반복, 반복당 6수씩 완전 임의 배치하였다. 산란율에 있어서는 처리구간에 유의적인 차이를 보이지 않았다(P>0.05). 난각 강도에 있어서는 3주째에 CP 처리구가 BS, BF, CD, CT 처리구와 비교하여 유의적으로 낮았으며(P<0.05), 4주째에는 BO와 CP 처리구가 다른 처리구들과 비교하여 유의적으로 낮았다(P<0.05). 난각 두께에서는 3주와 4주째 모두에서 CP 처리구가 BS, BF, CD, CT 처리구와 비교하여 유의적으로 낮았다(P<0.05). 난중에 있어서는 3주와 4주째 모두에서 CP 처리구가 다른 처리구들과 비교하여 유의적으로 낮았다(P<0.05). 시험 4주째의 난황고에 있어서는 BF와 CT 처리구가 BO, CD, CP 처리구와 비교하여 유의적으로 가장 높았으며(P<0.05), BO와 CD 처리구는 CP 처리구와 비교하여 유의적으로 높았다(P<0.05). 또한, 4주째의 난황색에 있어서는 CP 처리구가 BO와 BS 처리구와 비교하여 유의적으로 높았다(P<0.05). 호우 유닛(Haugh unit)에 있어서는 3주와 4주째 모두에서 BO와 CP 처리구가 다른 처리구들과 비교하여 유의적으로 낮았다(P<0.05). 본 시험 결과 산란계 사료내 CLA와 불포화지방산 함유 oil을 첨가.급여하면 산란율에는 아무런 영향을 미치지 않으나, 계란 품질에 있어서는 향상되는 결과를 보였다.