農業科學技術硏究, 第 49 輯, 2014 年 12 月 Agricultural Science & Technology Research, Vol. 49 갈색거저리 (Tenebrio molitor L.) 첨가급여가산란계의생산성과계란의품질에미치는영향 김선곤 1 구희연 1 김정은 1 강성주 1 선상수 2 1 전남농업기술원곤충잠업연구소, 2 전남대학교동물자원학부 Effect of Yellow Mealworms (Tenebrio molitor L.) Feed Supplementation on Egg Productivity and Quality in Broiler S.G. Kim 1, H.Y. Koo 1, J.E. Kim 1, S.J. Kang 1 and S.S. Sun 2 1 Insects and Sericultural Research Institute, Jeollanamdo Agricultural Research and Extention Services, 2 Department of Animal Science, Chonnam National University ABSTRACT Animal sources protein would be important for egg production in layers. Yellow mealworm (MW) was supplemented in layers feed to test as a protein sources for animal. Layers (Hy-Line Brown, one-hundred twenty, 15 weeks old) were randomly assigned in three treatment (control, 1% MW, 2% MW). Animal diet was mixed based on nutrient requirement for layers and then fed 12 weeks. Egg production rate was increased significantly (p<0.05) in mealworm supplemented group than that in control group. Egg production increased about 2~3% would be big benefit for poultry farmers. Egg shell color and Hough Unit were reduced in both treatment groups. However, linoleic acid and linolenic acid were significantly (P<0.05) increased in mealworm supplemented groups. Saturated fatty acid and unsaturated fatty acid were not affected by mealworm supplementation. Therefore, mealworm supplementation would be positive effect on egg production and egg quality in layers. Additional key words: Mealworm, Egg Productivity, Egg Quality, Layers 서론산란계에서생산된계란은완전식품으로서난각, 난백및난황으로구성되어있다. 계란은평균중량을 60g으로가정했을때, 난각이전체중량의 10.5% 를차지하고있으며, 나머지가가식부분으로이중난황이 31.0%, 난백이 58.5% 를차지하고, 가식부분중 75% 는수분이며, 인간이영양소로이용할수있는계란의고형물은계란한개당약 25% 정도라고보고되었다 (Na, 2010). 이밖에도계란의구성성분에대한많은선행연구가진행되었는데, Cunningham 등 (1960) 에따르면닭의연령이증가할수록계란내난백의비율은감소하는반면난황비율은증가하였고, Silversides - 1 -
(1994) 은산란주령이경과할수록난백높이는감소하지만, 계란중량과난백의총량은증가한다고보고하고있다. 산란일령이증가할수록계란의품질이저하할수있다 (Kim, et al., 2014). 일반적으로계란의중량은소비자가계란구매시우선선택지표이며, 계란의모양, 난각파손상태및청결도또한소비자의사에영향을준다 (Genchev, 2012). 곤충은여러종류의동물에서중요한자연식품으로인식되어왔다 (Anand et al., 2008). 예를들면, 곤충들은사람과동물들을위한영양소일뿐만아니라, 의약품과유기물을재활용하는용도로이용되고있다. 곤충을사육하면다른동물성단백질공급원에비하여적은면적에낮은비용으로사육할수있어서미래에유망한산업이다. 더욱이대부분의곤충종들은식물성단백질원을동물성단백질로바꾸는데대단히효과적이다 (Premalatha et al., 2011). 곡류위주의음식을섭취하는개발도상국에서대부분의식용곤충들은저렴하고좋은단백질과무기물공급원이다 (Ifie and Emeruwa, 2011). 거저리 (Mealworms, Tenebrio molitor L.) 는작은포유류와파충류를포함한애완동물의먹이로이용되고있으며, 곤충체내에 44-70% 의단백질을함유하고있어서좋은사료원이기도하다 (Ramos- Elorduy et al., 2002; Oonincx and de Boer, 2012). 농업적으로도거저리와같은가식용곤충들은단백질, 지질, 탄수화물, 비타민함량이높아서가금류의사료원으로우수하게평가되고있다 (Ramos-Elorduy and Pino, 1990). 또한거저리는필수아미노산함량이높으며, 딱정벌레목에속하는곤충들은특히유충시기에지방함량이높다 (Cerritos, 2009). 이러한높은영양소함량때문에, 거저리는년중이용이가능한미래유망한사료원으로가능성이높다. 다른보고에의하면거저리는암모니아를배출하지않으며 (Oonincx et al., 2010), 환경오염이낮다 (Pimental et al., 1975) 고한다. 건조한거저리유충은사료섭취량, 증체량, 사료효율에부정적인영향없이육계스타터사료에 10% (DM) 까지첨가할수있다. 또한거저리첨가사료에대한조직감이나기호성에따른영향은 없었다 (Ramos-Elorduy et al., 2002). 산란계에대한연구는제한적이지만거저리유충이산란계첨가사료로적합하며 (Giannone, 2003), 건조한거저리는산란계에서어분을대체할수있는좋은사료원이다 (Wang et al., 1996). 산란계에있어산란초기는전산란기간동안의난생산성에지대하게영향을미친다. 산란초기기간동안적절한수준의에너지, 조단백질및필수영양소를공급함으로써산란율이 90~95% 수준에도달하고, 난중은약 60 g까지증가하며, 체중은약 2.1 kg까지증가하게된다 ( 한국사양표준 -가금, 2012). 또한, 산란피크기간중영양소공급을적절히함으로서전체산란기간동안의난생산성이잘유지될수있다 (Leeson and Summers, 2001). 현재까지산란계에관한여러연구들이수행되었지만곤충이나거저리를사료공급원으로이용한사례는많지않다. 본연구는산란계사료내갈색거저리를첨가급여하여산란계의계란생산성과계란의품질을조사하기위하여실험을수행하였다. 재료및방법 1. 시험동물및사양관리시험동물은 1일령의하이라인 (Hy-line) 종산란계를 15주동안육추한후에 120 수를공시하여 3 개처리구 ( 대조구, 1% MW, 2% MW) 에각각 40수씩완전임의배치하고 12주동안시험하였다. 사양관리는전남술대학교부속동물사육장의관행에준하여 3단철제케이지에서사육하였다. 점등은전사양기간동안 24시간종일전등을실시하였고, 계사온도는 24~22 까지사육실온도관리프로그램에따라조절하였다. 시험사료는시판산란초기사료 ( 광주축산업협동조합 ) 를기초사료로이용하였으며, 건조된갈색거저리 (Mealworms, MW) 유충을분쇄하여수준별로첨가하였다. 영양소함량은산란초기영양소함량에적합한배합을하였다. 동물실험은동물보호법제13조및제14조에의거하여 전남대학교동물실험윤리위원회 에의해사전승인되었다. - 2 -
2. 산란계의생산성사료섭취량은급여량과잔량을측정하여계산하였으며, 매일동일한시간에산란수와난중을측정하였으며, 산란율은실험기간중생산된총산란수를공시수로나누어백분율로계산하였다. 난황은총난중에서흰자를제거한후평균난황을측정하였다. 3. 계란의품질계란의품질은실험종료후각처리구당 30개의계란을수집한다음, 계란의품질을측정하였다. 난품질중난각강도는난각강도계 (QC-SPA, TSS, UK) 를이용하였고, 난각색도, 난백고, Hough Unit과난황의색도는계란품질측정기 (QCM+, TSS, UK) 를이용하여측정하였다. 4. 난황지방산함량계란의난황내지방산조성을조사하기위해서각처리구당 5개씩수집된계란의난황을난백으로부터분리, 동결건조하여이후 0.5 g의난황을취한다음 Smith 등 (2002) 의방법에따라 saponification과메탄올에녹인 0.5 N potassium hydroxide를이용한 esterification을실시하였다. 이후헥산을이용하여 fatty acid methyl ester(fame) 을추출하였으며 scintillation vial로헥산을옮겨담은다음 GC-MSD (6870N-5973, Agilent, US) 를이용하여난황내지방산을분석하였다. 이때 GC-MSD는컬럼을 Fused silica capillary column (100 m 0.25 mm 0.2 um film thickness, SP(TM) 2560 No.48340-01) 으로하였다. 4. 통계분석모든얻어진결과에대한통계분석은 Statistical Analysis System(SAS, 2005) 의 General Linear Model (GLM) procedure를이용하여실시하였고, 처리구간의유의성검정은 Duncan의다중검정 (Duncan, 1955) 을통해유의수준 P<0.05에서검정하였다. 결과및고찰 산란계의생산성연구는오래전부터많은생산자들이실험하고있는내용이다. 사료효율을증가시키고사료요구율을감소시키는생산성증가는생산자의경제적이익을가져올뿐만아니라계란의풀질을향상시키는계기가되었다. 산란계의사료는영양소요구량에맞추어적합하게배합하는것이가장중요하다 (Table 1). 단백질함량을조절하기위하여대두박과거저리의함량을조절하였다. Table 1. Formula and chemical composition of experimental diet for layers. Ingredients (%) Corn 67.55 Soybean meal 17.28~18.28 Corn gluten meal 3.15 Rapeseed meal 0.50 Limestone 8.23 Vitamin premix 1 0.20 Mineral premix 2 0.10 Mealworm 1~2 Calculated chemical composition ME (kcal/kg) 2,800 CP (%) 16.00 Ca (%) 3.70 P (%) 0.40 1 Provided per kilogram of diet: vit. A, 5,500 IU; vit. D3, 1,100 IU; vit. E, 11 IU; vit. B12 0.0066 mg; riboflavin, 4.4 mg; niacin, 44 mg; pantothenic acid, 11 mg (Ca-pantothenate, 11.96 mg); choline, 190.96 mg (choline chloride 220 mg); menadione, 1.1 mg (menadione sodium bisulfite complex, 3.33 mg); folic acid, 0.55 mg; pyridoxine, 2.2 mg (pyridoxine hydrochloride, 2.67 mg); biotin, 0.11 mg; thiamin, 2.2 mg (thiamine mononitrate, 2.40 mg); ethoxyquin, 125 mg. 2 Provided in mg per kilogram of diet; MnSO 4, 120; ZnSO 4, 100; FeSO 4, 60; CuSO4, 10; Ca (IO 3) 2, 0.46; CaCO 3, min: 150 max: 180. - 3 -
Table 2. Effect of yellow mealworm supplementation on productivity of laying hens Treatments Control 1% MW 2% MW Egg production (%) 72.5±1.35 a 75.1±1.59 b 74.8±1.27 b Egg weight (g) 58.9±0.61 56.4±0.82 58.2±0.74 Feed intake (g) 116.8±1.07 117.3±2.01 118.31±1.83 * Mean values within a row different superscript are different (p<0.05). Table 3. Effect of yellow mealworm supplementation on egg quality of layers Treatments Control 1% MW 2% MW Egg shell color 25.36±0.70 24.18±1.04 23.84±0.89 Albumin height (mm) 5.89±0.27 5.73±0.38 5.81±0.29 Haugh unit 81.67±2.46 80.78±2.19 79.15±3.16 Yolk color 6.71±0.11 6.90±0.16 6.21±0.27 Egg shell strength (kg/cm 2 ) 4.57±0.16 4.92±0.26 5.05±0.25 거저리첨가급여에의한산란계의생산성은 Table 2에나타나있다. 산란율은대조구에비하여거저리첨가구에서유의적으로 (p<0.05) 증가하였다. 산란율의 2~3% 증가는농가의소득증대에커다란영향을줄수있다. 그러나난중에는별다른영향이나타나지는않았지만, 사료섭취량은거저리첨가급여에의하여약간증가하는경향을보였다. 직접적인곤충은아니지만지렁이분변토발효사료첨가제의급여에의하여산란능력개선효과를보고하였다 (Hwangbo et al., 2014). 또한조단백질급여수준에따라난중에관한영향을조사한많은연구가있으며, 대부분의경우조단백질수준이높을수록난중은증가하는결과를나타낸다 (Parsons et al., 1993; Scheideler et al., 1998). 그러나산란계사료에있어매리골드추출물의첨가는계란내과산화를억제함으로써저장기간동안의계란의신선도유지에긍정적인영향을미치는것을확인하였고, 천연항산화제로써의잠재적인가능성을확인하였다 (Kim, 2014). 일반적으로계란중량과난황중량또는난백중량사이에유의적인정의상관관계가존재하며, 계란의중량이증가할수록난백높이의감소와함께계란신선도평가시대표적인요인인 Haugh unit이감소함이보고되고있다 (Silversides, 1994; Mitrovic et al., 2010). 따라서본실험결과들은이전의연구와유사하며, 산란된계란을산란주령 과관계없이중량규격으로분류하였을때난각, 난황및난백중량은중량규격대가증가함에따라동일하게증가하지만, 난백높이와 Haugh unit 은중량규격대가증가할수록낮아지는것을확인할수있었다 (Lee, 2013). 산란계의사육방법이다른산란계운동장사육은산란초기의생산성을저하시키나, 중 후기의생산성은약간증가를보였으며, 면역성은증가하였으나스트레스는다소간더받는것으로나타났다. 따라서초기산란율을향상시키고, 적절한외부의환경에의한스트레스를줄일수있는사육환경이뒷받침된다면운동장사육이동물복지형사육이매우적합한사양방법이라고생각된다 (Kim, 2013). 계란의품질에관한결과는 Table 3에나타나있다. 난각의색깔은거저리첨가급여에의하여약간감소하는경향을보였다. 이러한결과는다른연구들과반대되는내용을보여주고있다. 또한 Hough Unit 는거저리첨가급여에의하여약간감소하였다. 그러나난각강도는거저리첨가급여에의하여조금증가하는경향을보였다. 난황색은계란의품질을판단하는데있어중요한요소로자리잡고있다 (Delgado-Vargas et al., 1998). 전세계적으로소비자들은금황색, 오렌지색등과같은짙은난황색을선호한다 (Hasin et al., 2006). 다른첨가시험에서약용식물가공부산물을산란계사 - 4 -
료에적용한결과, 대조구에비해약용식물가공부산물을첨가한처리구에서유의차는없었으나, 산란율및 Haugh unit이개선되었으며 (Kim et al., 2006), 산란계사료에인도자생허브 5종을첨가한연구에서허브를첨가한처리구가대조구에비해난질및 Haugh unit이개선되었다는연구결과 (Shon et al., 2004) 와일치한다. Haugh unit은계란의내부난질을평가하는지표이며, 시간경과에따라감소하는경향을나타났다 (Williams, 1992). Haugh unit은영양적요인에의해보통은잘변화하지않지만 (Naber, 1979), 천연항산화영양소의급여후난백의품질이향상되어 Haugh unit이개선되는결과가나타나기도한다 (Keshavarz, 1996; Sahin et al., 2003). 또한산란계가고온에노출되면체열을방출하기위해열성다호흡을함으로써혈액 CO 2 가과다하게배출되어호흡성알칼리혈증 (alkalosis) 이일어나, 산란율, 난중및계란의비중등의저하원인이되기도한다 (Deaton at al., 1986). 거저리첨가급여에의하여 linoleic acid 와 linolenic acid 는대조구에비하여처리구에서모두유의적으로 (p<0.05) 증가하였다. Myristic acid 와 Arachidonic acid 는거저리첨가급여에의하여약간증가하는경향을보였다. 그러나다른지 방산들은별다른영향을보이지않았다. 포화지방산과불포화지방산의함량에도변화가나타나지않았다. 그러나다른연구보고에의하면첨가에의하여난황중의불포화지방산및포화지방산의비율은처리구간유의적인차이를나타내었다 (p<0.05) (Hwangbo et al., 2014). 일반적으로인간의건강을위하여식품내 n-6/n-3의이상적인비율은 4 : 1 이하로알려져있다 (Park and Park, 2012). 본결과는거저리사료첨가급여가일반계란과비교할때이상적인비율에가까워짐을나타내고있기때문에고품질계란생산에기여할수있음을보여준다. 요약산란계의생산성을증진시키기위하여동물성단백질의공급이매우중요하다. 동물성단백질을높혀주기위하여거저리 ( 곤충 ) 의산란계사료에이용성을실험하였다. 하이라인산란계를 15주동안육추한후에 120 수를공시하여 3개처리구 ( 대조구, 1% MW, 2% MW) 에완전임의배치하고 12 주동안시험하였다. 시험사료는산란초기사료에건조된갈색거저리 (Mealworms, MW) 유충을분 Table 4. Effect of yellow mealworm supplementation on fatty acid composition of egg yolk. Treatments Control 1% MW 2% MW Myristic acid (C14:0) 0.33±0.01 0.38±0.02 0.36±0.01 Palmitic acid (C16:0) 24.53±0.32 24.72±0.38 25.17±0.41 Palmitoleic acid (C16:1n7) 2.38±0.20 2.72±0.31 2.63±0.26 Stearic acid (C18:0) 12.36±0.45 11.83±0.52 12.93±0.47 Oleic acid (C18:1n9) 43.74±1.38 42.94±2.09 44.17±1.83 Linoleic acid (C18:2n6) 13.97±1.05 a 14.18±2.18 ab 15.03±1.53 b Linolenic acid (C18:3n3) 0.22±0.01 a 0.35±0.02 b 0.31±0.02 b Arachidonic acid (C20:4n6) 3.38±0.20 3.94±0.31 3.62±0.27 SFA 1 37.22±0.61 36.93±0.72 38.46±0.58 UFA 2 63.69±0.61 64.13±0.83 65.76±0.73 UFA/SFA 1.71±0.04 1.74±0.08 1.71±0.06 1 Saturated fatty acid, 2 Unsaturated fatty acid. * Mean values within a row different superscript are different (p<0.05). - 5 -
쇄하여수준별로첨가하였다. 산란율은대조구에비하여거저리첨가구에서유의적으로 (p<0.05) 증가하였다. 산란율의 2~3% 증가는농가의소득증대에커다란영향을줄수있다. 난각의색깔은거저리첨가급여에의하여약간감소하는경향을보였다. Hough Unit 는거저리첨가급여에의하여약간감소하였다. 거저리첨가급여에의하여 linoleic acid 와 linolenic acid 는대조구에비하여처리구에서모두유의적으로 (p<0.05) 증가하였다. 포화지방산과불포화지방산의함량에도변화가나타나지않았다. 결과적으로거저리사료첨가급여가일반계란과비교할때이상적인비율에가까워짐을나타내고있기때문에고품질계란생산에기여할수있음을보여준다. 검색어 : 거저리, 계란생산성, 계란품질, 산란계참고문헌 1. Anand H, Ganguly A, Haldar P 2008 Potential value of acridids as high protein supplement for poultry feed. International Journal of Poultry Science 7(7): 722-725. 2. Cerritos R 2009 Insects as food: an ecological, social and economical approach. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 3. Cunningham FE, Cotterill OJ, Funk EM 1960 The effect of season and age of bird. 1. on egg size, quality, and yield. Poultry Sci 39: 289-299. 4. Deaton JW, Reece FN, Lott BD 1986 Effect of summer cyclic temperatures versus moderate temperature on laying hen performance. Poultry Sci 65: 1649-1651. 5. Delgado-Vargas F, Paredes-Lopez O, Avila- Gonzalez E 1998 Effects of sunlight illumination of marigold flower meals on egg yolk pigmentation. J Agric Food Chem 46: 698-706. 6. Duncan DB 1955 Multiple range and multiple F tests. Biometrics 11: 1-42. 7. Genchev A 2012 Quality and composition of Japanese quail eggs (Coturnix japonica). TJS 10: 91-101. 8. Giannone M 2003 A natural supplement made of insect larvae. Rivista di Avicoltura, 72(4): 38, 40-41. 9. Hasin BM, Ferdaus AJ, Islam MA, Uddin MJ, Islam MS 2006 Marigold and orange skin as egg yolk color promoting agents. J Poult Sci 5: 979-987. 10. Hwangbo J, Park SO, Park BS 2014 Effect of Dietary Fermented Earthworm Cast Additives on Odor Reduction of Poultry House and Egg Production. Korean J. Poult. Sci. 41(1): 1-5. 11. Ifie I, Emeruwa CH 2011 Nutritional and anti-nutritional characteristics of the larvae of Oryctes monoceros. Agric Biol J N Am 2(1): 42-46. 12. Keshavarz K 1996 The effect of different levels of vitamin C and cholecalciferol with adequate or marginal levels of dietary calcium on performance and eggshell quality of laying hens. Poultry Sci 75: 1227-1235. 13. Kim EJ 2014 The Dietary Effects of Marigold Extracts on Egg Production, Egg Quality and the Production of Lutein Fortified Chicken Eggs. Korean J. Poult. Sci. 41(2): 135-142. 14. Kim JH, Na JC, Kim SH, Jang BG, Kang HS, Lee DS, Lee SJ, Jwa SH 2006 Effect of dietary medicinal plant byproducts on egg production and egg quality in laying hens. Korean J Poult Sci 33: 121-126. 15. Kim KS, Lee SK, Choi YS, Ha CH, Kim WH 2013 Effects of Production Performance, Immunity and Egg Quality by Raising on Exercise Yard in Laying Hens. Korean J. Poult. Sci. 40(2): 097~103. 16. Kim SG, Koo HY, Kim JE, Oh HK, Kang SJ, Sun SS 2014 Feed Supplementation of Yellow Mealworms (Tenebrio molitor L.) Improves Blood characteristics and Meat quality in Broiler. Korean J. Poult. Sci. (accepted). - 6 -
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