초이사료 배합설계를 통한 육계 생산성 증대방안

남두석,이진영,공창수,Nam, Doo Seok,Lee, Jinyoung,Kong, Changsu 한국가금학회 2015 韓國家禽學會誌 Vol.42 No.3

본 총설은 부화 후 1주일간 급여되는 초이사료 적용의 필요성 및 배합설계방안을 제시하여 육계생산성을 증대하는 방안을 살펴보고자 한다. 육계는 지난 수년 간 괄목할 만한 증체 속도 증가, 출하일령 단축 그리고 사료효율 향상을 보 여줬다. 이는 육종 개량, 사육 환경 개선, 과학적인 사양관리기법 적용 및 적정 영양공급 등의 결과이며, 한국의 경우 다른 나라에 비해 육계사육기간이 매우 짧아, 부화 후 약 31일령이면 출하가 이루어지고 있는 실정이다. 따라서 육계초기 1주일간은 전체 사육기간의 20% 이상을 차지할 뿐만 아니라, 초기성장이 출하체중과 일령 그리고 사료효율에 지대한 영향을 미치고 있으므로 초기 1주일간의 사료공급을 통한 생산성 향상이 매우 중요하다. 생후 7일령까지의 어린 병아리는 소화기관 미발달과 효소의 분비 및 활력 부족으로 사료 내 영양소의 소화 흡수 및 이용률이 낮은 편임을 고려하여, 초이사료의 급여를 위한 영양적 접근 방법으로는 크게 3가지로 나눌 수 있다. 첫 번째로는 단순히 영양수준을 올리기보다는 양질의 원료 사용, 특히 단백질과 탄수화물 이용률 증진을 위 한 선택적인 원료 사용 및 원료의 가공처리가 필요하다. 에너지 공급의 경우, 에너지 수준 못지않게 에너지 공급원이 중요한데, 특히 불포화지방산공급원인 식물성이 기름 첨가를 권장한다. 영양소 공급의 경우, 단백질 함량을 증가시키기보다는 이상적 아미노산 비율에 따른 필수아미노산 공급이 중요하다. 필요 시 효소제를 비롯한 항생제 등의 대체 물질 첨가를 통해 항병력이나 소화흡수율을 향상시키는 방안을 고려해 볼 수 있다. 아울러 기타 제한 아미노산의 충족에 대한 연구와 부화 후 7일간 사료 내 전해질 균형의 영향에 대한 연구가 앞으로 필요하다. There are approximately 1,500 broiler farms in Korea, each raising 55,000 birds. Ninety-five percent of the farms are contracted with Integration Company. According to the Korean broiler performance index, broilers in Korea are marketed at 32 days with 1.52 kg of body weight. In contrast, the market age and body weight of broilers are 47 days/2.8 kg in the United States and 42 days/2.5 kg in Europe. Because of the younger market age of the Korean broiler, the pre-starter feed is important. Chicks exhibit poor absorption of dietary nutrients up to 7 days after hatching due to an immature digestive system and low enzyme secretion rate and activity. At the beginning of hatching, chicks obtain their nutrients from the egg yolk sac. It is highly recommended that chicks, after consuming the nutrients in the egg yolk sac, are given supplemented pre-starter feed to increase early growth rates and improve the performance of broiler production. Pre-starter nutrient requirements are not expressed in NRC, so Korean feeding standards for poultry and commercial breeding companies determine the nutrient requirements of pre-starter broiler chickens. Three approaches are followed to formulate specially designed pre-starter feeds for broiler chicks: (i) selective use of raw materials, (ii) proper standards of nutrient supply, and (iii) application of feed additives such as exogenous enzymes. In the selection of raw materials, those with high digestibility can be used. The absorption rate of carbohydrates in grains can be increased through feed processing at high temperature and high pressure. Soy proteins and fish meal can also be added as protein sources. As an energy source, vegetable oils are preferred over animal fats because of the former's high digestibility. It is suggested that the levels of proteins and amino acids are higher in pre-starter feed than in starter feed. With regard to energy, the sources of energy are more important than the levels of energy in feed. Feed additives such as exogenous enzymes can be used to improve nutrient digestibility. In addition, organic acids and plant extracts can be used as alternatives to animal growth promoters to stimulate immunity and prevent diseases. The growth performance of broilers is affected by various factors, such as management and disease control, in addition to the nutritional strategy; however, nutritional strategies play an important role in improving the productivity of broilers. Therefore, nutritional strategies, along with management and disease control, are required for improving the productivity of broilers in Korea.

육계에서의 칼슘 및 인 영양의 최신 연구 동향

이채원 ( Chae Won Lee ),공창수 ( Changsu Kong ) 한국축산학회 2023 축산기술과 산업 Vol.10 No.2

Calcium (Ca) and phosphorus (P) are essential for skeletal integrity and bird growth. In plant-based broiler diets, Ca and P are supplied by adding inorganic sources. Precision feed formulation involves accurately meeting the broiler requirements, and to achieve this, evaluating the availability of Ca and P in feed ingredients is necessary. Since Ca and P are deeply related to intestinal absorption and utilization, evaluating the Ca or P availability in feed ingredients requires an understanding of the metabolism of these two nutrients. Moreover, the concentrations and ratios of Ca and P in diets must be considered. Currently, broiler diets are formulated based on total Ca and available P contents, and generally, phytate P is used as available P. When formulating feed based on total nutrients content, there is a risk of oversupplying Ca or P, which is beyond the requirement. Therefore, it is imperative to accurately provide the available amounts of Ca and P to meet the requirements of broilers. Recent studies evaluating the digestibility of Ca or P in feed ingredients have led to the proposal of using digestible Ca and P as terms for available Ca and P. Digestibility can be measured by using total tract retention and ileal digestibility. However, specific standardized protocols have not been established, resulting in inconsistent digestibility values across experiments. Furthermore, with the constant genetic evolution of breeder companies, recommended requirements must be adjusted to enhance nutrient utilization and improve growth performance. This study discusses recent trends in Ca and P research in broilers, focusing on evaluating the digestibility of Ca and P in feed ingredients and measuring Ca and P requirements in poultry.

육계에서 에너지 및 조단백질 저감 사료 내 효소제의 적용 효과

김웅래(Woong Lae Kim),권소희(So Hee Kwon),김관응(Kwan Eung Kim),김은집(Eun Jib Kim),안수현(Su Hyun An),공창수(Changsu Kong),김수기(Soo Ki Kim),안병기(Byoung Ki An) 한국가금학회 2020 韓國家禽學會誌 Vol.47 No.3

대사에너지와 조단백질 수준을 낮춘 실험사료 내에 여러 종류의 효소제를 첨가, 급여하고 성장 성적을 조사함으로써 효소제의 가치를 평가하기 위한 목적으로 본 연구를 수행하였다. 부화 직후 동일한 사양 조건과 사료 급여 조건에서 사육한 7일령 수평아리 750수를 공시하였고(5처리, 6반복, 반복당 25수), 대사에너지와 조단백질 수준을 Ross 308의 권장 수준에 유사하도록 배합한 시판사료를 대조구로 하였고, 대사에너지를 100 kcal 낮추고, 조단백질 수준을 1.0% 저감시킨 사료에 4종의 효소제품을 각각 첨가한 실험사료 급여구(T1-T4)로 구분하였다. 21일령까지 전기사료(starter diet)를, 이후 28일령까지 후기사료(grower diet)를 급여하였다. 에너지 및 조단백질 저감 사료 내 효소제 첨가 급여 후 증체량과 사료섭취량에서는 처리간에 유의한 차이가 없었다. 사육 전 기간의 사료요구율(FCR)은 고에너지 대조구에서 유의하게 낮은 결과가 관찰되었고(P<0.001), 효소제 첨가구간에는 큰 차이를 보이지 않았다. 대조구의 1.5 kg 도달 추정 일령은 26.34일이었고, 효소제를 첨가한 처리구에서는 26.39일(T2)부터 26.84일(T4) 사이로 추정되었다. 혈액 영양지표 성분의 농도에서는 처리간에 유의한 차이가 없었다. 맹장균총 수에서는 차이가 없었으나, 우점균 조성에서는 처리간에 차이를 관찰할 수 있었다. 공장 내용물의 점도에서는 처리간에 차이가 없었으나, 회장 내용물 점도는 T2 첨가구에서 유의하게 낮은 것으로 나타났다(P<0.05). 결론적으로 에너지와 조단백질 수준을 낮춘 실험사료 내 효소제의 첨가급여는 사료요구율을 제외한 성장 성적에 영향을 미치지 않았으며, 생리적 지표에서도 큰 차이를 보이지 않았다. This study investigated the effects of the addition of commercial enzyme products to broiler feed with reduced levels of metabolizable energy and crude protein on the growth performance, blood profiles, and cecal microflora. A total of 750 seven-day-old male Ross 308 broiler chicks were randomly allotted to five treatment groups with six replicates (25 birds/replicate) for 28 days. A corn-wheat-soybean meal-based diet was formulated to meet or exceed the nutrient recommendations and used as the control diet. Experimental diets with metabolizable energy reduced by 100 kcal/kg and crude protein by 1% were formulated containing four different commercial enzyme products. Feed intake and weight gain were not affected by the dietary treatments; however, feed conversion ratios were significantly lower (P<0.01) in the control group than in the other treatment groups during the entire experimental period. There were no significant differences in the blood profiles and cecal microflora between the dietary treatments. However, the viscosity of jejunal contents in chicks fed a diet with enzyme B was significantly lower than that in the other groups. The tentative marketing age was unaffected by any of the dietary treatments, and ranged from 26.39 d to 26.84 d. Collectively, the use of commercial enzymes contributed to a similar weight gain as that in chicks fed diets with reduced energy and crude protein levels; however, it failed to maintain the feed conversion ratio.

초기 육계 사료내 토착미세조류(Parachlorella sp.) 첨가에 따른 성장 및 면역반응 변화

안수현(Su Hyun An),주상석(Sang Seok Joo),이효건(Hyo Gun Lee),김지훈(Z-Hun Kim),이창수(Chang Soo Lee),김명후(Myunghoo Kim),공창수(Changsu Kong) 한국가금학회 2020 韓國家禽學會誌 Vol.47 No.1

The present study determined the effect of dietary cultivated microalgae (Parachlorella sp.) on the growth and immune responses of pre-starter broilers. A total of 320 one-day-old birds (Ross 308) were allocated to 4 treatments with 8 blocks in a randomized complete block design. The four experimental diets consisted of a corn-soybean meal-based control diet, and three diets contained 0.5%, 1.0%, and 1.5% microalgae powder at the expense of cornstarch in the control diet. After feeding the experimental diets for 7 days, the body weight and feed intake of all birds were measured, and 8 birds were randomly selected from each treatment. Peripheral blood mononuclear cells (PBMCs) and serum were harvested for immune profile assessment, including cytokines and cell migration receptors. No differences in growth performance were observed among the treatments. The birds that were fed diets containing graded levels of microalga showed a linear increase in the mRNA expression of cytokine genes in PBMCs, including that of IL2, IL1β, and IL18 (P<0.05). With respect to the chemokine receptor genes in PBMCs, mRNA expression of CCR2, CCR9, and ITGA4 changed quadratically (P<0.05), but that of CCR7 increased linearly (P<0.01). Cytokine protein secretion in blood, including that of IL-1β and IL-6, increased linearly (P<0.01) with an increase in the microalgal content. Overall, the present results show that the indigenous microalgae powder used in this study could stimulate immunity with no detrimental effects on the growth performance of pre-starter broiler chickens.