• 한국가금학회지
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• 제42권1호
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• pp.87-100
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• 2015

It is well known that dietary protein affects the growth performance and carcass composition of poultry. Over the last several decades, numerous studies have been carried out to investigate to optimize the level of dietary protein since the protein is an important and expensive constituent in poultry feed. It is generally accepted that dietary protein should represent a balance of amino acids supporting the requirements for growth and maintenance of birds. A protein with balanced essential amino acids that matches a bird's requirement and sufficient non-essential amino acid nitrogen to enable the synthesis of all of the non-essential amino acids, is referred to as an 'ideal protein'. Feeding of excess protein or amino acids may result in an amount of nitrogen emission. Most common method to reduce nitrogen emission is using diet formulation which has lower dietary crude protein level and higher concentration of amino acid supplements. However, there are conflicting reports whether low protein diets supplemented with synthetic amino acids can obtain the growth performance equal to high protein diets. Excessive nitrogen excretion caused by amino acid imbalance also may influence the environment of poultry house due to ammonia production from uric acid. These environmental conditions may increase the incidence of skin problem or respiratory diseases of chickens. Various strategies based on comprehensive understanding should be tested to optimize nitrogen utilization and reduce nitrogen emission while maintaining the performance in poultry production.

• 한국식품영양과학회지
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• 제22권2호
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• pp.161-164
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• 1993

본 연구에서는 Kjeldahl 방법으로 시유의 질소분획물의 함량과 유청단백질 변성정도를 측정함으로써 이들이 시유의 열처리 정도를 비교할 수 있는 검색의 지표로서 타당하는지 알아보았다. 각 열처리법에 따른 질소분획물들의 함량을 보면, 원유에서는 시료 100g당 총질소가 431.3mg, 케이신질소가 341.0mg, 비케이신질소가 90.3mg, 이 중에서 비단백태질소가 31.6mg그리고 유청단백질소는 58.8mg을 보인 반면, 시유인 저온살균유, 고온순간살균유, 초고온처 리유의 질소분획물들의 함량이 다르게 나타났다. 유청단백질 변성정도는 저온살균유가 26.7%, 고온순간살균유가 32.9%, 초고온살균유가 60.7%, 그리고 초고온멸균유가 38.4%를 보여 열처리 정도가 높아질수록 변성정도도 높게 나타남으로써 열처리법에 따라 유청단백질의 변성정도의 구분이 뚜렷하였다.

• 한국수정란이식학회지
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• 제16권1호
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• pp.47-51
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• 2001

This study was done to examine the relationship between serum chemical values (urea nitrogen, glucose, total protein and cholesterol) of recipients and pregnancy rate following embryo transfer. Blood samples were taken from 184 Holstein heifers or cows on Day 6 or 7 (Day 0=day of estrus) to analysis for serum urea nitrogen, glucose, total protein and cholesterol concentrations. After selection of recipients, frozen Holstein embryos were thawed and directly transferred to recipients non-surgically. The average serum concentrations of urea nitrogen, glucose, total protein and cholesterol were 13.8 mg/dl, 56.5 mg/dl, 7.2 mg/dl, 124.8 mg/dl, respectively. The average concentrations of serum urea nitrogen and cholesterol were lower (P<0.05) in pregnant recipients (10.7 mg/dl, 99.2 mg/dl) than in non-pregnant recipients (13.0 mg/dl, 122.2 mg/dl), respectively, although the concentrations of glucose and total protein were not different. These results show serum urea nitrogen and cholesterol concentrations can be used important factors for selection of recipients in Holstein.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1521-1527
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• 2019

Objective: To study the contribution of plant enzyme and microbial activities on protein degradation in silage, this study evaluated the nitrogen transformation dynamics during ensiling of non- and irradiated alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.). Methods: Alfalfa and red clover silages were prepared and equally divided into two groups. One group was exposed to ${\gamma}$-irradiation at a recommended dosage (25 Gky). Therefore, four types of silages were produced: i) non-irradiated alfalfa silage; ii) irradiated alfalfa silage; iii) non-irradiated red clover silage; and iv) irradiated red clover silage. These silages were opened for fermentation quality and nitrogen components analyses after 1, 4, 8, and 30 days, respectively. Results: The ${\gamma}$-irradiation successfully suppressed microbial activity, indicated by high pH and no apparent increases in fermentation end products in irradiated silages. All nitrogen components, except for peptide-N, increased throughout the ensiling process. Proteolysis less occurred in red clover silages compared with alfalfa silages, indicated by smaller (p<0.05) increment in peptide-N and free amino acid N (FAA-N) during early stage of ensiling. The ${\gamma}$-irradiation treatment increased (p<0.05) peptide-N and FAA-N in alfalfa silage at day 1, whereas not in red clover silage; these two nitrogen components were higher (p<0.05) between day 4 and day 30 in non-irradiated silages than the irradiated silages. The ammonia nitrogen and non-protein nitrogen were highest in non-irradiated alfalfa silage and lowest in irradiated red clover silage after ensiling. Conclusion: The result of this study indicate that red clover and alfalfa are two forages varying in their nitrogen transformation patterns, especially during early stages of ensiling. Microbial activity plays a certain role in the proteolysis and seems little affected by the presence of polyphenol oxidase in red clover compared with alfalfaa.

• Current Research on Agriculture and Life Sciences
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• 제6권
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• pp.105-112
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• 1988

질소원(窒素源)을 달리한 비료시용(肥料施用)이 대두(大豆)의 생육(生育), 수량(收量), 영양성분(營養成分) 및 단백질(蛋白質) 소화율(消化率) 등(等)에 미치는 비효(肥效)는 다음과 같다. 대두(大豆)의 생육상황(生育狀況)은 시비조건간(施肥條件間)에 대체로 유사(類似)하였으나 유안구(硫安區)와 무질소구(無窒素區)에 있어서 절수(節數)가 적었다. 근류수(根瘤數)와 무게는 유안구(硫安區)와 무질소구(無窒素區)가 낮았고 그 밖의 처리구(處理區)에 있어서는 차이가 보이지 않았다. 근류수(根瘤數) 당(當) 질소고정력(窒素固定力)은 생육초기(生育初期)와 개화기(開花期)에는 거의 비슷하였으나 pod 신장기(伸長期)에서는 개발복비구(開發複肥區)가 타처리구(他處理區)보다 비교적 높았다. 대두(大豆)의 100립중(粒重) 및 10a 당(當) 수량(收量)은 개발복비구(開發複肥區)가 타처리구(他處理區)보다 높았고 무질소구(無窒素區)는 질소원(窒素源) 비료(肥料)의 시용구(施用區)보다 대체로 낮았다. 또한 대두(大豆)의 조단백질(粗蛋白質) 함량은 질소원(窒素源) 비료(肥料)의 시용구(施用區)가 무질소구(無窒素區)에 비해 높았고 조지방(粗脂肪) 함량은 오히려 낮았다. 조회분(粗灰分) 함량은 시용구간(施用區間)에 대체로 비슷하였으나 조섬유(粗纖維) 함량은 기존복비구(旣存複肥區)가 타처리구(他處理區)에 비해 높았다. Ca, P, Na, K, Mg, Zn, Mn 및 Cu 함량은 시비조건간(施肥條件間)에 대체로 비슷하였으나 Fe 함량은 무질소구(無窒素區)가 질소원(窒素源) 비료(肥料)의 시용구(施用區)에 비(比)해 월등히 낮았으며, 단백질(蛋白質) 소화율(消化率)은 무질소구(無窒素區)에서 가장 높았다.

• Asian-Australasian Journal of Animal Sciences
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• 제19권7호
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• pp.1010-1018
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• 2006

A glucose clamp technique was used to investigate the effects of non-protein energy intake on tissue responsiveness and sensitivity to insulin for glucose metabolism in intact adults male goats. Three goats were fed diets at 1.0, 1.5 and 2.0 times of ME for maintenance, each for 21 d. Crude protein intake was 1.5 times of maintenance requirement in each treatment. Tissue responsiveness and sensitivity to insulin were evaluated using a hyperinsulinemic euglycemic clamp technique with four levels of insulin infusion, beginning at 13 h after feeding. Concentrations of plasma metabolites and insulin were also measured at 3, 6 and 13 h after feeding, for evaluating effects of non-protein energy intake on the metabolic status of the animals. Increasing non-protein energy intake prevented an increase in plasma NEFA concentration at 13 h after feeding (p = 0.03). Plasma urea-nitrogen and total amino-nitrogen concentrations decreased (p<0.01) and increased (p = 0.03), respectively, with increasing non-protein energy intake across time relating to feeding. Plasma insulin concentration was unaffected (p = 0.43) by non-protein energy intake regardless of time relating to feeding. In the glucose clamp experiment, increasing non-protein energy intake decreased numerically (p = 0.12) the plasma insulin concentration at half-maximal glucose infusion rate (insulin sensitivity), but did not affect (p = 0.60) maximal glucose infusion rate (tissue responsiveness to insulin). The present results suggest that an increase in non-protein energy intake may enhance insulin sensitivity for glucose metabolism, unlike responsiveness to insulin, in adult male goats. The possible enhancement in insulin sensitivity may play a role in establishing anabolic status in the body, when excess energy is supplied to the body.

• Asian-Australasian Journal of Animal Sciences
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• 제22권9호
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• pp.1267-1278
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• 2009

Three beef steers fitted with permanent cannulae in the rumen and duodenum were used to determine the effects of protein supply from soyhulls (SH) and wheat bran (WB) on ruminal metabolism, blood metabolites, nitrogen metabolism, nutrient digestion and concentrations of soluble non-ammonia nitrogen (SNAN) in ruminal (RD) and omasal digesta (OD). In a 3${\times}$3 Latin square design, steers were offered rice straw and concentrates formulated either without (control) or with two brans to increase crude protein (CP) level (9 vs. 11% dietary DM for control and bran-based diets, respectively). The brans used were SH and WB that had similar CP contents but different ruminal CP degradability (52 vs. 80% CP for SH and WB, respectively) for evaluating the effects of protein degradability. Ruminal ammonia concentrations were higher for bran diets (p<0.01) than for the control, and for WB (p<0.001) compared to the SH diet. Similarly, microbial nitrogen and blood urea nitrogen were significantly increased (p<0.05) by bran and WB diets, respectively. Retained nitrogen tended (p<0.082) to be increased by SH compared with the WB diet. Intestinal and total tract CP digestion was enhanced by bran diets. In addition, bran diets tended (p<0.085) to increase intestinal starch digestion. Concentrations of SNAN fractions in RD and OD were higher (p<0.05) for bran diets than for the control, and for WB than for the SH diet. More rumendegraded protein supply resulting from a higher level and degradability of CP released from SH and WB enhanced ruminal microbial nitrogen synthesis and ruminal protein degradation. Thus, free amino acids, peptides and soluble proteins from microbial cells as well as degraded dietary protein may have contributed to increased SNAN concentrations in the rumen and, consequently, the omasum. These results indicate that protein supply from SH and WB, having a low level of protein (13 and 16%, respectively), could affect ruminal metabolism and nutrient digestion if inclusion level is relatively high (>20%).

• 농업과학연구
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• 제16권2호
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• pp.201-211
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• 1989

Mucor rennet의 이용(利用) 가능성(可能性)을 타진(打診)하기 위하여 Blue cheese를 제조(製造)하고 그 각종(各種) 질소화합물(窒素化合物)의 특성(特性)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. Blue cheese의 수율(收率)은 calf rennet과 Mucor rennet간(間)에는 큰 차이(差異)가 없었다. 2. 숙성과정중(熟成過程中) cheese의 고형분(固形分) 함량(含量)은 증가(增加)하였고 첨가비율(添加比率)에 따른 차이(差異)는 인정(認定)되지 않았다. 3. water soluble nitrogen은 숙성(熟成)이 진행(進行)됨에 따라 증가(增加)하였으며 숙성초일(熟成初日)부터 calf rennet에 비(比)하여 Mucor rennet 편이 높았고 숙성(熟成) 40일(日)부터는 혼합(混合)rennet이 calf rennet보다 낮았다. 4. non protein nitrogen, peptone amino nitrogen, water soluble protein nitrogen, proteose nitrogen, peptone nitrogen 및 숙성율등(熟成率等)도 water soluble nitrogen과 동등(同等)한 변화(變化)를 보였다. 5. Mucor rennet으로 제조(製造)한 Blue cheese casein을 전기영동(電氣泳動)한 결과(結果) as-casein과 ${\beta}$-casein의 분해도(分解度)가 높았으나 calf rennet로 제조(製造)한 Blue cheese의 as-casein과 ${\beta}$-casein의 분해도(分解度)는 비교적 낮았고 숙성(熟成) 60일(日)에는 Mucor rennet 처리구(處理區)의 casein은 다소 잔존(殘存)함을 알 수 있었다. 6. Blue cheese를 60일간(日間) 숙성(熟成)시켰을때 유리(遊離)아미노산(酸) 함량(含量)은 Mucor rennet으로 제조(製造)한 cheese보다 전(全) 숙성기간(熟成期間)동안 많았다.

• Asian-Australasian Journal of Animal Sciences
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• 제10권4호
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• pp.357-363
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• 1997

The effect of replacement of cotton seed meal (CSM), with various levels and sources of non-protein nitrogenous (NPN), substances on in vitro ruminal fermentation were studied. Cotton seed meal, in control ration provided nitrogen equivalent to 12.5 percent crude protein while in experimental ration was replaced at 30, 50 & 70 percent levels with urea, diammonium phosphate (DAP) and biuret, respectively. The results of incubation upto 48 hours indicated an improvement in digestibility by replacement of CSM with urea and biuret upto 50 percent protein equivalent, but not with DAP. Bacterial count from cultures containing 50% nitrogen from biuret was significantly higher than DAP, urea and CSM. Various sources of nitrogen produced $NH_3-N$ in increasing order of CSM, biuret, DAP and urea. Increasing levels of NPN resulted in progressive increase in the levels of $NH_3-N$. The levels of various NPN sources had no effect on pH. However, the pH values determined for urea and CSM were higher than biuret and DAP.

• Asian-Australasian Journal of Animal Sciences
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• 제16권10호
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• pp.1460-1468
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• 2003

An experiment was conducted to quantify the flow of soluble non-ammonia nitrogen (SNAN) in the liquid phase of ruminal (RD) and omasal digesta (OD), and to investigate diurnal pattern in SNAN flow in OD. Five ruminally cannulated Finnish-Ayrshire dairy cows in a $5{\times}5$ Latin square design consumed a basal diet of grass silage and barley grain, and that supplemented with four protein feeds (kg/d DM basis) as follows: skimmed milk powder (2.1), wet distiller' solubles (3.0), untreated rapeseed meal (2.1) and treated rapeseed meal (2.1). Ruminal digesta was sampled using a vacuum pump, whereas OD was collected using an omasal sampling system at 1.0 h interval during a 12 h feeding cycle. Both RD and OD were acidified, centrifuged to remove microbes and precipitated with trichloroacetic acid followed by centrifugation. The SNAN fractions (free amino acid (AA), peptide and soluble protein) in RD and OD were assessed using ninhydrin assay. Free AA, peptide and soluble protein averaged 60.0, 89.4 and 2.1 g/d, respectively, for RD, and 81.8, 121.5 and 2.5 g/d, respectively, for OD. Although free AA flow was relatively high, mean peptide flow was quantitatively the most important fraction of SNAN, indicating that degradation of peptide to AA rather than hydrolysis of soluble protein to peptide or deamination may be the most limiting step in rumen proteolysis. Diurnal pattern in flow of peptide including free AA in OD during a 12 h feeding cycle peaked 1 h post-feeding, decreased by 3 h post-feeding and was relatively constant thereafter. Protein supplementation showed higher flow of peptide including free AA immediately after feeding compared with no supplemented diet. There were no differences among protein supplements in diurnal pattern in flow of peptide including free AA in OD.