• 한국초지조사료학회지
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• 제37권4호
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• pp.308-314
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• 2017

본 연구에서는 옥수수의 가공방법 및 옥수수의 두께의 차이가 반추위 in situ 소화율 및 in vitro 반추위 발효와 메탄 발생에 미치는 영향에 대하여 알아보고자 실시하였다. Micronized corn(2.5 mm thickness) 처리구는 다른 처리구들에 비하여 in situ 48시간 건물 분해율이 모든 배양시간대에서 높게(P<0.05) 나타났다. 반면, steam flaked corn(3.3 mm thickness) 처리구는 모든 배양시간대에서 가장 낮은(P<0.05) in situ 건물 분해율을 보였다. 반추위 내에서 미생물에 의해 분해되는 b fraction은 이와 상반되는 결과인 steam flaked corn(3.1 mm thickness)과 steam flaked corn(3.3 mm thickness) 처리구에서 높게(P<0.05) 나타났다. b fraction이 반추위를 통과하는 속도인 건물 분해상수 k값은 micronized corn(2.5 mm thickness) 처리구에서 가장 높게 (P<0.05) 나타났고 steam flaked corn(3.3 mm thickness) 처리구에서 가장 낮게 (P<0.05) 나타났다. 반추위내 시간당 통과속도를 0.05로 적용한 유효 건물 분해도는 건물 분해상수와 유사하게 micronized corn(2.5 mm thickness) 처리구에서 가장 높게 (P<0.05), steam flaked corn(3.3 mm thickness) 처리구에서 가장 낮게(P<0.05) 나타났다. In vitro 반추위 48시간 건물 소실율은 micronized corn(2.5 mm thickness) 처리구에서 가장 높은 경향을(P=0.088) 보인 반면 steam flaked corn 처리구들 사이에서는 두께에 따른 건물 소실율의 상관관계는 나타나지 않았다. 총 가스발생량 및 메탄 발생량에 있어서도 건물 소실율과 같은 결과인 micronized corn(2.5 mm thickness) 처리구에서 가장 높게 나타났으며(P=0.001), 총 휘발성지방산은 steam flaked corn(2.9 mm thickness)의 처리구에서 가장 높게 나타났으나(P=0.015) 나머지 처리구들에서는 유의적인 차이를 보이지 않았다. aectate: propionate의 비율 또한 steam flaked corn(2.9 mm thickness)의 처리구에서 가장 높게, micronized corn(2.5 mm thickness) 처리구에서 가장 낮게 나타났다(P=0.008). 본 연구의 결과를 종합하면 steam flaked corn 처리구들에서 in vitro 휘발성지방산 농도에 있어 in situ 반추위내 건물 분해상수와 유효 건물 분해도의 결과와 비교하여 상관관계가 나타나지 않은 결과로 유추해 보면 옥수수 가공방법에 의한 두께의 차이는 반추위 메탄 발생량에 영향을 미치지 않은 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.851-858
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• 2002

This study was conducted to determine effects of whole (intact), coarsely-ground (4 mm), finely-ground (1 mm), steam-flaked and steam-flaked-ground (1 mm) corns on in vitro and in situ DM digestibilities and also in vitro fermentation characteristics. After 48 h incubation, in vitro dry matter digestibilities of whole, steam-flaked, coarsely-ground, steam-flaked-ground, and finely-ground corns were 6.79, 61.68, 76.48, 85.72 and 90.31%, respectively. Steam-flaked-ground corn showed the highest digestibility until 24 h incubation (p<0.01). After 48 h incubation, pH of whole corn decreased with a small range. However the values of pH of other media significantly decreased (p<0.01). The gas productions of finely-ground and steam-flaked-ground corns were higher than those of the other corns (p<0.01). After 24 h incubation, $NH_3$-N concentration of finely-ground and steam-flaked-ground corns increased rapidly. Total VFA was the highest in finely-ground corn, followed by steam-flaked-ground, steam-flaked, coarsely-ground and whole corns. Incorporating steam-flaked corn resulted in the highest propionate concentration (p<0.01) and the lowest acetate : propionate value (p<0.05). Finely-ground corn showed the highest in situ DM digestibility throughout the incubation period (p<0.01), followed by coarsely-ground, steam-flaked and whole corns, respectively. Overall, DM of whole corn was merely digested in vitro as well as in situ.

• Asian-Australasian Journal of Animal Sciences
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• 제15권5호
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• pp.708-712
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• 2002

Effects of unprocessed (whole) or steam-flaked corn with or without enzyme additives on in vivo nutrient digestibilities and distribution of corn particles in the feces of Holstein steers were determined in a $4{\times}4$ Latin square experiment using four Holstein steers fed the diets containing 1) whole corn without enzyme additive, 2) whole corn with enzyme additive, 3) flaked corn without enzyme additive, or 4) flaked corn with enzyme additive. With regard to nutrient digestibilities such as DM, CP, CF, NFE, NDF, and ADF, no significant differences were detected among treatments, and also the nutrient digestibilities were not affected by the addition of enzyme additive. When distribution of corn particles in the feces was examined, there were no significant differences in the amount of 2, 8 mm and total corn particles. However, feeding flaked corn resulted in less corn particles (4 mm) in the feces than feeding whole corn (p<0.05). There were no significant differences in amounts of corn particles in the feces due to the addition of enzyme additive.

• Asian-Australasian Journal of Animal Sciences
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• 제32권10호
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• pp.1573-1579
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• 2019

Objective: The research was conducted to determine the digestible (DE) and metabolizable energy (ME) contents as well as the apparent total tract digestibility (ATTD) of nutrients in corn, waxy corn and steam-flaked corn fed to growing pigs. Methods: Eighteen growing pigs with initial body weight of $15.42{\pm}1.41kg$ were randomly allotted to three diets including a corn diet, a waxy corn diet and a steam-flaked corn diet in a completely randomized design. Each treatment contained six replicates. The experiment lasted for 12 days, which comprised 7-d adaptation to diets followed by a 5-d total collection of feces and urine. The energy contents and the nutrient digestibility in three ingredients were calculated using direct method. Results: Compared to normal corn, both the amylose and dietary fiber contents in waxy corn were numerically lower, but the starch gelatinization degree was numerically greater. Moreover, the DE and ME contents as well as the ATTD of neutral detergent fiber and acid detergent fiber (ADF) in waxy corn were significantly greater (p<0.05) than those in normal corn when fed to growing pigs. Furthermore, the steam-flaked corn had greater (p<0.05) DE and ME contents, and ATTD of ether extract and ADF compared to normal corn. Conclusion: Both variety and processing procedure have influence on chemical compositions, energy contents and nutrient digestibility of corn. The waxy corn and steam-flaked corn had greater degree of starch gelatinization and DE and ME contents compared to normal corn when fed to growing pigs.

• 생명과학회지
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• 제18권11호
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• pp.1561-1569
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• 2008

본 연구는 옥수수 수입원과 steam flake 처리에 따른 in situ 건물 분해율 및 보관기간별 mycotoxins 함량을 조사하기 위하여 수행되었다. 미국과 인도산 옥수수(yellow dent corn)를 공시재료로 하여, steam flake 처리 효과에 대해 조사하였다. 시험구는 총 4개의 처리구(USCW, 미국산 무처리 옥수수; USCF, 미국산 steam flaking 옥수수; IDCW, 인도산무처리 옥수수; IDCF, 인도산 steam flaking 옥수수)를 두고, 각 처리구당 보관기간(0, 1, 2, 3, 4, 5, 6, 7, 8주)별 4반복으로 수행되었다. In situ 시험을 위해서 반추위 누관이 장착된 Holstein 수소 2두가 이용되었고, 공장환경분야 표준상태 (STP, standard temperature and pressure, $25^{\circ}C$ 1 atm.)에서 보관기간 동안 매주, 곰팡이 독소인 aflatoxin과 ochratoxin의 농도를 측정하였다. 옥수수의 반추위 내 발효시간별 in situ 건물 소실율은 무처리구에서는 미국산이 인도산보다 약 $3.0{\sim}44.1%$ 높았으나, steam flaking 처리를 함으로써 건물소실율의 차이가 없어졌다. 미국산 옥수수는 무처리 알곡의 건물 분해율이 높은 편이었으나, flake처리에 의한 영향이 적은 반면, 인도산 옥수수는 무처리 알곡의 건물 분해율은 낮은 편이지만 flake 처리를 하였을 때, 분해율이 크게 증가되었다. 미국산 옥수수와 flake 처리 옥수수의 aflatoxin 함량은 보관기간 동안 매우 낮은 수준이었으나, 인도산 옥수수 알곡을 6주 이상 보관할 경우, 허용기준치를 초과하였다. 따라서 인도산 옥수수 알곡을 장기보관 해야 할 경우, steam flake 처리를 하는 것이 aflatoxin 오염방지를 위해서 필수적이며, 알곡으로 보관할 경우는 6주 이상을 넘기지 않는 것이 중요할 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권6호
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• pp.823-829
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• 2016

Eight Holstein steers ($216{\pm}48kg$ body weight) fitted with ruminal and duodenal cannulas were used to evaluate effects of wheat straw processing (ground vs pelleted) at two straw inclusion rates (7% and 14%; dry matter basis) in dry rolled or steam-flaked corn-based finishing diets on characteristics of digestion. The experimental design was a split plot consisting of two simultaneous $4{\times}4$ Latin squares. Increasing straw level reduced ruminal (p<0.01) and total tract (p = 0.03) organic matter (OM) digestion. As expected, increasing wheat straw level from 7% to 14% decreased (p<0.05) ruminal and total tract digestion of OM. Digestion of neutral detergent fiber (NDF) and starch, per se, were not affected (p>0.10) by wheat straw level. Likewise, straw level did not influence ruminal acetate and propionate molar proportions or estimated methane production (p>0.10). Pelleting straw did not affect ($p{\geq}0.48$) ruminal digestion of OM, NDF, and starch, or microbial efficiency. Ruminal feed N digestion was greater (7.4%; p = 0.02) for ground than for pelleted wheat straw diets. Although ruminal starch digestion was not affected by straw processing, post-ruminal (p<0.01), and total-tract starch (p = 0.05) digestion were greater for ground than for pelleted wheat straw diets, resulting in a tendency for increased post-ruminal (p = 0.06) and total tract (p = 0.07) OM digestion. Pelleting wheat straw decreased (p<0.01) ruminal pH, although ruminal volatile fatty acids (VFA) concentration and estimated methane were not affected ($p{\geq}0.27$). Ruminal digestion of OM and starch, and post-ruminal and total tract digestion of OM, starch and N were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal NDF digestion was greater (p = 0.02) for dry rolled than for steam-flaked corn, although total tract NDF digestion was unaffected (p = 0.94). Ruminal microbial efficiency and ruminal degradation of feed N were not affected (p>0.14) by corn processing. However, microbial N flow to the small intestine and ruminal N efficiency (non-ammonia N flow to the small intestine/N intake) were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal pH and total VFA concentration were not affected ($p{\geq}0.16$) by corn processing method. Compared with dry rolled corn, steam-flaked corn-based diets resulted in decreased acetate:propionate molar ratio (p = 0.02). It is concluded that at 7% or 14% straw inclusion rate, changes in physical characteristics of wheat straw brought about by pelleting negatively impact OM digestion of both steam-flaked and dry-rolled corn-based finishing diets. This effect is due to decreased post-ruminal starch digestion. Replacement of ground straw with pelleted straw also may decrease ruminal pH.

• Journal of Animal Science and Technology
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• 제44권6호
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• pp.757-768
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• 2002

본 연구는 반추가축에 있어 통옥수수를 주로 이용한 조사료 무급여사료의 발효특징을 알아 보기 위하여 실시하였다. 대조구는 steam- flaked corn으로 구성된 농후사료 (80%)와 볏짚(20%)을 혼합한 사료 SFCR)와 통옥수수와 면실피로 구성된 조사료 무급여사료(WC)를 사용하였다. 실험 1은 한우 반추위 미생물을 이용하여 in vitro 시험을 2처리 3반복 시험을 배양시간 48시간 동안 실시하였고, 실험 2는 한국재래산양을 이용한 반추위 내 발효 특성을 알아보기 위하여 in vivo 시험을 2처리 4반복 실험을 15일간 실시 하였으며, in sacco 시험은 2처리 3반복으로 시험을 3일간 실시하였다. 실험 1에서 SFCR구와 WC구 모두 반추위 적정 pH를 유지하였으며 처리간에 유의성은 없었으나 배양 4시간 대에 SFCR에서 다소 낮은 경향을 나타내었다. Gas 발생량은 SFCR구에서 유의적으로 높았으며(p<0.01), $NH_3$-N 농도는 WC구에서 다소 높은 경향을 나타내었다. Total VFA농도는 8시간대까지 WC구에서 유의성있게(p<0.01) 낮았고 이후 유의성은 없었으나 두 처리구 모두 점차적으로 증가하는 경향을 나타내었다. 전체 평균 Acetate 함량은 SFCR구에서 모두 유의적으로 높았으며(p<0.01), 전체배양시간에 동안 propionate 함량은 WC구에서 유의적으로 높았다(p<0.01). 건물소화율은 두 처리구 모두 유의적 차이가 없으나 SFCR구에서 다소 높은 경향을 보였다. 실험 2에서 두 처리구 모두 전체적으로 다소 낮은 pH를 보였으며 유의적 차이는 없었으나 SFCR구에서 다소 높은 경향을 보였다. 반추위 미생물단백질 함량은 SFCR구에서 유의하게 높았으나, $NH_3$-N 농도는 WC구에서 유의하여 높았다(p<0.01). Total VFA함량과 propionate 함량도 WC구에서 유의하게 높았으나(p<0.01), acetate 함량은 유의성은 없었고 WC구에서 다소 높았다. 전체적인 Lactate 함량은 두 처리구에서 유의적 차이를 보였으나(p<0.01) 산독증 발병 수준 이하의 함량을 나타내었다. Nylon bag에 의한 한국재래산양 반추위 내 in sacco 건물소실율은 SFCR에서 유의적으로 높은 경향을 나타내었다(p<0.01). 이상의 시험 결과에 의하면 농후사료 80%와 볏짚 20%로 구성된 SFCR 사료가 반추위 내 발효 특성에 있어서 통옥수수와 면실피로 구성된 조사료 무급여사료와 큰 차이가 없었으며, 반면 조사료 무급여사료는 사료 가공비용 감소에 의해 경제성이 증가할 것이다.

• 생명과학회지
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• 제19권1호
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• pp.65-74
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• 2009

본 연구는 미국산 옥수수와 인도산 옥수수의 steam flaking 처리가 in vtro 가스발생량과 미생물 성장량 그리고 곰팡이 독소 aflatoxin $B_1$과 ochratoxin A의 농도에 미치는 영향을 구명하기 위하여 수행되었다. 실험 설계는 4개의 처리구, (1) USCW (미국산 무처리 옥수수), (2) USCF (미국산 steam flaking 옥수수 ), (3) IDCW (인도산 무처리 옥수수) 그리고 (4) IDCF (인도산 steam flaking 옥수수), 처리구당 4반복으로 6개의 발효시간대(3, 6, 9, 12, 18 및 24)를 두고 in vitro 실험을 수행하였다. 공시한 옥수수중 aflatoxin $B_1$이나 ochratoxin A와 같은 곰팡이 독소의 함량은 항구, hopper, 사일로 그리고 가공 전까지 보관기간이 길어짐에 따라 증가하는 경향을 보였다. 공정라인별로 곰팡이 독소를 측정한 결과 입고 시 인도산 옥수수(IDCW)와 미국산 옥수수 (USCW)의 aflatoxin $B_1$ 수치는 각각 11.71 ppb와 1.78 ppb으로 나타났지만 steam flaking 후의 aflatoxin $B_1$ 함량은 USCW 구와 IDCW구에서 전혀 검출되지 않아(0.00 ppb) steam flaking 처리가 곰팡이 Aspergillus flavus를 감소시킬 수 있는 것으로 조사되었다. 그러나 이러한 경향은 ochratoxin A 함량에서 관찰되지 않았다. In vitro 실험에서 gas 발생량은 원산지별로는 미국산 옥수수 (USCW & USCF)가 인도산 옥수수 (IDCW & IDCF) 보다 유의적으로 높았으며 가공 처리별로는 steam flaking 처리한 옥수수가 알곡 옥수수보다 발효 3시간대를 기준으로 $1.5{\sim}2%$ 정도 높았다. 배양액 중의 pH 는 $6.05{\sim}6.54$의 범위로서 미생물이 성장하기에 적정한 pH를 유지하였으며 처리 구간에 유의적인 차이는 찾아 볼 수 없었으나 USCF구의 pH가 다른구에 비해 다소 낮았다. pH는 배양 12 시간까지 감소하였으며 이 시간 중에 가스 발생량은 급격히 증가하였다. In vitro 미생물 성장량도 발효 18시간까지 증가하다가 그 이후 시간대에서는 성장량이 증체를 보이거나 오히려 감소하는 경향이었다. 결론적으로 원산지별로는 in vitro 실험결과와 곰팡이 독소 함량을 기준으로, 미국산 옥수수가 인도산 옥수수보다는 품질이 훨씬 높았으며, 수입산 옥수수의 steam flaking 처리는 invitro 가스발생량 및 미생물 성장량을 개선 시킬 뿐만 아니라, aflatoxin $B_1$이나 ochratoxin A와 같은 곰팡이 독소를 감소시키는 역할을 하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권4호
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• pp.491-500
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• 2010

Three experiments were conducted to investigate the effects of polyurethane coated urea on in vitro ruminal fermentation, ammonia release dynamics and lactating performance of Holstein dairy cows fed a steam-flaked corn-based diet. In Exp. 1, a dual-flow continuous culture was run to investigate the effect of polyurethane coated urea on nutrient digestibility, rumen fermentation parameters and microbial efficiency. Three treatment diets with isonitrogenous contents (13.0% CP) were prepared: i) feedgrade urea (FGU) diet; ii) polyurethane coated urea (PCU) diet; and iii) isolated soy protein (ISP) diet. Each of the diets consisted of 40% steam-flaked corn meal, 58.5% forages and 1.5% different sources of nitrogen. PCU and FGU diets had significantly lower digestibility of NDF and ADF (p<0.01) than the ISP diet. Nitrogen source had no significant effect (p = 0.62) on CP digestibility. The microbial efficiency (expressed as grams of microbial N/kg organic matter truly digested (OMTD)) in vitro of the PCU diet (13.0 g N/kg OMTD) was significantly higher than the FGU diet (11.3 g N/kg OMTD), but comparable with the ISP diet (14.7 g N/kg OMTD). Exp. 2, an in vitro ruminal fermentation experiment, was conducted to determine the ammonia release dynamics during an 8 h ruminal fermentation. Three treatment diets were based on steam-flaked corn diets commonly fed to lactating cows in China, in which FGU, PCU or soybean meal (SBM) was added to provide 10% of total dietary N. In vitro $NH_3-N$ concentrations were lower (p<0.05) for the PCU diet than the FGU diet, but similar to that for the SBM diet at all time points. In Exp. 3, a lactation trial was performed using 24 lactating Holstein cows to compare the lactating performance and blood urea nitrogen (BUN) concentrations when cows were fed PCU, FGU and SBM diets. Cows consuming the PCU diet had approximately 12.8% more (p = 0.02) dietary dry matter intake than those consuming the FGU diet. Cows fed the PCU diet had higher milk protein content (3.16% vs. 2.94%) and lower milk urea nitrogen (MUN) concentration (13.0 mg/dl vs. 14.4 mg/dl) than those fed the FGU diet. Blood urea nitrogen (BUN) concentration was significantly lower for cows fed the PCU (16.7 mg/dl) and SBM (16.4 mg/dl) diets than the FGU (18.7 mg/dl) diet. Cows fed the PCU diet had less surplus ruminal N than those fed the FGU diet and produced a comparable lactation performance to the SBM diet, suggesting that polyurethane coated urea can partially substitute soybean meal in the dairy cow diet without impairing lactation performance.

• Asian-Australasian Journal of Animal Sciences
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• 제31권6호
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• pp.859-863
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• 2018

Objective: Since very little information exists about the topic; in this experiment we compare, in a long-term finishing program, the growth-performance responses and carcass characteristics of Holstein steers where non-structural carbohydrate concentration of the diet is reduced from 64% to 51% (dry matter basis). Methods: Sixty Holstein steer calves ($129{\pm}2.2kg$) were blocked by initial weight into five groups and randomly assigned within weight groupings to 10 pens. Calves were fed with a steam-flaked corn-based finishing diets containing 51% higher fiber (HF) or 64% lower fiber (LF) nonstructural carbohydrates. Non-structural carbohydrates concentrations were manipulated substituting dried distiller grain with solubles and alfalfa hay for flaked corn. Cattle were weighed every 112 days and at the end of the experiment (day 308) when the cattle were harvested and carcass characteristics were evaluated. Results: Steers fed the HF diet showed improvement (8.8%) in average daily gain (ADG) during the initial 112-d period. This effect was followed by a numerical trend for greater ADG throughout the remainder of the study so that overall ADG tended to be greater (4.9%, p = 0.06) for the HF than for LF. There were no treatment effects on dry matter intake. Gain efficiency and estimated dietary net energy (NE) were greater 8.3% and 5.2%, respectively for HF during the initial 112-d period. Overall (308-d) gain efficiency and estimated dietary NE were similar for both dietary treatments. However, due to differences in tabular dietary NE, the ratio of observed:expected dietary NE tended to be greater (4.1%, p = 0.06) for the HF vs LF diet. There were no treatment effects on carcass characteristics except for a tendency toward a slightly greater (0.5%, p = 0.09) estimated carcass yield. Conclusion: Reducing the non-structural carbohydrate concentration of a conventional steam-flaked corn-based growing finishing diet for Holstein steers can effectively enhance growth performance, particularly during the early growing and late finishing phases.