• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.885-891
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• 2022

Plant-based protein sources such as soybean meal have low digestibility and are generally promoted accumulation of undigested proteins into the intestine by enzymatic treatments. Moreover, potential intestinal pathogens ferment undigested proteins, producing harmful substances, such as ammonia, amines and phenols, leading to an overactive immune response and diarrhea in weaned pigs. As a solution, dietary proteases hydrolyze soybean-based antinutritive factors, which negatively affect immune responses and gut microbiota. In this study, we investigated the effects of dietary proteases (PRO) in a low-crude protein (CP) commercial diet on the immune responses and gut microbiota of weaned pigs. The experimental design consisted of three dietary treatments: a commercial diet as a positive control (PC; phase1 CP = 23.71%; phase 2 CP: 22.36%), a lower CP diet than PC as negative control (NC; 0.61% less CP than PC), and NC diet supplement with 0.02% PRO. We found that PRO tended to decrease the frequency of diarrhea in the first two weeks after weaning compared with PC and NC. In addition, pigs fed PRO showed decreased TNF-α and TGF-β1 levels compared with those fed PC and NC. The PRO group had a higher relative proportion of the genus Lactobacillus and lower levels of the genus Streptococcus than the PC and NC groups. In conclusion, the addition of PRO to a low CP commercial weaned diet attenuated inflammatory responses and modified gut microbiota in weaned pigs.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.462-470
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• 2022

The addition of dietary proteases (PRO) to weaner diets hydrolyzes soybean-based anti-nutritive factors and improves weaned pig's dietary digestibility and growth performance. Therefore, this study explores the effects of PRO in a lower crude protein (CP) level diet than that in a commercial diet on the growth performance, nutrient digestibility, and intestinal morphology of weaned pigs. A total of 90 weaned pigs were randomly assigned to 3 dietary treatments with 6 pigs per pen and 5 replicated pens per treatment using a randomized complete block design (block = body weight [BW]): 1) a commercial weaner diet as a positive control (PC; phase1 CP = 23.71%; phase2 CP: 22.36%), 2) lower CP diet than PC as a negative control (NC; 0.61% less CP than PC), and 3) an NC diet with 0.02% PRO. Pigs fed PC and PRO had higher (p < 0.05) final BW, average daily gain, and/or gain to feed ratio for the first three weeks and the overall experimental period than NC. The PC and PRO groups had greater (p < 0.05) apparent ileal digestibility of dry matter, CP, and energy than the NC group. Moreover, pigs fed PC and PRO increased (p < 0.05) apparent total tract digestibility of CP compared with those fed NC. In addition, the PRO group had a higher number of goblet cells than the PC and NC groups. However, pig fed PC and PRO increased (p < 0.05) villus height and height to crypt depth ratio in the ileum compared with those fed NC. In conclusion, PRO supplementation in a commercial weaner diet with low CP levels improves growth rate and nutrient digestibility by modulating the intestinal morphology of weaned pigs.

• Animal Bioscience
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• 제35권10호
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• pp.1592-1605
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• 2022

Objective: The objective of this study was to select an effective in vitro digestion-fermentation model to estimate the effect of decreasing dietary crude protein (CP) on odor emission during pig production and to suggest potential prediction markers through in vitro and in vivo experiments. Methods: In the in vitro experiment, three diet formulations with different CP contents (170 g/kg, 150 g/kg, and 130 g/kg) but containing the same standardized ileal digestible essential amino acids (SID-EAA) were assessed. Each diet was evaluated by two different in vitro gastric-intestinal phase digestion methods (flask and dialysis), combined with fresh pig feces-ferment inoculation. Eighteen growing barrows (31.9±1.6 kg) were divided into three groups: control diet (180 g CP/kg, without SID-EAA adjustment), 170 g CP/kg diet, and 150 g CP/kg diet for 4 weeks. Results: The in vitro digestion results indicated that in vitro digestibility was affected by the gastric-intestinal phase digestion method and dietary CP level. According to the gas kinetic and digestibility results, the dialysis method showed greater distinguishability for dietary CP level adjustment. Nitrogen-related odor compounds (NH₃-N, indole, p-cresol, and skatole) were highly correlated with urease and protease activity. The feeding study indicated that both EAA-adjusted diets resulted in a lower odor emission especially in p-cresol and skatole. Both protease and urease activity in feces were also closely related to odor emissions from nitrogen metabolism compounds. Conclusion: Dialysis digestion in the gastric-intestinal phase followed by fresh fecal inoculation fermentation is suitable for in vitro diet evaluation. The enzyme activity in the fermentation and the fecal samples might provide a simple and effective estimation tool for nitrogen-related odor emission prediction in both in vitro and in vivo experiments.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.840-853
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• 2020

The present study was conducted to investigate the effect of a multi-protease on production indicators of broiler chickens fed a crude protein and amino acid deficient-diets for 35 days immediately after hatch. A total of 448 one-day-old Ross 308 male broiler chicks were allocated in a completely randomized design into one of eight dietary treatments (positive control [PC], negative control [NC: minus 0.5% from PC, and minus 2% of lysine, methionine, threonine and methionine plus cysteine], extreme negative control [ENC: minus 1% from PC, minus 4% of lysine, methionine, threonine and methionine plus cysteine], and plus multi-protease 150 or 300 g per ton [e. g., PC-150]; PC, PC-150, NC, NC-150, NC-300, ENC, ENC-150, ENC-300) to give eight replicates with seven birds in a battery cage. Body weight, average daily gain, average daily feed intake, feed conversion ratio, and mortality were measured every week. Carcass traits, proximate analysis of breast meat, and ileum digestibility were analyzed on day 21 and 35. Feeding a multi-protease (i.e., more than 150 g/ton) for 35 days immediately after hatching improved feed efficiency and ileum digestibility (i.e., dry matter, crude protein, and energy) compared to their counterparts (i.e., diets without multi-protease: PC, NC, and ENC). In conclusion, our results indicated that broiler chickens fed nutrients deficient-diet (i.e., crude protein and amino acids) supplemented a multi-protease had an ability to compensate and (or) improve their growth performance commensurate with increased ileal digestibility for 35 days immediately after hatch.

• 동아시아식생활학회지
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• 제26권2호
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• pp.163-170
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• 2016

본 연구는 된장 제조 시 자연 발효시킨 대조구와 B. subtilis KACC15935, B. subtilis HJ18-9 균주를 starter로 접종하여 발효시킨 콩알된장의 품질특성을 측정하였다. 된장의 단백질을 분해하여 특유의 구수한 맛 성분을 유리하는 protease 활성의 경우, 대조구와 HJ18-9를 접종한 시료에서 높게 나타났으며, 이는 아미노태 질소 함량에서도 같은 경향을 나타냈다. 식물세포벽 구성성분 중 대부분 차지하고 있는 cellulose을 분해할 수 있는 능력을 가지고 있어 장내 이용성 증진을 위해 널리 사용되는 효소인 cellulase의 활성은 모든 시료에서 발효기간에 따라 증가되는 경향을 보였으며, 60일 발효 후에는 HJ18-9 처리구에서 대조구에 비해 1.38배, KACC15935에 비해서 1.99배 더 높게 나타났다. 환원당을 유리하는데 관여하는 ${\alpha}-amylase$ 효소활성의 경우 대조구와 HJ18-9를 접종한 시료에서 높게 나타났다. 이러한 결과로 본 연구를 통해 선별한 균주를 starter로 접종하여 된장 제조에 알맞은 균주를 개발, 평가하여 가공품으로 개발할 수 있는 기초연구가 되고자 하였다.

• Journal of Animal Science and Technology
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• 제63권3호
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• pp.491-500
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• 2021

The objective of this study was to evaluate the effects of low protein diets added with protease on growth performance, nutrient digestibility, and blood profiles of weaned piglets and growing-finishing pigs. A total of 96 weaned pigs ([Yorkshire × Landrace] × Duroc) with average body weight (BW) of 6.99 ± 0.21 kg were used in a 20-week experiment. The dietary treatments were arranged in a 2 × 3 factorial design. Treatments were as follows: In phase 1 (1-2 weeks), two protein levels as high protein (HP; 19.0%), low protein (LP; 17.0%), and three protease (PT) levels (PT0, 0%; PT1, 0.3%; and PT2, 0.5%); in phase 2 (3-4 weeks), protein levels (HP, 18.05%; LP, 16.15%) and protease levels (0%, 0.3%, and 0.5%); in phase 3 (5-12 weeks), protein levels (HP, 17.1%; LP, 15.3%) and protease level (0%, 0.15%, and 0.3%); in phase 4 (13-20 weeks), protein levels (HP, 16.15%; LP, 14.45%) and protease level (0%, 0.15%, and 0.3%). At 4 weeks and 20 weeks after treatment, BW was higher (p < 0.050) in the PT2 group than PT0 group. From weeks 0 to 4, average daily gain (ADG) and feed efficiency (G/F) were higher (p = 0.006 and p = 0.014; p = 0.014 and p = 0.044, respectively) in the PT2 group than PT0 and PT1 groups. From weeks 16 to 20, ADG and G/F were higher (p < 0.001 and p = 0.009; p = 0.004 and p = 0.033, respectively) in the PT2 group than PT0 and PT1 groups. Crude protein (CP) digestibility was higher (p = 0.013, p = 0.014, and p = 0.035, respectively) in the low protein (LP) group than high protein (HP) group at weeks 4, 12, and 20. At weeks 4 and 20, the LP diet group had lower (p < 0.001 and p = 0.001, respectively) blood urea nitrogen (BUN) levels than the HP diet group. Therefore, a low CP diet added with protease could increase growth performance and CP digestibility of weaned piglets and growing-finishing pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.1053-1058
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• 2008

A total of 392 twenty eight week-old laying hens was used to study the effects of dietary inclusion of solvent-extracted palm kernel cake (PKC) (0%, 12.5% and 25%) and enzyme (mixture of mannanase, ${\alpha}$-galactosidase and protease) supplementation (0 kg/t, 1 kg/t and 2 kg/t) on the performance of laying hens. The levels of PKC did not significantly influence nitrogen corrected true metabolizable energy (TMEn) of the diets. Enzyme-supplemented PKC had significantly higher AME and TMEn values than PKC diets with no enzyme supplementation. Dietary inclusion of 12.5% and 25% PKC in the diets of laying hens did not adversely affect mean egg production or daily egg mass. However, layers consumed significantly more PKC-based diets and had significantly poorer feed conversion ratios (FCR) than controls. However, the feed intake and FCR of hens provided the 12.5% PKC-based diets with enzyme supplementation at 1 kg/t did not differ from the controls. Dietary inclusion of PKC or enzyme did not affect eggshell quality, but egg yolk colour was significantly paler when layers were fed the 25% PKC diet.

• Journal of Animal Science and Technology
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• 제48권1호
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• pp.49-58
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• 2006

본 연구는 비육돈 사료내 갯벌 미생물 유래 단백질 분해 효소제를 첨가하였을 때 성장률, 아미노산 소화율, 혈액성상, 육질 특성 및 분내 휘발성 지방산과 NH3-N 함량을 알아보기 위해 실시하였다. 3원 교잡종(Landrace×Yorkshire×Duroc) 비육돈 80두를 공시하였으며, 시험개시시의 체중은 60.08±2.69kg이었다. 시험설계는 기초사료내 영양소 함량과 효소제의 첨가 유뮤에 따라 high nutrient density diet 처리구, high nutrient density diet에 단백질 분해효소제를 첨가한 처리구(high nutrient density diet+0.1% protease), low nutrient density diet 처리구, low nutrient density diet 처리구에 단백질 분해효소제를 첨가한 처리구(low nutrient density diet+0.1% protease)로 4처리를 하여 처리당 5반복, 반복당 4마리씩 완전임의 배치하였다. 전체 사양시험 기간동안 일당증체량은 고 영양소 사료에 단백질 분해효소제를 첨가한 처리구가 저 영양소 사료를 급여한 처리구와 비교하여 유의적으로 증가하였다(P<0.05). DM과 N의 소화율은 고 영양소 사료를 급여한 처리구들 및 저 영양소 사료에 단백질 분해효소제를 첨가한 처리구가 저 영양소 사료를 급여한 처리구와 비교하여 유의적으로 증가하였다(P<0.05). 필수 아미노산 소화율은 저 영양소 사료에 단백질 분해효소제를 첨가한 처리구가 다른 처리구들에 비해 유의적으로 증가하였다(P<0.05). 비필수 아미노산 소화율에서는 고 영양소 사료에 단백질 분해효소제를 첨가한 처리구가 고 영양소 사료와 저 영양소 사료를 급여한 처리구들에 비해 유의적으로 증가하였다(P<0.05). BUN 함량은 고 영양소 사료에 단백질 분해효소제를 첨가한 처리구가 저 영양소 사료를 급여한 처리구와 비교하여 유의적으로 증가하였다(P<0.05). 육색에서는 명도를 나타내는 L*값은 저 영양소 사료를 급여한 처리구들이 고 영양소 사료를 급여한 처리구들과 비교하여 유의적으로 증가하였다(P<0.05). 결론적으로 비육돈 사료내 갯벌 미생물 유래 단백질 분해 효소제의 첨가는 성장률을 향상시켰고 아미노산 소화율 개선하였으며, BUN 함량과 육색에 영향을 미친 것으로 사료된다.(색인어：성장률, 아미노산 소화율, 혈액성상, 육질 특성, 휘발성 지방산, NH3-N)

• 한국가금학회지
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• 제34권3호
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• pp.217-222
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• 2007

본 연구는 육계 사료 내 조단백질 수준에 따른 갯벌 미생물 유래 단백질 분해효소제를 첨가하였을 때 생산성, 영양소 소화율 및 혈액 내 total protein과 BUN 함량에 미치는 영향을 알아보기 위해 실시하였다. 사양 시험은 2일령 Arbor Acres 육계(male) 480수를 공시하여 5주간 실시하였다. 시험 설계는 기초 사료 내 조단백질 함량과 효소제의 첨가 유무에 따라 high crude protein diet 처리구, high crude protein diet에 단백질 분해 효소제를 첨가한 처리구(high crude protein diet+0.1% protease), low crude protein diet 처리구 및 low crude protein diet에 단백질 분해 효소제를 첨가한 처리구(low crude protein diet+0.1% protease)로 4처리($2{\times}2$ factorial)를 하여 처리당 6반복, 반복당 20수씩 완전 임의 배치하였다. 전체 사양 시험 기간 동안, 증체량은 high crude protein diet 처리구들과 low crude protein diet에 단백질 분해 효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 높게 나타났다(P<0.05). 사료 섭취량에서는 처리구간에 유의적인 차이를 보이지 않았다. 사료 요구율에서는 high crude protein diet 처리구들과 low crude protein diet에 단백질 분해 효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 낮게 나타났다(P<0.05). 또한, 건물 소화율은 high crude protein diet 처리구들과 low crude protein diet에 단백질 분해효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 높게 나타났고(P<0.05), 질소 소화율에서는 high crude protein diet에 단백질 분해 효소제를 첨가한 처리구가 low crude protein diet 처리구와 비교하여 유의적으로 증가하였다(P<0.05). 혈액 내 total protein 함량은 high crude protein diet 처리구가 다른 처리구들과 비교하여 유의적으로 증가하였고(P<0.05), BUN 함량은 처리구들 간에 유의적인 차이를 보이지 않았다. 결론적으로, 육계 사료 내 조단백질 수준에 따른 갯벌 미생물 유래 단백질 분해효소제의 첨가는 증체량, 사료 요구율, 영양소 소화율을 개선시켰고, 혈액 내 total protein 함량에 영향을 미쳤다.

• 동아시아식생활학회지
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• 제15권5
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• pp.598-605
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• 2005

Effects of chitosan-ascorbate(CA) and calcium lactate(CL) on fermentation and quality of squid sikhae were investigated CA and LA were added at $0.5\%$ (designated CA1 and CL1) and $1.0\%$(CA2 and CL2) concentrations, respectively and fermented for 12 days at $10^{\circ}C$. pH of CA-added sikhae was higher than that of control, while acidity of the former was lower than that of the latter. During 12 days of fermentation, CA-added sikhae showed higher protease activity than control by $2.3\~2.6$ times and CL-added sikhae by $2.8\~3.6$ times. At 12 days of fermentation, CA-added sikhae revealed higher protease activity than control by $1.2\~1.4$ times and CL-added sikhae by $1.5\~1.9$ times. CA-added sikhae also showed higher amino-nitrogen content than control by $1.4\~1.7$ times and CL-added sikhae by $1.9\~3.5$ times. In comparison of CA1 with CA2, CA2 showed all higher pH, protease and amylase activity, and amino-nitrogen content than CA1. In analysis of electrophoresis, molecular weights of major proteins in ~w squid were $116.9\~119.0$, 96.5 and 59.3kDa. However, after fermentation for 12 days, a protein band of 119.0kDa disappeared but a new protein band with below 14 kDa appeared in sikhae, especially CA-added sikhae. In sensory evaluation, the intensity of sour taste was the highest for control and the lowest for CA2. Softness of squid was the highest for control and the lowest for CA2. Overall acceptability was the best for CA2. In conclusion, these results suggest use of $1\%$ CA in sikhae preparation as addition of CA(CA2) increased the protease and amylase activity, nitrogen content of amino form, sensory acceptability as well as shelf-life of sikhae.