Evaluation of the equation for predicting dry matter intake of lactating dairy cows in the Korean feeding standards for dairy cattle

Lee, Mingyung,Lee, Junsung,Jeon, Seoyoung,Park, Seong-Min,Ki, Kwang-Seok,Seo, Seongwon Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.10

Objective: This study aimed to validate and evaluate the dry matter (DM) intake prediction model of the Korean feeding standards for dairy cattle (KFSD). Methods: The KFSD DM intake (DMI) model was developed using a database containing the data from the Journal of Dairy Science from 2006 to 2011 (1,065 observations 287 studies). The development (458 observations from 103 studies) and evaluation databases (168 observations from 74 studies) were constructed from the database. The body weight (kg; BW), metabolic BW (BW^0.75, MBW), 4% fat-corrected milk (FCM), forage as a percentage of dietary DM, and the dietary content of nutrients (% DM) were chosen as possible explanatory variables. A random coefficient model with the study as a random variable and a linear model without the random effect was used to select model variables and estimate parameters, respectively, during the model development. The best-fit equation was compared to published equations, and sensitivity analysis of the prediction equation was conducted. The KFSD model was also evaluated using in vivo feeding trial data. Results: The KFSD DMI equation is 4.103 (±2.994)+0.112 (±0.022)×MBW+0.284 (±0.020)×FCM-0.119 (±0.028)×neutral detergent fiber (NDF), explaining 47% of the variation in the evaluation dataset with no mean nor slope bias (p>0.05). The root mean square prediction error was 2.70 kg/d, best among the tested equations. The sensitivity analysis showed that the model is the most sensitive to FCM, followed by MBW and NDF. With the in vivo data, the KFSD equation showed slightly higher precision (R² = 0.39) than the NRC equation (R² = 0.37), with a mean bias of 1.19 kg and no slope bias (p>0.05). Conclusion: The KFSD DMI model is suitable for predicting the DMI of lactating dairy cows in practical situations in Korea.

Evaluating feed value of native Jeju bamboo (Sasa quelpaertensis Nakai) for beef cattle

Lee Seul,Baek Youl Chang,Lee Mingyung,Jeon Seoyoung,Bang Han Tae,서성원 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.2

Objective: Recently, indigenous Korean grass Sasa quelpaertensis Nakai (SQ) has garnered much interest as a roughage source for livestock to mitigate its adverse effects on habitat diversity. Thus, the objective of the present study was to evaluate the ruminal fermentation, palatability, and nutrient digestibility of SQ for Korean native beef cattle (Hanwoo) using in vitro rumen fermentation, in situ rumen degradability, and in vivo feeding trials. Methods: Using in vitro tests with rumen fluid as the inoculum for 48 h, ruminal fermentation of SQ was evaluated and compared with that of other roughage sources commonly used in Korea (i.e., rice straw, Timothy hay, and Italian ryegrass [IRG]). Additionally, an in situ trial 96 h was performed using three cannulated Hanwoo steers. Further, an in vivo trial was performed using eight Hanwoo steers to compare the palatability of SQ with rice straw in total mixed ration (TMR) and forage-concentrate separate feeding conditions. Finally, an in vivo digestibility trial of SQ fed as TMR of two particle sizes was performed with four Hanwoo steers. Results: In vitro and in situ trials revealed that SQ was comparable or superior to rice straw in terms of the ruminal fermentation characteristics of pH, gas production, total volatile fatty acid content, and effective ruminal dry matter digestibility (DMD), although its fermentability was lower than that of Timothy hay and IRG. In the palatability test, steers showed a greater preference for SQ when given as TMR. The total tract DMD of SQ fed as TMR was 75.9%±1.37%, and it did not differ by particle size. Conclusion: The feed value of SQ as a roughage source for Hanwoo steers is comparable or superior to that of rice straw, particularly when provided as TMR.

한국 낙농 농가의 정밀 축산 기술 도입 실태 조사

이민경(Mingyung Lee),서성원(Seongwon Seo) 한국산학기술학회 2022 한국산학기술학회논문지 Vol.23 No.2

Effect of flaking on the digestibility of corn in ruminants

( Hamin Kang ),( Mingyung Lee ),( Seoyoung Jeon ),( Sang Moon Lee ),( Ju Hwan Lee ),( Seongwon Seo ) 한국축산학회 2021 한국축산학회지 Vol.63 No.5

In this study, we aimed to assess the effect of flaking on the nutrient digestibility of corn grain in ruminants. In this regard, in vitro rumen fermentation, in situ rumen degradability, and in vivo metabolic experiments were performed. The automated gas production technique was used for the in vitro fermentation experiments. Six types of corn flakes with various degrees of gelatinization (32%, 41%, 48%, 66%, 86%, and 89%) were ground and incubated in rumen fluid to measure rumen fermentation characteristics and digestion rate. The in situ degradability of ground corn, whole corn, and corn flakes with 62% and 66% gelatinization was measured by incubation in the rumen of two cannulated Holstein cows. In vivo metabolic experiments were performed using 12 crossbred goats (29.8 ± 4.37 kg) using a 3 × 3 Latin square design. The dietary treatments consisted of ground corn and flaked corn with 48% or 62% gelatinization. In vitro experiments showed that as the degree of gelatinization increased, the digestion rate increased linearly, while the discrete lag time decreased linearly (p < 0.05). The effective rumen dry matter degradability, determined by in situ fermentation, was 37%p lower in corn flakes than ground corn, assuming a passage rate of 6%/h (p < 0.01), and there was no difference between the two flakes. In the in vivo experiment, there was no difference in dry matter intake, average daily gain, feed efficiency, and nitrogen utilization among the treatment groups (p > 0.05); however, the crude fat digestibility was lower for corn flakes than for ground corn (p < 0.05). To summarize, the rate of fermentation of corn flakes increased as the degree of gelatinization increased. However, non-ground corn flakes had lower rumen digestibility and did not improve in vivo apparent nutrient digestibility, compared with ground corn. In contrast to the assumption that flaked corn provides more energy to ruminant animals than ground corn, we conclude that the digestibility and energy value of corn flakes are lower than those of ground corn if mastication does not sufficiently reduce the particle size of corn flakes.

Multi-Algorithmic Data Processing to Remove Noise in Daily Milk Production Data

Jae-Woo SONG,Mingyung LEE,Hyunjin CHO,Dae-Hyun LEE,Seongwon SEO,Wang-Hee LEE 한국생물공학회 2023 한국생물공학회 학술대회 Vol.2023 No.10

High-level dietary crude protein decreased backfat thickness and increased carcass yield score in finishing Hanwoo beef cattle (Bos taurus coreanae)

( Seoyoung Jeon ),( Mingyung Lee ),( Jakyeom Seo ),( Jeong-hoon Kim ),( Dong-Keun Kam ),( Seongwon Seo ) 한국축산학회 2021 한국축산학회지 Vol.63 No.5

Recently, a high level of dietary crude protein (CP) has become of interest as a possible practice to improve the carcass quality of beef cattle, and its level has been increasing in the field. However, there is little scientific evidence that supports this. This study was conducted to test whether a high dietary CP level would improve growth performance, body metabolism, and carcass traits in Hanwoo beef cattle. A total of 32 Hanwoo finishing beef cattle (18 multiparous cows, six heifers, and eight steers) participated in a 12-weeks feeding trial. Two kinds of total mixed rations were prepared to contain two different CP; 156 g/kg for the control (CON) and 173 g/kg of CP for the treatment (HCP), while maintaining a similar level of metabolizable energy. The experiment was ended when more than half of the steers reached the target body weight (730 kg). Blood was collected at the end of the experiment. After harvesting, the carcass trait was evaluated at the slaughterhouse according to Korean standards. The carcass yield score and grade were also calculated based on revised criteria. Overall, dry matter intake, average daily gain, blood metabolites concentration, and the carcass traits, except for backfat thickness and the yield score, did not differ between the treatments. The HCP had lower backfat thickness than those of CON. There was no difference in the carcass yield grade, but the yield score was higher in the HCP treatment. According to the newly revised carcass grading criteria, both yield score and grade were higher in HCP than in CON. Increasing CP supply decreased the carcass’s backfat thickness without altering growth performance and body metabolism, resulting in improved yield score and grade. Therefore, feeding a high CP diet may be beneficial in the farm income, although it may also increase feed cost and nitrogen excretion to the environment.

추력 650 kgf 급 하이브리드 로켓 모터의 연소시험

이정표(Jungpyo Lee),김수종(Soojong Kim),김기훈(Gihun Kim),조정태(Jungtae Cho),김학철(Hakchul Kim),우경진(Kyongjin Woo),도규성(Gyu-Sung Do),소정수(Jungsoo So),오정수(Jung-soo OH),조민경(Mingyung Cho),문희장(Heejang Moon),성홍계(Honggye S 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.11

본 연구에서는 추력 650 kgf 급의 PE/N2O 하이브리드 로켓 모터의 지상 연소시험을 수행하였다. 초기 실험에서 산화제 유량이 작게 유입됨으로 인해 연소실 압력 및 추력이 설계치 만큼 확보되지 못함을 확인 하였다. 이를 보완하기 위해 노즐목 감소 및 산화제 유량을 증대하여 실험을 수행하였고, 실험에서 발생하는 연소현상을 분석하였다. 또한 sub-scale과 lab-scale의 실험결과를 통해 scale에 따른 연소특성 변화를 비교? 분석 하였고, 동일 산화제 유속에서 sub-scale의 후퇴율이 lab-scale의 후퇴율보다 차이는 작지만 낮게 나타남을 확인했다. 본 연구의 결과를 통해 실제 하이브리드 사운딩 로켓 개발을 위해 고려되어야 할 사항을 파악할 수 있었다. In this study, we presented the results of static firing tests on the PE/LN2O hybrid rocket motor, which has a thrust of 650 kgf level. Through the early tests, we found that the combustion chamber pressure and the thrust were lower than design values because an actual oxidizer flow rate was less than that expected. In order to complement this result, the methods of decrease of nozzle throat and the increase of oxidizer mass flow rate were conducted in the next experiment, and we studied the combustion phenomena with the experimental results. Also we compared and analyzed a difference of combustion characteristics on scale effect. It show that a sub-scale motor regression rate was a little less than that of a lab-scale motor with the same oxidizer mass flux. Results of this study might be used as a basic data for development of hybrid sounding rocket.

Effects of tannin supplementation on growth performance and methane emissions of Hanwoo beef cows

Jeong, Sinyong,Lee, Mingyung,Jeon, Seoyoung,Kang, Yujin,Kang, Heejin,Seo, Seongwon 충남대학교 농업과학연구소 2019 Korean Journal of Agricultural Science Vol.45 No.3

The objective of this study was to investigate the effects of dietary hydrolysable tannin on growth performance and methane emissions of Hanwoo beef cows. Fifteen cows participated in a seven-week experiment. The cows were stratified by initial methane emissions and assigned to one of two treatments: Control and tannin supplementation. Commercial hydrolysable tannin was top-dressed to a concentrate mix at 3 g/kg based on the dry matter. Enteric methane production was measured for 4 consecutive days at 1 week before and 1, 3 and 7 weeks after the initiation of the experiment using a laser methane detector. The feed intake was measured daily during the methane measurement periods and an additional two days prior to each measurement. The body weight of the cows was measured every 4 weeks. Hydrolysable tannin had no effect (p > 0.05) on body weight, average daily gain, dry matter intake (DMI) and feed conversion ratio. After one week, the methane emission of the tannin supplementation group was 3.66 ppm-m / kg DMI, which was about 3.4% lower (p = 0.078) than that of the control group; however, this tendency disappeared at 3 weeks after the start of the experiment (p > 0.05). The results of this study show that hydrolysable tannin supplementation can reduce enteric methane emissions for a limited period in Hanwoo beef cows. More research, however, is needed to determine the optimal level of hydrolysable tannin supplementation to reduce enteric methane emissions for a longer period without adversely affecting the animal performance of Hanwoo beef cattle.

Synthetic Jet 발생을 위한 유체소자 작동 특성

이지웅(Ji Ung Lee),허준영(Jun Young Heo),조민경(Mingyung Cho),정기연(Ki Yeon Jeong),성홍계(Hong Gye Sung),최현영(Hyun Young Choi) 한국추진공학회 2015 한국추진공학회 학술대회논문집 Vol.2015 No.5

Synthetic Jet 발생을 위한 유체소자 작동 특성에 대해 연구하였다. 선행연구를 통하여 형상과 작동범위를 결정하였고, 수치해석과 실험결과를 비교 및 분석하였다. 유동방향 제어가 가능한 최소의 제어유동과 주유동의 압력비를 도출하였고, 그 압력비가 다른 압력을 가진 주유동에도 적용이 되는지에 대하여 연구를 수행하였다. 주유동과 제어유동의 교차로에서의 유동특성 분석을 통해 주유동을 편향시키는 주요 파라미터를 예측하였다. The purpose of this report is to investigate the dynamic characteristics of a fluidic valve for synthetic jet. The configuration and experimental setup were figured out through the previous study. The minimum pressure ratio of control flow and main flow to control the main flow were determined, and the possibility of controling main flows with different pressures was figured out by using the same minimum pressure ratio that were already found. Through this study, an interesting result that the configuration of the control valve could be one of parameters to change the main flow was found.

Data Screening to Extract a Complete Data Set Available for Explaining Daily Milk Production Pattern Over Time

Jae-Woo SONG,Mingyung LEE,Seongwon SEO,Wang-Hee LEE 한국생물공학회 2023 한국생물공학회 학술대회 Vol.2023 No.4