• Asian-Australasian Journal of Animal Sciences
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• 제26권9호
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• pp.1205-1217
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• 2013

Pigs require energy for maintenance and productive purposes, and an accurate amount of available energy in feeds should be provided according to their energy requirement. Available energy in feeds for pigs has been characterized as DE, ME, or NE by considering sequential energy losses during digestion and metabolism from GE in feeds. Among these energy values, the NE system has been recognized as providing energy values of ingredients and diets that most closely describes the available energy to animals because it takes the heat increment from digestive utilization and metabolism of feeds into account. However, NE values for diets and individual ingredients are moving targets, and therefore, none of the NE systems are able to accurately predict truly available energy in feeds. The DE or ME values for feeds are important for predicting NE values, but depend on the growth stage of pigs (i.e., BW) due to the different abilities of nutrient digestion, especially for dietary fiber. The NE values are also influenced by both environment that affects NE requirement for maintenance ($NE_m$) and the growth stage of pigs that differs in nutrient utilization (i.e., protein vs. lipid synthesis) in the body. Therefore, the interaction among animals, environment, and feed characteristics should be taken into consideration for advancing feed energy evaluation. A more mechanistic approach has been adopted in Denmark as potential physiological energy (PPE) for feeds, which is based on the theoretical biochemical utilization of energy in feeds for pigs. The PPE values are, therefore, believed to be independent of animals and environment. This review provides an overview over current knowledge on energy utilization and energy evaluation systems in feeds for growing pigs.

• 한국가금학회지
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• 제21권4호
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• pp.257-266
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• 1994

Three protein feeding systems for egg-type pullets involving conventional step-down protein 18-15-12%), step-up protein(12-15-18%) and single-stage low protein (13-13-13%) with an iso-energy level of 2,900 ME kcal /kg were compared to examine the effect on pullet growth and subsequent laying performance. During the growing period, pullets subjected to the step-up and single-stage low protein feeding systems were lighter in body weight and consumed less feed and netabolizable energy than those on the conventional step-down protein feeding system(P<0.05). 3ut the pullets on the step-up protein diet consumed more protein, and those on the single-stage low protein diet consumed less protein than those on the step-down protein diet(P<0.05). Also, he feed cost was less in pullets on the single-stage low protein diet than in those on the other systems(P<0.05). During the laying period, sexual maturity was later in hens reared on the step-up and single-stage low protein diets than in those on the step-down protein diet(P<0.05), however, average hen-day egg production and egg weight were not significantly affected by the protein feeding systems in the growing period. Daily feed intake and feed required per egg were significantly reduced in hens on the single-stage low protein diet compared to those on conventional protein feeding system(P<0.05). It was concluded that the 13% single-stage low protein feeding system produced smaller pullets with less feed, energy, protein, and feed cost during the growing period, and hens reared on that system consumed less feed during the laying period without any impairment of production compared to the conventional rearing system.

• 에너지공학
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• 제27권1호
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• pp.12-20
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• 2018

FEED(Frond End Engineering Design) 프레임워크는 FEED 단계에서 수행할 활동과 산출물을 정의한 것이다. 그 동안 FEED에 대한 연구가 많이 수행되었으나 대부분 경험에 의존하여 연구마다 서로 조금씩 다른 내용을 주장하고 있는 상황이다. FEED가 무엇이고 어떻게 하는 것이 좋은지에 대한 절대적인 정의보다는 FEED를 해당 사업에 적합하게 정의하고 이에 필요한 활동과 산출물을 정의하는 것이 중요하다. 또한 FEED 프로세스도 경험보다는 국제시스템엔지니어링 프로세스 표준과 같은 확고한 기반위에서 개발하는 것이 필요하다. 본 연구에서는 FEED를 광물탄산화시스템 개발 사업에 적합하게 정의하고, 이를 만족시키기 위한 프로세스와 산출물을 개발하기 위한 방안을 시스템 엔지니어링 표준 프로세스에 기반하여 제시하였다.

• 한국정밀공학회지
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• 제32권4호
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• pp.329-337
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• 2015

In this paper, a simulation based estimation method of energy consumption of the spindle and feed drives for the NC machine tool during the cutting process is proposed. To predict energy consumption of the feed drive system, position, velocity, acceleration and jerk of the table are analyzed based on NC data and then the power and energy are calculated considering friction force and mass of the stages. Energy consumption of the spindle is estimated based on models from acceleration motion of rotating parts, friction torque and power loss of motors. Moreover, simulation models of cutting power and energy for the material removal along the NC tool paths are proposed.

• Asian-Australasian Journal of Animal Sciences
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• 제16권4호
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• pp.609-624
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• 2003

The genesis of methods for defining the nutritional value of feeds and the nutrient requirements of animals, and their development in the late 19th and early 20th centuries in Europe and the USA are outlined. Current energy and protein feeding systems for ruminants are described. Particular reference is made to the Australian systems which are applicable to grazing animals as well as to those given prepared feeds, and enable the effective nutritional management of a imals at pasture by means of the decision support tool GrazFeed. The scheme for predicting intakes by cattle and sheep from pastures allows for the effects of selective grazing on the composition of the feed eaten, and for reduction in herbage intake when a supplementary feed is consumed. For herbage of any given concentration of metabolizable energy (ME) in the feed dry matter the changes with season of year in the net efficiency of use of the ME for growth and fattening and in the yield of microbial crude protein, g/MJ ME, which both vary with latitude, are defined. An equation to predict the energy requirements for maintenance (MEm) of both cattle and sheep includes predictions of the additional energy costs incurred by grazing compared with housed animals and the cost, if any, of cold stress. The equation allows for the change in MEm with feed intake. A flexible procedure predicts the composition of liveweight gain made by any given breed or sex of cattle and sheep at any stage of growth, and the variation with rate of gain. Protein requirements for maintenance, production including wool growth, and reproduction, are related to the quantities of microbial true protein and undegraded dietary protein truly digested in the small intestine.

• 한국가금학회지
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• 제21권2호
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• pp.101-111
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• 1994

From the observations of dietary self-selection by growing pullets, step-up protein or reverse protein and single-stage low protein pullet feeding systems were developed. They offered another pullet feeding concept that appears to control the body weight effectively and to reduce the consumption of feed and nutrients without impairment of subsequent laying performance. It is obvious from the feed and nutrient consumption pattern of layers fed diets for self-selection of energy, protein and calcium that they have a daily cyclic requirement rather than a constant requirement for nutrients. It seems that a practical self-selective feeding system is needed to meet the daily cyclic requirement for nutrients without consuming an excess of energy and protein at certain times of the day as compared to the complete or single diet where layers have to consume extra energy and protein in the afternoon when they have a specific appetite mainly for calcium.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.296-300
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• 2005

Human-induced soil salinity is becoming a major threat to agriculture across the world. This salinisation occurs in both irrigated and rain-fed agricultural zones with the highest proportions in the arid and semi-arid environments. Livestock can play an important role in the management and rehabilitation of this land. There are a range of plants that grow in saline soils and these have been used as animal feed. In many situations, animal production has been poor as a result of low edible biomass production, low nutritive value, depressed appetite, or a reduction in efficiency of energy use. Feeding systems are proposed that maximise the feeding value of plants growing on saline land and integrate their use with other feed resources available within mixed livestock and crop farming systems. Salt-tolerant pastures, particularly the chenopod shrubs, have moderate digestible energy and high crude protein. For this reason they represent a good supplement for poor quality pastures and crop residues. The use of salt-tolerant pasture systems not only provides feed for livestock but also may act as a bio-drain to lower saline water tables and improve the soil for growth of alternative less salt tolerant plants. In the longer term there are opportunities to identify and select more appropriate plants and animals for saline agriculture.

• 대한기계학회논문집B
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• 제40권7호
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• pp.477-484
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• 2016

다중효용 태양열 담수기에서 다중효용부 각 효용단의 해수 공급유량은 효용수 증가에 따른 열에너지 감소를 고려하여 점차 줄어드는데, 선행연구에서는 효용단 별 서로 다른 공급유량 감소율을 제시하였다. 이론적으로 열에너지 감소율이 일정하기 때문에 효용단 별 서로 다른 유량감소율은 적절하지 않다. 본 논문에서는 수치해석을 통해 다중효용부의 공급유량 감소율에 따른 담수생산량 특성을 분석하였다. 해석결과 공급에너지가 같은 조건(12MJ)에서 동일한 감소율(11%)일 때와 그렇지 않을 때의 생산량 차이는 0.56%로 거의 비슷하였다. 또한 수치해석을 통해 고온의 배기가스로부터 얻은 공급 에너지량에 따라 다중효용부 해수공급유량의 최적값을 도출하였다. 최적 유량은 에너지의 공급 형태에 따라 선형적으로 증가하거나 증가 후 평형상태에 도달하는 현상이 발생하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제28권1호
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• pp.1-13
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• 2015

Feed is single most expensive input in commercial pork production representing more than 50% of the total cost of production. The greatest proportion of this cost is associated with the energy component, thus making energy the most important dietary in terms of cost. For efficient pork production, it is imperative that diets are formulated to accurately match dietary energy supply to requirements for maintenance and productive functions. To achieve this goal, it is critical that the energy value of feeds is precisely determined and that the energy system that best meets the energy needs of a pig is used. Therefore, the present review focuses on dietary supply and needs for pigs and the available energy systems for formulating swine diets with particular emphasis on the net energy system. In addition to providing a more accurate estimate of the energy available to the animal in an ingredient and the subsequent diet, diets formulated using the this system are typically lower in crude protein, which leads to additional benefits in terms of reduced nitrogen excretion and consequent environmental pollution. Furthermore, using the net energy system may reduce diet cost as it allows for increased use of feedstuffs containing fibre in place of feedstuffs containing starch. A brief review of the use of distiller dried grains with solubles in swine diets as an energy source is included.

• Asian-Australasian Journal of Animal Sciences
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• 제15권6호
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• pp.800-805
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• 2002

Two experiments were conducted to compare digestibility of 12 diets in sheep, red and fallow deer. No differences (p>0.05) between sheep, red and fallow deer in digestibility of dry matter, organic matter and digestible energy content for all diets were found except for the sorghum diet and medic hay. Sheep and fallow deer digested the sorghum diet better than red deer. An in vitro study showed that sheep had a lower in vitro dry matter digestibility and digestible energy content than both red and fallow deer, with a significant interaction between animal species and feed ingredient. Deer digested straws and hays better (p<0.05) than sheep. In vitro digestibility was lower (p<0.05) than in vivo digestibility, but significantly correlated with in vivo digestibility for red and fallow deer. The in vitro method for digestibility estimation has potential as a rapid feed evaluation system for deer, but needs further validation.