How to get to Tianjin Fourth central hospital

Energy is the power source of livestock and poultry to maintain life, growth, reproction and various proction activities. At present, the unit of energy measurement is Joule (J), which is often expressed in kilojoule (kJ) and megajoule (MJ) in practice

1 kJ = 1000 kJ

1 MJ = 1000 kJ

in the past, Cal was used as the unit of energy, and 1 cal was equivalent to 1 g of water, the heat required for heating from 14.5 ℃ to 15.5 ℃; Kcal, also known as kcal, is 1000 times of kcal; Megacalorie (MCAL) is 1000 times of kilocalorie. As a unit of feed energy, calorie is still used today. The conversion relationship between calorie and Joule is as follows:

1 joule (J) = 0.239 calorie (CAL)

1 calorie (CAL) = 4.181 Joule (J)

livestock and poultry must obtain energy from feed to maintain life and proce procts. The organic matter (carbohydrate, fat and protein) in feed can be oxidized in the body of livestock and poultry to proce heat energy for life activities, sports, growth and proction. In these three kinds of organic matter, the more the content of "carbon" and "hydrogen", the more energy will be proced ring oxidation. Carbohydrate, fat and protein contain different carbon, hydrogen and oxygen, so they proce different energy (Table 7)

in table 7-3 can be seen from the above table that the total amount of carbon and hydrogen in fat is as high as 89%, so the calorific value of fat in livestock is the highest; The total amount of carbon and hydrogen contained in carbohydrate and protein is similar, both of which are less than that of fat, so their caloric proction in livestock is lower than that of fat. The average caloric value of three organic pure nutrients in the calorimeter is as follows: 1 g carbohydrate is 17.36 kJ; 85 kJ / G protein; 1 g fat is 38.91 kJ

the digestibility and utilization efficiency of different feed dry matter by livestock and poultry are different, so their effective energy to livestock and poultry is also different. For example, the caloric content of 1 kg corn dry matter is 19.08 MJ, while that of 1 kg corncob is 18.51 MJ, which is very close, but the nutritional value of feeding pigs is very different. Therefore, the total energy measured in the calorimeter can not really represent the effective energy of dry matter in the animal body. Therefore, when evaluating the nutritional value of feed, the index of "total energy" is not used, but expressed by digestible energy, metabolic energy and net energy according to the utilization and transformation of energy in the body

digestible energy

the energy contained in digestible nutrients in feed is called digestible energy. Some of the organic matter that pigs eat into feed can be digested and absorbed, and the other part that cannot be digested and absorbed is discharged from feces. There is still energy in the feces, which represents the undigested part of the feed dry matter. Therefore, the digestible energy is equal to the total energy of feed minus the energy in feces

digestible energy = total energy fecal energy

in addition to the energy contained in undigested feed, there are other undigested decomposition procts in the body, such as digestive juice, exfoliated digestive tract epithelial cells, and the energy contained in digestive tract microorganisms and their procts. Therefore, the digestible energy in the formula is not the real digestible energy, but the apparent digestible energy. However, because the determination method of apparent digestible energy is simple and easy, the Digestible Energy listed in the table of feeding standards and feed nutritional value of pigs in China generally refers to the apparent digestible energy. Metabolizable energy refers to the energy that is used by the body after digesting and absorbing the feed. The energy in digestible carbohydrate and digestible fat can be fully utilized in the process of metabolism, and the metabolites are carbon dioxide and water, which no longer contain energy; In the process of feed digestion, some gases will be proced in the digestive tract, and the energy carried by these gases is very little, about 0.5% - 1% of the digestive energy, which can be ignored; In the process of digestible crude protein metabolism, the nitrogen-containing part can not be oxidized in the body and excreted by the urine, so the urine energy represents a part of the energy in the feed that can not be used by pigs. The calculation formula of metabolizable energy is as follows:

metabolizable energy = digestible energy net energy of urine energy

the net energy value of feed is the energy that feed can really use for livestock, which can be used to maintain life and proce livestock procts. After feed intake, not only fecal energy, urine energy and gas energy are excreted, but also body heat is lost in pigs. For example, within a few hours after feeding, the caloric proction of a hungry animal is higher than that of its basal metabolism (starvation). This increase in caloric proction e to eating is called body heating. In addition to maintaining body temperature in cold season, body heat gain is a waste of feed. The calculation formula of net energy is as follows:

net energy = metabolizable energy - net energy of body heating feed is essentially the proct energy of animals, which seems to be the most accurate in theory. However, because it is restricted by many factors, and is very unstable, it is difficult to determine, so the net energy value of most feeds is calculated based on digestible substances. Digestible energy value is the energy contained in the material digested and absorbed by animals, which is relatively stable and reasonable. The results showed that the ratio of digestible energy to metabolizable energy was 100:96, and the determination of digestible energy was easier than metabolizable energy. At present, digestible energy is widely used in pig feeding standard and feed nutritional value table in China and many countries; Poultry use metabolizable energy because it is difficult to separate feces from urine

No.1 Zhongshan Road, Hebei District, Tianjin

bus line: Metro Line 3, the whole journey is about 6.7km

1. Walk about 330m from Tianjin Fourth central hospital to the North Station

2. Take Metro Line 3, after 6 stops, to Yingkou station

3. Walk about 570m to Maimai leisure square

I agree with this scholar's view, because our country has started to implement digital currency, and the digital economy will surely account for a large proportion of GDP in the futurevirtual currency needs to be considered. According to the limitations of personal understanding, it is impossible to understand that virtual currency can be widely used