国产三级精品三级_亚洲老妈激情一区二区三区_黄又色又污又爽又高潮动态图_久久午夜夜伦鲁鲁片免费无码影视,久久无码人妻一区二区三区午夜_久久久久精品久久久久影院蜜桃_亚洲综合欧美色五月俺也去_交换娇妻呻吟声不停中文字幕 ,国产精品久免费的黄网站,天堂AV电影AV无码免费,欧美动漫日韩一区第2页,日本午夜精品理论片A级APP发布 ,亚洲精品NV久久久久久久久久_久久男人av资源网站_国产成A人亚洲精V品久久网_丁香色欲久久久久久综合网,人人操操人人,久久人爽爽人爽爽AV无码自慰,一级137片内射偷拍,欧美A区

What are the feeding techniques

What are the feeding techniques
Even high-quality feed cannot achieve the expected feeding effect if fed improperly. There is a saying in the Chinese agricultural proverb that "the same grass, the same material, different feeding methods, different fat". This emphasizes the importance of feeding technology. Therefore, it is necessary to explore feeding technology.
Regulation of feed intake of arthropods
Feeding is the basic method for animals to consume nutrients from human feed. Feed intake is an indicator that measures the amount of nutrients consumed by animals in feed. The essence of animal production is the process of producing products (meat, eggs, milk, etc.) using feed materials within the animal "machine". Only when animals consume enough nutrients can they produce more products. Therefore, food intake is an important factor affecting animal production performance. The purpose of regulating the feed intake of animals is to produce Animal product (meat, eggs, milk, etc.) in quantity and quality with appropriate feed nutrients.
1、 Related concepts
1. Voluntary feed intake (VFI) refers to the amount of feed that an animal can consume within a certain time interval based on their instinctive needs under conditions of free contact with feed. Random food intake is regulated by the sexual system in the body (such as the nervous Endocrine system).
2. Actual feed intake (AFI) When animals feed, it is not only regulated by intrinsic systems, but also influenced by environmental factors and feed composition. Under such conditions, the amount of feed actually consumed by animals within a certain period of time is called the actual feed intake.
3. Regular feed intake (RFD): In animal production, in order to maintain animal health, maintain a certain production level, and ensure sufficient nutrients for human consumption, the daily feed intake of animals is artificially set, which is called the prescribed feed intake. The feed intake given in the feeding standards is the prescribed feed intake.
2、 Method for measuring food intake
1. The daily feed intake is usually expressed as the amount of feed consumed within 24 hours. However, due to differences in dry matter content and nutrient concentration in feed, the same daily intake does not necessarily mean the same amount of nutrients consumed.
2. Daily intake of energy Energy is an extremely important nutrient for animals, and animal feeding is to some extent "for the sake of energy". Therefore, the daily energy intake as an indicator of food intake is superior to the daily feed intake. The regression formula for predicting pig feed intake at different stages by NRC (1998) is as follows
Although the exact location of the central nervous system for controlling food intake is not yet fully understood, there is sufficient experimental evidence to suggest that the hypothalamus in vertebrates is an important site for regulating food intake. There are two centers in the hypothalamus that are related to food intake, namely:
The feeding center is located in the lateral area of the hypothalamus, which is the central site for stimulating feeding. When the feeding center is excited, the animal's appetite is strong, stimulating feeding.
2. The satiety center is located in the ventromedial nucleus of the hypothalamus, which is the central site for inhibiting food intake. When the satiety center is excited, the feeding center is inhibited, causing the animal to experience satiety and stop feeding.
At present, research has confirmed that more than ten species of animals, including pigs, sheep, chickens, and geese, exist in the aforementioned two centers. Destroying the satiety center can lead to hyperphagia, leading to overeating and obesity in animals; On the contrary, chemical or electrical stimulation of the satiety center can cause anorexia, inhibit animal feeding, damage the feeding center, and cause anorexia until the animal dies; Stimulating the feeding center can cause hyperappetite.