(1) Heat-treated plant protein feed (beans and their cake, etc. ) contains a variety of protease inhibitors, urease and other harmful substances, which need to be steamed, boiled, fried and other heating treatments before feeding. Can increase palatability and improve the digestibility of protein. According to the experiment, 90% antitrypsin can be inactivated by heat treatment of raw soybean and raw soybean cake at 65438 0 28℃ for 5 minutes. Cooking, puffing and tempering in the process of making dried fish meal can be used as heat treatment of protein raw materials. But the heating time should not be too long, otherwise the protein will be denatured and lysine will be destroyed.
(2) Water Treatment For toxic protein raw materials such as cottonseed meal and rapeseed meal, because some harmful substances are easily soluble in water, water immersion can be considered to remove the toxic and harmful factors. Soaking and washing rapeseed cake with clear water can remove toxicity and spicy taste; Cottonseed cake (meal) contains toxic free gossypol, which can be combined with ferrous sulfate. 0. 1% ~ 0.2% ferrous sulfate aqueous solution can be evenly sprayed on cotton meal according to the weight ratio of ferrous sulfate to free gossypol of 5: 1, and stirred overnight. The content of free gossypol in cottonseed cake is about 3000 mg/kg, and that in cottonseed meal is about 1000 ~ 2000 mg/kg. However, water treatment will also wash away nutrients. Try not to wash them with water, but soak them. Furthermore, the water treatment time should not be too long, otherwise it will be moldy and deteriorated.
(3) Squeezed seed feeds such as black beans and peas are often used to feed cattle and horses. If they are squashed with water before feeding and dried before feeding, the digestibility can be obviously improved. At present, the new technology and related equipment of steam flaked grain have appeared. Studies have shown that feeding beef cattle and dairy cows with corn, barley, wheat, soybeans and other grains with steamed slices can improve the production performance of animals.
(4) puffing: adding a proper amount of water or steam to feed the raw materials and compound feed. Under the conditions of high temperature (100 ~ 170℃) and high pressure (20 ~ 100 Pa), the volume of continuously sprayed materials will suddenly expand and the water will evaporate rapidly. The porous puffed feed prepared by this method has high digestibility and low content of toxic and harmful substances. Common puffed raw materials are: puffed soybean, puffed corn, puffed soybean meal, puffed cotton meal, etc. Because of the high price, puffed raw materials are mostly used to prepare the diets of young animals (such as piglets and broilers) and fur animals. There is also puffed feed, which is a product made of various feed raw materials into compound feed and then puffed, which improves the biological value of feed, but will affect the activities of nutrients such as vitamins and enzyme preparations in feed.