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What breeds of black goats are there? An overview of common excellent breeds
What breeds of black goats are there?
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What are the breeds of improved pigs? A overview of common excellent pig breeds
What are the breeds of improved pigs
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Overview of Research Progress and Current Utilization of Propolis
Propolis is a resinous substance collected by honeybees from tree buds, bark and other parts of plants, mixed with secretions from the bees' hypopharyngeal glands, wax glands and other glands, and processed and transformed by the bees. Propolis is an opaque solid, brown, reddish-brown or grayish-brown in color, sometimes with a greenish tinge, and in a few cases nearly black. Natural fresh propolis has a resinous fragrance and is sticky and malleable. It begins to soften at 36°C, becomes hard and brittle and can be pulverized at 15°C, and melts into a viscous liquid at 60-70°C. Propolis is a resinous substance, highly soluble in ether, chloroform, acetone,
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What kind of fish is the pond smelt? Characteristics and habits overview
(Osmeridae) Hypomesus oidous [local name] cucumber fish. [Morphological characteristics] Small fish, generally 6-8 cm in body length. Body elongate and laterally compressed. Head length greater than body depth. Snout terminal, mouth cleft relatively large, upper and lower jaws with villiform teeth, maxilla extending to below the eye. Eye present, eye diameter equal to snout length. Dorsal fin tall, its height greater than body depth, opposite the pelvic fins. Adipose fin present. Pectoral fins small. Caudal peduncle very slender, caudal fin deeply forked. Back light grass green, sides of body silvery white, scale edges with small dark spots. Fins grayish black
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Basic Overview of Protein in Pig Nutrition
(1) Carbohydrates Carbohydrates are the most widely available and the largest proportion of nutrients in the diet, and are the main energy source for pigs. In cereal grain feeds, there is very little soluble grass sugar and disaccharide, mainly starch, so it is the main energy source for pigs. Starch is broken down by amylase in the digestive tract into glucose, which is then absorbed into the blood as blood sugar. It provides energy through biological oxidation in the body. The digestibility of soluble sugar and starch by livestock is 95%-100%. For piglets before 2-3 weeks of age, due to insufficient pancreatic amylase and intestinal disaccharidase secreted in the digestive tract, piglets fed large amounts of starch feed grow poorly. Before 7 days of age, piglets fed glucose and lactose can utilize them effectively. After 7-10 days of age, they can utilize fructose and sucrose, but young pigs after feeding generally suffer from severe diarrhea, weight loss and high mortality. Crude fiber, after treatment with a certain concentration of acid and alkali, the remaining residue is called crude fiber. This determination method is incorrect. Generally, crude fiber in feed contains cellulose, hemicellulose and lignin, and their composition ratio is unstable. In typical feed crude fiber, the contents of cellulose, hemicellulose and lignin are 50%-80%, 20% and 10%-50% respectively. Cellulose and hemicellulose are polysaccharides. Cellulose is a glucose polymer, and hemicellulose is composed of hybrid sugars (glucose, fructose, mannose, galactose, arabinose, xylose, rhamnose, uronic acid). Lignin is a group of complex and difficult-to-digest substances - incomplete polymers of phenylpropane derivatives. These substances are the main structural components of plant cell walls. In the Van Soest analysis method, neutral detergent fiber (NDF) estimates the total plant cell wall components mainly composed of cellulose, hemicellulose and lignin. Acid detergent fiber (ADF) includes cellulose and lignin. The difference between NDF and ADF is the hemicellulose in the feed. The pig small intestine has no enzymes to digest crude fiber and cannot digest cellulose, hemicellulose and hemicellulose, but crude fiber enters the large intestine and undergoes microbial fermentation. The main end product of its digestion is volatile fatty acids, which supply about 5%-28% of the maintenance energy requirement. The digestibility of crude fiber is generally 30%-39%. Its digestibility is affected by fiber source, degree of lignification, content in the diet and degree of processing, so it varies greatly. The utilization of fiber is affected by the physical and chemical composition of the diet, the nutritional level of the diet, and the age of the animal. The digestibility of crude fiber varies from 0 to 97%. There is still no conclusion on the fiber level in diets for growing-finishing pigs. It is generally believed that for growing pigs around 20 kg body weight, the dietary crude fiber level is 6%. Some also believe that the level of neutral detergent fiber with low lignin should be less than or equal to 15%. Some experts believe that the crude fiber level in sow diets is 10%-12%. If the crude fiber level in the diet is too high, it reduces the digestibility of feed organic matter and energy. Increasing crude fiber in the diet by 1% reduces total energy digestibility by about 3.5%. It has also been reported to affect protein digestibility. In diets in the late finishing period, a higher level of crude fiber can be used to limit feed intake, reduce body fat deposition, and improve carcass quality. For every 1 percentage point increase in crude fiber content in the diet, backfat thickness is reduced by about 0.5 mm.
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