The role of crude fiber in rabbit nutrition

The role of crude fiber in rabbit nutrition

Crude fiber levels in 1 rabbit diet

1.1 Crude fiber level for rabbits

Mechanism of Action and Effects of Nutrition Due to the absence of cellulase in the stomach and small intestine, crude fiber is transferred to the cecum without any change; under the action of cecum cellulase, some fibers are decomposed into volatile acids such as acetic acid, propionic acid and butyric acid. Fatty acids, where acetic acid participates in the formation of body fat by the tricarboxylic acid cycle, propionic acid forms hepatic glycogen in the liver, and butyrate inhibits motility of the digestive tract. When the content of crude fiber in the feed is low, there is less acetic acid, more propionic acid and butyrate, and on the one hand intestinal motility slows down, on the other hand, in order to ensure the supply of sufficient energy to the rabbit. The low-fiber dietary starch content will be higher, so that a considerable amount of starch enters the cecum without digesting in the small intestine and acts as a substrate for bacterial growth in the cecum, so that the microorganisms in the cecum will experience a large proliferation of starch. Clostridium perfringens or Escherichia coli produces large amounts of toxins that increase the osmotic pressure of the intestine, increase mucosal permeability, and allow water and electrolytes to enter the intestine from the bloodstream, causing dehydration, bleeding from the intestinal wall, and imbalance of acid-base balances. Rabbits have digestive disorders, diarrhea, growth retardation, and even death.

Cheek et al. (1983) reported that feeding low-fiber diets causes rabbits to lose weight. Serafty (1980) reported that all rabbits fed a diet containing 2% crude fiber had died within four weeks. Hange (1998) reported that fattening rabbits fed 8%, 10%, 12%, and 15% diets containing crude fiber, and those fed the first two diets had 27.1% and 13.3% mortality due to enteritis. The latter two types of diet did not show enteritis. Studies have pointed out that diarrhea caused by feeding low fiber diets can be eliminated by adding 10% of fiber. Bias (1994) reported that feeding low-starch and high-fiber diets to weanling young rabbits can reduce rabbit mortality, but this does not mean that high-fiber diets are beneficial to rabbits. When the rabbit's dietary crude fiber level rises, in addition to aggravating the burden of the digestive tract, more acetic acid and less propionic acid and butyrate can also be produced in the cecum, which reduces the inhibition of intestinal motility. Increased excitability of the intestine, increased bowel movements, resulting in a short residence time of the feed in the cecum, and reduced digestibility of nutrients. Jin Lingmei (1994) reported that when the crude fiber level increased from 12% to 16%, the feed conversion rate decreased by 31.7% accordingly. A Val- lone et al. (1987) reported that diets containing 12.5 % crude fibre and 16.5 % dietary fibres resulted in an increase in crude fibres in the diet and dry matter in rabbits. The apparent digestibility of organics, energy, nitrogen-free extracts and cellulose decreased. Tensing et al. (1993) reported that in the range of 10% to 13% of crude fiber, the energy digestibility of rabbits decreased by 1.5% to 4.55% for each 1% increase. Saltcka et al. (1992) reported feeding 5 to 6 months old rabbits with 4 diets containing 17%, 20%, 23% and 265 crude fibres. The results showed that with the increase of crude fiber level, body weight, body weight and fur quality were increased. Both are falling.

1.2 The appropriate amount of crude fiber in rabbit diets Heckman et al. (1970) pointed out that 6 to 12 weeks old rabbits fed crude fiber at 8% to 9% diets can obtain the highest growth rate and feed conversion efficiency. And in good health. Serafy et al. (1980) conducted tests with crude fiber containing 2%, 11%, 15% and 20% diets showed that body weight and carcass weight were 15% crude fiber. Zhang Guilin et al. (1985) reported that the fiber level is best from 15% to 20%. The amount of crude fiber in the compound feed of the rabbits in the Beijing Local Standards (1992) is 10% to 15%. According to the French Rabbit Nutrition Standard (1984), the crude fiber usage for growing rabbits, lactating rabbits, and pregnant rabbits was 14%, 12%, and 14%, respectively. Feeding standards of the former Soviet Union, the optimum amount of crude fiber in the diet of adult female rabbits is 15% to 20% of DM, lactating female rabbit diet is 10% to 16%, and growing young rabbits are 2% to 15%. In the AEC (1987) Rabbit Feeding Criterion, crude fiber requirements for pre-weaned rabbits were 12% and 13% after weaning. From the above data, the appropriate crude fiber content in rabbit diets was 10% to 20%. In fact, if you need more precise information, we can identify the components of the rabbit's diet. We can use the SZF-06B crude fat analyzer or crude fiber analyzer to determine the rabbit's feed. In general, if the feed is of good quality, then the feed will contain a certain amount of crude fiber and crude fat, because these two kinds of substances are the necessary nutrients for rabbits to grow.

The quality of dietary crude fiber for 2 rabbits

Different sources of crude fiber have different qualities, so the source of fiber in rabbit diets is one of the limiting factors of rabbit nutrition. A large number of research data show that alfalfa meal is ideal for foragers in rabbits. The crude fiber content was lower than that of wheat straw after analysis. The lignin content was less than 10% at the flowering stage, and the wheat lignin content was as high as 15% or more. Jin Lingmei (1994) reported that the feed conversion rate of rabbits fed on earthworm meal was significantly better than that of natural wheat straw diet vp<0.01w, which is consistent with the report of Payn et al. (1983). Tortuero (1991) reported that sources of dietary crude fiber affect cesarean volatile fatty acid production, intestinal microbiological environment and mineral absorption in young rabbits. Fraga (1991) studies have shown that the source of crude fiber in feed affects the retention time and soft feces content of digestive matter in puppies. From this point of view, the mix ratio of roughage in the diet depends on its quality, and the mix ratio of high-quality roughage is 30% to 50%, and the mix ratio of poor quality straw feed should be less than 30%.