Improving the digestibility and utilization of fiber in sow compound premix feed requires a comprehensive approach across seven dimensions: fiber type selection, physical processing optimization, chemical treatment improvement, microbial fermentation application, nutrient balance regulation, fiber particle size management, and environmental adaptability adjustment. Through systematic improvements, the utilization rate of fiber in the sow's digestive system can be significantly increased, thereby optimizing feed conversion efficiency and sow health.
The selection of fiber type is fundamental to improving digestibility and utilization. Sow compound premix feed should prioritize ingredients with a reasonable ratio of soluble to insoluble fiber. Soluble fiber (such as pectin and gums) forms a viscous solution in the foregut, slowing gastric emptying and promoting nutrient absorption; insoluble fiber (such as cellulose and hemicellulose) stimulates intestinal peristalsis, increases fecal volume, and prevents constipation. For example, beet meal is rich in soluble fiber, while alfalfa meal contains a high proportion of insoluble fiber; a proper combination of the two can achieve complementary functions.
Physical processing techniques significantly affect fiber digestibility. Mechanical treatments such as chopping and pulverizing can disrupt the cell wall structure of plants, increasing the contact area between fiber and digestive enzymes. For example, pulverizing straw to a suitable length significantly improves palatability and digestibility. However, care must be taken to avoid over-pulverization, which can lead to excessively fine particles and potentially increase the risk of gastric ulcers in sows. The appropriate particle size should be controlled between 1-2 mm, ensuring some fiber structure is preserved while promoting the penetration of digestive juices.
Chemical treatments can further improve fiber properties. Alkalinization uses alkaline substances (such as sodium hydroxide) to break the ester bonds between fiber molecules, increasing fiber interfacial space and enhancing the surface area for microbial attachment. Ammoniation utilizes ammonia to react with fiber, softening the fiber structure and providing an additional nitrogen source for microbial use. These treatments effectively reduce the content of anti-nutritional factors in fiber and increase its degradation rate in the sow's digestive tract.
Microbial fermentation is a core method for improving fiber utilization. Adding exogenous fiber-degrading enzymes (such as xylanase and β-glucanase) to sow compound premix feed can accelerate the decomposition of fiber into monosaccharides or oligosaccharides. Co-fermentation technology, combining specific bacterial strains with enzyme preparations, can more efficiently degrade complex fiber structures. For example, using lactic acid bacteria and cellulase to treat feed can significantly reduce the content of neutral detergent fiber while producing beneficial metabolites such as volatile fatty acids.
Nutritional balance regulation is crucial for fiber digestion. The ratio of fiber to nutrients such as protein and energy needs to be precisely controlled. Appropriately increasing the metabolizable energy density in high-fiber feeds can compensate for energy losses during fiber digestion. Supplementing with minerals such as calcium and phosphorus (maintaining a 2:1 ratio) and vitamins A and D can strengthen the bone health and immune function of sows. For example, when adding fiber to the feed of gestating sows, energy supply must be increased simultaneously to meet the needs of fetal development.
Fiber particle size management directly affects digestibility. Excessively large coarse fiber particles may cause difficulty in feeding sows, while excessively fine particles may reduce the effect of stimulating intestinal peristalsis. Grading and screening technology can obtain fiber raw materials with uniform particle size distribution. For example, classifying fiber raw materials into coarse, medium, and fine particle sizes and mixing them in specific proportions before use can ensure feed palatability while maintaining normal intestinal motility.
Environmental adaptation is a key aspect of optimizing fiber utilization. In hot and humid environments, sows experience decreased appetite and digestive capacity; therefore, the fiber content in feed should be appropriately reduced to lessen the digestive burden. In cold seasons, the fiber proportion can be increased to help sows maintain body temperature through fermentation and heat generation. For instance, adjusting the fiber content of sow feed to the lower limit of the appropriate range in summer and closer to the upper limit in winter can significantly improve feed utilization.
