Объективный контроль обработки зерна: как оптимизация кормовых технологий повышает рентабельность скотоводства

Grain processing is one of the cheapest wins in the feedlot Corn’s dense endosperm is why steam flaking pays off there but adds little for barley and wheat 2 days ago 6 min read Earlier this year, we highlighted results from the first Canadian Feedlot Benchmark Survey and discussed the cereal grains most used in Canadian beef production. While most feedlots process grain, few use objective measurements to determine whether processing is adequate. Most rely primarily on visual assessment. Because grain is one of the largest costs in beef production, optimizing processing can improve feed efficiency and profitability while reducing digestive risks. The benchmark survey showed barley remains the dominant grain in western Canadian feedlot diets, followed by corn and wheat. In Eastern Canada, corn is the primary cereal grain, with barley and wheat also common in backgrounding and finishing diets. Across Canada, the three most common grain-processing methods used in finishing diets were dry rolling (36 per cent), high-moisture storage systems (34 per cent) and temper rolling (14 per cent). Despite grain processing’s importance to starch use, only about one-quarter of survey respondents used processing index (PI), per cent fines, or both to evaluate grain processing. Another 22 per cent relied primarily on visual assessment. Why grain processing matters The primary objective of grain processing is simple: to make starch more accessible to rumen microbes. Read Also The outer coating, or pericarp, is the first barrier to microbial access. Rolling, grinding, tempering and steam flaking fracture this layer and expose the starch-rich endosperm. Once the pericarp is broken, starch digestion varies among grains because of kernel structure. Barley and wheat have relatively loose protein matrices that allow rapid microbial access once cracked. Corn contains a dense vitreous protein matrix that continues to limit access to starch. This difference explains why more aggressive processing methods such as steam flaking or high-moisture storage often improve the feeding value of corn but provide little benefit for barley and wheat. Common grain processing methods include dry rolling, tempering, grinding, high-moisture grain systems and steam rolling or steam flaking. Processing targets for barley and wheat The goal is to fracture virtually every kernel while limiting the production of fines. Once the seed coat is damaged, additional processing provides little benefit because rumen microbes already have excellent access to starch. For dry-rolled barley and wheat, it is recommended to target a processing index of 70 to 75 per cent while maintaining less than five per cent fines. Consistent roller settings and grain flow rates are key to achieving these targets. For tempered barley and wheat, moisture addition improves feed handling characteristics, reduces dust and helps create a more uniform particle size. Current research suggests a target processing index of approximately 65 to 70 per cent. Kernel size variability can complicate processing because settings that adequately process large kernels may over-process smaller ones. Monitoring processing measurements becomes especially important when grain size variability is high. Why corn behaves differently Corn’s dense vitreous endosperm and protein matrix limit access to starch even after the kernel is cracked. As a result, high-moisture processing and steam flaking can improve starch digestibility and feed efficiency by disrupting these barriers. As a result, processing index and per cent fines are less useful indicators than for barley and wheat. Where visual assessment falls short Visual assessment can identify obvious issues but should not be used alone. Objective measurements help monitor consistency and identify problems early. How to read a processing index (PI) Processing index compares the bulk density of processed grain to its original bulk density. As processing intensity increases, particle size and bulk density decrease, resulting in a lower PI. The benchmark survey showed that processing index values in finishing diets ranged from 66 to 88 per cent, with a median value of approximately 68 per cent. When monitored routinely, PI can help identify changes caused by roller wear, grain variability or equipment adjustments before they affect cattle performance. Why fines signal over-processing Per cent fines measure the proportion of very small particles, typically less than 1.5 mm in size. Fines serve as a useful indicator of over-processing because these particles ferment rapidly in the rumen. Excessive fines can increase the risk of acidosis, bloat and other digestive disturbances. In most barley finishing diets, maintaining fines below five per cent helps balance thorough kernel fracture. Measuring both fines and whole kernels provides a more complete assessment of processing quality than either measurement alone. Flake density targets for steam-flaked corn For steam-flaked corn, flake density is the preferred measure of processing quality. Flake density directly reflects the extent of steaming and rolling and is associated with starch availability and animal performance. Properly processed steam-flaked corn should generally have a flake density between 24 and 28 lb./bu. (approximately 310 to 360 g/L). Within this range, starch digestibility is improved while maintaining an acceptable rate of ruminal fermentation. Over-processing corn and producing flakes with densities below approximately 20 lb./bu. (250 g/L) can substantially increase the risk of digestive disorders, including acidosis and bloat. Grain should typically remain in the steam chest for 30 to 45 minutes, steam temperatures should exceed 95 C, and grain moisture before rolling should be between 18 and 22 per cent. What to know The greatest opportunity to improve starch use in beef cattle is not through expensive additives or novel technologies, but through proper grain processing and routine evaluation. Regardless of the grain being fed, the objective remains the same: maximize starch use while maintaining rumen health. When grain represents one of the largest costs in a feeding program, ensuring it is processed correctly may be one of the simplest and most profitable management decisions a producer can make. Dr. Gabriel Ribeiro is an associate professor and the Saskatchewan Beef Industry Chair in the animal and poultry science department at the University of Saskatchewan. He has a DVM, and M.Sc. and PhD in animal science (ruminant nutrition).