By minimizing digestive disorders we can keep cattle on feed and maximize performance. Poor bunk management and not the ration being fed can be "the first domino to fall" resulting in digestive disturbances such as bloat, acidosis, and liver abscesses.
Cattle feeders should strive to have uniform day to day consumption of fresh, high-quality feed. The bunk management tools described below can aid in preventing large fluctuations in intake caused by acidosis and recovery from a bout of acidosis. Determining how much feed to offer requires a certain amount of skill and good judgement. Cattle are big fermentation vats (ruminants) and fermentation vats work best under constant conditions (Pritchard, 1993). Careful bunk management during the winter months when ice, snow and freezing rain are a problem is especially important since weather conditions alter consumption patterns.
One method of monitoring intake and determining how much to feed is to use a feedbunk-scoring system on a scale from zero to five. A score of zero implies that the feedbunk is empty or "slick". A score of zero-minus (0-)means the bunk has been empty for more than an hour. A score of zero-plus (0+) means the bunk is empty except for a few fines or clumps of feed. A score of one means something less than or equal to one inch of feed is left in the bottom of the bunk. A score of 2 means that 2 inches of feed is left. 3 means three inches and so on.
THE FEEDBUNK SCORING SYSTEM
| Score 0 - 0 0 + 1 - 1 2 3 |
Bunk Description Empty for more than 1 hour Empty bunk for less than 1 hour A few fines or clumps in bunk Thin layer, 1 kernel deep Less than 1 inch of feed in bunk Less than 2 inches of feed in bunk Less than 3 inches of feed in bunk |
Normally, if the score is zero for two consecutive days, increase the feed delivered to cattle by 5-10 percent. If the score is two or more, reduce the feed offered by 5-10 percent.
A bunk sheet should have a place for date, pen of cattle, amount of feed delivered and a bunk score. A feeder should have at least 4 days of records whenever determining how much feed to put in the bunk (Pritchard, 1993). Scoring bunks should be done the same time each day. Looking back, the bunk score, combined with the amount of feed provided can tell you if intakes are going up, coming down or holding steady. Scores constantly in the 2 to 3 range may lead to feed wastage and reduced feed efficiency due to the possibility of large fluctuations in feed intake.
CATTLE OBSERVATION: You also need to be looking at the cattle when you make a decision. If the bunk is empty (slick), do the cattle look like they are hungry or do they look content? If they look content, wait for a second or third day of slick bunks before increasing the amount of feed. One cool night or a small front can cause steers to slick a bunk that normally would not be slick. Increasing the feed delivery may only cause them to back off feed in the next 2 to 3 days. If they truly appear hungry, increase the feed delivered 5 percent today and hold it there tomorrow to find out if they can actually handle the extra feed. If they do handle the feed, try increasing it again on the third day.
STOOL OBSERVATION: Tall firm stools are a sign the cattle are consuming significant levels of roughage. Flat brown stools indicate that the cattle are consuming a higher amounts of grain but are not incurring digestive upsets. Flat gray stools are a sign of acidosis. Flat gray stools may be observed before an actual drop in intake occurs. Pens that have a majority of flat brown stools and a few gray stools are a sign that cattle are optimizing intake. MONITORING THE ENVIRONMENT
SEASONAL VARIATION: Feeding schedules may need to be changed during different seasons of the year. Cattle may eat more during the day and less during the night in the winter. Conversely, cattle may eat more during the night than during the day in hot weather. Cattle that look hot at 6 A.M. will not eat much that day. In winter, the footing on feed aprons can become difficult, discouraging intake, especially in heavy cattle.
WEATHER CONDITIONS: Mud and changing weather cause erratic intake patterns by cattle. Intake frequently increases prior to a storm, declines during the storm, and increases after the storm. A feeder might consider adding more roughage (5-8%) to the diet or using the previous step-up ration until cattle get reaccustomed to the increased intake. Cattle may consume their daily allotment of feed within as little as 2 hours time, after not eating any significant amount for 10 to 20 hours. A situation for bloat or acidosis exists even though 24-hour consumption patterns look fairly regular.
FEED MIXING: If every handful of feed coming out of the bunk is not uniform, the cattle are not all on the same diet. This situation can cause some cattle to go off feed within groups that may not be observed on the feed sheet. Differences in cattle condition may appear that are not explained by genetic composition of the cattle.
TIMES A DAY FEEDING: Dry feeds based on dry grain and hay may be fed only once per day. Data from South Dakota indicates feeding once a day in the evening was as good as feeding twice a day and was better than feeding once a day in the morning (during summer months). Dry feeds will be fresher for cattle if fed twice a day during rainy or snowy weather. High moisture rations such as those based on silage or high moisture corn, may need to be fed twice daily to avoid molding and spoiling during hot weather and freezing during cold weather.
FEED ACCUMULATION: Feed should not be allowed to accumulate from feeding to feeding. Dry matter intake will decline if this is allowed to occur for very long. Upon cleaning out large accumulations of stale feed, cattle may engorge themselves on the new, fresh feed and some cases of "grain bloat" may occur. The other scenario that may occur is the cattle will engorge themselves on the fresh feed in a short amount of time and "slick" the bunk and not consume the next batch of feed you provide.
Clumps of feed in an otherwise empty bunk will probably not be consumed by the cattle and thus should be cleaned out before fresh feed is added. Clumps of feed in a bunk that has been empty for less than an hour would receive a score of zero/plus. A bunk receives a score of zero/minus if it has been empty for more than hour and contains clumps of feed.
SLICK BUNKS: It is not considered poor management to have cattle clean the bunks once a day, as long as cattle are not out of feed to the extent they become restless or engorge when fed again. If it goes much longer than 1 hour on a high-energy diet, there is risk of overeating, acidosis (grain bloat) and irregular intake patterns.
FINES: Take time to investigate the type of material in the bottom of the bunk. Make sure finely ground meals and heavy ingredients such as minerals are not all falling to the bottom of the bunk. This can happen when small particle feeds such as ground protein or mineral are fed with large particle feeds such as whole shelled corn or ground hay. If such fines do appear in the bottom of the bunk, consider adding moisture in the form of silage, molasses, water or other wet products to help hold the fines in suspension.
SELF FEEDERS: Many of the same principles apply to cattle producers utilizing self feeders. Check the feeders on a regular basis. Avoid feeding wet feeds and keep the total moisture content of the ration to less than 14 percent. Make sure fines are not accumulating in the bottom of the bunk. This problem is minimized when the various feed ingredients have a similar particle size. Additionally, self feeders need to be examined more than once a day during wet weather to clean out spoiled feed. During hot/wet weather conditions, diets containing a high amount of urea may become unpalatable if allowed to become wet, and are not promptly removed.
WATER: Feed intake is related to water intake. A slow water fountain during hot weather will reduce intake. Frozen water fountains shut off intake. Clean water fountains on a regular basis. If irregular intake continues to be a problem, check the water quality and perhaps the fountain for stray voltage.
Water requirements for feedlot cattle (Gallons/Day) Temperature
| Animal Type | Weight (lbs) | 40°F | 70°F |
| Growing Calves Finishing Cattle |
400 600 800 800 1000 |
4.0 5.3 6.3 7.3 8.7 |
5.8 7.8 9.2 10.7 12.6 |
THE USE OF IONOPHORES: Ionophores can help control variations in daily intake and reduce occurrence of acidosis and bloat.