The Cow-Calf Manager
Livestock Update, December 2007
Dr. John B. Hall, Extension Beef Specialist, VA Tech
Limiting Hay Intake by Cows
Several articles that the VT Extension Beef Team has written over the last few months indicated that one way to stretch hay supplies was to feed grain/by-products and limit feed hay. Since those articles appeared, many folks asked for methods to decrease or limit hay intake.
How much is enough?
Long stem hay is important for healthy rumen function. There must be sufficient “scratch factor” to stimulate rumen motility and salivation. Rumen motility is important for proper mixing of feed with rumen microbes to enhance digestion. Salivation is critical to maintaining the rumen at the correct pH. A minimum of 5 lbs of hay per cow per day is needed to maintain rumen function.
Methods to control intake
Back when we all fed small square bales limiting intake was rather easy. Knowing the weight of the bales (usually 40 to 60 lbs), we simply decided how many cows per bale and put out the correct number. With large bales (round or square), the job of limiting hay intake becomes more difficult. The first step is to know how much the bales you make weigh. Your baler salesman is a nice guy, but the figure he gives you on bale weight is usually the maximum. Weigh a few bales on a cattle scale or take a load to the truck scale and weigh them.
Bale busters or bale unrollers. These machines can deliver precise or controlled amounts of hay to cattle. However, they are expensive and cost prohibitive for all but the largest operations.
Unrolling. This method is the second most precise method we have to limit hay. This sounds simple, especially if you have a hydraulic bale mover; just take the amount of hay you want to put out and divide it by the bale weight right? Wrong. Let’s do a little geometry review. In a 5 ft. diameter bale, 1/3 of the hay is in the outer 4 inches and 1/2 of the hay in the bale is in the outer eight inches. For a 6 ft. diameter bale, 1/3 of the hay is in the outer 6 inches and 1/2 of the hay is in the outer 12 inches.
For example, you have a 5x5 bale that weighs 1000 lbs. and you have 50 cows. You want to feed those cows 10 lbs of hay each, so you need to feed 1/2 of the bale. On the first day, you roll out the outer 8 inches of the bale. On the second day, you roll out the rest of the bale.
Wastage is still a factor with unrolling. Cows and calves will trample and soil about 5 to 10% of the hay rolled out. In high wind conditions, you may be feeding the neighbor’s cows instead of your own. Losses due to waste are increased in wet or snowy conditions.
Limiting access. This method is extremely effective especially for smaller herds of <50 cows. Cows are allowed access to hay for only a few hours per day then they are moved to an adjacent area or pasture. Temporary electric fence can be used if kept adequately charged.
Recent research from the University of Illinois (Miller et al., 2007) indicates that as little as 3 hours of access is needed with high quality hay, and 6 to 9 hours of access is needed for medium quality hays to achieve cow performance similar to 24 hour access. In this particular research, hay was the only feed offered these gestating cows. If hay is to be stretched by feeding by-products then 3 to 4 hours of access may be sufficient. It is important that there are enough feeding locations so all cows can eat at the same time. Therefore, multiple hay bale feeders may be needed. However, with today’s hay prices you can pay for a couple of new round bale feeders very quickly.
Two on - One off. This is a very simple method that does not save as much hay as other methods, but most producers can achieve some reduction in hay usage this way. Cows are fed all the hay they want for two days and then hay feeding is skipped on the third day. Cows should be fed the supplement portion of their diet on the day hay feeding is skipped. Cow performance will not be compromised by skipping a day of hay feeding if supplements such as corn gluten feed are fed. Cows will have sufficient rumen fill to continue to have cud to chew and produce extra heat from fermentation on the day without hay. It takes 48 to 72 hours for the rumen to empty if cattle receive no feed.
Adapting to conditions
It is critical that with all of these methods consideration is given for weather conditions. If a week of extremely cold weather is predicted then limiting hay intake may not be the best idea. During these extreme periods, using more hay will provide addition nutrition needed by the cattle. In addition, cow body condition should be monitored throughout the winter, and feeding practices adjusted to maintain a body condition score of 5 to 6.