Many producers utilize winter annuals, small grains
and/or ryegrass, to complement their forage program. The question
is, are they utilized in the most optimal way? Instead of unrestricted
access to the forage, what about limited access such that the high-quality
forage becomes a supplement? Most producers base their winter feeding
program on free-choice hay with the use of some supplements after calving.
Winter annuals typically contain 70 to 75% TDN (total
digestible nutrients) and in excess of 20% crude protein. This makes
an excellent supplement to hay because the energy in the winter annuals
is in the form of very digestible fiber which does not reduce hay digestion.
In addition, the protein fraction is highly digestible. For much
of the hay that is produced in Alabama, providing cows with 5 to 7 pounds
of dry matter from these winter annuals would provide adequate nutrition
to a lactating cow.
The most efficient manner in which to provide
this amount of dry matter per day is by limit grazing. Every producer’s
circumstances are different; nevertheless, I would start with about an
acre of winter annuals for every 2 cows and allow an accumulation of 6
to 8 inches of forage. At this point, mid-December to mid-February
depending where you are in the state, begin to utilize the forage with
lactating cows. Experience indicates that a period of about 1.5 to
2 hours per day is sufficient time for the cows to meet their needs.
In fact, the Noble Foundation in Oklahoma has conducted research to determine
the amount of winter annuals consumed by steers in 15 minute intervals.
These steers consumed 1.41 pounds of dry matter in 15 min., 1.92 in 30
min. and 2.72 in 45 min. The values indicate cumulative consumption
so as you can see, the amount consumed in each 15 min. interval is decreasing.
These were fully grown steers; however, one would presume that mature cows
would probably consume greater amounts in the same time frame although
this data is not available. A good rule of thumb would be to remove
the cows from the grazing as soon as the first cow starts looking for a
place to lie down. Furthermore, this does not have to be a daily
routine, similar results can be achieved with every other day access to
the grazing. The time period may need to be slightly extended with
this option.
In the beginning, it will take some time to
get the cows on and off of the winter annuals but in just a few days it
will become a very routine procedure and the cows will meet you at the
gate both coming and going. Establishing winter annuals can be costly
(i.e., $100/acre) and is quite weather dependent; however, the nutrition
is excellent and the requirement for mechanized daily feeding is all but
eliminated. The key to success is using limit grazing rather than
allowing the cows continual access to the winter annuals. Keeping
winter annuals grazed down to the ground is not conducive to maximum production.
Obviously, if ideal growing conditions exist and forage production is exceeding
animal demands, then by all means utilize more of the forage.