Introduction
Most of our state's grazing land is currently moderate to excessively dry. Drought stressed forages and
reduced forage dry matter accumulation has been reported across the entire state even in areas that have
received rainfall relief in the past couple months. As we look toward the coming winter and early spring,
many beef cattle producers are asking, "Will it be a tough one"?
Tough winters are not foreign to Florida's beef cattle producers. In general, our state's cowherd calves
in the late fall through winter, a time when our available perennial pastures are lacking and our cowherd's
nutritional needs are the greatest. During average winters, or even good winters, we have moderate to mild
winter temperatures with a few much-needed rain showers to coax the growth of winter annuals in central and
northern Florida and Hemarthria limpograss in southern Florida. In contrast, tough winters are characterized
by excessively cold and dry conditions often lasting late into the spring. As an example, our Research and
Education Center in Ona has a 60-year running average of about 3 episodes annually that the air temperature
reaches 32 degrees (F) or lower. In the winter of 1999 to 2000 we experienced 15 episodes of air temperatures
falling below the freezing point. This was a tough winter, which was associated with prolonged cold events and
dryer than normal conditions. Cattlemen throughout the state scrambled to identify management systems to
maintain the cowherd until the coming summer season.
It is impossible to know exactly how this upcoming winter will turn out or when spring rains will bring
back adequate grazing conditions. Predictions call for dryer than normal conditions throughout the state.
The current status of our grazing lands, coupled with the overall lack of stored forages in the southeastern
US, suggest that we would be wise to plan for a tough winter. In this Ona Report, several suggestions for
dealing with a tough winter are provided. As you review these options, attempt to identify those that might
make your operation more productive and/or more profitable in the face of a potentially tough upcoming winter.
Choosing a Winter Supplement
Supplementation of the cowherd is a common annual practice to provide cows and heifers with additional
nutrients that may be lacking through inadequate forage quality or quantity. Managing supplementation
varies annually and changes should be closely aligned to the body condition of the cows and status of
available forage resources. The two most important nutrients targeted in winter supplementation strategies
include protein and energy (energy is typically referred to as TDN). There are multiple choices available
when purchasing winter supplements. Some important considerations to keep in mind when making this decision
include:
- Cost per Unit of Nutrient Purchased - The protein and TDN content of winter supplements differ.
Calculate the cost per pound of protein and TDN offered in the supplement and use this as a partial
indicator of the value of one purchase versus another.
- Protein Source - Non-protein nitrogen (typically urea) is sometimes used as a source of supplemental
protein in winter supplements. Urea is certainly an acceptable source of protein for mature cows; however,
supplements containing urea should be more affordable than those containing natural protein sources
(cottonseed meal, soybean meal, etc.). Supplements with natural protein should be considered when they
are offered at a similar price to those containing non-protein nitrogen.
- Excessive Protein Supplementation - Be cautious to not over-supplement protein. In an attempt to
increase body condition, producers sometimes feed too much high-protein supplement. This practice may have
a detrimental impact as the cow will expend considerable energy in attempt to clear her body of excessive
protein. Body weight gain can be compromised and in some cases body weight loss can be created. As a rule
of thumb, do not provide more than 2 to 3 pounds of supplemental protein daily. If additional energy is
needed and the maximum crude protein intake has been reached, attempt to change your winter supplement
toward a lower protein option.
- Storage and Feeding - Some winter supplement choices require an investment in storage and/or feeding
resources. For example, a mixed commodity bulk feed may be less expensive compared to a bagged range cube
product, but a storage facility with capacity for 20 tons may be required for the bulk commodity purchase.
This expense can greatly offset the perceived savings. In other cases, complete liquid feed supplements
may be favorable due to opportunities for field delivery into bulk, lick-wheel delivery systems.
Separate the Cowherd
When the entire cowherd is managed through the winter as a single group, there are always individuals that
receive more nutrients than required and also those that receive fewer nutrients than required. One of
the easiest and most effective methods of increasing the efficiency of the winter supplementation program
is by separating the cowherd into individual groups based on nutritional need. At a minimum, three groups
should be created, including; 1) growing yearling replacement heifers, 2) cows nursing their first and
second calf, and 3) mature cows. If possible, a fourth group can be created consisting of two groups of
mature cows separated based on body condition score and age. Once these cow groups are created the producer
can focus their management resources (both pasture and winter supplement) on the groups that need it the most.
This is a very effective procedure for individually directing resources toward distinct cow groups that have
been organized to provide the greatest return on investment.
Early Calf Weaning
One of the most effective decisions for managing cows through a tough winter is early weaning of calves.
Calves can be successfully weaned from their cow at any time after 70 days of age. The removal of the
calf creates a physiological response in the cow that initiates cyclicity even when the cow is in less
than optimal body condition. In addition, once lactation ceases the cow's voluntary forage intake will
reduce by about 25% allowing forage resources to extend further during times of limited availability.
Once early weaned, there are several options for managing the calf, including; 1) sell at the time of
early-weaning, 2) graze on dormant perennial pasture with free-choice access to a complete grain-based
mixture containing 18 to 20% crude protein, or 3) graze on winter ryegrass with supplement (16 to 18%
crude protein) provided at approximately 1% of body weight. Many Florida producers have begun using early
weaning management systems in their cowherds, especially young cows, with considerable success.
Maximize the Fertilizer Investment
Try to avoid fertilizing bahiagrass, bermudagrass, and stargrass pastures in the winter months.
It is always best to save this investment for an early spring (February / March) application when
the grass is entering its summer growing phase and when spring and early summer grazing is most
needed. In contrast, fertilization of winter annual pastures and winter Hemarthria limpograss
pastures may provide critical winter grazing if fortunate to receive at least some rainfall near
the time of application.
Save on Mineral Supplements
Almost all commercially available winter feed supplements are fortified with minerals. Check
your feed tag or consult your feed supplement supplier. When offering these winter supplements
to the cowherd, producers can typically replace their normal free-choice trace mineral supplements
with plain white stock salt. The cows will be receiving their mineral needs through the winter
supplement and forage. The extra free-choice mineral won't harm them, but most likely won't help
either. These savings can be directed toward other needs such as spring fertilization or additional
winter supplement purchases.
Cow Culling
Tough winters may also be an opportunity to cull down the cowherd. Culling consideration
should include eye and mobility problems. Opportunities to sell cows that have advanced
eye lesions or mobility impairment are now greatly limited resulting in a condemned carcass.
Producers should establish a management system to identify these cows early so that they can
be culled and marketed with little loss in salvage value. Culling cows that wean small calves
is another consideration. In a University of Arkansas study, 4,379 records were examined over
two consecutive years from 18 cow/calf herds. Their results show that cows that produce calves
in the lightest 1/3 of the total calf crop in one year are likely to continue to produce the
lightest calves in subsequent years.
Summary
It is probably wise to begin planning for a tough 2008 winter and spring season.
The purchase of harvested and stored winter forages will be greatly limited.
Considering some of the options provided in this article will help producers to
manage their cowherd through a difficult season with hopefully little reductions
in performance. Additional educational articles related to winter supplementation,
early weaning, fertilization, and mineral nutrition can be found at Solutions for
Your Life at the University of Florida, IFAS-Extension;
http://edis.ifas.ufl.edu.
