Cattle Today

Cattle Today







cattle today (10630 bytes)
STUDY WINTER GRAZING TO DETERMINE IF FEED IS ADEQUATE

by: Heather Smith Thomas

Many cattle spend part or all of the fall and winter on pastures. The challenge for the stock grower is to manage these cattle to make use of inexpensive forage, yet keep cows in satisfactory body condition for calving and the next breeding season.

Pay attention to grazing behavior - whether they are slow to start in the mornings, whether they are working on the willows and brush in an attempt to generate more heat energy from their diet. Grazing behavior will tell you whether or not feed is adequate for their condition (even before they start to visibly lose weight), or if they need a little help. If you pay close attention to grazing behavior, the animals will give you clues that will help you get them through the winter without any serious weight losses, or serious feed bills.

Here are 5 hints for capitalizing on the beef animal's winter grazing behavior:

1. Assess the pasture's nutritional health

Plant varieties vary in nutritional quality, and this can also vary from season to season. Grasses peak at the height of the growing season and decline as they mature and dry out. Some native grasses don't lose as much nutritional value when they mature as tame pasture species. Just as the early buffalo thrived on native western grasses year-round, the cattle of today can usually manage on it, under normal conditions. Good types of grasses generally provide an adequate maintenance diet for the dry cow, meeting all her nutritional needs except for salt.

2. Check grazing patterns when assessing forage volumes

As days get colder, cattle spend less time in shady areas and may stop using them altogether during the shortest, coldest days of the year.

Even if there is a lot of good feed left in those parts of a pasture, the cattle may prefer to stay in the sun and lose weight eating themselves into the ground.

Any adverse weather will likely alter this naturally balanced grazing pattern. Drought, for example, lowers grass quality, and in time, will increase the cow's need for Vitamin A and protein. Excess snow cover will bring grazing to a halt as cattle won't paw through deep snow to graze as horses or buffalo do.

In other words, you can't assess the carrying capacity of a winter pasture based solely on how much forage is there. You must take into account how much forage the cattle will go after.

3. Monitor feed intake

Ultimately, feed intake determines whether cows on winter range will hold condition or lose weight. And we know intake will vary with texture of the feed, weather, and amount of daylight.

Poor-quality bulky feeds fill the rumen, limiting the amount a cow can eat, but probably won't provide enough needed nutrients.

Even though cattle need more food energy in cold weather to keep warm, they often eat less on range pasture when temperatures dip. This is partly because the days are short, and partly because of the way the rumen functions.

After a cold night, it takes longer for temperatures to warm up in the mornings, and cattle on pasture will stand around trying to conserve energy and body heat, waiting for the sunshine. Then they often stand awhile in the sun trying to warm up, before they start grazing. They may only graze a few hours during the warmest part of the day, stopping again when temperatures drop sharply at sundown.

One study at Miles City, Montana, found that cattle grazed only about half as long at -40 degrees C (-40 degrees F) as they did at -18 degrees C (0 degrees F). During extreme cold, some cows grazed only half an hour each day.

Cattle don't like to move around much when it is extremely cold. Nor do they like to eat grass with frost on it, or nose through the snow at cold temperatures (they won't do it if snow is crusted).

Cows will eagerly eat hay or straw, even at night in cold weather, but they usually won't graze under those conditions.

4. Look to protein supplements for winter pastures

Some types of supplements can be used to advantage on these cold range pastures, but others are actually detrimental. Wyoming and Montana studies found energy-rich grain supplements counter-productive because they reduced a cow's intake of range plants, whereas protein-rich supplements had the opposite effect.

At one site, 2.1 pounds of cracked corn fed on alternate days reduced forage intake by eight percent, on average, but cows eating 3.3 pounds of soybean meal every other day consumed 18 percent more forage than unsupplemented cows, and 27 percent more than cows supplemented with corn.

Cold tends to decrease digestibility by increasing the rate at which food passes through the gut and by changing the rumen bacteria. Also, during extremely cold weather, cattle tend to eat more browse and woody plants (and will readily eat straw, if provided) since the digestion and breakdown of cellulose and fibrous parts of plants creates more heat energy in the body for keeping warm. In very cold weather, cattle need more roughage in order to generate enough body heat, and if cows are confined without access to pasture roughage or browse, you should give them straw in addition to the regular hay ration, or increase the amount of grass hay being fed.

This is when the added protein is needed to balance the diet and stimulate appetites.

5. Remember the rumen

In cold weather, cattle eating feeds barely meeting minimum requirements of the rumen bacteria have a hard time digesting forages because the cold slows down microbial activity in the gut. This is another reason why a little protein at these times can make a big difference to a cow's intake. Protein increases the ammonia-nitrogen concentration in the rumen to improve forage digestion.

(Heather Smith Thomas is a rancher and freelance writer from Salmon, Idaho)

[Home]

Send mail to webmaster@cattletoday.com with questions or comments about this web site.
Copyright 1998-2000 CATTLE TODAY, INC.