Post on 17-Dec-2015
MIDWEST BEEF COW HERD MANAGEMENT
By
David R. Hawkins
Michigan State University
Principles of Least Cost Feeding Programs
• Match the available feeds with the cow’s nutrient requirements.
• Overfeeding wastes money but underfeeding results in lower conception rates, lighter calves at weaning and less value on cull cows.
• Use high quality feeds during early lactation and rebreeding.
• Maximize use of pastures and crop residues that have little or no alternative value and minimize use of harvested feeds.
Annual Energy Requirements
Divide Herd Into Nutritional Groups
• Dry mature cows in good body condition.
• Lactating mature cows.
• Dry thin cows and two year olds.
• Lactating thin cows and two year olds.
• Bred heifers.
• Weaned heifer calves.
• Herd sires (mature vs young)
Develop a Feeding Plan for Each Group by Periods
• Each period should be no longer than 100 days and have specified targets for each group of cattle.
• Maintenance vs. growth vs. lactation.
• Maintain BCS versus change BCS.
General Guidelines
• Fresh clean water should be available at all times.
• Minerals including salt are usually provided “free-choice”– Mature cows will usually consume 0.1 lb. per
cow per day ( 3 lb/hd/mo)
• Pasture will usually provide adequate energy and protein.
Macro Minerals
• Salt ( Sodium & Chlorine) Required for acid base balance & digestive enzymes.
• Calcium – forages are a good source. Required for skeletal growth, blood clotting, muscle contraction, lactation & reproduction.
• Phosphorous – grains contain high levels. Required for energy transfer, skeletal growth & reproduction. Could be deficient with all forage diets.
Macro Minerals cont.
• Potassium – required for muscular contraction & acid base balance. Forages are high and grains tend to be marginal.
• Magnesium – related to calcium and phosphorous metabolism.Required for muscle activity. Forages can be low in early spring and fall. Deficiency is “grass tetany”.
Trace Minerals
• Great Lakes region is deficient in cobalt, iodine & selenium and it is marginal in copper
• Usual source is trace mineral [T.M.] salt (red colored).
• Some T.M. salt also contains higher levels of selenium.
• Sulfur is usually only supplemented when NPN is used in the ration.
Vitamins A & D
• Vitamin A found as carotene in green growing forages & stored in liver. Poor quality forages and crop residues are low. Required for maintenance of epithelial tissue (vision & reproduction).
• Vitamin D is required for Ca & P metabolism. Sunlight irradiates skin oil & absorption occurs.
Vitamins E & K
• Vitamin E is an antioxidant that facilitates absorption & storage of vitamin A. It is closely linked to selenium status. Deficiency results in “white muscle” disease of newborn calves.
• Vitamin K is involved with blood clotting. Deficiency is rare.
B Vitamins
• These water soluble vitamins are normally synthesized in adequate quantities by the rumen microorganisms.
• Calf normally gets adequate levels in milk.
Permanent Pasture
• Permanent pastures are usually bluegrass or quackgrass.
• They vary in productivity. It may require 2 to 10 acres per cow unit for the summer.
• They usually grow in the spring, go dormant in July & August and then grow again in September & October.
Improved Pasture
• Usually grasses & legumes are reseeded every few years.
• Grasses include: orchardgrass, bromegrass, timothy, reed canarygrass and tall fescue.
• Legumes include: alfalfa, red clover, white clover, ladino clover and birdsfoot trefoil.
• Carrying capacity of improved pasture may range from 1 to 3 acres per cow unit.
Pasture Management Guidelines
• Bluegrass should be 4” high before grazing.• Tall grasses should be 8” to 10” high before
grazing & tall legumes should be 10” to 12” high before grazing.
• Cattle should be removed from pastures when it is grazed down to 2” in height.
• Grasses need 25 to 35 days to recover & legumes require 35 to 45 days to recover.
Pasture Mgt. Continued
• Soil test to determine nutrient needs.
• Clip pastures to remove seed heads and old growth.
• Control brush by herbicides or burning.
• Manage grazing to maximize yields.
Continuous Grazing
• Turn cattle into one field for the entire grazing season.
• Low labor cost
• Up to 40% of forage may be wasted by trampling, etc.
• Difficult to keep legumes in stand.
Rotational Grazing
• Requires several paddocks and cattle are rotated every 10 to 15 days.
• Allows plants time to recover between grazing.
• More labor and fence required than with continuous grazing, but get about 20% more productivity.
Strip Grazing
• Use electric fencing to allow cows access to a 10 to 20 ft. strip of new pasture each day.
• More labor intensive to move fence each day.
• Expect about 35% more productivity than continuous grazing.
Harvested Forages
• Allows recovery of entire plant minus harvest & storage losses.
• Requires more labor and mechanization than grazing.
• Hay is most popular forage for beef cows in Michigan, but corn silage and haylage are also utilized.
• Quality of forage is highly variable due to stage of maturity at harvest & storage conditions.
Hay Guidelines
• Some improved pastures will be managed to make 1 cutting of hay and then graze the regrowth when the permanent pastures are dormant.
• Average hay yields are 2.5 T. per acre but can be as high as 6 T. per acre if well fertilized and multiple cuttings are made.
Land Required Per Cow
• This varies according to productivity, length of wintering period, etc.
• If a dry cow needs about 25 lb. of hay per day and a lactating cow needs about 35 lb. of hay per day, winter hay needs will vary from 1.9 to 3.2 T. depending on when she calves.
• Land for pasture and winter feed ranges from 1.5 to 5 acres per cow with improved pastures and up to 12 acres per cow on permanent pastures.
Extending The Grazing Season
• Small grains (barley, oats and wheat) can be grazed early without significantly reducing grain yields.
• Thousands of stocker cattle graze wheat pastures in Kansas & Oklahoma.
• Corn stalks and other crop residues can be grazed after the grain is harvested.
Grazing Corn Stalks
• One acre of corn stalks will carry one cow for 40 to 50 days, if properly supplemented.
• In addition to calcium, phosphorous, protein is critical after the first 30 days.
• Some producers will feed hay in addition to the cornstalks.
• If hay is worth $50/T., then cornstalks are valued at $12/cow/month.
Supplemental Feeding of Cows
• If overstocked or drought conditions, supplemental feeding of hay or silage may be required.
• Cows prefer green succulent forage to dry hay.• If hay is expensive, grain can be fed (4 to 6
lb./cow/day), but a minimal level of roughage is critical to maintain rumen function.
Drylot Feeding of Beef Cows
• Increases the # of cows that can be fed per unit of land – 5 T. of corn silage/cow for summer or 8 T./year. If yields are 15 to 16 T per acre, then land required is 0.3 to 0.5 acres per cow unit.
• Requires feed storage and mechanization.• Higher labor requirement but lower land cost than
pasture system.• Flies and disease challenges are greater with
drylot.
Summary
• There are many options to consider when formulating rations for beef cows.
• The goal is to meet the cow’s nutrient requirements for her stage of production as economically as possible.