As the temperature starts dropping, you may be taking steps to get your home and machinery ready for the cold of winter. Maybe you’re adding some insulation to your attic, wrapping pipes or topping off the antifreeze in the truck. While you’re taking time to winterize those areas around the farm, don’t forget to take steps to make sure the cow herd is ready for the chill this winter, as well.
1. Sort animals based on nutritional needs The best place to start is to divide and conquer. To make sure nutritional needs are being met, you may need to sort animals based on stage of production and body-condition score.
Start by giving animals a body-condition score, a 1 through 9 value ranging from emaciated to overly fat. Ideally, you want mature cows going into the calving season with a BCS of 5 or 6, and heifers with a BCS of 6 or even 7. From there, for example, you might separate the mature cows from the heifers and thin cows, since the latter typically need more management and a more nutrient-dense diet.
“It’s going to be more economical and effective to get them in separate pens and manage them according to their needs,” says Greg Lardy of the North Dakota State University Extension Service.
2. Understand nutritional needs based on stage of production Matching a cow’s nutrient requirements to nutrient content in forages and other feeds is essential to keep the cow in optimal condition. Research shows that nutrition during the last two to three months of gestation is critical to the reproductive performance of the cow and the health of the calf.
Typically thinner, marginal cows and heifers have a number of production problems if they go into calving season in inadequate condition. For instance, during the last part of gestation, the cow is laying on fat to assist in lactation once the calf arrives, says Twig Marston, Kansas State University beef specialist. He points out that the consequences of inadequate nutrition during this period include:
1. Lighter calf birth weights (although calving difficulty won’t be reduced).
2. Lower calf survival.
3. Lower milk production and calf growth.
4. Delayed estrus — this means a later calf next year and subsequent reduced weaning weights.
By keeping cows on a steady plane of nutrition during late gestation, you will be playing less of the catch-up game once those cows calve. Poor nutrition during this stage has also been linked to females producing weak calves that have lower immunity.
Energy is typically the most deficient nutrient, but limited protein is also a concern and usually the most costly to supplement. Minerals and vitamins may also need to be supplemented. Since deficiencies in these nutrients vary widely by region, you may want to work with a nutritionist to determine optimal supplementation to create the most cost-effective program.
3. Test feed sources You can’t make up for deficiencies in the diet until you know current nutrient levels. This requires that you test forages, hay or other winter feed sources to determine nutrient content rather than relying on listed book values. From there you know whether you need to increase protein or energy in the cows’ diets as well as balance minerals. It also helps you evaluate supplement options to find the most cost-effective one.
Rick Rasby, an animal science professor at the University of Nebraska, recommends testing for at least three things: moisture content, energy value and protein value. Moisture tells you the amount of water in the feed, which dilutes the concentration of all nutrients. Energy values are represented as total digestible nutrients, and protein is given as percent crude protein.
Byproduct feeds — such as brewers’ grains, wheat midds, distillers’ grains, corn gluten feed, cottonseed, etc. — also need to be analyzed for nutrient content. Often times, by-products contain higher mineral levels. For example, corn gluten feed sometimes contains twice the level of sulfur as corn grain. Some of these minerals can have an antagonistic affect so it’s best to have the analysis and make adjustments as necessary.
4. Follow recommended animal health protocols Your veterinarian is your best source to determine an optimal animal health regimen to follow during the winter months. There are, however, some typical protocols you can follow to optimize the health of the herd and ensure a healthy calf.
First, deworming animals in the fall can pay dividends, especially in regions where there are liver flukes, says Steve Wikse, Texas A&M University veterinarian. Liver flukes have been shown to lower reproductive performance as well as reduce beef quality.
While deworming, also give a booster for Leptospira hardjo-bovis since most products don’t promise immunity past six months. Wikse says that if you are using killed virus vaccines, those must be given two times a year, so this might be a good time to administer those, as well.
5. Implement a biosecurity program Next, implement a biosecurity program if you don’t already have one. Begin by quarantining new arrivals for at least 30 days. Wikse also recommends testing new additions for diseases such as PI-BVD and brucellosis, and neospora in younger replacements since young animals testing positive for this disease are more likely to abort.
Beyond that you may want to test for bovine leukosis if you have a purebred herd and plan to export those offspring, since some countries require that test. The effectiveness in testing for Johne’s disease in beef herd replacements remains controversial, Wikse says, since the tests are not as reliable in animals less than 2 years of age. The only definitive test at the moment is culturing the manure which can take three months to complete.
Leptospirosis is a disease you also want to keep out of the herd, but the hardjo-bovis variety is difficult to test for since it requires urine and blood work. He recommends that animals be treated with a broad spectrum antibiotic, following label directions. Then give a primer dose of a leptospirosis vaccine and follow up with the recommended booster.
For more information
- Kansas State University Beef Cow Nutrition Guide (PDF file)
- You can access for free the online NRC guidelines for beef cattle through the National Academies Press. Go to their Web site at http://books.nap.edu. In the search box, type in “nutrient requirements beef cows” and the book Nutrient Requirements of Beef Cattle: Seventh Revised Edition: Update 2000 will come up. Click it to access the book and find the NRC tables.