Estimating Hay Needs
by Mark Z. Johnson, Oklahoma State University Extension
Below are some basic rules of thumb to follow when determining the hay supplies you will need to sustain your cow herd over the next few months.
Determine your average mature cow size. This can be done by weighing your four- to seven-year-old cows and calculating the average weight. From mature cow size, we can approximate the amount of forage dry matter cows will need to consume per year or per day. For example, a 1,000-pound cow will consume about 26 pounds of forage dry matter per day. A 1,400-pound cow will consume around 36.4 pounds of forage dry matter per day.
Determine your cow inventory. Estimate the amount of time you expect to be feeding cows. From this information, you can calculate the total amount of hay needed. For example, 100 cows weighing 1,400 pounds will consume around 3,640 pounds of hay per day. We should take into account that a certain amount of the hay will be wasted, and there will be a certain amount of spoilage in each bale that won’t be consumed. With this in mind, we will add another 10% to the daily total to bump it up to around 4,000 pounds (two tons) per day.
Remember, the amount of hay wasted or spoiled could be higher. If you are feeding hay from last year, expect a higher percentage spoiled in each bale. If we are expecting to feed hay from mid-October to mid-May, that is approximately 200 days of feeding hay. With 4,000 pounds of hay needed per day, for 200 days, you will need a total of 800,000 pounds (400 tons) of dry matter forage. If we are feeding or buying large rounds with an average weight of 1,250 pounds, that equates to 640 (800,000 divided by 1,250) big bales needed to sustain the 100 cows. If possible, purchase hay by the ton. It leads to less error in securing the amount of hay you will need to purchase or have on hand. If buying hay by the bale is your only option, make sure to weigh enough of the bales to have an accurate representation of bale weight. Also, take into account the amount of spoilage of each bale. One of the upsides of hay baled this summer (and the drought we are dealing with now) is less spoilage of warmseason grass.
Don’t Let Cow Herd Condition Slip
by T.L. Meyer and Travis Mulliniks, University of Nebraska–Lincoln
To build a nutrition program for a cow-calf system, it is important to know the herd’s nutritional requirements, have set trigger points to make rapid changes in nutritional management if needed, and know the quality and quantity of your forage resources. With many producers starting to or already weaning calves, it’s a good time to note the body condition score (BCS) of the cow herd. For many spring-calving herds, the time between fall and when winter hits is the best time to increase the condition score of the cow herd prior to winter weather. The last chance to economically increase cow BCS during late gestation is the last 90 days prior to calving. However, weather changes and forage availability/quality can make achieving an optimum BCS 60 to 90 days before calving difficult. After that, adding additional body condition on a thin cow that has calved and is
lactating can require large amounts of high-quality feeds to meet her increased nutrient requirements.
Weather and Temperature
When the effective temperature is below the animal’s lower critical temperature, the animal must increase heat production to maintain a constant body temperature. To produce more heat, a cow must either receive more energy from the feed ration or draw on her body stores. Seven days or more of cold, windy, or wet weather will increase cow energy requirements by 10 to 30%. If hay or forage quality is good, intake will increase; however, the increased intake and overall energy intake may not meet requirements. With low-quality forage, cows will need additional energy supplementation during extreme weather. If cows are not fed enough during cold stress periods, they can easily drop a body condition score (BCS) in 30 days or less. Thin cows going into a wet, cold winter have less body condition or fat reserves available to help offset the lack of dietary energy. These types of cows will be more susceptible to decreased performance and health of both them and subsequent offspring.
Current BCS of the cow herd determines supplementation goals and strategies. Thin (BCS ≤ 4) or young cows can be sorted and fed separately from the mature cow herd. This would allow for more strategic supplementation and decrease overall feed costs. Typically, a cow must gain 75 to 100 lbs. to increase one full BCS, but during late gestation that number increases to account for fetal growth and placental weight. Cows in a BCS of 6 or slightly greater prior to winter influence the winter supplementation strategy, too. This additional fat cover on the cow can be utilized as an energy supplement to offset potential energy deficiencies. However, this needs to be done mindfully, not allowing cows to lose too much BCS prior to calving.
At the end of the day, BCS is an insurance policy or risk management. It is easier to stay ahead while maintaining adequate BCS than letting cows slip and get behind. Getting behind during late gestation and early lactation can decrease pregnancy rates and calf performance.
Things to consider for winter management:
• Use body condition score (BCS) as a guide to proactively monitor the cow herd now and throughout the winter.
• Obtain a nutrient analysis of forage resources.
• Inventory forage resources by nutrient quality.
• Sort and manage cow herd by their nutritional needs (thin and young cows vs mature, adequate BCS cows).
• Match forage resources (i.e., quality of feedstuffs) for each management group to minimize cost.
• Adjust supplemental energy for periods of cold stress, especially for thin cows.
Saying Goodbye to Metal “Bangs” Tags and Hello to EID Tags
If your heifers are “bangs” tagged, those orange metal clips will soon be a relic of the past. As of November 5, 2024, your veterinarian is no longer tagging with metal clips, but instead will use electronic identification (EID) tags.
Veterinarians used metal clips to identify heifers receiving the brucellosis vaccine (“bangs”), and to identify animals moving between states. In the spring of 2024, the Animal and Plant Health Inspection Service (APHIS) announced mandatory EID tags for certain bovine classes. This builds upon the 2013 ruling that only requested visual ID tags. The electronic version will be used to track and contain animal disease outbreaks, just as the metal identification clips did.
What is a USDA 840 EID Tag? The EID tags replacing the metal clips are USDA 840, showing the country code for the United States (840), with the official USDA shield. The remaining 12 numbers are unique to the tag/animal. The 840 tags provide animal identification to trace animal movements in the event of an animal disease. The 15 numbers can be visually read off of the EID button, or can be read with a computerized EID reader or wand. There are other types of EID tags, but only 840 EID tags will fulfill the APHIS ruling to replace the metal clips.
What does the EID mandate mean for cattle producers? Animals with the old metal tags already in their ears are “grandfathered in” and will not need new 840 EID tags. 840 EID tags can come as “buttons” with no hanging tag, as long as the 15-digit number is visible on the top of the button.
The buttons can come with matching visual hanging tags. Some 840 EID tags should be placed in the middle rib of the ear, unlike the metal clips that were placed in the top portion of the ear.
This could be an issue if you have a visual tag in each ear, plus a fly tag in each ear. Adding an EID tag would make five tags per animal, and you may run out of room in their middle ribs. Reach out to the tag manufacturer for tag placement recommendations.
Producers will need to establish a premise ID number or use the premise ID number of their veterinarian. You or your veterinarian may put in 840 EID tags. Your vet will put 840 EID tags only into animals that used to require a metal clip for identification. For example, if a producer tags all their calves at weaning with 840 EID tags, your vet will record those EID numbers when they give the “bangs” vaccine to your heifers. The vet would not have to put a new EID tag in.
Check with your sale barn on what records are required. For example, if you are selling breeding heifers, records showing the EID numbers matching the “bangs” vaccination might be helpful.
What will change for your veterinarian? As of November 5, 2024, your vet will be tagging with 840 EID tags instead of the metal tags. The United State Department of Agriculture (USDA) is providing a certain number of tags for each state, during the transition. If a disease is traced back to that veterinarian’s premise ID number, then the vet will work with the appropriate state department of agriculture to track the path of that animal. Ideally, the EID tags will speed up the process and reduce losses during a disease outbreak. .
