Why should I wean early in drought conditions?
Weaning early is a common strategy during drought conditions, because it removes the nutrient demands of lactation. This can greatly reduce the amount of forage required and benefit cow performance. Don’t wait until you are out of grass to react to a drought situation. Not only does this leave you with limited management strategies, but overgrazing makes pastures much less resilient in dry conditions and slower to recover for the following growing season. Weaning early is one of the simplest strategies to immediately reduce grazing pressure and forage requirements.
How does early weaning benefit cow performance?
Cow nutrient requirements fluctuate throughout the year depending on what stage of production they are in. A cow’s nutrient requirements are rarely ever at maintenance, because the cow is either lactating, gestating, or ideally, both. Nutrient requirements are the greatest during lactation and the least directly after weaning (Figure 1). This is because weaning ceases lactation. Thus, weaning early can significantly reduce the amount of nutrients required by the cow and allow her to gain body condition before winter.
Rebreeding a first-calf heifer can be one of the hardest and most-difficult parts of maintaining an operation. This is because those heifers are still growing while growing their first calf. Early weaning can also help first-calf heifers maintain body condition, because nutrients that support lactation are freed up to go toward growth again.
How does early weaning reduce forage intake?
Forage intake is highly dependent on animal size, forage quality, and lactation status (Table 1). Consumption is figured on a percentage of body weight, because it is directly impacted by a cow’s body weight. Thus, larger cows will eat a greater amount than smaller cows.
Intake also changes depending on the time of year and the quality of available forage. Cows that are grazing high-quality forage will consume more, because it is more digestible and moves through the animal quicker. In contrast, cows that are grazing low-quality, winter forage will consume less forage, as it takes longer to digest.
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as a % of Body Weight |
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|---|---|---|---|---|
| Forage Quality | TDN, % | Example Forages |
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| Low | < 52 | Dormant pasture Mature legume and grass hay |
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| Average | 52 – 59 | Dry summer/fall pasture Bloom legume and grass hay |
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| High | > 59 | Lush, vegetative pasture Early bloom legume and grass hay |
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Adapted from Oklahoma State Extension
Lastly, cows that are lactating have higher nutrient requirements and will consume more forage than dry cows. Creating dry cows by weaning early will reduce daily forage consumption. Thus, weaning early can create more grazing options. For example, the grazing season can be extended, cow numbers can be retained or increased, or forage can be stockpiled for later use.
How much forage can I save by weaning early?
In a study done on mixed-grass prairie in Dickinson, North Dakota, the effects of weaning time on pasture utilization were evaluated. On average, cows weighed 1,400 pounds and calved on April 11. Early weaning was done at four months of age in August, while normal weaning was done at seven months of age in November. The 90-day grazing period began in August, with half of the pastures stocked with dry (recently weaned) cows, and the other half with pairs.
It was determined that grazing dry cows saved an average of 36% of the pasture’s forage resources. An additional 1,701 pounds (dry matter) forage per cow was left in the early weaned pasture. Using a 50% grazing efficiency, that leaves another 850 pounds of grazeable forage. If a 1,400-pound dry cow requires 28 pounds (dry matter) forage per day, then this provides an additional 30 days of grazing.
Increasing grazing days can reduce the requirement of feeding harvested forages. Considering the high cost of feeding hay, every day the cows can graze for themselves provides a financial incentive. Having more grazeable forage available could mean the difference between destocking and retaining a cow herd in a drought situation. Additionally, leaving more standing forage will benefit pasture recovery when moisture does occur.
What do I do with an early weaned calf?
Weaning can be a stressful time, especially for younger calves. Stress can reduce feed intake and create a higher risk of sickness. Consider low-stress weaning methods during this process. It can also be beneficial to put pairs into the weaning area a few days ahead of time so the cows can show the calves where feed and water can be found.
Young calves have a small rumen capacity, so it’s important to get them started properly on a nutrient-dense diet. Managing early weaned calves can be a big concern, especially if weaning calves under three months of age.
Consult with your veterinarian and a nutritionist to help manage those calves effectively. If facilities are lacking, or feed resources are scarce, marketing those weaned calves as lightweight stockers can also be a good option.
What is the current outlook on drought conditions?
Despite a wet spring, the summer months have brought less than favorable precipitation to much of the High Plains region. The current outlook indicates 65% of the region is abnormally dry, with 10% of the region experiencing severe drought (Figure 2). At this point in the year, most forage production is complete, and the dormant season is rapidly approaching.
Producers experiencing drought conditions should consider early weaning to reduce fall grazing pressure and facilitate some pasture recovery before dormancy. If dormant season precipitation is scarce, soil moisture and plant recovery will suffer, which can significantly compromise the spring green up. Therefore, if drought conditions persist through the fall and winter, plan to delay grazing turnout and lessen grazing pressure for the next growing season.
Several online tools, such as RAP Production Explorer, SD Mesonet, and the NOAA Climate Center, can assist with monitoring moisture, forage, and climate conditions. A simple guide to using these free tools is available in SDSU Extension article, Online Tools To Help With Rangeland Drought Planning.
