Prepare Your Herd for Grazing Season Stressors
Nutrition factors into reducing summer stressors.
After a stressful winter across the country, cattle producers are surely looking forward to the sunshine and turning their cattle out to green pastures. Just as Mother Nature can cause havoc in the winter months, she can also add unnecessary stress to your herd in the spring and summer. However, with proper management, you can take a proactive approach to reducing and eliminating these summer stressors.
Heat
Perhaps the most obvious of summer challenges is heat. Although sunshine and warmer temps will be welcome after the bitter cold of winter, extreme high temperatures can negatively affect several production phases. Higher temperatures increase body temperature and therefore lower conception and breed-back rates on spring-calving cows. Fall calves that are being weaned might perform slower than normal due to increased body temperatures that typically cause lower intake and lead to reduced gains. Any cattle out grazing will head to shade or ponds, decreasing the time they spend grazing and decreasing their dry-matter intake.
Decreased nutrient levels
Most of the country has had ample moisture and with a good warm-up and sunshine, pastures should be lush and full. At turnout, lush and immature forages are abundant and highly concentrated in key nutrients needed to sustain a cow that is providing for a rapidly growing calf while meeting her own needs to maintain and reproduce. However, forage quality changes on a daily basis. As a forage matures, nutrient quality decreases. Therefore, later in the grazing season forages may not sufficiently meet nutrient requirements for both cow and growing calf. When forage quality and availability begin to decrease, nutrient intake drops, lowering the average daily gain for your calves. Conception rates can be compromised if nutrient levels are not adequate.
Flies and parasites
Flies and other external parasites are pests that add stress to cattle during the summer. Horn flies, horse flies and ticks are the biggest culprits around cattle. Horn fly females can lay up to 500 eggs, and their eggs typically hatch within 10-14 days, making the amount of the files that can move into a pasture a huge stress on the animals that are trying to get them off their backs and faces. Flies typically “feed” or suck blood 20-30 times per day, causing significant weight loss. Flies and ticks also spread anaplasmosis, which can increase mortality rates and lower production outputs.
Grass tetany
Finally, grass tetany is a challenge when first turning out pairs to lush pastures. Most producers think of tetany as a magnesium deficiency, because many use magnesium to prevent occurrence. Really it is caused by excessive intake of potassium. Potassium and magnesium compete for the same absorption pathway. Think of it like a funnel, where three potassium marbles are trying to get through the funnel at the same time as one magnesium marble. Since the percentage of potassium marbles is greater, that nutrient is more likely to go down the funnel and get absorbed before the magnesium does.
Tetany typically occurs in older animals rather than younger animals because of an inability to mobilize the magnesium from the bones. Mature cows will show signs long before a young calf.
Prevention of stressors
Since the warmer temperatures, sunshine and lush green pastures are much anticipated, it is inevitable that the heat, flies and other stressors associated with spring and summer will be present. However, with some proactive steps, you can help keep the stress on your herd reduced.
The most important step you can take to ensure your cattle are comfortable during the heat is to provide them with plenty of clean, fresh water. Water is the most vital nutrient to survival and becomes even more critical during the summer. Be sure to have a free-flowing constant source of water or be available to check water levels regularly to make sure cattle have fresh water and the tanks are at a level where even young calves can reach their necks in to drink.
You’ll also want to provide adequate shade for your cattle. This might be a tree grove, a wooden wind break that doubles as shade, an open-sided or open-fronted building that also has adequate air flow or another man-made structure. Whatever the shade source, make sure it is big enough for the amount of cattle in the pen, and that there is adequate air flow in or around it, especially if it is a building.
The most important step you can take to ensure your cattle are comfortable during the heat is to provide them with plenty of clean, fresh water.
In the summer months, you will want to reduce the amount of handling you do with your cattle. If you must do any work, be sure to work them in the early morning or in the evening, avoiding the hottest times of the day. Have all your necessary supplies ready, gates set and practice proper handling techniques to reduce the amount of time you have to work the animals and the amount of stress you put on them.
For fly control there are a variety of external methods like insecticide sprays, back-rubbing devices, dust bags and insecticide-based ear tags. Parasites can be controlled through deworming at least once a year. Work with your local veterinarian to determine the best protocol for pests in your specific area.
Perhaps the best step you can take to help combat these stressors on your herd is to feed a high-quality mineral program. A prebiotic can help maintain core body temperature in extreme heat, while increasing intake, digestion and absorption. Therefore, the cattle will get the most good from the nutrients they do consume even when the nutrient content begins to diminish.
There are also mineral mixes that target heat stress by aiding in improving internal thermoregulation through improved circulation and intake modification. In other words, better circulation helps cattle to more efficiently cool themselves. Consuming smaller meals more frequently throughout the day not only increases dry-matter intake, but also alleviates some heat generated by the rumen during digestion.
The sunshine and lush green grass will be very welcome to cattle producers after the winter of 2019. However, with heat comes more stress. Eliminate some of that stress with a sound vitamin and mineral program.
Editor’s note: Shelia Grobosky is a public relations coordinator for BioZyme Inc.
