Summer Grazing in the Southeast

By Dan Glenn

Spring in the southeast can last a couple months or what seems like a few days.  Each year the weather seems to be unpredictable and managing grazing animals during this time requires attention and flexibility. Here on our ranch, when the wild ryegrass and volunteer clover start growing in earnest, so does the BCS of our cattle.  We sell breeding stock private treaty throughout the year, although I wish all our customers would come look in the Spring.  While April doesn’t always bring showers, it almost always brings those perfect pancake batter cow patties and shiny fat cattle, especially if we manage our grazing thoughtfully and are consistent.

When Summer arrives in May or June, the cattle are chased by flies and searching for shade. Bermuda and Bahiagrass are growing with vigor and some pernicious weed species will be competing for the stage lights. On our farm in south Georgia, horse nettle, dog fennel, pigweed, vasey grass, smut grass and smart weed are our primary concerns.  Instead of herbicides we apply grazing density to reduce selectivity, but not so much that we repress too much performance.  Managed grazing is a balance between your pasture goals and your animals’ performance. Getting this right requires careful observation of your cattle and the sward.  We typically follow grazing events with mowing, usually once in the early summer and once in the early fall. This resets the undesirable species and uses their plant material as a ‘fertilizer’.  The grasses seem to respond well when the broadleaf plants are scalped and distributed as litter.  We keep cost down by using a fully depreciated 1982 JD 4240 and a well maintained wide swath mower.

While manure distribution is an important element to managed grazing, shade has to be a primary concern when summer grazing in hot climates.  One can allow cattle to retreat to shade areas or move shade with the cattle.  Some farms have constructed small water holes to allow for cooling and some utilize overhead sprinklers.  Each farm must weigh the pros and cons of these systems based on infrastructure and management costs, but the need to keep cattle cool is an important economic interest.  If you rotational graze your cattle, be sure to consider heat stress when designing your paddock layout.

Silvopasture is another management strategy to mitigate heat stress. Thinning existing stands of timber or planting trees in wide spaced rows are the two methods of creating Silvopasture. The first is the easiest to manage, as the trees don’t have to be protected. The latter will either require exclusion fencing or one can use the pastures as a hay crop until the trees get large enough to survive the animal impact. We have thinned pine stands to create wide open rows and fed hay extensively over winter to increase the organic matter and the PH. Thinning pine stands to around 150 trees per acre, or more specifically to a basal area of 40-60 sq. Feet per acre, is the recommended density to balance forage and tree growth.

Your breeding and calving season are also important considerations to manage temperature. Heat stressed cattle are less likely to breed on time, more likely to abort, and also more likely to raise inferior calves. Bulls are also stressed during breeding season when temps push above 90f.  When picking a calving window in extremely hot and humid climates, one must consider when bulls will be working, when calves will drop, the nutrition of their dams at and beyond calving, and when those calves will be weaned and sold.  Everything must work as well as it can for each environment and marketing goals. There is rarely a perfect window, but some will work much better than others. Our farm in southern Georgia has found success breeding in late April through early June. We calve mostly in February while grazing winter annuals and then the spring flush, and typically wean in the late Fall.  If we didn’t have winter annuals we would probably push back breeding a month, use a heavier bull pressure, and calve on the spring flush. Other farms in our area successfully calve in the fall, but this requires good nutrition in a time that requires more feed or more fall/winter annuals. If you live in the fescue belt Fall calving could be ideal.

Breed selection is also important to managing heat stress, as cattle that have evolved and been selected from hot climates are more likely to thrive in those environments. Its important to balance your end product goals with a breed or bloodline that will thrive in your environment. The more extreme your heat and humidity, the more likely you will need to utilize heat adapted genetics into your herd. Some heat adapted breeds are later maturing, less docile, and don’t have the premium carcass characteristics of temperate breeds. However, each environment, management, and marketing plan must find the right balance towards sustainable profitability.

Improved species and annual plantings can also play a role in mitigating heat stress. Higher quality annuals and heavy tonnage production allow cows to fill up quicker, meeting their nutritional needs with less bites. This could look like a dedicated field of sorghum sudan, pearl millet, and or well fertilized crabgrass. One could also utilize improved perennial stands with red and white clover, crabgrass, and or chicory. Strong perennial stands with diversity or well managed annual stands, ideally with diversity, can help provide a salve to those long summer days.

Finally, cold, clean water can also be an added boost to performance. Studies have shown that water quality affects cattle performance, and with the increased hydration requirements during the summer, investing in water infrastructure will pay yearly dividends. Smart water placement can also control traffic and be used as a grazing tool to affect manure distribution. Movable water tanks that have the proper flow capacity can help move those valuable nutrients to places other than the shade.

Each farm must balance environmental goals with cattle performance, and would be wise to work with nature when possible. Paying close attention to your pastures and cattle will tell you what improvements you can make as good stewards of your land and herd.