By: Allen R Williams, Ph.D.
We live and farm in the Deep South. That means hot and humid conditions are the norm through our sultry summers and into the fall months. It also means we have an obligation to our livestock. What are some key factors we must consider to make sure our animals are not stressed and have reasonable comfort?
Genetics & Epigenetics
The first thing I consider is genetic and epigenetic selection. Are we selecting animals that can survive and thrive in our heat and humidity? What are we looking for?
I want them to fit my environment from a size and frame score perspective. Many of the cattle that are large framed can have a hard time in our deep south summers, especially if they are not Brahman influenced. We have found that 4-Frame cattle (BIF Frame Score) with some depth of body and good body capacity work best.
Second, they must shed their winter hair coat early in the spring and have a slick hair coat with a nice, oily sheen throughout the summer and fall. Cattle that hold onto their hair too long inevitably suffer and that affects their ability to graze through the heat of the day and to perform.
It is possible within the Angus and Red Angus breeds to select for animals that can perform well in the heat of the summer, but infusion of genetics that have greater heat tolerance can improve performance. Breed options for crossbreeding for heat and humidity tolerance include South Poll, Senepol, Barzona, Mashona, Brangus, Tuli, etc.
Water
Water is crucial. Too many grazers do not have enough water sources for the hot weather conditions. Good, clean, and plentiful water is an investment and not simply a cost. I have stopped installing permanently fixed water troughs and moved to a system of risers with quick couplers. This allows for a portable water trough to be placed anywhere within a reasonable radius of the riser.
The ability to place water in a number of locations around a riser provides several key advantages;
- You never produce a “beat up” area where there is a lot of bare dirt. In the summer this bare dirt can heat to temperatures of 130-160 F. Livestock are then subjected to those temperatures whenever they come to water. That would be analogous to us standing on pavement in the middle of a hot summer day.
- By moving water placement around you prevent creating conditions that favor fly and parasite reinfestation. With permanent water sources that are used repeatedly, livestock will tend to defecate and urinate where they drink. The flies lay their eggs in the fresh manure and the manure can contain parasites. Every time they come to the frequently used permanent water trough, they have a greater chance of being reinfested with flies and worms. Enduring hot conditions is more difficult when you also have to fight internal and external parasites.
- During the summer months you will often see explosive growth of undesirable plants. By having portable water troughs you can place water in the middle of these problem spots to get a high stock density impact and begin to gain control.
- Options for water placement also allow for better grazing impact within each paddock.
When watering cattle out of ponds or lakes we like to construct watering ramps that extend down into the water and are heavily rocked to prevent mud and muck. The rest of the pond is circled by a single strand of polywire so that cattle can only drink from the ramp.
Watering ramp constructed in a pond. The ramp should be no more than 10-12’ wide and rocked with large rock. The animals can only access the pond at the watering ramp.
Other options for more water sources can include using portable solar pumps to move water from ponds, creeks, streams, and rivers to wherever you need it. Instead of allowing the livestock to get into these water sources, you are bringing the water to them. We often simply run line on top of the ground to place water troughs wherever we want them.
A solar pump system set up on a pond. The ag tote serves as a reservoir for water storage and to provide head pressure for proper water flow to remote troughs. Courtesy: Rixon Simmons, MS.
Cool zones
We can create effective cool zones in our pastures by the way we graze and the forage biomass we allow to grow between grazing events. Overgrazed pastures and continuously grazed pastures can heat up significantly in the summer months. Within Understanding Ag, we have routinely measured soil temperatures on overgrazed/continuously grazed pastures ranging from 120 F to over 160 F. Cattle subjected to those soil temperatures are definitely not comfortable and will be seeking shade or water quickly.
Think about how any of us feel when we are standing on pavement on a hot summer day. We are most uncomfortable and want nothing more than to get off that pavement and into some decent shade.
Dense grass swards protect soil moisture and temperature and create what we refer to as “cool zones”. This is easily measured by thermal thermometers. Cool temperatures extend up into the sward for the height of the sward. Cattle standing on the cooler, moist soil and in a tall, dense sward benefit from capillary cooling. The cooler conditions create a capillary cooling effect similar to the way a radiator works to cool the engines of our automobiles.
Shade
Shade is important and often necessary. The best option for shade is natural shade from actively growing trees. It can often be 20 F cooler in natural woodland than in the surrounding pastures. Too many folks fence their woodland out from their pastures and do not allow access. We like to use the woodland as an additional grazing resource for the hot summer months. For woodland that is dense and choked with undergrowth, goats and pigs can be used to clear out the understory and stimulate a respond from the latent seed bank. Additionally, we have often used bale grazing with cattle to clear dense understory. We start by placing intact round bales as far into the understory as possible, then repeating this process.
It may also pay to rent a skid steer with a mulching head to clear out selected understory and smaller trees. The resulting mulch is carbon that can go back into the soil.
Our strategy is to intentionally stockpile the forages growing in the woodland and reserve for the hottest summertime periods. During these times we can put the cattle into paddocks within blocks of woodland and the cattle have adequate shade virtually all day.
Unfortunately, far too many people have removed most of their trees thinking they needed all the open acres they can get. Or, they have certain areas of their farm or ranch that have little to no natural shade. In these areas, it may become necessary to use portable shade structures. The key with these structures is economy, ease of use, durability, and having enough shaded area to accommodate the number of head you may have.
Portable shade shelters can be constructed on farm using a variety of materials. They have to be heavy enough to not be flipped in stout winds, but light enough to be easily moved on a daily basis. I will not spend time on designs and construction ideas as these are readily available via the internet and on YouTube.
Portable shade shelters can not only be used to provide shade, but to also have targeted impact on problem spots. Cattle crowded around a shade shelter provide a high stock density impact that can be used to help control undesirable plants. If you have spots where there are a lot of thistle, blackberry, dog fennel, locust, etc., intentionally place the shade shelter in the middle of these areas to elicit a trample effect to control the problems plants and stimulate the existing seed bank.
Place the shade shelters on the opposite end of the pasture from the water source. This encourages the cattle to better use the entire paddock or pasture and spreads out their grazing impact. Placing the shade shelter near the water almost assures that you will over-impact that area of the pasture and you will concentrate their exposure to fly and internal parasite reinfestation.
Summary There are several key strategies to keep your livestock cool and comfortable in the heat of the summer. These include genetic and epigenetic selection, strategic use of water and water placement, creating cool zones, and shade options. It is the combination of strategies that will produce the best results.