While growing up on a dairy farm, I always loved this time of year because of the heightened activity and the new growth of crops — but we also face the “dog days” of summer, which comes on the heels of the long, cool spring we experienced this year. This week, as I write, temperatures are forecast to reach the 90s in much of the U.S. — even in parts of the country that are usually cooler, like Minnesota and Wisconsin. I think we can safely say that summer is here, so let’s be prepared for what lies ahead and equip ourselves with tools that could effectively counteract some of the heat stress our livestock are expected to experience over the next 3 to 4 months.
It has been written in previous blogs that the thermoneutral zone for cattle — or the range at which a cow does not need to burn extra energy to either stay warm or to cool herself — is somewhere between 20–30 degrees Fahrenheit on the low end to approximately 70 degrees Fahrenheit on the high side. When cattle hit this critical upper level, which is a combination of the temperature and humidity levels (or the temperature humidity index, known as the THI), heat stress occurs, and additional energy is required as cattle increase their respiration rate, blood flow increases to dissipate heat through the extremities, and the body generally goes through physiological changes to rid itself of excess heat. Simultaneously, cattle tend to reduce their intake in an attempt to decrease the extra heat created by digesting the diet. This lowered intake can reduce productivity during heat stress.
While a single heat-stress episode is not highly detrimental in most cases, an accumulation of three or more separate episodes can seriously impact production for both dairy and beef cattle, manifesting as lowered milk production, decreased weight gains and challenges to breeding performance, among other effects. (For an excellent review of the implications of rumen acidosis in cattle, refer to this CRYSTALYX® blog by Tim Clark). Several university research trials have been done studying the impact of heat stress on dairy cattle, with recommendations to boost the levels of certain minerals in the diet — like sodium, potassium and magnesium — to compensate for the nutrients that are lost due to heat stress. The inclusion of sodium bicarbonate in the diets of dairy cows is standard, as it helps cattle overcome the typical drops in pH in the rumen when high-grain diets are fed.
Although bicarb supplementation is a standard practice, the primary goal for nutritionists is to keep the rumen healthy with adequate fiber in the diet, as this encourages the natural production of buffer in the saliva of cattle. An early study with dairy cows reported that cows fed 44 pounds of dry matter can produce the equivalent of 7.5–8.0 pounds of sodium bicarbonate per day in their saliva, depending on the level of forage in the diet. Cows consuming a higher ratio of forage produce more bicarb (Erdman, J., Dairy Sci. 71:3246 (1988). Today, dairy cows eating 50–60 pounds of dry matter would be expected to produce even more natural bicarb. One of the challenges associated with heat stress is that, as cows pant to reduce the heat load in their bodies, they tend to lose saliva. As such, a common nutritional recommendation is to increase the amount of supplemented bicarb during the summer. Keeping the rumen healthy will improve feed efficiency and reduce the amount of total feed needed to produce a pound of milk or pound of gain, which is critical with current feed prices.
One way to supplement bicarb and other buffering agents is by utilizing CRYSTALYX® Blueprint® Buffer-lyx®. The original Buffer-lyx formulation was patented several years ago and utilized research from the University of Wisconsin that demonstrated a reduction in the severity of sub-acute rumen acidosis (SARA) when supplementing Buffer-lyx. This formulation provides additional sodium, potassium and magnesium, all of which are recommended at higher levels for cows under heat stress, as well as organic copper, zinc, manganese and cobalt in the new Blueprint formulation. Beyond the added supplemental buffers, the licking action by the cow will induce additional bicarb production in the saliva when it is needed most. This could be a great asset for robotic dairies, where grain tends to be supplemented mostly through the feeders when cows are milked — a move away from the TMR in which each mouthful of feed contains both forage and grain. Research at the University of Kentucky in 2015 also showed that the strategic placement of Buffer-lyx changed cow movements in a free-stall setting. Field trials have also shown an improvement in cow flow through a robotic milking system when Buffer-lyx was placed near the robot.
While Blueprint Buffer-lyx is most commonly used on dairy productions, we know that rumen acidosis is common in beef cattle on high-grain rations. I have been asked several times over the years by producers selling freezer beef and finishing cattle on a self-feeder how they can help cattle that have suddenly gone off feed. Providing a self-feeding Blueprint Buffer-lyx or Meta-bolyx block can be a useful tool in preventing some of these digestive upsets.
While discussing the importance of mineral supplementation in dairy herds, I would be remiss not to mention the options available for dry cows. Dry cow nutrition continues to be a challenge in many herds as a result of several factors, including the flux of animals moving into and out of the dry cow lot disrupting the social order with each change, the physiological changes in the cow due to her impending calving, and dry matter changes as cows get closer to calving. Unless you have a very large farm, there may be challenges in providing a uniform TMR for a smaller group of cows. The CRYSTALYX® Blueprint® Dry Cow, Close-Up and Transition Stress™ formulas all help to provide a safety net of nutrition with the proper balance of minerals and vitamins and are designed to reduce the incidence of metabolic disorders that often occur at calving. With all of our formulas now including Blueprint, the trace minerals in these products are 100% organic, offering additional immune system support at a highly stressful time.
Check out these CRYSTALYX dairy products and more in the updated CRYSTALYX Dairy Cattle Supplement Guide, coming soon. Here’s a sneak peek:
Please visit your local CRYSTALYX dealer or go to CRYSTALYX.com to learn more.