BCRC notes drought is not just a summer challenge

In a Beef Cattle Research Council (BCRC) webinar dated Nov. 15, Cattle Producer Jesse Williams of Whiskey Creek Ranch in Alberta, Canada and Western College of Veterinary Medicine Department of Large Animal Clinical Sciences Professor and Veterinarian Dr. John Campbell share critical insight on how to ensure a cow herd can best withstand severe or prolonged drought.

Prairies are experiencing a common occurrence – drought. Drought conditions result in feed shortages, forcing producers to make critical decisions which can impact productivity and profitability.

Drought conditions can cause short-term impacts on feed quality and quantity, while also causing residual effects through the next several years of production.  

Maintaining body condition 

“During a drought, feed resources are the limiting factor, and producers have some tough decisions to make around finding feed or culling the herd to ensure cattle maintain a proper body condition score,” says Campbell.

“While it might seem tempting to allow cows to drop a condition score, it can cause long-term issues such as reproductive wrecks in the fall,” he adds. “Plus, it is cheaper to maintain cows in good condition than to add condition later when feed sources are limited.”

Another option to reduce a cow’s stress level, which will allow them to stay in better shape, is to consider early weaning or creep feeding. 

“The cow will sacrifice her own energy reserves to take care of the calf,” says Campbell. “Early weaning can create challenges with marketing or feeding smaller calves, but a dry cow will consume three-quarters of the feed a lactating cow with a calf will require.”

Weaning sooner than expected can allow producers to stretch feed resources further and help get cows back in better condition for the following year.  

Cattle health problems

Cattle can experience vitamin A deficiencies brought on by drought conditions since the best source of this vitamin is beta-carotene, a pigment in green plants that animals convert to vitamin A.

According to Campbell, vitamin A is an essential fat-soluble vitamin for cattle, and it plays a crucial role in their vision, kidney function, nervous system and reproductive system. 

“Cattle can store up to four months of vitamin A in the liver if they eat fresh green forage all summer,” Campbell adds. “However, utilizing a mineral mix will help cost-effectively supplement cattle and ensure they are getting enough vitamin A.”

Campbell continues, “In drought conditions, cows are going through a significant portion of their pregnancy without access to green grass, causing problems in both cows and calves, as they don’t receive an adequate supply of colostrum.”

Another common vitamin deficiency resulting from drought is vitamin E. Vitamin E complements the antioxidant functions of vitamin A and helps maintain the integrity of keratin, protecting eyes and boosting immunity.

Deficiencies and toxicity

Drought conditions also affect water quality.

“Water, which may have been acceptable for cattle consumption, may become toxic as summer progresses and evaporation lowers water levels in dugouts, while concentrating mineral levels,” states Williams. 

Sulfates are a common mineral component present in most water sources, and they can interact and bind with copper, making water unavailable to animals, which can result in copper deficiency. 

Campbell continues, “There are two main causes of copper deficiency in cattle. First, they are not receiving adequate levels of copper, and second, copper is being bound up in the rumen by other minerals such as sulfates, molybdenum or iron.”

Copper deficiency can create low growth rates, impaired fertility, anemia and hair color changes.

“Cattle can also suffer from another trace mineral deficiency – selenium – an essential trace element for ruminants,” Campbell explains. “It is required in cattle for normal growth and fertility and helps prevent other health disorders such as calf scours.”

“Another health issue caused by drought conditions that cattle may experience is nitrate toxicity, which can cause oxygen starvation, weakness, tremors and sudden death,” he adds.

“Drought-stressed crops which cause nitrate toxicity include barley, canola, sugarbeet tops, flax and sorghum,” he continues. “This can become a problem when grazing or feeding annual crop residue. If cattle ingest plants containing high levels of nitrate, nitrite will accumulate in the rumen.”

He notes, “Crops like canola may be diverted to silage during drought, so when feeding alternative forages, utilize feed testing to reduce risk of toxicity and ensure cattle’s nutrient needs are met.”

Plan ahead to reduce challenges

Feed testing is even more critical with salvaged crops. With many places declaring agricultural states of emergency, producers may have access to alternative feeds like canola, lentils or peas that they would not usually have. 

These products can be beneficial in extending the grazing season or providing stored feed, but they can also come with issues such as high sulfur levels. 

“It’s all about adaptation of your animals,” says Williams, “With respect to grazing or feeding alternate crops, giving animals seven to 10 days to transition onto these salvage crops will help their rumen adjust to the different fiber source and can help prevent issues with toxicities.” 

She adds, “Both water quality and quantity can change rapidly during a drought and frequent water testing and investing in infrastructures, such as portable watering or remote monitoring systems, can help prevent nutrition issues.”

“Make plans now for possible shortages next year and know your forage varieties to handle better grazing pressuring during a dry year,” Williams explains. “Don’t forget – litter matters. Litter has an insulating factor which moderates soil temperature and can help capture small amounts of rainfall.”

When conditions become dry, producers often look for ways to reduce stocking rates on pasture to balance cow needs with forage availability.

She concludes, “It may be tempting to graze pastures shorter than normal, but leaving litter is more important. It will speed up pasture recovery in the long run and help prevent further deterioration.” 

Keeping some of these points in mind may help prevent short-term decisions from having long-lasting effects on the herd. 

Melissa Anderson is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.