Vitamin, mineral deficiencies increase disease prevalence
Phoenix, Ariz. – Vitamin and mineral abnormalities in livestock can significantly impact cattle producers, and Jeffrey Hall of Utah State University looked at the prevalence and impacts from mineral deficient animals during the 2018 Cattle Industry Convention and National Cattlemen’s Beef Association Convention, held in Phoenix, Ariz. in early February.
“The number one deficiency we see in the U.S. and worldwide is copper deficiency,” Hall said. “In some areas, we’ll see copper deficiency as high as 70 percent of animals that we test.”
Overall, more than half of cattle are copper deficient.
Selenium deficiency varies across the U.S., but Hall said, even in areas where selenium poisoning is common, he also see deficiencies, reaching as high as 73 percent deficient cattle.
“These problems aren’t uncommon, and they become a big issue for animal health,” he noted.
Vitamin A and E deficiencies are environmentally induced, and sometimes, manganese and zinc deficiencies are seen sporadically across the U.S.
Producers have pointed out mineral problems haven’t appeared in their herds until the last 10 to 15 years, and Hall said, “If we think about it, 45 years ago, how many people were testing for mineral deficiencies? One of the reason we see deficiencies more now is more people are testing.”
“Mineral deficiencies have always been there. We just weren’t testing for them until now,” he explained.
If pneumonia is seen in the herd, producers often only want to know what bug caused the disease and what the disease can be treated with.
“Oftentimes, we don’t go further to see if there was a predisposing cause that led to disease,” Hall commented.
However, the reasons for higher level deficiencies extend deeper.
From 2008-15, fuel prices were high, the economy was depressed, and many ranchers started to see mineral deficiencies again.
“They were going out price shopping and seeing where they could save some money, and they were getting what they paid for,” he said.
Increased production output is also a factor. Using USDA data, on average going back 30 years, a cow produces two calves every three years, after she is two years old.
“The cow was given a year off every two or three years to build her production back up. How often do we let a cow do that today?” Hall asked. “If we go back to old literature, we find, on average, most ranchers expected a 50 percent calf crop.”
Effectively, Hall noted cows are expected to produce 1.5 times the live calf at weaning than was expected 45 years ago, with the same resources.
“It’s not very viable unless we put the added supplement in to correct for it,” he said.
Further, altered management has impacted production.
“Look at evolution. Animals evolved to be the most efficient in their environment,” Hall explained. “When do animals have their babies in the wild? About 30 to 45 days after spring green-up. Today, we’re asking our spring calving cows to have their babies 30 to 45 days before anything has a chance to turn green.”
“From a physiological standpoint, we’re asking our cows to calve in the worst time to be having a baby – unless we supplement them,” he added.
“I’ve been tracking this for years, and the years that I see a higher amount of zinc deficiency is generally during or for about a two-year period after major drought, so there are environmental effects that come into play,” Hall said, noting there is little research to prove the theory that drought is a major player in mineral deficiencies.
He continued, “As we aerate the soil deeper during drought, some of the ionizable zinc that plants can take up changes to zinc oxide.”
Because plants can’t take up zinc oxide, they are forced to wait until microbes in the soil convert the zinc oxide back to zinc, resulting in increased zinc deficiency during and after drought.
“There are a number of different reasons that we see for increased deficiencies, but how do we deal with them?” he asked.
The calf crop sees the biggest impact from mineral deficiencies on young animals, including poor immune system and poor growth rates.
“The animal’s immune system is set up to try to protect against disease,” Hall explained. “Animals are exposed to numerous microorganisms, bacteria, etc. every day, but do they get sick every day? No. The natural immune system protects against that diseased state.”
However, if the immune system is impaired, increased disease results, including diarrheas, pneumonias and more when the immune system is depressed.
“When we have animals that do not have adequate mineral status, we’re going to see increased amounts of disease,” Hall emphasized.
One of the most common reasons for mineral deficiency is interference between minerals.
For example, in alkaline soils, sulfur builds up over time in the soil and in plants. As a result, when consumed, the cow’s sulfur concentrations increase.
“Sulfur can interfere with a number of different minerals – only in ruminants,” Hall said. “Excess sulfur gets converted to sulfide, and sulfide can covalently bond to copper, manganese, iron or more.”
Sulfur binds most readily to copper, making the mineral insoluble, so it passes through the cow’s system without being absorbed, which results in a copper deficiency.
“Basically, what goes in one end comes out the other end unabsorbed,” Hall said. “Getting around deficiencies means we have to get around interferences in the rumen.”
Saige Albert is managing editor of the Wyoming Livestock Roundup. Send comments on this article to firstname.lastname@example.org.