Dairy farmer finds biochar boosts cow health

Researchers have also recently determined that cows that eat biochar produce less methane.  | File photo

Ont. producer says feed additive ‘helps their gut and promotes overall better health by pulling toxins out of their system’

It was a lucky accident of sorts for dairy producer Aaron Smith.

A broken bag of biochar inside his barn allowed his cows to sample the powdery black charcoal when it spread on the floor near the feeder.

“As we were sweeping it up, the cows all came over and next thing you know, two or three of them were actually eating mouthfuls of it, which I had not expected,” said Smith, the owner of Don-Mair Farms near Mount Hope, Ont.

“I thought the palatability of it would probably deter them from doing it, but actually one by one they would all get a mouthful of it and walk away and go stand off to the side chewing on it like they were chewing on dirt out in the pasture,” said Smith.

“We observed that it was the recently fresh cows that were consuming it by the mouthful.”

Smith operates a 75-head milking herd of purebred registered Holsteins on his 500-acre dairy farm.

He recently completed a one-year trial where activated charcoal was used in his calf starter and dairy ration. He recounted the results during a recent webinar about activated charcoal and herd health in Canada.

Sponsored by Titan Carbon Smart Technologies in Craik, Sask., the webinar also featured Kathleen Draper from the Ithaka Institute for Carbon Intelligence and Gail Carpenter, diary nutritionist and assistant professor at Iowa State University.

Smith said he is accustomed to seeing his cows sample dirt when in pasture.

“They’ll kind of lick away or eat at a spot of dirt trying to settle their own stomach or get their own mineral requirements. So seeing them eat the charcoal, although it was surprising from a palatability side, it kind of made sense from a natural side, of the cow kind of balancing her own stomach out. Nature tries to take care of itself kind of an aspect,” he said.

Cows in the calving pen also showed a taste for biochar.

“About 40 percent of them would put their face in the hanger pail and eat some out. Less than 10 percent will eat it at high levels for a day or two and typically they’ll have visible manure issues.

“Those are the ones that I watch after they leave the pen to see how they do performance wise because clearly they had something bothering them that they chose to actively try and treat their own guts,” he said.

“You can tell when the charcoal gets going through their system because it’s very noticeable coming out the other end.”

Charcoal use in agriculture is as ancient as the Aztec civilization, when it was used to improve soil.

More recently its environmental benefits have been discovered because cows that eat biochar produce less methane.

Studies have also found that when added to animal feed, initially as a colourant, biochar allows animals to recover more quickly from illness, with less need for antibiotics. Dairy cattle also produce more milk and the barns smell better.

Armed with this knowledge, Smith conducted a trial with his Holsteins.

“I put two and two together that if it’s a full pass-through product, it’s kind of like getting double bang for your buck. It’s like dumping a bag of charcoal out in your field, but first it goes through the cows. So it helps their gut and promotes overall better health by pulling toxins out of their system.”

He said veterinarians and artificial insemination consultants had reservations about biochar because it’s an indiscriminate binder that could create mineral or vitamin blockage. That could decrease reproductive performance.

However, Smith found no major disruptions in reproduction cycles during the trial. Pregnancy rates improved and lost pregnancies decreased.

“From my results it’s pretty evident that it has no effect on repro or overall health in a low therapeutic dose over the year that I was using it,” he said.

“I’m thinking it’s helping them reproductively find a good balance in their energy so that when they do have a pregnancy, they’re able to hold it.”

In his trial, Titan’s Carbon 2M activated charcoal was fed at 0.19 to 0.23 percent of dry matter for each animal, which worked out to about five kilograms of fine grade charcoal in the total mix for 75 cows per day throughout the year.

Calf rations were formulated into a custom 22 percent textured ration.

The calves were fed free choice up to three kilograms per day. It was also added during the pellet forming process at a rate of 0.10 percent dry matter.

Besides binding pathogens in calves’ digestive systems, Smith anticipated the biochar would help maintain a balanced stomach pH, resulting in fewer nutritional scours.

“Proof in the pudding,” said Smith.

There was no sickness after starter intake reached about one kg per day to about day 21, and it was easy to track which animals were eating a lot.

He consistently saw 2.5 to 2.8 pounds of gain per day with accelerated weight gain at the end of the fluid diet.

There was also zero lag in the transition period with six-month weights at 450 to 550 lb.

“I’m a big proponent of, if they’re going to eat it at a young age, you let them eat it because that is your highest feed efficiency across all age groups of cows,” said Smith.

“Calves will convert it very easily and it’s a lot easier to get gains in zero to six months than it is from six months to 12 months. I think the best money is always at the calf end and going to get you the best bang for buck.

“Now we’re seeing great consistency of gains. So no longer do you have a peak in a valley. Our transition calves, when they come off milk they don’t slow down. They keep moving forward.”

Smith’s results relative to feed efficiency were inconclusive, requiring further study on higher dry matter forage-based diets.

“On the feed efficiency side, it’s hard to judge one single ration change over a period of a year, especially because in our situation we ended up in a very dry summer. So we had to change our ration forage-wise multiple times.”

Smith is now in a six-month period without biochar in rations so he can compare and gauge the impact.

He’s sold on providing free choice at calving because it’s a specific area of feeding. However, he said he would probably use it for the entire herd as an alternative to sodium bicarbonate.

“During the study we actually ended up reducing our use of sodium bicarb by a fairly good amount while we were feeding the charcoal,” he said.

“Going forward, now that we don’t have the charcoal, the sodium bicarbonate is going back up again. It’ll be interesting to see if we can offset some of the cost of the biochar by offsetting bicarbonate.”

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