Inclement weather creates challenges when processing cattle, whether preg-checking, vaccinating or weaning in the fall, or giving cows pre-calving vaccinations, or delousing treatments in midwinter.
Dr. Eric Laporte of Nagel and Company Veterinary Services, Cow-Calf Health Management Solutions in Crossfield, Alta., says one of the main challenges in cold weather is keeping your vaccines from freezing.
Freezing inactivates modified-live vaccines so they lose their potency, and freezing the adjuvants in killed vaccines may create certain compounds that could actually make the animals sick. So there is a need to keep vaccines at a safe temperature when working cattle.
Many people put a jar of warm water in the box or cooler with the vaccines and syringes to keep the temperature above freezing. “A friend told me about using containers that windshield-washer antifreeze fluid comes in. They come in a box of four, so you can have four of those bottles that you partially fill with hot water. The All-flex multi-dose syringe guns fit in there perfectly; this can keep the vaccine in the syringes from getting too cold,” says Laporte.
Others use heat lamps or electric blankets, but this may create spots that are too warm. Jugs of hot water keep the interior of the cooler warm for quite a while and when they eventually cool down you just freshen the hot water.
“You could put a heating blanket underneath the cooler to keep the water warmer and the heat won’t be directly on the gun,” he says. If it gets too warm, the heat can start to kill the modified live virus.
You also need a container for your extra vaccine, a place where it can remain cool but not in danger of freezing.
In cold weather, needles freeze up too, so syringes need to be protected when not in use. The body heat of the animal usually thaws a frozen needle but it may take a second or two, and the plug of frozen vaccine won’t be viable if it was frozen for very long.
In some instances it may be best to thaw the needle first and push out a bit to ensure you have fresh vaccine in the needle, or just change needles.
“When vaccinating, we also don’t want to forget to change to a new, clean needle every time we refill the syringes,” says Laporte.
It’s also important not to mix up more modified live vaccine than you will use within the next hour.
When mixing vaccines, you don’t have to shake them aggressively. “You can just roll them between your hands to mix them,” he adds.
Cold temperatures create a whole other set of challenges for pour-on dewormers or delousing products.
“The product will generally not be harmed by the cold, and some of them contain alcohol which will keep it from freezing. The product in suspension may gel, however, which can make it difficult to run through the tubing for application onto the animal. If it forms a gel, the product is fine, but it may plug the tube when trying to apply it.”
When it is very cold the product may gel as it is applied to the hair, and that can affect how well it works. That, says Laporte, may be a sign that you would be better off to wait for a warmer day to treat. “If it stays in gel form for a while on the hair it might not be effective.”
“You also don’t want to apply these products to a wet animal. If cattle have a lot of snow or ice on their backs, take time to scrape that off, using something like a curry comb, then make sure you pour the product as close to the skin as possible. Then follow the directions and try to apply a long line from poll to tail head, and not just a puddle in the middle of the back.”
If there is a lot of snow on the top rail of your running chute it would be wise to knock it off before you start to put the cattle through. Also, watch for ice on the walkway and the end of the squeeze chute. Some gravel or sand may be needed to ensure safe footing, particularly with concrete, which gets slippery in cold weather.
Frozen manure left in the chute can have some sharp edges until the cattle break it down, but the first few animals through may suffer a cut to their feet or legs, leaving them open to foot rot.
“We sometimes see injuries and lameness,” says Laporte. “Manure buildup that freezes may also impair movement of gates that are low to the ground.”
“I had an experience with a gate that was supposed to latch over a crossbar at the bottom. There was so much manure accumulation down there that it couldn’t close properly and a wild heifer put her nose down and popped the gate open. I was inside the chute palpating the heifer in front of her and I was stuck between the two animals. She was determined to come on through, to get out of there!”
“I usually bring a few chains and if there is a side panel on the chute that opens I may chain it shut. The last thing I want is for it to open at an inopportune moment. If I am suspicious of the latch I make sure we have safety chains or pins. When cold, metal tends to be more brittle and some things may break,” he says.
He also suggests working a hydraulic chute beforehand to warm it up, same with the headcatch.
“Lighter grade oils can be used during cold weather. Here in Alberta it’s not uncommon to have cold weather when we are running cattle through, and it helps to have lighter oil and a magnetic heater to go on the side of the hydraulic tank to keep the oil warm. If the oil is cold it slows the chute and it won’t operate efficiently,” he says.
He says it pays to be patient when working cattle in cold weather to avoid stressing them.
“If you start overcrowding them, they might get sweaty from stress and exertion and then chill when they go back to their pens or pastures. This may set them up for respiratory disease. Allow them adequate room and work more slowly. If you are bringing them in from a field that has hills and slopes, footing may be slippery so you don’t want them hurrying and falling down.”
It also pays to do your sorting ahead of time before you run them through the chute. “Some vets will charge extra while they are sitting there waiting for you to sort cows, so it’s a good idea any time of year to have that done already,” he says.
“If cattle balk and don’t want to move, it may be because of ice and snow or reflection off something that has them worried. We talk about minimizing use of electric prods, yet at the same time I don’t think a person should be standing there striking the animal repeatedly with a cane. If you are beating animals with a plastic cane on their cold backs, it would be more humane to just give them a little snap with the prod to encourage them to move forward. If we are just using a cane or a paddle we still need to use it judiciously,” he says.
If cattle refuse to move forward, take a closer look at why they are balking. “In winter the sun angle is different. There may be a reflection off something they haven’t experienced before, or it may be bright everywhere but dark inside the snake leading to the chute, or the crowding tub. Don’t overload the crowding tub.”
When working for a long time on a cold day, Laporte says it’s nice to have some heat near the working chute. “I use a 20-pound propane tank with a heater mounted on top. I don’t advise using this for keeping vaccines warm, but it could be a source of heat for the people working at the chute, if they need a short break to warm their hands. If people are comfortable and not miserable they tend to take less shortcuts and do a better job. It also raises their spirits if someone has supplied donuts and hot coffee. Don’t forget to feed the volunteers!” says Laporte.
You may need extra lighting as well. “If it gets to be 5 o’clock and it’s already dark before you finish the last bunch and you can’t see what you are doing, it’s wise to have a generator and some extra fuel and some lights. This is when you are getting tired and just want to get done and if you can’t see very well you are not going to do a very good job.” You might make some mistakes and mix the wrong vaccines or fill the wrong syringes.
“We always assume the cattle will move forward but if it’s dark you may need a light at the back of the chute pointing forward so they can see where they are going, even in the snake if it’s dark in there and they don’t want to move ahead.”
“I always carry a battery-powered light and a head lamp because you never know what you might experience. Canadian Tire sells a really nice head lamp that’s very bright. It goes through batteries a little faster, but I’d rather carry extra batteries and have bright light than try to do things in the dark,” he says.