A lot of requests have been coming in regarding information on boluses. I’m going to go through the most frequently asked questions. PLEASE KEEP IN MIND THIS PROTOCOL IS USED WITH ICELANDIC SHEEP. NEEDS CAN VARY BASED ON BREED & ENVIRONMENT.
What is a bolus?
There’s a long answer and short one.
The short answer is: a time-release tablet that stays in the rumen of cattle, goats, and sheep.
The long answer is: “The bolus is a concept that was invented more 40 years ago. This format is suited to ruminants’ anatomical specificities (adult and growing cattle, sheep, goats). Ruminants have three pre-stomachs before the true stomach (abomasum), which is similar to the stomachs of non-vertebrate species. These pockets - the rumen, the reticulum and the omasum – enable these animals to digest the fibers of the forages. This combination of three pre-stomachs is similar to a continuous fermentor. The rumen is the pocket in which bacteria grow. This is where the food is broken down chemically and mechanically into small particles. It is worth noting that the rumen is where volatile fatty acids are absorbed (the energetic nutrients produced by rumen bacteria). This compartment acts as a kind of valve which links rumen with the rest of the digestive tract.
Only suspended particles can carry on their way. The omasum can be compared to a filter that only allows the transfer of small particles. It also serves to dry the diet’s digestive content before the ingested compounds reach the "true stomach" to be broken down. The shape of the bolus is therefore designed to the advantage of ruminants’ specific anatomy.
Thanks to their high density, boluses that are given to cattle, sheep and goats "fall" to the bottom of the rumen and stay there for as long as necessary. This fixed position in the digestive tract is convenient because it either ensures regular release of nutrients, or it can also host a fixed sensor.”
Source:
How do you administer a bolus?
Using a balling gun. Sometimes called a bolus gun. I prefer the one Mayo sells (Santa Cruz may have a metal one out by now) because it’s all metal. It costs a little more but it lasts forever and there isn’t a plastic sleeve at the end that can grow loose overtime and present a choking hazard. Yes, I’ve heard stories of these sleeves getting stuck in throats or going into stomachs. If you use one with plastic just be aware of that. As for the use of balling gun, they come with instructions on use. A bolus does require you to extend the gun down into the sheep’s throat (similar to a drench) and you want to be careful not to scrap the esophagus. Some shepherds with small flocks will rub olive oil on the end of the bolus gun before inserting to avoid any rough scraping. I don’t do this, but if you are concerned it is an option.
What are the point of boluses?
This is actually a complex question due to the cattle industry spending a lot more time and money on bolus research and development. It uses boluses for many things! They have boluses with sensors that can even monitor animal temps to serve as early indicators of problems. The humble sheep industry usually only uses boluses for the slow-release of minerals. This is the only type I use & the focus of this post.
What boluses do you use and why?
I use 3 different boluses for different reasons.
Mayo 5-1 Bolus
Santa Cruz Cobalt Bolus
Santa Cruz COWP Bolus
I know this sounds like a lot. I didn’t begin with these. I started out with nothing and after careful data collection, health monitoring, liver testing, wool analysis, and parasite resistance I slowly honed in what supported my sheep best. Let me break down the boluses.
MAYO ALL GUARD EWE 5 IN 1 is a slow release multi Trace Element bolus containing Cobalt, Copper, Iodine, Selenium & Zinc. I have found it to be a powerful tool in maintaining the sheep at the highest level. I feel it bolsters their immune systems and improves their wool. These two indicators give me a window into whether a sheep is thriving. The selenium plays a large role in maintaining a healthy Icelandic (especially a breeding animal) as well as Zinc and Cobalt. I give one of these boluses in the fall just before breeding season and another one in the spring just before lambing. It is a large bolus and can feel intimidating but once you’re accustomed to giving them it isn’t a problem.
Since Covid I have had difficulty ordering these from Ireland. For the last 4 years, I have gotten them from this distributor in Ohio. Shipping & price has fluctuated, but the product has always arrived in good condition.
Santa Cruz COWP (copper oxide wire particles) bolus is a small plastic bound bolus that comes in 4g and 2g sizes. Copassure also makes the product and it is readily available at most feed stores. It will have a goat on the package. I only use these in the summer, but only because I’ve never needed them any other time. I give one to every sheep and lamb over 25 lbs (2g capsule) before they go out to pasture.
I monitor FAMACHA scores over the summer and if in August (usually when my flock can begin to droop due to the heat, humidity and parasite load) I have a sheep with less then red eyelids I will give another COWP. If FAMACHA is bad enough to indicate that traditional dewormer is necessary then I will always give a COWP alongside the two dewormers. Studies have proven that copper oxide wire particle will embed itself in the stomach lining of the ruminant and make the environment inhospitable to the barberpole. This effect is most powerful in the first 72 hours after administration so it adds extra ‘punch’ to your chemical dewormers. Copper oxide is not easily absorbed and should be used carefully, but it is without the same risk of copper toxicity as the copper sulfate.
Santa Cruz Cobalt This is the only bolus that has me doubling up on a mineral. Cobalt assists in production of Vitamin B12, which works with iron and copper to support normal red blood cell heath and supports reproductive functions. For me personally, with the assistance of liver testing, I know my sheep need extra cobalt. Lambs that are cobalt deficient begin showing signs of lethargy, rheumy eyes, and poor appetite and gain by mid/late summer. This bolus can be given to breeding animals every year. The product says non-breeding animals can go 3 years between dosages. I’ve never done this. I give mine one bolus annually. UPDATE: Beginning in May 2023, after 4 years of using this specific cobalt bolus I stopped giving it to the entire flock. My liver tests no longer indicate a deficiency. I now will only give it if I see a sheep with a fleece that needs improvement.
The four primary deficiencies that sheep suffer from are: cobalt, copper, vitamin E and selenium. The Mayo helps with the cobalt/copper, Vitamin E is found in green pasture, good hay that hasn’t been stored over 6-8 months, and there are pour on selections for Vit E if you don’t have access to the previous two options. I’ve never used them. Selenium needs to also be addressed in your loose minerals. Icelandics need more selenium then many breeds. I will give an injection of BoSe to my ewes at the same time I bring them in pre-lambing to check: body score, FAMACHA, & administer the bolus & CDT. Lack of selenium can result in weak contractions as well as WMD (white muscle disease) in lambs.
This is an article that addresses the most common trace mineral deficiencies and treatments. In the case of cobalt, you can give an injection of B12 to help.
Why do you spend money on boluses when you could just put out minerals for them?
The truth is every farm must adjust its methods to fit its flock and its environment. I do put out loose minerals. Honestly I’ve tried so many different type of minerals it makes me laugh. As shepherds it’s easy to become like an over-anxious chef spicing this and spicing that desperate to find what keeps the flock healthy AND what they’ll eat! When the flock was small, everyone shared the same indoor space, and one mineral feeder was enough I could easily monitor what was happening. I could keep the minerals dry, throw them out in small quantities if they caked during humid summers, and usually tell who wasn’t consuming enough. I could also afford to try every fancy blend there was and not worry about waste as much, or the cost of shipping large quantities and many bags.
Once the flock started to grow I needed multiple mineral stations. Some of these weren’t indoors so if the rain surprised me I’d be out some minerals. Many times I was dumping out expensive minerals with high shipping costs. It wasn’t cost effective. I also couldn’t always tell who liked the mineral and was consuming enough, and who wasn’t. I wasn’t being as efficient as I needed to be. I began to see that eventually I could tell who wasn’t consuming enough, but sadly not by the method I prefer. I could begin to see the sheep and lambs that were not thriving, and even sometimes dying. When I started using boluses I didn’t give them universally. I wanted to see if they worked. I gave them to the struggling sheep ie poor or coarse wool growth, fading fleeces, parasite problems, slow weight gain, lethargy etc.
After about two years, when I could really see a difference, I switched to giving them to the entire flock. I began with the Mayo 5-1. I added the COWP but only in May because I was nervous about too much copper. At the suggestion of another shepherdess, I began giving a second COWP to those who needed it in late July/early August. That helped immensely to avoid chemical dewormer in a hot challenging part of the summer. Then I added cobalt a couple years ago after analyzing liver results and wool quality. I’m always collecting data and weights but last summer we grazed 75 sheep & I’m pleased with the bolus results.
I’d never go back to not using them. I still put out loose mineral. I provide kelp (phased out in 2022) and a Redmond 90 salt as well as Redmond 10 Garlic, but I fluctuate between buying the more expensive mineral blends (phased out in 2023) and getting the less expensive minerals. Those minerals didn’t ‘cut it’ in the beginning and my only hypothesis is that they work now because they’re in coordination with the slow-release boluses. I find that boluses provide me with what I’d call ‘cheap insurance’. If my loose minerals get rained on, or aren’t perfectly formulated, or occasionally get neglected I’m not in a heap of trouble. I believe the slow release of trace minerals is a good management tool for my farm and in the long run has saved me money. UPDATE: I get asked a lot about minerals. Currently (01/24) I’m giving Redmond 90 with Selenium & the Redmond 10 Fine with garlic.
One final note, have your record keeping in order before giving boluses. It is important to keep an accurate record of when you give them. It will also allow you to see if they work for you. I hope this helps you to have a healthier and happier flock. I know how challenging summers can be in areas with barberpole. Sending you all the best!
Kimberly