Old McDonald did indeed have a farm and what made his farm so entertaining to us as children, and to us perhaps now as we sing it with the children in our lives, was all the different animals he had. There was an oink oink, a moo moo, a baa baa, here a cluck, there a cluck, everywhere a cluck cluck. Multispecies farms are becoming more common and they do bring joy as the song indicates. There are, however, a few considerations when multiple species of animals are housed in proximity to one another. Certain medications, feeds, and feed additives that are advantageous to the health of one species can actually be detrimental to other species.
Here are my top 5 dangers on multispecies farms:
Copper is an important trace mineral that is required by all animals for a variety of important biological processes. The amount of copper required in the diet by our livestock species varies widely and, as such, the amount in their feed varies widely.
Sheep are by far the most sensitive livestock species to copper. While sheep do require a small amount of copper in their diets, providing them almost any feed that isn’t labeled for sheep is potentially dangerous. Goats are slightly more tolerant of copper than sheep are and require a little more in their diet, but we do diagnose copper toxicity in goats as well. As a rule, feeds for swine and poultry are the most dangerous to sheep and goats, followed next by horse feeds and cattle feeds. My first rule of livestock nutrition is: feed only a feed that has a picture of your animal on it and other species should not be able to access that feed.
Remember, also, that anything that is eaten also shows up in the feces. So, the manure of these higher copper-tolerant species is also high in copper. I was once called to consult on a case of several deaths of sheep on a farm that was adjacent to a swine operation. The sheep were in a pasture below the swine barn and there was runoff to the sheep pasture. The grass along the fence between the two was lush from all that fertilization and the sheep would graze down that fence line and die from copper toxicity.
Feeds are not the only sources of copper on an operation. Loose and block trace minerals, injectable trace mineral supplements, copper boluses, algaecides (copper sulfate), and other farm chemicals may also contain copper and be toxic.
Ionophores are a class of feed additive drugs that promote growth and help control coccidia in ruminants, such as cattle, sheep, and goats. The ionophores include such drugs as monensin (Rumensin®) and lasalocid (Bovatec®). Their usefulness ends with the ruminants, though, as they are fatal if consumed by horses. There are many stories of horses being accidentally fed or breaking in and consuming ionophore-containing cattle feeds. The ionophores cause acute heart failure, which is rapidly fatal and not treatable. Even traces of these drugs can be fatal, with some reports of deaths of horses coming from feed mills that mixed horse feed after cattle feed in the same mixer without adequately cleaning it.
Grains, especially corn, are used in the feeding of all livestock species, so how can they be problematic on a multi species farm? Let’s talk about the digestibility of grains, using corn as an example. Corn comes to us for feeding in a variety of forms: whole corn, steam flaked, rolled, cracked, ground, etc. The less processing that is done to corn, the less digestible it is – you know this because you are used to seeing whole kernels of corn in the manure of animals on diets with whole corn. With increased processing (cracking, rolling), however, more of the starch of the corn is exposed, making it more digestible, but also potentially more dangerous. With increasing processing and starch exposure, the risk of grain overload or rumen acidosis increases. So, whole corn is much less likely to cause grain overload and rumen acidosis than corn ground much more finely for poultry or pig feed, for example. If a steer were to break in to a bin of
whole corn, he may get a bad bellyache that requires treatment, but if he breaks into chicken or pig feed corn, he could rapidly bloat and die because of the extra processing.
I recently saw one of the worst cases of rumen acidosis I have ever seen in a beloved pet goat because she broke into the feed room and ate a large amount of waterfowl feed. She came in to us on Christmas morning unconscious and required a week of hospitalization to recover. The fine corn grind used in poultry and wild bird feeds is extremely dangerous to cattle, sheep, and goats.
Alfalfa is an important high protein feed fed on many farms to a variety of species. While it is a safe feedstuff for all of our common domestic livestock species, there is one group of animals who should never be exposed to alfalfa and that is male sheep and goats, especially if they are pets or miniature breeds, such as Nigerian Dwarf or Pygmy. Male sheep and goats are at high risk for bladder stones that can become lodged in the urethra, causing rupture of the urethra or bladder and kidney failure.Bladder stones can also be formed in these males from eating high grain diets as well, but the stones created from alfalfa-based diets are by far the most difficult to treat. If you are feeding grains and alfalfa to horses or cattle, it is best to keep male sheep and goats away from those feeders.
- Avermectin-class dewormers
The avermectin class dewormers include those products containing ivermectin (Ivomec® and generics), doramectin (Dectomax®), moxidectin (Cydectin®) and eprinomectin (Eprinex®, LongRange®. Many equine paste dewormers of various brand names contain an avermectin dewormer – be sure to read the labels. Farm dogs are the concern here. As you know, when you are giving a dewormer, especially an oral paste to a horse, some gets dropped on the ground. In addition to that, the drug gets excreted via the feces and is present in manure on the pasture. Some dog breeds, particularly white-footed herding breeds (Border collies, Australian Shepherds, etc), are very ivermectin sensitive and should never be exposed to these drugs as they can cause damage to the nervous system and be fatal. Most fatal farm dog exposures stem from paste dewormers that drop onto the ground during administration or from eating the manure of a treated animal, as the drugs are excreted into the feces.
Here are some safety tips for caring for multiple species of animals:
- Keep each feed in a bin with a secure lid, inside a secure room. Make sure that the bin is clearly labeled with the species for which the feed is manufactured.
- Separate species at feeding time to limit other species from sneaking feed or picking up feed dropped on the ground.
- Store ionophore-containing feeds in a completely separate area from horse feeds.
- Review safety and health concerns with ranch help and ranch sitters so they are aware of the dangers. Provide clear, written instructions on feeding, including exactly how much to feed.
- Keep stalls picked and cleared of manure.
- Always read the label of any supplement or medication you intend to use. Never use a product in a species that is not on the label unless directed to do so by your veterinarian.