The thing is this also applies here
Ways for Sheep to Die in Australia
drferox:
I have alluded to sheep being a rather unfortunate species in terms of survival, and many of you have been patiently waiting for me to elaborate. I intend to start now. So let me try to explain just a fragment of why we veterinarians say “the goal in life of a merino ewe is to die, and take 50 of her closest friends with her).
Sheep (specifically in Australia where we probably have more than 70 million of them) can and do die in any of these ways:
- If it rains too much while a sheep has a full fleece. They get soaked, weighed down, can’t move and die.
- If it rains too much when a sheep has too little fleece, they get hypothermia and die
- If it rains too little, there’s no water to drink and they die.
- If there’s not enough grass or food available, they die.
- If they eat too much perennial ryegrass, the most common pasture species in Australia, they can develop tremors from the neurogenic toxins it contains, and die.
- Annual rye grass, which is the second most common pasture species, also causes staggers if the grass carries a particular bacteria, and if sheep eat too much or it then they die.
- Merino sheep in particular are often bad mothers. They commonly (20-30%) will give birth and just wander away without a second thought, leaving the lamb to die.
- We also have foxes that like to eat lambs (or at least their tongues), sometimes while they are being born, and they die.
- Eagles will also take lambs or young sheep, and then they obviously die.
- Sheep pregnant with twins are susceptible to Twin Lamb Disease where the mother physically cannot consume enough energy for herself and the growing fetuses. Without great care they will all die.
- Sheep producing milk commonly develop hypocalcaemia and can die
- Sheep given intravenous calcium to treat the hypocalcaemia, if it is given too fast, will die.
- Sheep producing milk on lush pasture are at risk of hypomagnesaemia (grass staggers) and can, you guessed it, die.
- Grazing pasture that is too lush or too high in protein can cause bloat, which can take out an entire flock of sheep and cause them to die.
- Grazing too much red clover, a very popular pasture species in Australia, can cause both infertility and bloat. Then they die.
- Sheep in Australia are very prone to flystrike, where blowflies lay eggs i the wool or flesh of the sheep so maggots can eat them. This starts while they’re alive, but it will cause them to die.
- They also carry huge numbers of worms which compete for nutrients from their food, cause diarrhea and can cause sheep to die.
- That diarrhea in their wool makes them extra attractive to files and, again, death.
- Johne’s Disease is a chronic wasting disease similar to Crohn’s, which will result in a slow wasting away as individuals are often infected for most of their life, and then they die.
And this list is by no means complete.
Many of these would also apply to US sheep, though white/bur clover is more common for grazing for exactly the reasons mentioned. Still bloat risk but less fertility risk (though that risk is variable and depends on what season the clover is grazed).
Mothering ability is also pretty variable between breeds, admittedly. I would say that the incidence of birthing and wandering away is a lot lower around here, but the Australian sheep industry is mostly Merinos (which will be featured on breed of the week soon!) and in the US, there is a wider variety of breeds.
I would also add that in the US, we have problems with temperature swings leading to pneumonia (from very warm days and very cool evenings), coyotes, feral dogs, feral pigs, and sometimes ravens and crows, though canines are still the biggest predator issue out here (western US). And sheep give you a lot less warning when they are sick, so the time to react and treat is a narrower window.
Johne’s Disease is a nasty disease, too, and any ruminant can get it. I know some people studying it in cattle. It’s extremely unpleasant.
But agreed, sheep, as Terry Pratchett said, are “just bags of bones, eyeballs, and teeth, lookin’ for new ways to die.”