Sheep in clover

[kev67]

In chapter 21 the sheep break into a field of clover, which causes their bellies to expand. The flock is in danger of dying, so Gabriel Oak has to lance their stomachs at a certain point to let the gas out. Is too much clover or vetch dangerous to sheep? Does lancing their stomachs cure them? I would have thought pricking a hole in a sheep's stomach would cause perotinitis or blood poisoning.

[108 fountains]

This is quite a vivid and memorable scene in one of Hardy's classics. I'd always just taken it for granted, since I first read the book, that clover can cause bloat and that treatment (in those days if not now) was lancing of the sheep's abdomen. Your question spurred me to do a little Internet research, and I found an article, "Preventing Pasture Bloat in Sheep" that first appeared in The Working Border Collie, Inc. Jan/Feb in 1997 by Mike Neary, Extension Sheep Specialist, Purdue University. He says,

"...Pasture bloat is often brought on by a rapid intake of immature, highly nutritious green legumes (alfalfa or clovers). These plants, when in a vegetative state, contribute high levels of ruminally degradable protein, high levels of carbohydrates and are digested quite rapidly. This causes a drop in the pH of the rumen, an increase in gas production and a binding of protein molecules into a surface film over the ruminal contents. These events contribute to the production of froth, and subsequently, trapped gas.

"There are some legumes that are considered to be less of a bloat problem than others. Birdsfoot trefoil is less likely to cause bloat than alfalfa and many types of clovers, not because it does not have a high protein content, but because the rate of digestion is considerably slower. Also, grasses do not usually cause bloat, because the protein content is lower than legumes...

"If animals can be caught, use a stomach tube to help release free ruminal gas. Also, mild agitation of ruminal contents can aid in the release of the trapped gas bubbles. Mineral or vegetable oils can be used as antifoaming agents and help release gas. Treatment with commercially available anti-bloating agents can also be done at this time.

"Some people will actually use a rumenotomy (puncturing the rumen - located high on the left side of the lumbar region in severe bloat cases) in severe, life-threatening situations. This procedure is not for the weak stomached, as the pressure will result in the expulsion of a significant amount of the rumen contents. Also, the area will need to be cleaned and sutured after the rumenotomy is performed..."

Here is the link to the article: http://ag.ansc.purdue.edu/sheep/articles/pasbloat.html

[kev67]

Interesting, I will have to re-read that chapter. I do not think it mentioned Gabriel Oak cleaning or suturing the sheep's rumens, but surely this must have been necessary. I don't think it mentioned the contents of the sheep's stomachs splurging out either. Oak had to repeat this operation on a flock of about fifty sheep. Surely this is not possible in the time. Can bloat actually lead to death as portrayed in the book? In the chapter, a couple of the sheep suddenly leap in the air and die.

I wonder what that field of clover was intended for. Presumably it was part of a crop rotation scheme, and its purpose was to put nitrates back in the ground. Presumably they must have fed the clover to something. Humans cannot eat it.

[kev67]

Maybe the hole put it the rumen is small enough not to need suturing. There is an example of a similar operation here (http://www.infovets.com/healthysmrm/c078.htm). Looks :ack2:

[prendrelemick]

I was waiting for you to get to that part KeV, I remember my dad telling how grand dad saved a sheep with a kitchen knife . Nowadays we use a trocar and cannula, which is a spike and a tube.
The clover may have been for drying into a high quality hay, or for seed production, or you can graze it very carefully making sure you provide plenty of roughage as well.


Now, about those sheep that jumped off a cliff....

[kev67]

I was waiting for you to get to that part KeV, I remember my dad telling how grand dad saved a sheep with a kitchen knife . Nowadays we use a trocar and cannula, which is a spike and a tube.
The clover may have been for drying into a high quality hay, or for seed production, or you can graze it very carefully making sure you provide plenty of roughage as well.


Now, about those sheep that jumped off a cliff....

Ok, tell me about those. That seemed plausible to me because I have read about how Native Americans or stone age men deliberately stampeded herds of animals off cliffs. I noticed the word 'worrying' was used in that chapter. When I was a boy there used to be public information films on the television telling people to keep their dogs on leads to stop them worrying the sheep. There were some images of sheep being chased and then lying dead on the ground. This confused me. I thought the sheep must have dropped dead from anxiety, and that maybe it was safer not to take your dog into a field that had sheep in it at all, but then sheep could tolerate the presence of sheep dogs.

I wondered whether Gabriel Oak had been slightly negligent because he knew the young dog to be unreliable, but I suppose it was just bad luck.

Going back to the spike in the rumen, does the hole need suturing afterwards?

[kev67]

Looks like bloat is a deadly hazard (link (http://www.sheepmagazine.com/27-2/laurie_ball-gisch/)). Interestingly, it looks like it happens more often in spring when the sheep are taken off hay and moved into fresh fields. I think the incident in the book occurs in spring, about a month after St Valentines Day, so March probably.

Still, I wonder why Gabriel did not use the stomach tube method; it seems safer. Maybe there wasn't time.

[108 fountains]

My own feeling is that given the setting - a very rural area in early to mid-19th century - Gabriel did the best he could with the materials he had on hand in an emergency situation. I don't know if the idea of using a stomach tube for this type of veterinary illness had been conceived of yet (plastic tubing for sure was not yet available for the purpose). Suturing of the wound with proper antiseptic would also be desirable, but perhaps not practical in the situation Gabriel faced. In a real situation, probably some of the sheep would have become ill with infection, and some small number perhaps would die from infection, but I would think that the vast majoriy of sheep would be able to fight off the possible infections with their natural immune systems. I don't know for sure, of course, but I surmise that what Gabriel did and how he did it was probably the way that sort of thing would have been done in rural southern England in those days. Hardy himself describes it as though it was an accepted and not unusual procedure.

[kev67]

Gabriel had some sort of antiseptic I think. There is a bit in another chapter when he accidentally cuts a sheep he is shearing and calls for the bottle (Bethsheba had just gone off with Mr Boldwood). I cannot remember what was in the bottle. I would have thought they might have rubber tubing. In another chapter it says Gabriel had a veterinary book among his small library.

The thing with Hardy is that he is not always to be trusted. I enjoy reading about agricultural and woodland practices. He seems usually to describe them pretty well, but sometimes Hardy distorts the laws of man and nature for dramatic purposes.

I read the chapter again. It says that a lot of gas came out of the sheep's rumens, but does not mention any great splurges of green stuff. Perhaps Gabriel lanced the sheep's rumens, dabbed them with whatever is in the bottle, and sutured them up a bit later when the immediate emergency was over.

[prendrelemick]

They had iodine and Stockholm tar and potassium permanganate I would ve thought. I think there is frothy bloat and gassy bloat, gassy can be relieved with a tube. - certainly that is the case with cattle, frothy is more difficult, also an oily drench of liquid paraffin can do the trick. However in an emergency with a whole flock to treat I'd go for the knife.

As to the cliff I had three sheep chased over one by a tourist's dog once.

[prendrelemick]

They had iodine and Stockholm tar and potassium permanganate I would ve thought. I think there is frothy bloat and gassy bloat, gassy can be relieved with a tube. - certainly that is the case with cattle, frothy is more difficult, also an oily drench of liquid paraffin can do the trick. However in an emergency with a whole flock to treat I'd go for the knife.

As to the cliff I had three sheep chased over one by a tourist's dog once.