Melbourne botanic Garden,
18 June 62
Sir
I have the honor to inform you, that having in the afternoon of Saturday 14. instant
received your letter, dated 13 June,
desiring me to investigate by personal inspection the cause of the recent death of
a number of sheep at Mr Wallace's run at Ballark, I proceeded on Monday 16. instant
by the noon train to Meredith and reached Mr Wallace's station early the following
morning.
The Ballark Station is situated at one of the upper branches of the Moorabul
River, the homestead occupying part of a beautiful basaltic valley.
Conducted by Mr Wallace to the paddock, in which the sheep had been pasturing immediately
previous to their sickness, I found after a careful search of the whole ground no
indication of the existence there of any herb known to me as deleterious or poisonous
in the strict sense of the word. Like in all vallies rich of decomposed trap rock,
the vegetation of grasses and herbs is also on this spot very luxuriant, especially
at this season of the year, but is constituted only by ordinary native plants, whilst
amongst the immigrated weeds I noticed only such as have become abundant in most districts
of the colony, including
,
,
,
,
,
,
and
, all from Europe and the originally South African
, all widely spread over the colony.
Having learnt from Mr Wallace that the flock of sheep, of which the 87 died, had been
brought from a drier upland part of his run to the deep humid valley in which the
disaster occurred, and that the animals before they were brought to this paddock had
been for about a day without food, my opinion became more confirmed, that the illness
and death of these animals was not caused by their feeding on any particular poisonous
herb growing at the spot, but most probably in consequence of the creatures after
some abstinence gorging themselves with an exuberance of wet soft green food, which
in its young state and taken in excess proves not unfrequently noxious to herds and
flocks, especially when the latter are not accustomed to such localities, and it is
not improbable that the large amount of soft and wet foliage of the
produced particularly the destructive effect on the animals, altho' at the time of
my visit to Ballark a small flock of sheep, bred at the low valley of the homestead,
was pasturing in the same paddock without any apparent injurious consequences.
No sheep or cattle had been kept in the paddock for months previous to the disaster;
hence the growth of the weeds, augmented by the favorable season, was at the time,
when the sheep were lost, most abundant. Mr Wallace informed me that under similar
circumstances losses amongst his flocks had been sustained last season.
The loss of the sheep, which was the immediate cause of my visit, having taken place
2-3 weeks ago, it was beyond possibility to institute a very satisfactory examination
of the stomachs of two of the perished animals, kept by Mr Wallace for the purpose.
They did however not present any marks of internal abrasion, indicative of the action
of metallic poison, nor did I discover on application of the ordinary chemical tests
any traces of such poisons as usually are employed for dressing sheep, altho' many
instances are on record of the incautious use of arsenic and mercury preparations
for sheep-washing, which are often allowed to saturate the ground and may remain as
anorganic poisons, an everlasting danger of destruction on such spots.
In examining the stomachs of the sheep I found the rumen and reticulum gorged with
a semiliquid pulp of green food. The psalterium and abomasum were also more or less
filled with triturated herbs, which on account of their softness would be rapidly
regurgitated. But neither these stomachic cavities nor the oesophagus nor the pylorus
showed traces of the action of metallic poison. The specific recognition of the herb
in the stomachs of the animals would under any circumstances be equally out of the
question as the recognition of any peculiar organic poison.
Mr Wallace informed me, that the sheep were removed after a nights stay from the paddock
and that a few days after their removal no further deaths occurred amongst the flock.
The internal application of a spoonful of mustard and a spoonful of unmixed tar to
most of the animals, which died, was evidently calculated to increase the inflammation,
consequent on the overcramming of these sheep, as the above remedies would act as
strong irritants, whilst under the circumstances emetic evacuants and demulcents would
be indicated in order to remove the inciting cause of the disease and to involve the
inflamed membranes and linings with an oleaginous and mucilaginous covering. Such
remedies would be specially indicated by any of the Gentlemen of the veterinary profession,
when consulted on the subject.
I am gratified to be enabled to dispel the fears of the settlers in the locality,
that a new noxious weed had sprung up on their runs, in as much as it is apparent
that the danger of the reoccurrence of losses similar to those in Mr Wallace's flocks
might readily be obviated by keeping the flocks at the early spring season in higher
ground.
Should the cramming food, consisting of
have been, as I suppose, the primary cause of the disaster in this instance, then
its effect must be ascribed to mechanical irritation, since this plant has under ordinary
circumstances not proved deleterious to herds and flocks and would become only dangerous
when it forms in moist weather the momentary prevailing and rapidly devoured food
of stock unaccustomed to this plant, similar hurtful actions of green food, when consumed
immoderately, and in wet weather being by no means of rare occurrence.
As the Cryptostemma has widely spread over the country, the ready opportunity is offered
every where to investigate its varied effect on pastural animals.
I may add, that after explaining my views, Mr Wallace fully concurred in the lilekihood
of their correctness.
I have the honor to be,
Sir,
your most obedient and humble servant
Ferd. Mueller, M.D.
Gov. Botanist
The honorable the Chief Secretary
&c&&
