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This article was published in 1966
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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
WHAT HAVE WE LEARNT FROM THE 1965 DROUGHT?
Drought Problems in the Armidale Pastures Protection District
F. L. CLARK, B.V.Sc., Veterinary Inspector, Armidale. N. J. CAMPBELL, B.V.Sc., Veterinary Officer, Department of Agriculture
The Armidale Pastures Protection District is situated on the New England tablelands. In recent years, particularly in the last decade, the district has been going through a pastures improvement "explosion" and this has resulted in greatly increased stocking rates both in sheep and cattle.
For example, from December 31, 1960, to December 31, 1964, sheep numbers increased from 2,612,532 to 3,612,827 and cattle numbers from 141,615 to 220,388.
Much of the improved pasture has been established by aerial application of fertiliser and seed. This leads to clover dominance at least for several years.
The establishment and maintenance of improved pasture involves considerable expenditure and graziers generally neglected to provide adequate water supplies for the increased numbers of stock. Stock on green improved pastures need little water and it was not until the pasture dried off that many graziers realised how inadequate were their water reserves. Severe shortages of surface water added greatly to the adverse effects of the drought.
Before pasture improvement became widespread many graziers relied on sown crops, mainly oats and turnips, to provide additional Winter feed. However, with a series of good years for pastures this practice was largely discontinued. Thus when the pastures failed during the Autumn and Winter in 1965 there were no reserves of feed on many properties and it was necessary to completely hand feed stock, in many instances for periods up to seven months.
Drought conditions have generally been more severe on the heavily stocked pasture improved eastern half of the district. With the failure of the normally reliable Summer and Autumn rains in 1965, improved pastures disappeared. Many heavily stocked properties were forced to hand feed as early as March.
Throughout the Winter of 1965 hand feeding was universal on all areas previously sown to improved pastures. The improved pastures had eliminated native grasses and when the pastures died there was little left for stock.
Stock fared better generally on the native pastures which predominated in the more western area of the district, due to lower stocking rales, higher proportion of dry stock and better reserves of dry feed.
Few landholders conserve feed in this district. Normally lucerne hay is purchased when needed from growers in the Tamworth district.
Little feed is grown locally for conservation as the district is not suitable for large scale grain or hay production. It is doubtful whether it is economical to conserve large quantities of hay or grain on properties on the New England tablelands. Possibly the best drought reserves for this district are financial reserves to enable fodder to be purchased when needed.
Although drought conditions have continued through the Summer and Autumn of 1966, on most properties there has been sufficient short green shoot to avoid hand feeding. However, as it has become increasingly obvious that there will be no relief before the Winter, graziers have generally been selling large numbers of stock, particularly cattle, rather than be involved again in a prolonged period of hand feeding. At the end of April 1966 it was estimated that cattle numbers in the district had been reduced by at least 70 per cent and sheep numbers by 33 per cent.
Extensive areas of crops were sown in 1966 for Winter feed in contrast with 1965.
PROBLEMS ASSOCIATED WITH HAND FEEDING DURING THE AUTUMN, WINTER AND EARLY SPRING OF 1966
(1) Availability of Feeds for hand feeding.
The most economical of the feeds readily available was undoubtedly wheat and eventually most stock owners used this feed.
There were, however, some graziers who continued to feed their cattle hay even when it was costing them at least twice the price of wheat in relation to food units. As the Winter progressed good quality lucerne hay became practically unobtainable and then graziers had to turn to poorer quality pasture and cereal hays.
Some sheep owners fed pelleted food (sheep nuts) right through the Winter. Pelleted feed is easier to handle and feed out and no doubt this contributed greatly to its popularity. However, in some cases it was obvious that graziers had been misled by information on feed labels. Some also considered the higher protein in some brands of pellets to be an advantage.
High protein pellets are probably useful as a supplementary feed in the early stages of a drought where there are reserves of dry feed, but economically unsound for complete hand feeding. Much of the wheat fed on the northern tablelands was from northern wheat areas and would have been of higher protein content than the state average.
As the Winter progressed the quality of sheep pellets appeared to deteriorate markedly.
Other sheep owners were just frightened to feed wheat. Despite considerable publicity on the economic advantages they had been conditioned by exaggerated reports of the toxicity of wheat. It was difficult to convince these people that losses from grain poisoning could occur just as readily with pellets.
(2) Interval of feeding.
Feeding once weekly was generally not successful, possibly due to the added stress of cold in this district.
For example one owner fed 1000 merino wethers at weekly intervals at recommended levels of wheat and lost 25 per cent of them over the six months' feeding period. These sheep consumed their entire weekly ration in 24 days and just stood about on bare ground the rest of the week.
Feeding either twice or three times a week was usually adopted and proved more successful.
(3) Levels of Feeding.
It was found that the recommended levels of feeding need to be increased due to the cold stress in this area.
(4) When to Commence Feeding.
Generally it was recommended that hand feeding be commenced whilst stock were still in good condition, and before all natural feed was exhausted. In this way a small amount of supplementary food could be given to enable stock to become accustomed to hand feeding. The level could be gradually increased as the amount of natural feed deteriorated gradually allowing the stock to lose condition to the desired level.
It was not considered advisable to allow stock to drop to poor condition under the severe cold stresses experienced in this district.
(5) Shy Feeders.
A problem frequently encountered with total grain feeding was a percentage of sheep going off their feed. It is felt that this shy feeding was often the aftermath of grain poisoning.
The problem was far more complex in weaners where the effect of parasitism also played a part.
Many owners experienced trouble in getting poorly grown weaners on to wheat. It was common to see weaners six months old weighing as little as 25 lb.
(6) Drought Units.
Stock are said to be held in drought units where they are confined to small paddocks usually in some central point handy to feed stacks. The advantages are that the rest of the pastures can be spelled, and costs of feeding and watering are reduced. Usually several lots of stock can be fed in rotation with the one set of troughs.
Although graziers generally had little trouble with adult sheep in drought units this was not a successful method with young sheep. Several severe losses, up to 50 per cent, were experienced in weaners held and fed in confined spaces.
Parasitism, cold stress and the inability of weaners to handle complete grain rations contributed to these losses. When returned to paddocks weaners could be more successfully hand fed with less mortality.
Few attempts were made to feed cattle in drought units. On one property 3000 head of cows were fed on wheat in units. Although these cows were brought on to twice weekly feeding and finally on to once weekly feeding, few losses occurred from grain poisoning. Despite adequate levels of feeding it was found impossible to rear calves under unit conditions. Calves were either deserted by their mothers at birth or became separated during feeding. Not one calf that was dropped in the units was saved and eventually the cattle had to be returned to large paddocks.
No cases of lambing in units were studied as fortunately graziers had generally mated for November lambing. Hand feeding of sheep on most properties ceased early in October.
(7) Pregnant Ewes.
Although a few owners successfully fed pregnant ewes, malnutrition and pregnancy toxaemia were common in early Spring lambing ewes. Fortunately with the advent of warmer weather in the Spring there was re-growth and nutrition improved over the main lambing period, otherwise heavy losses could have been expected.
(8) Scouring.
Outbreaks of scouring were common, particularly in young sheep. Internal parasites, grain poisoning and possibly coccidiosis and bacterial infections were incriminated.
It was found necessary to drench young sheep fed in small bare paddocks at intervals of four to five weeks to control internal parasites.
Nematodirus infestations were particularly prevalent. Heavy tapeworm and Trichuris infestations were also frequently observed. Trichuris infestations were believed to contribute towards scouring and illthrift in some instances and lesions were noted on the caecal mucosa in some sheep. Where scouring and illthrift continued in young sheep after drenching with broad spectrum anthelmintics, treatment with sulphadimidine often resulted in a dramatic improvement.
(9) Phalaris Poisoning.
Although white clover and most grasses disappeared in the Autumn, Phalaris tuberosa continued growing slowly during the Winter. This often resulted in a short green pick of Phalaris being the only available feed in spelled paddocks. Some cases of acute Phalaris poisoning occurred when hungry sheep were placed in these paddocks. The incidence of acute Phalaris poisoning diminished with the onset of warmer weather, possibly because the Phalaris was diluted with weeds and annual grasses.
Losses in two instances occurred in sheep, drenched with carbon tetrachloride, which had been grazing in paddocks containing practically 100 per cent short green Phalaris shoot. In one of the instances 385 sheep died out of 618 drenched.
(10) Toxaemic Jaundice Syndrome.
On several properties where British Breeds and their crosses were fully hand fed, losses occurred in which the symptoms and autopsy findings were typical of toxaemic jaundice. The aetiology of this condition was obscure. One owner experienced approximately 100 deaths out of 2000 first cross ewes from this disease.
(11) Grain Poisoning.
All owners experienced trouble to greater or lesser extent from this condition, particularly in the early stages of hand feeding.
The incidence of this condition was greater with sheep pellets than grain. This was probably due to the ease with which the pellets can be picked up by the sheep and the fact that the grain component is crushed.
Even when sheep were used to pellet feeding the changing from one batch to another of the same brand occasioned losses.
(12) Vitamin "A" Deficiency.
We saw no evidence of Vitamin "A" deficiency during the Winter and Spring of 1965. A small amount of green pick was usually available at most times in contrast with the western districts where long periods without can occur.
(13) Entero-toxaemia.
Although the feeding of large quantities of grain is reputed to be favourable to the development of entero-toxaemia only a few isolated cases were observed. However, vaccination against this disease is regularly carried out in this area and it is probable that most sheep on former improved pasture areas at least had some protection.
(14) Lack of grain storage facilities.
Few graziers have grain storage facilities in this area, thus in many instances bulk wheat was dumped in the open. This led to wastage of grain where it was damaged by moisture and in at least one instance botulism occurred in sheep fed this mouldy wheat.
(15) Feeding cattle on wheat.
Many graziers were reluctant to feed grain to cattle and continued to feed them hay even though the cost per food unit was at least doubled, and the quality of the hay, in many cases, poor.
Wheat was however successfully fed to cattle on a number of properties.
Many cases of illthrift in hand fed cattle were investigated. Inadequate levels of feeding were often determined as the cause. In most instances the combined effects of sucking lice, Ostertagiosis and chronic fluke damage contributed to the illthrift.
Routine sampling sometimes revealed marginal liver copper levels.