Goat Eating Weeds
Goat’s have the ability to control a wide variety of weeds, and of the fact that this has been the animal’s only recognised value until recent years, apart from producing milk. It should not be thought, however, that because goat fibre is now creating such interest, there is no longer any reason for the animal’s ‘weed-eating’ propensities to be considered.
The reason we should give serious thought, in fact, to this potential, was succinctly stated by Garrick Batten when he told an audience that “cheap male goats eating worthless scrub to produce high-value cashmere is the low-cost, highreturn enterprise. It must be a future plank in New Zealand’s pastoral prosperity”.
And research scientists of DSIR’s Grasslands Division have gone so far as to suggest that “the funding of noxious weed control programmes on a lamb icide-only basis, should be replaced by funding on a project basis, especially group projects, and should include “projects using goats”.
In the past year or so, considerable research has been carried out to discover how goats can be most effectively used in this role on a variety of problem weeds, and a few farmers have initiated such systems on their own farms. Reports on some of these are given below.
It seems likely, from the evidence available so far, that goats will increase rapidly in numbers in areas where weeds are a serious problem, with particular emphasis is on blackberry, gorse, manuka and sweet brier. The reason is basically economic, but the possibilities of success have been greatly enhanced by the development of electric fencing systems which will control goats.
The returns from sheep, on hill-country farms especially, are now down to a level where high annual expenditure on chemical or mechanical control of weeds is not justified. It is not merely a matter of the actual cost of the spray and its application; hormone sprays such as 2,4,5-T kill clover as well as the weeds. Clovers play such an important part in the establishment of pasture through their ability to add nitrogen to the soil, that it is ridiculous to spray them out when goats will effectively control the weeds and promote clover growth.
Weed patrol
In addition, former rates of application of phosphatic fertilisers are becoming impossible, in view of returns from sheep, and reduction in topdressing will inevitably lead to lower pasture production and lower stocking rates. Weed growth and reversion will increase.
If goats did no more than reduce the weed threat, without competing seriously for available feed with sheep and cattle, they would be worth taking seriously.
If one takes into account the impact which the environmental lobby is having, and the prospect of 2,4,5-T manufacture being discontinued, then goats can be seen as making a very real contribution to the pollution-free status of New Zealand.
That, of course, is not the end of the list of advantages. Goats are now seen as being able not merely to reduce weed growth, but to utilise such feed in production of products with high potential return.
It is now becoming clear that goat farmers in this situation may actually manage gorse or blackberry, just as they would pasture or a crop. There are certainly a number of farmers who, having set out to eliminate blackberry or gorse, are now no longer concerned to see it disappear entirely, and would regret the fact if it did. Gorse, after all, is a legume, and therefore makes an as-yet-unmeasured nitrogen contribution to soil fertility, and produces more DM (dry matter) per hectare than pasture on hill country.
These developments have enormous implications for the country’s economy, but even more important is the significance to many farmers as a source of diversification offering new viability. There are in this country something like 1.2 million hectares covered by gorse, at least half of it too steep to be cultivated. And there will be something like 30-40,000 male G4 kids born which could be used in this situation.
According to Clark, Lambert, Rolston and Dymock in ‘Proceedings of N.Z. Society of Animal Production 1982′, “… attempts to eradicate gorse from New Zealand hill country have failed. Gorse represents substantial feed source for goats. The other factor which we now have to take into account, as the result of research work and farmer experience, is that goats can, by proper management, be kept in good condition even while performing this weed-control function.
Crop With Weeds
In effect, therefore, we have found an animal that makes good use of the plants that insist on growing on our hill-country grasslands — despite our efforts to have grass and clover monopolise the scene — and those animals are now found to have a high commercial value. In this respect goats are an even better prospect than deer, which started life as the saviours of the hill country but have now graduated to the pampered pastures of the lowlands.
It is perhaps possible to consider this whole area by suggesting three main combinations of goats and plant cover:
1) breaking in country heavily infested with such species as gorse, blackberry, brier or manuka;
2) controlling regrowth of such species where they threaten to over-run pasture;
3) improving pasture conditions for sheep through elimination of weeds and control of rank pasture growth.
There is one other situation in which goats could play an important role, and that is in grazing under pine plantations. Unfortunately there is very little evidence, and what there is tends to be rather contradictory.
If goats could be grazed in pine plantations there would be a double benefit. In the first place they would find feed and shelter in a situation at present not being used, and they would provide a short-term cash-flow where normally there is little or none for many years after original capital outlay.
Secondly, the goats would reduce growth which, when it dries out, constitutes a serious fire hazard, and improve access for forestry workers. in the trials (outlined later) at Ballantrae, goats were run in a plantation of 7-year-old pines at 11 goats/ha. The pines had been thinned to 240 stems/ha. At the end of 4 months, 20 percent of the pines had been partially or totally ringbarked.
Several small pines had been completely defoliated, while older pines with thicker bark had not been damaged. Australian research has indicated that pines less than 14 inches in diameter are usually damaged by goats. In Nelson, NZ Forest Service had a block of 7-year-old pines that had not been pruned, and because of the low branches and low cover of gorse and blackberry, workers were unable to get in to prune. A mob of 70 goats were fenced onto one hectare as a trial. The goats considerably reduced the undergrowth but did little damage to the pines, partially because of the ‘skirt’ of low branches protecting the trunks.
Until more experience is gained with different stocking rates and pines of varying ages, little can be said in respect of goats in pine plantations. It does appear that they may be of benefit in mature plantations, but stocking rate will be an important consideration and shelter may still be a problem at certain times. Nevertheless, working out solutions to these problems will be no more difficult than evolving an agro-forestry sheep/cattle/pasture/pine management system. The following reports cover some of the varied situations in which goats are contributing to weed control and/or improving the quality of feed available to sheep.
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