- Incidence and Distribution of Nenta Poisoning (Krimpsiekte)
|Last update: March 30, 2012 08:59:00 AM|
Incidence and Distribution of Nenta Poisoning ("Krimpsiekte")
P. Botha, Department of Agriculture, Karoo Region, Middelburg, C.P.
AMONG others, there are two main factors which have a limiting effect on the westward expansion of the Angora goat and mohair industry. Firstly the high susceptibility of Angora goats to Nenta poisoning ("krimpsiekte") and secondly the high incidence of plants responsible for this type of poisoning in the districts of Prince Albert, Uniondale, Willowmore and Oudtshoorn. For this reason the Department of Agriculture was requested to carry out a survey of the incidence and distribution of Nenta and Nenta poisoning in these districts. In order to determine the extent of the problem, a questionnaire was compiled and sent to farmers in the four districts concerned.
Distribution of respondents
The distribution of the respondents in the four districts, the total area covered in the survey as well as the losses as a result of Nenta poisoning during 1979-1981 are shown in Table 1.
It became clear from this questionnaire that Nenta poisoning occurred on all the farms in the area. The distribution was more than 90 per cent in the case of hilly areas, and as a rule occurred on the shady side. Almost 50 per cent of the respondents also reported an incidence on mountains and ridges, while on plains and in valleys and watercourses the incidence was under 5 per cent.
Deaths as a result of Nenta poisoning fluctuated from an average of 18 per respondent in 1981 to 40 in 1979. These deaths occurred mainly among kids (58070), while deaths among ewes (23%), wethers (15070) and young goats (4070) were appreciably lower. In only one case was the condition of the stock poor, while in most cases it was average (54%) to good (44%).
Although only one respondent found that these deaths occur throughout the year, 29 per cent said that they occur mainly during the summer, 26 per cent during the winter and spring and 15 per cent during the autumn. It is, however, apparent that after a drought (23%) and especially after good rains (61%) Nenta poisoning is generally more prevalent. According to the respondents plants in all stages of growth cause deaths among goats, but especially young plants (55%), old plants (36%), plants in active growth (44%) or when in bloom (40%).
As far as grazing is concerned, it is considered that the problem mainly occurs on satisfactory to good grazing (35 per cent and 52 per cent respectively) while the incidence on both poor and outstanding grazing occurs less generally (less than 10 per cent in both cases). Similarly 80 per cent experienced the problem after a camp had been rested while 20 per cent had the problem even though there had been stock in the camp for some time.
Although the description of the symptoms were many and varied, all the respondents (1000/0) agreed that Nenta poisoned goats tire easily and shiver. Symptoms such as convulsions, paralysis, protruding tongue, paralysis of the jaw, bloat, abortion and twisted neck were given, among others.
Nearly 70 per cent of the respondents carry out preventative measures such as transferring stock to camps free of Nenta (40%) or even the eradication of the plants (50%). The majority (93%) of the respondents follow a system of grazing management and attempt to control the Nenta by physically chopping it out. The success rate varies and 47 per cent of the respondents have only moderate success while 12 per cent have good results.
Judging from the extremely long list of remedies where almost every respondent favours a different kind of treatment, it is clear that there is no infallible treatment yet. Almost 12 per cent of respondents do not use any form of treatment, while vaccinating for pulpy kidney (11%), resting the animals and shade (22%) and the dosing of sulphur and hypo (80/0) are the most common forms of treatment. Added to this are treatments and dosing with lemon or mixtures of pepper, salt, mustard and paraffin or methylated spirits and brandy or limewater, permanganate of potash, chicory and sugar and many others such as the letting of blood through "a cut under the tail".
Seeing that most of the farmers take preventative measures against the incidence of Nenta poisoning the consequences of Nenta poisoning in the south-western mohair producing area is of greater extent than the numbers indicated in the survey. Should stock have to be withdrawn from certain parts of the farm during specific periods, the effectiveness of the production unit is decreased. Consequently the loss as a result of Nenta poisoning cannot be measured only in terms of the number of animals lost.
It is also apparent that the only sure way of combating Nenta poisoning is to rid the affected camps of the plants by physically chopping them out. In the past a great deal of research was done in connection with the influence of Nenta on the animal itself. Future research will have to be directed more towards the prevention of poisoning.