1. The first phase, which started in May last year, has already been completed. This phase contained basic research designed to prove that the method will work in African elephant. Ovaries were collected from dead elephant cows during 1995, processed, and reacted with antibodies raised in rabbits against pZP. The results were strongly positive, showing that the method should work in African elephant.
   


2. During the second phase, which is ongoing, the vaccine was tested in three zoo elephant in the USA and Canada. This was to establish the dose of vaccine required and to test the response in terms of antibody formation. Two of the animals tested so far, one of which was first vaccinated a year ago, have shown an excellent response.
   


3. The third phase, which is the field trial in the Kruger National Park, has just been successfully launched. A total of 41 non-pregnant adult cows were randomly selected in the Skukuza, Malelane and Lower Sabie areas. The cows were selected from the air in a helicopter on the basis that they had small calves at foot. The chances that such animals would be pregnant were thus much smaller. Confirmation of the non-pregnant status was carried out by means of transrectal pregnancy diagnosis, performed by a German group of scientists from Berlin, on the immobilised cows. Twenty-one cows were fitted with radio-collars and vaccinated with 600 µg pZP each (Treatment Group). The other twenty were marked with plain collars and will serve as the Control Group. As the latter group were injected with a placebo, they should reproduce normally.

In November 1996 and in June 1997 a booster vaccination will be administered remotely from a helicopter by means of a dart to each of the treated cows. In June 1998 half the treated cows will be re-vaccinated.

Both the treated and control animals will be monitored on a regular basis by the Parks Board to observe the cows for behavioural changes and side-effects of the vaccine, although these are unlikely to occur. Because of the long gestation period of 22 months in African elephants, Phase 3 will last 5 years. Only then, if pregnancy and calving has been delayed in the treated group, will the research team be able to declare the method successful. Dr Kirkpatrick and co-workers are investigating a non-invasive faecal pregnancy detection method on the faeces of African elephant. If successful, the method, which is based on monitoring hormone metabolites in faeces , will provide some information on the contraceptive action of the vaccine as early as 1998.

The team of investigators would like to stress that, at this stage, they are merely investigating immunocontraception with pZP vaccine as an alternative to culling in African elephant. We would not like to create the perception that this should be seen as the answer to population control in African elephant.

The project is being funded by the Humane Society of the United States.

2. CAPTIVE BREEDING OF DISEASE-FREE BUFFALO

The buffalo population in South Africa is concentrated in a few areas. These are the Kruger National Park (KNP) and the Kwazulu-Natal Parks. The animals in these areas are genetically fairly closely related and are phenotypically superior, especially as trophy (hunting and photographic) to the other populations in the country. The remaining buffalo in South Africa occur in small numbers in national, provincial and private conservancies. Genetically, the majority of these buffalo are of the Addo type but, especially in many of the private conservancies, the ancestry is largely unknown, with some of the original animals having come from zoos overseas.

Disease-free buffalo have become a much sought-after item in SA. Sales of animals in 1996 resulted in record prices of over R 60 000 per buffalo, which clearly reflects the value of this commodity. The reason for the the inflated prices is the availability of disease-free animals. These occur in small numbers and only outside the KNP and most of the Kwazulu-Natal Parks. They are also genotypically and phenotypically inferior.

The diseases that prevent the sale and movement of buffalo out of the major parks are Foot and Mouth Disease (FMD), which is endemic in the buffalo of the KNP, and Corridor Disease, which is found in buffalo of both the KNP and the Kwazulu-Natal Parks along the east coast of Kwazulu-Natal. Neither of these diseases are of clinical significance to the affected buffalo populations - they are subclinical carriers but, as such, would pose a major risk to production animals if they were to come into contact with them.

During the last couple of years another disease has established itself in the buffalo of the KNP. This is bovine tuberculosis. Recent surveys in culled buffalo have revealed an extremely high prevelence rate of over 80 % in the southern half of the KNP. Although the impact on the buffalo population is as yet unknown, it could turn out to be disastrous. Unfortunately, it is not only the buffalo themselves that are at risk but a number of other species in the food chain. A number of predators have been found to be heavily infected with TB, with the most likely source of their infection having been the buffalo which they preyed upon.

The intention therefore is to obtain both semen and embryos from the KNP and, by using this genetic material, to upgrade the buffalo populations outside the parks.

Heterologous transfer of buffalo embryos to cattle has so far failed on account of the small numbers of embryos available for transfer at any one time. The only practical way to overcome the problem is to opt for in vitro fertilisation of oocytes harvested from the ovaries of buffalo culled in the National Parks. The goals for this project are therefore to:

1. Develop the basic techniques in cattle that can then be applied to buffalo
   


2. To establish a buffalo semen bank for the purpose of IVF. At the same time, the semen could be marketed commercially provided that the semen stems from animals of excellent genetic quality
   


3. Once the IVF method yields results in buffalo, large numbers of embryos will be frozen for storage. When a sufficiently large bank has been built up, interspecies transfer to other buffalo, cattle or Water Buffalo can commence. Whenever buffalo recipients outside the Parks can be found these will be used in preference to other species
   

Currently we are busy with two projects. The first is to prove that buffalo that are serologically positive for FMD virus do not harbour the virus in the semen, and the second is to develop a management system which will allow us to handle buffalo on a regular basis without stressing them. The first nine buffalo semen samples from the KNP tested for FMDV were found to be negative. Many more samples are needed before we have the final proof, however. We have also designed and built a special crush, which has been tested in cattle, for buffalo. At the moment it is being built into a buffalo boma system.

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3. BLACK AND WHITE RHINOCEROS

Breeding of black and white rhino should be a priority of the group because of the seriousness of the rhino situation in Africa. In just over a decade the number of black rhino have been reduced from over 15 000 to a meagre 3 500. Even the Kruger National Park is not exempt from poaching and recently four white rhino were killed close to Pretoriuskop.

The goals of this project are:

1. To establish a method for faecal hormone assays.
   


2. To use these assays to establish the oestrous (heat) cycle of cows, especially during lactation;
   


3. Once this pattern has been established, to attempt manipulation of the intercalving period;
   


4. To develop our own expertise regarding optimal management and breeding systems for the reproduction of rhino in captivity, and
   


5. Where necessary, because the animals cannot breed naturally, to employ biotechnology for breeding captive rhinos.

For basic studies, wild living and zoo populations will be used. However, it is essential to acquire and breed rhinos at Onderstepoort. Kwazulu-Natal Parks Board may be prepared to supply us with rhinos on a loan basis. In the case of captive animals that do not breed we will first attempt to establish the cause thereof and to correct this where possible. Systems that are successful in the breeding of rhino in captivity locally and overseas will be studied in order to establish optimal breeding management systems.

Biotechnological techniques will rather be used as a last resort to breed animals unless these methods can be made perfectly safe to use in terms of the animals involved. Unnecessary immobilization of rhino should be avoided where possible. In any case, most immobilisation drugs have a negative effect on the reproductive system.

In October 1994 we sucessfully induced heat in a white rhino cow using a norgestomet (Crestar) subcutaneous implant. The cow was served naturally at induced heat and produced a healthy calf 17 months later on 16 May 1995. The procedures used to induce heat were all carried out with immobilisation of the rhino cow. We are now building a housing system which will hopefully allow us to handle and treat rhino cows with a minimum of immobilisation.

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