Last update: April 2, 2012 09:38:17 AM E-mail Print

 

PASTEURELLOSIS: KILLER OF ANGORA GOATS

EM van Tonder 


Pasteurellosis is one of the biggest killers amongst the infectious causes of disease in Angora goats, said Dr E M van Tonder, Chief of the Regional veterinary Laboratory, Middelburg Cape, in an address given at a Flock Competition Day organized by the South African Mohair Growers' Association at Cradock on 21 May.

It is not only responsible for high losses in kids, but also in adult goats. Apart from causing the common syndrome, pneumonia, Pasteurella organisms are also the most important cause of blue udder (mastitis), which can sustain heavy losses in young suckling kids as a result of starvation and/or mismothering.

He urged farmers to have all suspected cases investigated or examined in order to have the particular Pasteurella strain involved identified, so that, if not provided for in the existing vaccine, a special vaccine is made.

Other more common infectious diseases discussed by Dr van Tonder included: pulpy kidney, post-parturian clostridial infections, corynebacterial brain absesses, foot absess, colibacillosis and heartwater.

 

Internal parasites

With regard to internal parasites, brown stomach worm, bankrupt worm, and particularly coccidiosis constitute the most important ones responsible for weight and mohair losses, as well as kid losses.

Replying to a question on swelling disease, Dr van Tonder explained that although the cause of this dramatic disease is still enigmatic. The whole mechanism of the disease has now been elucidated and further experiments are in progress. Trials with the object to incriminate brown stomach worm in the aetiology of this condition have thus far proved to be negative, but will have to be repeated.

Although the incidence of animals affected by swelling disease can be alarmingly high. He pointed out that, in general, the mortality rate is very low. Good nursing and sheltering of affected animals usually cause symptoms to disappear overnight.

 

Abortion

In the field of reproduction, so-called habitual abortion still remains the most prominent problem, but has to be clearly differentiated from other types of abortion such as caused by infections, like enzootic abortion, Rift Valley fever, Wesselsbron disease, etc.

One of the distinct types of habitual abortion caused by hereditary hyperactivity of the maternal adrenal gland and characterized by the expulsion of oedematous foetuses can however be easily recognized. In this case culling of aborter ewes has proved to be the only practical way out.

On account of the diversity of causes that may be involved, it will always be advisable to have all incidences of abortion investigated for an accurate diagnosis.

 

PERFORMANCE TESTING

Speaking on the genetic improvement of Angoras, Mr Gert Erasmus, Chief of the Fleece Testing Centre, Middelburg Cape, predicted that the adoption by the Angora Breeder's Society, and the consequent implementation, of the proposed performance-testing scheme will in time to come prove to be the most important development in the Angora goat industry. He said that animal breeding should not be regarded as an art but as a science. It is, however, not an exact science and should, therefore, not be practised by people who tend to be dogmatic. The recording and processing of production data is the cornerstone of modern breeding practices and the implementation of performance testing will immediately put science to work for the Angora goat breeder.

 

Selection of breeding stock

The Angora goat, like other breeds of livestock, is a sexually reproducing species and consequently difficult to improve by breeding, because the offspring always tend to revert back to the average of the unselected flock. All possible aids should, therefore, be exploited. Although immediate progress may be slight, selection can lead to dramatic long-term changes. Selection does not necessarily lead to greater uniformity and uniformity as an aim in breeding is completely unrealistic. Our aim in breeding should be simply to raise the average of the flock or stud. Selection of rams should be done with great care, as the ram is responsible for most of the breeding progress. Breeders should be strict on goats that do not fulfil their basic function, namely to reproduce. One cannot shear a goat that has not been born.

 

Published

Karoo Regional Newsletter Winter