Last update: March 30, 2012 11:59:55 AM E-mail Print

 

The Various Kinds of losses among Angora Goats and their Financial Implications

E. M. van Tonder, Veterinary Laboratory of the Karoo Region, Middelburg, Cape


AS in any other type of stock farming, the Angora goat industry is subject to a variety of diseases and parasites which make inroads into its profitability. Losses due to diseases and parasites undoubtedly are the biggest single factor determining the economic viability of any Angora goat farming enterprise. The fact that there are other basic factors such as supply and demand in respect of products and production, as well as marketing costs which also playa role is not questioned in the least, but in a stabilized industry such as the mohair industry these matters are dealt with on a virtually daily basis. It may be claimed that deficient nutrition as a result of erratic rainfall conditions is responsible for the biggest losses in any farming industry and thus also of Angora goats. This is freely admitted, but it also falls within the scope of this discussion, seeing that in certain respects nutrition can give rise to certain diseases and that precautionary measures can be taken to avoid deficiencies. It must also be accepted that in the biological world it is impossible to eliminate losses, including losses due to nutritional conditions, completely. The aim should always be to keep losses at a minimum under all circumstances and at all times.

An established fact that must be lived with is that there will always be some diseases and parasites against which no preventative measures or treatment will be effective. In fact very few diseases and parasites can be totally eradicated in spite of extremely effective vaccines and remedies or other forms of treatment and management. The goal must therefore be to eliminate losses resulting from controllable diseases and to limit as far as possible those against which no or less effective control measures are available. As far as Angora goats are concerned, there are a wide variety of diseases and parasites which must be taken into account. These conditions can be divided into various categories, depending on their cause, nature, transfer, course, incidence and distribution.

In the first instance diseases may be contagious or non-contagious in nature, while the contagious diseases in their turn could be infectious or non-infectious. The cause would also determine if a disease would affect one or more animals simultaneously. The nature of the disease will determine whether it would be systemic or localised in the body.

Diseases and parasites can also be spread and transmitted in various ways from animal to animal. For example diseases may be spread through direct contact, droplets, orally, the presence of hosts, etc. The course of a disease or parasitic infection indicates if it is acute or chronic or if it will be immediately or eventually fatal or non-fatal. The incidence of diseases or parasites may also vary from regular, i.e. daily or annually or sporadic, i.e. at irregular intervals.

In the last instance diseases and parasites may occur throughout the country or may occur only in certain regions, which again is determined by a large variety of factors.

There are a number of diseases and parasites which constantly take their toll of Angora goats both on a regular annual and sporadic basis, a few of which will be named. Those of an infectious nature include the ever-present pasteurella, pulpy kidney, cheesy glandular infection and mastitis in all its forms, while on a sporadic and regional basis diseases such as blindness, heartwater, orf, diphtheria, foot abscess and enzootic abortion are responsible for considerable losses.

The non-infectious diseases which constantly, either on a regular or sporadic basis generally or regionally, cause virtual daily losses of Angora goats include the following: exposure, acidosis, bezoars, swelling disease, nenta poisoning, "waterpens" and "ganskweek" poisoning.

Internal parasites are probably one of the biggest causes of losses among Angora goats and they are exposed to virtually the entire spectrum of internal parasites over the whole farming area. The most important of these parasites are wireworm, brown stomach worm, bankrupt worm, longneck bankrupt worm and coccidiosis.

As regards external parasites, Angora goats are largely prone to infestation with lice, especially the blue louse which in the general nature of things and in spite of regular dipping can cause considerable losses. Apart from the "bont" tick which carries heartwater in certain districts, there is naturally a wide variety of ticks which cause losses.

 

The kind of losses among Angora Goats as a result of Diseases and Parasites

Losses among Angora goats from diseases and parasites can be placed in various categories, depending upon the type of disease and its intensity, i.e. if it is severe or mild, acute or chronic.

Losses which may be suffered embrace the following:

 

1. DIRECT LOSSES

(1) Deaths

Most infectious and other diseases are normally responsible for a variable percentage of deaths. In most cases this percentage, based on a total flock basis, is generally not very high, especially if it is taken over a number of years. Various factors playa role here such as the annual or seasonal tendency of diseases, climatic conditions, susceptibility of the population, age groups, type of disease or parasite in question, general management and so on.

 

(2) Abortion and perinatal losses

These losses embrace the rejection of the embryo at any stage of development, stillbirths, and early post-birth losses, that is to say losses of potential kids. Losses of this nature must thus also be seen as direct losses, considering that kids lost in this way would have been productive under normal circumstances and within reasonable expectations and time.

Once again these losses vary from severe to mild, depending on the cause and time of appearance, i.e. from mating to kidding time and even during the kidding season. These are undoubtedly the causes of the greatest losses in the Angora goat industry. Even though the two types of habitual abortion can be controlled through selection and improved nutrition during the critical period, losses are still generally suffered.

 

2. INDIRECT LOSSES

(1) Decreased kidding percentages

This is apparently also one of the most common kinds of loss among Angora goats. The most common cause can be ascribed to faulty management at mating time and faulty handling of flocks during this time, while another factor could be the use of infertile rams or rams with low fertility.

 

(2) Loss of mohair

These losses are to do with lower production from the living animal, i.e. losses through death are not taken into account here. Losses of this nature are usually caused by low nutritional conditions, diseases not leading to death, especially chronic conditions, parasitic infestation and damage due to external parasites and skin and fleece affections.

 

(3) Loss of weight

Loss of weight due to retarded appetite, and thus decreased food intake, is an inevitable result of any disease or parasitic infestation. Although it is not such an important factor among Angora goats, unless it results in decreased hair production, it must nevertheless not be underestimated. The fact remains that it brings about losses among culls marketed for slaughter.

 

The Economic Implications of Angora Goat Losses

In these estimates it is only attempted to give a conservative picture of the economic losses which could result from losses in the Angora goat industry. These estimates have been compiled using certain suppositions and estimates and are not intended to be an absolutely accurate report. Accurate numbers and statistics are in any event not available. The estimates, as presented, are based on the national flock and no distinction is made between stud and flock animals. Values given for the various products are based on the latest prices and, in order to simplify the calculations, very conservative averages have been used.

According to the information at, the time of writing, Angora goat numbers total 1,6 million, and this figure is used throughout. Based on this total it is accepted that the national flock is made up as follows: 32 000 (2%) breeding rams, 632 000 (39,5%) breeding ewes, 184 000 (11,5 %) young ewes, 272 000 (17%) wethers and 480 000 (30%) unweaned kids.

 

1. DIRECT LOSSES

(1) Deaths

In order to give an idea of what the annual loss to the Angora goat industry is in this respect, estimates are calculated on the following basis;

(i) Deaths among adult goats (including young ewes) are taken at averages of 1,3 and 5% respectively, which experience has shown is not excessive. Deaths among kids (unweaned) are usually higher and the estimates are calculated on averages of 3, 5 and 10 per cent respectively.

(ii) The values taken on a flock basis are as follows: Rams - R400; flock as well as young ewes - R50; culls - wethers and ewes (slaughter value) - R25 and young kids - R35. Based on these figures, the possible losses are shown in Table 1.

 

 

(2) Abortions and perinatal losses

Although these losses are regarded as a direct loss and that it can be assumed that the kids would have reached maturity, the value of these losses are based on kid prices in order to comply with the conservative approach.

Calculations are based on the assumption that 80 per cent of the adult ewes became pregnant. Losses in respect of abortions and perinatal losses are also calculated on averages of 3, 5 and 10 per cent respectively and are given in Table 2.

 

 

2. INDIRECT LOSSES

(1) Decreased kidding percentages

Although it is generally accepted that the Angora goat has a low fertility potential, this is not the case and repeated tests have shown that where mating management is correct, the conception rate will equal that of any other breed at any time.

For calculation purposes it is assumed that every adult ewe will produce a kid. Earlier it was accepted that 80% of the ewes would become pregnant, that is to say provision was already made for a 20 per cent loss on conception.

If the calculations are based on a 100 per cent conception rate and the averages are decreased by 3, 5 and 10 per cent, the potential losses, calculated at kid values (R20,00), will be as set out in Table 3.

 

 

(2) Loss of mohair

There is hardly any disease or parasitic infestation which will not adversely affect hair production. The fact is that any condition which in any way affects food intake and the body's metabolism will inevitably lead to a decrease in hair production.

Seeing that conditions such as internal parasites are particularly common and it is well known that they can lead to a considerable loss of hair in a very short time, it is a problem which requires constant attention. Relatively heavy infestations can lead to a decrease in food intake of as much as 50 per cent in six weeks, while light infestations can cause hair production to decrease by 16,7 per cent in 3 months.

Assuming that only 50 per cent of the goat population will be affected in this way and an estimated 0,5 and 1 kg is allowed respectively, the financial loss would be as given in Table 4.

 

 

For the purpose of simplification, an, average price of R7,00 per kg for all adult goats and R10,00 for young ewes is taken. Unweaned kids have not been taken into account, even though they would have been shorn once or even twice during the course of a year.

 

(3) Loss of Mass

Although meat production from Angora goats is regarded as unimportant at present, it is nevertheless a source of income which should be taken into account. In the calculations which follow it is accepted that approximately 15% wethers and 11 % old ewes will be marketed for their meat annually. Loss of mass is a direct result of any disease or parasitic infestation because food intake is always more or less affected. For example it is known that mild parasitic infestations can cause a decrease in mass of as much as 3,5 kg in 3 months.

In order to illustrate the implications of loss of mass as a result of diseases and parasites it will be accepted that only 50 per cent of the marketable goats are affected and that a loss of mass of 1 kg is involved. An average price of R2,00 per kg will be used as is shown in Table 5.

 

 

Total losses

The total annual losses which could be suffered by the Angora goat industry as given in the previous estimates are set out in Table 6.

 

 

General remarks

The foregoing estimates are not only applicable to the national flock, but also furnish a basis for the calculation of losses in individual flocks.

Smaller losses such as losses in the quality of hair and losses in skins and the quality of skins have not been taken into account.

Should a prevention programme be adopted, which at present is estimated to cost plus minus R1,80 per goat, it would mean that the cost in respect of the national flock would work out at R2,88 million. In order to avoid a minimum loss of R10 million this would not be a bad investment.

 

Published

Angora goat and mohair journal 25 (2)