Cold (Hypothermia) and the Angora goat

Friday, 15th September 2017

THE incidence of losses among Angora goats during periodic cold spells is a problem faced by all Angora goat farmers. An estimated 60 000 to 70 000 goats died from exposure to cold conditions over a ten year period from 1997 to 2007

A lot of research has been conducted over the years into the aspect of cold, wet and windy conditions due to these losses.

How cold and wet must it be for deaths to occur?

Investigating historical weather patterns when Angora goat deaths occurred Rowswell deduced that a criterion of ≥ 5 mm rainfall and ≤10° C average daily temperature were threshold levels that increased the probability of goats dying of hypothermia.

 

What farmers do to reduce these losses?

  1. Place goats in a shed – it is vital to keep the goats DRY and OUT OF THE WIND to reduce the chilling factor.
  • Care needs to be taken when sheltering the ewes with kids during a cold rain as overcrowding will lead to kid deaths. No more than 150 ewes should go into a 9x4m shed and adjoining kraal.

The smaller the shed the fewer kid mortalities. The ideal situation would be small sheds with  housing about 20 ewes but is not always practical.

  1. Feeding these goats is critical (nutritional stress reduces blood glucose by 28% and cold stress by 65%)
  • Some form of roughage such as lucern hay
  • Energy in the form of ‘chocolate mielies’ (See options at end of article)

Why is feeding a cold Angora goat so important?

 

The goats are often placed in sheds in cold weather without feed. We already know from research that nutritional stress causes a drop of approximately 28% in the blood glucose concentration of Angora goats. It is also noteworthy that the blood glucose concentration of cold goats decreases by 65%.

Wentzel  conducted a trial where  mature pregnant and young (two-tooth) shorn Angora does were subjected to cold (0-5°C), wet and windy conditions. According to the results:

  • Mature pregnant goats withstood the cold much better than the young animals. 40% of the mature ewes endured the cold treatment for a period of 48 hours. The first mature goat collapsed after 12 hours of cold treatment.
  • Young goats (two-tooth)- the first goat collapsed after only 4 hours, while all collapsed after 12 hours of cold treatment.
  • The rectal temperature of the goats which withstood the cold stress of the 48 hour experimental period, remained relatively constant at approximately 38,9°C.The goats which collapsed the rectal temperature decreased to approximately 34°C.
  • The blood glucose concentration of the experimental group showed an initial increase from 47 mg% to 82 mg%. Thereafter it decreased rapidly to a minimum of 22 mg% at the point of collapse.

Treatment of the collapsed experimental goats by intravenous glucose resulted in the rapid recovery of the cold stressed goats.

  • Within approximately 4 hours after this treatment these animals had recovered to such an extent that they could get up, and after about 12 hours no differences could be observed between these and the animals of the control group. (Wentzel, Viljoen & Botha, 1979).

 

Giving intravenous emergency glucose treatment is obviously not a practical way for farmers to treat the problem so researches looked at raising the glucose levels via nutrition.

Nutrition to increase the blood glucose levels.

Trials prove that the increase in circulating glucose is directly related to the amount of starch ingested by the goat (Wentzel, 1980)

 The feeding of high starch diets has some serious risks if Angoras are not adapted to high concentrate diets and can result in:

  • acidosis
  • clostridial bacterial overgrowth leading to ‘Rooiderm’ and ‘Bloednier’.

 

Research conducted with the aim of overcoming the problem of acidosis led to the development of ‘chocolate milies’. Alkali-ionophore-treated whole grain (commonly known as chocolate grain - Wentzel, 1982, 1983) which prevented acidosis in goats not previously adapted to the diet.

 

  • Goats having access to this treated grain showed average increases of 50-60% in circulating glucose levels within 48 hours after offering the grain.
  • Of special significance was the finding that already within 4 hours an average rise in blood glucose of 12% occurred.

 

During cold spells the timeous and rapid increase of the energy status of the cold stressed goat, achieved in this way, could be a crucial factor to prevent serious losses.

 

 

A Long term strategy?

 

A long term solution is to select a hardy Angora goat that is best adapted to survival during these cold snaps.  Snyman, Storbeck, Swart in their research suggested that the Hu genotype is the most susceptible to cold stress while the He genotype was the most likely to survive during cold periods. Angora goats farmers could cost effectively select their rams with the He genotype. It has been shown that selecting for this genotype will not influence other production parameters negatively.

See the Article under the Reproduction section of our web page

https://www.angoras.co.za/article/selecting-for-hardy-angora-goats#243

The importance of nutrition during periods of cold must not be underestimated (critical in preganant Angora ewes to prevent abortions) but the long term solution may be the selection of a ‘hardy’ Angora goat.

Other research done to protect goats during cold weather.

 

Oil-based emulsion

In order to form some sort of protection against the elements trials where dipping Angora goats in an oil-based emulsion enabled the goats to maintain body temperature for a longer period of time than untreated animals were conducted by MA Snyman, PJ Griessel, M van Heerden & MJ Herselman (GADI) 1997.

 

Ripstop coats.

Coats made from Ripstop proved that Angoras wearing the coats had rectal temperatures which dropped by 2.21C less than those goats not wearing coats (M.A. Snyman).

 

 

Also see article on Treating a Cold (hypothermic kid) under the Reproduction section of our website

 

Nutrition to increase blood Glucose levels

 

  1. ’Chocolate mielies’

First mix smallest ingredients in water then molasses powder then mielies.

First feed 50g per day  then 100g for 3 days then 200g for 3 days.

Normally feed no more than 350-500g/day

Urea can cause problems in pregnant and lactating ewes so preferably exclude

Ingredients

kg

Feed %

Mielies

70

76.8

water

6

6.5

Salt

5

5.5

Sunflower oil cake     (Optional)

4

4.5

Molasses powder

3

3.3

CLC lime or cement

2

2.2

Urea                           (Optional)

1

1.1

Epsom salts

100g

0.1

Monensin

12g

 

 

  1. Energy Lick

 

Intake should be less than 270g per 50kg body mass to limit salt intake

 

 Ingredients

% of lick

Mieliemeel

76

Molasses

8

Feed lime

1

salt

15

 

 

Dr Mackie Hobson

(SAMGA Vet)

 

 

REFERENCES

  1. ROWSWELL .Weather related danger regions in the Angora Goat Industry. Agrometeorology, SIRI.Grootfontein College of Agriculture

VAN HEERDEN, K.M., 1963. Investigations into the cause of abortions in Angora goats in South Africa. Onderstepoort J. Vet. Res. 30, 23.

VAN RENSBURG, S.J., 1963. Endocrinological aspects of habitually aborting Angora goat ewes. S. Afr. med. J. 37, 114.

WENTZEL, D., 1973. The habitually aborting Angora doe; Recognition and endocrinology of two types of abortion. Ph.D.(Agric.) thesis, Univ. Stellenbosch.

WENTZEL, D., 1982. Alkalinization of grain for high energy feeding of cold-stressed Angora goats. Proc. 3rd Int. Conf. Goat Prod. & Disease, Tucson, Arizona.

WENTZEL, D. & BOTHA, L.J.J., 1976. Steroid function in nutritionally stressed pregnant Angora goat does. Agroanimalia 8, 163.

WENTZEL, D., LE ROUX, MARITA M. & BOTHA, L.J.J., 1976. Effect of the level of nutrition on blood glucose concentration and reproductive performance of Angora goats. Agroanimalia 8, 59.

WENTZEL, D., VILJOEN, K.S. & BOTHA, L.J.J., 1979. Physiological and endocrinological reactions to cold stress in the Angora goat. Agroanima

 

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