Last update: January 17, 2011 02:36:46 PM E-mail Print

 

DIPPING OF ANGORA GOATS IN AN OIL-BASED EMULSION TO PREVENT MORTALITIES DURING COLD SPELLS


MA Snyman, PJ Griessel, M van Heerden & MJ Herselman

Grootfontein ADI, Private Bag X529, Middelburg (EC), 5900, South Africa

 


INTRODUCTION

High mortality rates of Angora goats during periodic cold climate spells cause considerable annual monetary loss in the mohair industry. Investigation of the physiological changes preceding death caused by cold stress revealed a dramatic drop in blood glucose concentration (Wentzel et al., 1979). This observation resulted in the widespread supplementation of alkali-ionophore treated grain to Angora goats during cold spells to increase blood glucose concentration and to prevent losses. Recently, it has also been claimed by some producers that by dipping Angora goats after shearing in an oil-based emulsion, losses during cold weather are effectively reduced. During the annual congress of the SA Mohair Growers’ Association, Grootfontein Agricultural Development Institute has been requested to evaluate this technique (Anon, 1997).

 

MATERIAL AND METHODS

Ten one year old Angora wethers were randomly divided into two groups. All animals were shorn and one group was dipped in a mixture of 2500 litre water, 15 litre hydraulic oil, 3 litre Little’s dip, 3 litre diesel and the recommended dose of Dazzle-dip. The control group was dipped in water and the recommended dose of Dazzle-dip. Three weeks after shearing, a cold spell was experienced. All animals were placed in a small camp in shade and drenched by spraying them with water every 30 minutes. This was continued for a period of 5.5 hours. During this period, temperature ranged between 9.5 °C and 16.0 °C. A mild wind caused wet bulb temperatures to vary between 4.0 °C and 10.5 °C. Lucern hay was freely available during the cold spell. Rectal temperature was recorded every 30 minutes. Animals which rectal temperature dropped below 32 °C were removed from the camp and placed in a heated room for recovery. Statistical analyses were performed using the GLM procedures of SAS (Littell et al., 1991).

 

After the results of the first trial were known, a second trial was done to investigate the possible mechanisms through which the maintaining of body temperature by goats dipped in an oil-based emulsion is achieved. For this part of the study, eight Angora wethers were randomly divided into two groups. The groups were dipped in the same mixtures as those in the first trial. The animals were slaughtered one week after dipping. Skin weight was recorded after slaughtering, the skins were submerged in water and weighed again. The skins were draped over wires in a temperature-controlled room (11 °C). Electric fans were used to simulate wind. Temperature on the inside of the skins, as well as skin weight, were recorded every 5 minutes for an hour period. Statistical analyses were performed using the GLM procedures of SAS (Littell et al., 1991).

 

RESULTS AND DISCUSSION

The individual as well as average rectal temperatures of control and oil-based emulsion dipped Angora goat wethers during exposure to cold and wet conditions are illustrated in Figure 1. From these graphs it is evident that although rectal temperature tended to be lower in the control animals, one of these animals maintained normal rectal temperature throughout the 5.5 hours of cold stress. Due to the small number of animals used, the higher mean rectal temperature observed in Angora goats dipped in the oil-based emulsion only reached significance (P < 0.05) 3 hours after commencement of exposure to cold stress.

 

The amount of water retained by and temperature on the inside of the skins of control and oil-based emulsion dipped Angora goat wethers after submersion are illustrated in Figure 2. From these results it is evident that skins of the control group absorbed more water when submerged than those of the treatment group (P< 0.05). Water was lost at a higher rate by the control skins, which resulted in there being no significant difference in water retention between the groups after 5 minutes after submersion. It is also evident from Figure 2(b) that there was no significant difference in skin temperature between the two groups.

a) Individual rectal temperatures

b) Average rectal temperature

Figure 1. Effect of dipping Angora goats in an oil-based emulsion on rectal temperature during exposure to cold and wet conditions

 

 

a) Water retention 

 

b) Temperature

Figure 2. Effect of dipping Angora goats in an oil-based emulsion on a) the amount of water retained by and b) temperature on the inside of their skins after submersion

 

CONCLUSION

From the results obtained in this study it can be concluded that by dipping Angora goats in an oil-based emulsion, the goats are able to maintain body temperature for a longer period of time than untreated animals. Further trials, with more animals, are planned to investigate the mechanisms through which oil-emulsion dipped Angora goats are able to maintain their body temperature at a higher level for a longer period when being exposed to cold spells.

 

REFERENCES

Anon, 1997. Angora Goat & Mohair Journal, 39 (2), 66

Littell, R.C., Freud, R.J. & Spector, P.C., 1991. SAS System for Linear Models, SAS Institute Inc., Cary, NC

Wentzel, D., Viljoen, K.S. & Botha, L.J.J., 1979. Agroanimalia, 11, 19

 

Published

Proc. S.A. Soc. Anim. Prod. 36, 271, Stellenbosch, 5-8 April