Effect on Mohair quality traits
By Dr Mackie Hobson BSc(Agric),BVSc

1. Nutrition

Extracted from research by Margaretha A Badenhorst, J C Diedericks & P A Schlebusch (Grootfontein College of Agriculture, Middelburg Cape) and N M Kritzinger (Mohair Board)

As a natural fibre, mohair has certain unique qualities (probably the most important of which is its unparalleled lustre) which make it very sought after. The quantity and the quality of mohair play vital roles in this. For this reason it is logical that, over the years, in the selection of breeding animals, strong emphasis has been placed on both quantity (amount of mohair) and quality (fineness, style and character, lustre, length, etc).

The question arises whether those goats which perform ideally under optimum nutritional conditions, will maintain their performance under less favourable conditions. This trial was therefore aimed at investigating the effect of the level of nutrition on the most important quality traits of mohair.

 Experimental procedures

The investigation was carried out at the Grootfontein College of Agriculture over a period of six months.

• Group 1 (High level = HL) received a pelleted ration consisting of 10 per cent mealies, 10 per cent molasses and 80 per cent lucerne,
• Group 2 (Low level = LL) received a much less nutritious ration of 70 per cent milled lucerne plus 30 per cent milled wheat straw.

Linear score card for subjective assessment of various mohair characteristics in Angora goats

Results

• Except for fibre diameter, no significant differences occured between sexes in respect of any of the traits measured.
• In both groups the average fibre diameter of the ewes was two micron stronger (P

The effects of level of nutrition on the various mohair qualities are presented in Table 2.

 TABLE 2. Effect of nutrition on the linear score of various characteristics in Angora kids

** Significant (P

ns Non-significant

From Table 2 it is clear

• HL-group maintained better gains and eventually weighed on average approximately 60 per cent more than LL-group.
• Mean mohair production of the HL-group was 78.7 per cent higher,
• HL-group  average fibre diameter 30 per cent stronger (39.7 vs 30.7 micron) than that of the LL-group.
• HL-kids had significantly (Pless facial and neck hair covering.
• In respect of character, HL-animals were inclined to be over-curly when compared to the much straighter hair (P
• Fleece density and kemp content (as scored subjectively) were both significantly higher in the HL-group.
• Style and evenness of fleece, however, did not differ significantly between the two groups.

Conclusions

With the exception of style and evenness of fleece, nutrition appears to have a substantial effect on all the important quantitative and qualitative characteristics of mohair production. The selection of breeding animals based on these qualities can therefore be effective only if all the animals receive the same nutritional treatment. Similarly, the pronounced effect of nutrition, as displayed in this trial, signifies that between-flock comparisons should be treated with great caution. Superior character, for example, may be the result of a high nutritional plane, but when such animals are subjected to nutritional stress, this "quality trait" may largely disappear.

An important finding of this study was that style and character are affected differently by the level of nutrition. This is in accordance with the results of another investigation, into the repeatability of style and character between successive shearings, where it has been found that style has a much lower repeatability than character when measured at 10 and 18 months of age. These findings suggest that style and character cannot be regarded as one combined quality or trait, but must rather be assessed as two separate traits.

References

EFFECT OF NUTRITION ON CERTAIN MOHAIR QUALITY TRAITSS

argaretha A Badenhorst, J C Diedericks & P A Schlebusch

Grootfontein College of Agriculture, Middelburg Cape, 5900

N M Kritzinger

Mohair Board, P O Box 2243, Port Elizabeth, 6056

HARVEY, W R, 1990. Mixed Model Least-Squares and Maximum Likelihood Computer Program. Walter R Harvey