Scientific Research Projects: Keeping Mohair In South Africa At The Forefront

Ray Hobson

Research is a mandatory function of Mohair SA and research projects are conducted to help resolve perceived or real problems in the production and processing of mohair. They are conducted scientifically under the auspices of the Research Committee of Mohair SA and with the full participation of Onderstepoort Veterinary Institute, Grootfontein Agricultural Institute at Middelburg, the CSIR in Port Elizabeth, the University of Stellenbosch or the Agricultural Research Council of South Africa.

A summary of some of the research programmes being conducted at the moment includes:

 1.         A comparative study of the healthcare and wellness related properties of mohair

Project leaders: AF Botha and L Hunter, CSIR

This research is aimed at comparing the wellness and healthcare related properties of mohair, a relatively expensive fibre, to those of other natural and man-made fibres (which are generally cheaper than mohair) with a view to establishing the comparative advantages of mohair in terms of these increasingly important consumer and niche product requirements.

The research could also serve as a basis for further exploration and identification of the protein molecule responsible for  the antibacterial properties of mohair and how this can be  further accentuated.

Although considerable research has been done and data generated on the physical and mechanical properties of mohair and textile fibres in general, little work appears to have been done on the wellness and healthcare properties of particularly mohair. More and more, consumers around the world are becoming aware of and demanding wellness and healthcare qualities in their clothing and in automotive textiles. In addition, more consumers, particularly those in affluent countries, are demanding products which do not harm the environment.

However, there is little scientific evidence to back up and promote the perceived benefits and advantages of mohair. If scientific evidence can be produced of the wellness and healthcare related properties of mohair, such as water and water vapour transportation; absorption and release dynamics; and wetting, wicking and antibacterial properties, it will be possible to establish specific applications and end-uses for mohair in which the fibre can out-perform other cheaper fibres.

Another area which appears to hold promise for mohair is that relating to bedridden and physically handicapped persons who spend a great deal of time in bed or in a (wheel)chair. If such persons do not have specifically designed mattress and wheelchair covers that help spread the weight of the body over a large area, thereby reducing the pressure points, they will develop pressure sores. This research is in the project stage and results will only be known late in 2011/2012.

2.  The development of a genetic marker for the identification of more hardy Angora goats in South Africa in respect of cold stress

Team leaders: G Snyman and Prof P Swart

This project is aimed at identifying a genetic marker for more hardy Angora goats and to use that marker in a breeding programme in order to breed hardier goats. Previous research  has shown that the Angora goat is unable to produce enough cortisol (the adrenal steroid hormone released in response to physiological stress) in response to cold stress. This has been investigated in terms of adrenal steroidogenesis, and a single enzyme, cytochrome P450 17 hydroxylase/17, 20 lyase (CYP), was identified as the probable cause of the problem. During the study, two CYP 17 genes with significantly different activities were identified. The one CYP 17’s genes inability to produce cortisol precursors has been demonstrated to be the probable cause of the observed hypocortisolism

Three unique genotypes were subsequently identified, and a rapid and accurate genotyping method has been developed, for the purpose of identifying hardier goats for breeding. An insulin-induced stress experiment was carried out on the experimental farm at Jansenville, which revealed that the ability to produce cortisol in response to physiological stress is significantly different for each of the three different genotypes. This was followed by a breeding programme in collaboration with Dr Gretha Snyman of GADI. Two generations of kids have been born from this programme. These have been genotyped to determine whether the pattern of inheritance we have proposed is correct. The mohair produced from genotyping the goats was investigated and no significant differences were found.

The final work in terms of this programme involves analysing samples from the stress test performed at GADI, where cold and wet conditions were simulated under veld and kraal conditions.

 3. Mohair lustre measurement

Project leaders: L Hunter and AF Botha, CSIR

This project explores the possibility of identifying and of developing a cost-effective method for the routine and accurate measurement of mohair lustre, preferably on-farm and at-brokers.

Research is underway at WSU (Walter Sizulu University) and NMMU, in the endeavour to establish which particular fibre surface characteristics – for example, scale structure and roughness – provide a good measure of mohair lustre. If such surface characteristic(s) could be identified, ways could then be sought by which such characteristic(s) can be measured quickly and accurately. One such a method of measurement might be a high resolution image analysis, based on the concept embodied in the OFDA instrument.

 4. The evaluation of a frozen semen protocol for Angora goats in South Africa

Project leader: Dr G Snyman, in co-ordination with Ramsem and Angora Goat Breeders

The aim of this project is to evaluate the frozen semen protocol for implementation in the Angora goat industry, through which superior genetic material could be distributed in the industry on a large scale.

 The background

A project on the evaluation of a protocol to successfully freeze Angora goat semen was implemented in 2007. There were variable results in terms of freezability and durability. The results – at three localities – of the laparoscopic insemination of ewes with the frozen semen pellets were 22,6%, 39,8% and 51,5% of ewes that kidded per number of ewes that were inseminated.

The above results were discussed during the Angora Goat Research Advisory Committee meeting held on 12 August 2010 and the following recommendations were made:

Further work needs to be done on the protocol. A new freezing agent should be evaluated with the aim of improving the durability of the semen and also the number of pellets that can be frozen per sire.

The possibility of using trans-cervical insemination instead of laparoscopic insemination should be investigated, as this option will be cheaper for producers.

The nutritional management of sires should be resolved.

The objectives of the continued part of the project are to:

• evaluate the effect of melatonin implant in Angora rams on the freezablity of semen outside the breeding cycle;
• evaluate the viability of semen frozen inside and outside the normal breeding season via laparoscopic insemination, in terms of the kidding percentages obtained;
•  freeze semen in pellets and straws;
• evaluate the viability of semen frozen in pellets vs. that frozen in straws via laparoscopic and trans-cervical insemination respectively, in terms of the kidding percentage obtained.

The seasonality of Angora goats still poses a problem for the large-scale implementation of a semen freezing programme  in the industry. Superior sires will not be available to the  programme if semen-freezing can only be done during the normal breeding season.

 5. Maintenance of a biological bank for Angora goats in South Africa

Project leader: MA Snyman

A project aimed at the establishment and maintenance of a DNA bank for Angora goats was initiated in 2004 at the Grootfontein Agricultural Development Institute (GADI), involving three Angora producers and the experimental herds at Jansenville Experimental Station. To date, blood samples have been collected from 10 480 animals and stored in the Angora Goat Blood and DNA Bank and all the phenotypic data recorded has been entered into the database. There are already three research projects that have obtained blood and DNA samples as well as phenotypic data from the bank.

During 2006/2007, the DNA bank project was extended to include an investigation into the longevity of Angora ewes. This part of the research will take place over a ten-year period.

The programme, Establishment of the South African Biological Reserve for Small Stock Research and Conservation, driven by the Department of Agriculture, Aquaculture and Fisheries, has been implemented at GADI. The aim of the programme is twofold – to promote the improvement of the South African sheep and goat population, and its conservation. The Angora Goat DNA Bank Project now forms part of the bigger programme.

The above is a glimpse of the research projects currently being supported with grower’s funds in the interest of solving production problems and attempting to find new markets.

 6. Swelling disease

Project leader: JA van Rooyen, GADI

Outbreaks of swelling disease still occur periodically and Angora goat producers are still suffering some losses. No definite cure  is known; various farmers administer different treatments, not all  of which are always successful. The aim of this study is to identify the causative agents responsible for swelling disease in South African goats.

From all the information available on swelling disease in Angora goats, it is evident that it is a complex condition, and that little is known about the mechanisms involved in the origins of the disease and the course it follows. 

Results obtained thus far with the present study, indicated that although Teledorsagia circumstancta (brown stomach worm) infection has been listed as one of the predisposing factors for the disease, it alone cannot cause it.

The results of the study further indicate that higher dietary protein levels could possibly help prevent swelling disease. In a questionnaire investigating the epidemiology of swelling disease, 65% of the respondents reported having encountered swelling disease on their farms, while 35% had never encountered or seen the disease. A few cases of swelling disease were reported during this period, with only one serious outbreak. The standardised battery of tests was applied to this outbreak. However, there will have to be further cases before a statistically meaningful analysis can be done.

 It seems unlikely that there will be a simple solution to this complex problem. The prevention of swelling disease should therefore rather be based on a multidisciplinary flock health management approach.