Natural fibres

Natural fibres

Natural fibres allow the skin to breathe more easily than most synthetic fibres, and have a less harmful impact on the environment.
These fibres come directly from plants or animals. They include wool, cotton, linen, hemp and silk (from the cocoons of silkmoth caterpillars that feed on mulberry leaves).

• Natural fibres wick water and sweat away from the skin, so they are more breathable than synthetic fibres

• Natural fibres are usually easier to dye than synthetic ones, so fewer chemicals are needed to manufacture them

• Natural fibres will rot away. You can even put discarded clothes on the compost heap

• Natural fibres are made from renewable resources that can be re-grown. Synthetics are made from oil, which cannot be replaced once it has been used

Wool can save our planet

Wool can help save the planet

Wool is the ideal fibre to help reduce global warming. 

According to international research, a household can significantly reduce its carbon emissions by living with wool: insulating with wool, wearing wool, walking, sleeping and sitting on wool. The European Commission reports that a household can cut its CO2 emissions by up to 300kg a year and energy bill by 5-10% simply by reducing its heating by a mere 1°C.

Wool has an important role to play as part of the everyday carbon solution.

Wool is a planet-friendly fibre made from the simple combination of sunlight, water and grass. It is made of up to 50% carbon, stored in a stable form. It is renewable, has the ability to biodegrade without harm to the environment and can be recycled.

Furthermore, it takes significantly less energy to produce wool products than man-made fibre products, and this ensures CO2 emissions are kept very low. Therefore, the increased usage of wool can positively reduce the level of greenhouse gases in the atmosphere. Wool also gives advanced and developing countries alike the opportunity to reduce their reliance on fossil fuels. 

Winter Grazing - Sweetveld and Sourveld

Winter Grazing

How can existing forage resources be used for winter grazing?

Veld in certain areas on a farm might provide useful, cheap, grazing for winter. The mountaintops and higher slopes on a farm might be sourveld, and thus not much use for winter grazing, but there could be areas of sweetveld in the warm, drier river valleys.

 The livestock could graze the sourveld (photos left)  in summer and be moved into the sweetveld areas for winter. 

Crop residues can also provide useful grazing for winter. Wetland and floodplain areas near to rivers are valuable sources of good quality forage for domestic livestock or antelope in wildlife areas, especially during winter when forage may be scarce.

They tend to have more fertile soils than the surrounding veld and remain moister than veld during the dry season. They may be the only source of forage during very dry years, especially in the dry sweetveld areas where droughts are common. Because wetlands and floodplains are such important forage resources they need to be looked after carefully to ensure they are not destroyed through erosion or too much cultivation.

What is the difference between sweetveld and sourveld?  

The main difference between sweetveld (photo right) and sourveld is that in sweetveld areas the quality of the forage available to livestock in winter is usually good but in sourveld areas the quality of the forage during winter is poor. 

Good-quality forage is nutritious because it contains high levels of energy and nutrients that animals need, and can be easily digested by animals. Poor-quality forage is not very nutritious because it is difficult to digest and does not contain many useful nutrients.

Tips for Drench Resistance - Worm Management

Worm management

The 4 key principles of worm management everywhere:

1. Do regular worm egg counts

2. Know your drench resistance status

3. Maximise non-chemical worm management

4. Seek professional advice

What Causes Drench Resistance?

• Drench resistance is caused by exposing worms to several treatments of same drug
• This can kill susceptible worms but leaves increasing numbers of resistant worms
• The resistant worms are genetically different to susceptible worms
• Resistant worms pass on their resistance to future worm generations
• The practice of drenching sheep onto clean pastures with drenches that are not 100% effective leads to the rapid development of resistant worm populations.

How Quickly Can Drench Resistance Develop?

The rate of development of drench resistance is influenced by factors including:

• The chemical group and persistency of the product involved
• The frequency of treatments
• The timing of treatments
• The worm species involved
• Environmental factors

 ·         The earlier you detect resistance, the EASIER IT IS TO MANAGE

·         UNNECESSARY DRENCHING is the major cause of drench resistance

There are several effective non-chemical ways to control worms.

Some management tools are:

• Cross-Grazing with Cattle;
• Buying Rams from studs that breed sheep resistant to worms;
• Using “Smart Grazing”;
• Managing Nutrition to help sheep develop resistance to worms.

Pneumonia infections in sheep

Pneumonia infections in sheep may present in some cases as chronic or acute symptoms resulting in

death.

More often, young and unvaccinated sheep that have not been vaccinated for some period, may become infected. Poor hygiene conditions may often also have an additional impact in this condition. 

Certain conditions e.g. weaning, transportation, exposure to infected animals in feedlot conditions may cause stress and result in “losses” due to this disease complex.

Diagnosis:

Generally, diagnosis is conducted when deaths occur. A veterinary conducted post mortem may indicate a case of pneumonia. Ideally samples should also be sent to a veterinary pathology laboratory. Diagnosis will often be made with bacterial cultures, tissue sectioning for histopathology and circumstantial history.

Prevention:

The vaccination of all sheep of the correct “responsive” age, approximately 2-3 months should be

conducted.

Strategic Dosing - Sheep and Goats

                                   

As winter approaches in South Africa many farmers believe that the worm problem associated with the humid and often hot summer months will be drastically reduced with the decreasing temperatures. 

While this may be true, winter is not without its worm challenges. This said, flukes (conical and liver flukes), roundworms (Brown stomach worm, Bankrupt worm (Long necked), White bankrupt worm, over wintering roundworm and nasal bots larvae’s are some of the worm burdens your stock has to deal with during the winter period.

 There is increasing recognition that larvae arrest in development as a result of prior experience of certain climatic or seasonal influence, a phenomenon referred to as hypobiosis.  Low or zero egg counts in winter is therefore no assurance that there exists a low or no worm burden. These hypobiotic larvae will continue from their arrested development when favourable environmental conditions ensue:

     ·         During the next spring or,

    ·      When host (ewe) immunity around the next lambing time is reduced – a “normal” occurring phenomenon that we need to manage. 

Winter is also a critical time for ewes, most of whom are pregnant during a period often characterised by poor grazing quality and harsh weather conditions. Ewes are required to maintain and grow the foetus inside them – especially during the last third of pregnancy. Closer to term, there is an increased nutrient requirement towards formation of colostrum. An increased winter worm burden will, despite improved nutrition, erode on the ewe’s body condition (fat reserves), increase the risk of poor oöcyte (egg) quality and conception, decrease the quality of colostrum and put the newborn at risk. Additionally, anaemia, poor growth and diarrhoea are also seen in winter due to worm problems.

The fact pointed out above should make “pre-winter strategic dosing” an essential component of any farm’s integrated parasite management (IPM) system. Farms applying a “before winter strategic dosing” dose all their animals usually in May, after the frost, when there is little or no re-infection of the animals from the pasture. 

Using the correct remedy, pre-winter strategic dosing should achieve the following:

• Eliminate nasal bot larvae in the sheep when there are no longer free living flies around that lead to re-infestation. Pre-lambing dosing against nasal bots is important as we need to ensure that the ewe can identify her lamb after birth by olfactory means. Similarly, rams are more efficient in detecting ewes in oestrus when nasal cavities are free of bots and the mucus secretion this infestation causes    
• Remove hypobiotic roundworm larvae (positive egg count is therefore not a requirement for dosing).  

Did Ewe Know? Sheep Breeds

Sheep Breeds

There are more breeds of sheep than breeds of any other livestock species. 

Worldwide, there are more than one thousand distinct sheep breeds. Sheep come in all different sizes, shapes, and colors. 

Breeds are usually classified according to their primary purpose (meat, milk, or wool), the type of fibers they grow (fine, medium, long or carpet wool; or hair), the color of their faces (black, white, red, or moddled), and/or by specific physical or production characteristics.

Durability of Wool

Where cotton fibre falls apart after 3,000 bends, and silk risks tearing at only 2,000,  wool can stand up to 20,000 flexures before breakage occurs.

 This means it retains its shape and appearance far longer than many other fibres.
Wool is a highly complex structure comprising of two main parts. The first is a rigid and elastic section, which makes up about 30 per cent of the fibre volume.

The second is a tough-when-dry, soft-when-wet matrix phase allowing the wool to react with the moisture in the atmosphere. This provides a resilient fibre in almost all conditions.


The reaction with moisture is key to  wool. When saturated, it can stretch up to 30 per cent without damage and still retain its shape once returned to normal.


At a microscopic level, wool has the distinctive ability to change its elastic elements from a helix (spiral) to sheet (flat) structure, a process that can be repeated as many times as the weather.

All these characteristics make wool one of the best fibres in the world for creating quality clothing.

Trace elements, Copper and Selenium in wool production

Copper deficiency

In sheep, the characteristic crimp in the wool becomes less distinct, until the fibres emerge as almost straight, hair-like growths, to which the terms ‘stringy’ and ‘steely’ wool have been applied. The tensile strength of the wool is reduced and the elastic properties are abnormal. A spectacular restoration of the crimp and physical properties can be achieved by copper supplementation.

The abnormalities are most obvious in the wool of merino sheep, which is normally heavily crimped. The crimp is dependant on the presence of disulphide bridges that provide the cross-linkages or bonding of keratin and on the alignment or orientation of the long-fibre fibrillae in the fibre. Both of these are adversely affected in copper deficiency.

Lack of pigment in black-woolled sheep is also a clinical sign of copper deficiency. The pigmentation process in sheep is so sensitive to changes in copper that alternating bands of unpigmented and pigmented wool fibres are produced.

High molybdenum and sulphur intakes further reduce copper absorption and increase the possibility of copper deficiency.

Sheep are however extremely intolerant of excess copper. Chronic copper poisoning has been found in sheep receiving large amounts of copper. Diets/licks/copper supplements containing over 15mg Cu/kg can cause poisoning. Poisoning rarely occurs with grazing sheep under natural conditions.

Selenium

In ewes, high embryonic mortality between 3 and 4 weeks after conception has been attributed to selenium inadequacy in association with white muscle disease and unthriftiness. In certain areas 20 – 50% of ewes were infertile, losses of lambs were high and fertility was dramatically improved by administration of selenium before mating.

Sub clinical manifestations of selenium deficiency in sheep show no distinctive pathological features but have an economically disadvantageous effect.

Selenium supplementation of the ewe increased the probability of lamb survival from 61 – 91%. It also significantly increased lamb weights at birth (4%) and weaning (11%). Wool production may also improve following selenium supplementation. Fleece yields from ewes increased by 3.8-7.5%, and that of their lambs by 9.5%. The mortality of weaned lambs (5 months of age), supplemented with selenium, was reduced from 27 to 8% and highly significant weight gains were observed (1.9kg more).

General Pathology:

Animal well-being is a priority for farmers and if one of the flock falls ill there is a best practice to follow. Here are some guidelines on what to do when things go wrong, to protect the rest of the flock. 

What you should keep in mind and do when you have a sick animal, before calling the vet for advice. 

 

General Pathology:

1.    In the living animal look for clinical signs. General examination – start at the head, remember feet and mouth (blue tongue); openings (discharges, colour, swellings, diarrhoea); mucous membranes, behaviour, temperature; general body condition;

2.    History!!!! – Clinical signs, vaccinations and previous treatments, diet, age group, veld type etc. are important.

Post Mortem:

1. Animal must lie on it’s right hand side, lift forelimb and hind limbs and cut – look for subcutaneous lesions (bruising; anaemia).
2. Cut abdominal cavity open gently along the midline – note if fluid comes out, and colour of fluid. Cut up to the end of the rib cage. Cut attachment of the diaphragm to the rib cage – listen for a popping sound – lugs collapsing due to loss of negative pressure. If the lungs do not collapse it could be a possible pneumonia/
3. Cut open the thorax along the sternum so all the organs in the chest are exposed.
4. Remove organs of the abdominal cavity: spleen (sample for bluetongue); gastrointestinal tract (parasites; bacterial infections; faecal collections); rumen contents (acidosis; plant remnants) mesenteric lymph nodes and ileocaecal lymph nodes (Johnes disease); liver (liver fluke; toxic plants; copper deficiency/toxicity; domsiekte); kidneys (pulpy kidney, copper toxicity). Look at the bladder and if full look at urine (possible copper toxicity if urine is red). Remove all organs carefully and only once samples have been taken cut into the organs.
5. Do the same for the thorax. Cut open the trachea into the bronchi and into lung tissue. Cut open the heart (look at clot in ventricle).
6. Head and Brain – brain can be sent in for histopathology if nervous symptoms have occurred e.g. thiamine deficiency.

Sample Collection – label them clearly!!!!

·         Bacteriology – as sterile as possible; all affected organs; tied off GIT loops; swabs;       abscess contents; take many samples in separate containers – keep cold/on ice.

·         Virology – spleen and lymph nodes on ice; blood tubes with green lid.

·         Histopathology – in formalin, numerous samples about 1cm thick with bit of normal tissue with abnormal tissue.

·         Mineral analysis -  fresh and frozen / in formalin: liver and kidneys

Lucerne powers lambing

Joining ewes on lucerne can stimulate more eggs to be released from the ovaries. 

According to research Merino ewes grazing on lucerne prior to ovulation to improve ovulation rates could play a big part in increasing conception rates. 

Ewes that were joined on the green pasture were in better condition and showed a greater percentage of twins results when scanned. 

Research showed 12% more lambs in the mob of ewes that grazed on lucerne during joining and 10% more twins. Ewes were in condition score two-three before joining. It just goes to show there are big gains to be made using lucerne not just for fattening prime lambs but also for the Merino.

In South Africa it is generally recommended that lucerne be planted in the autumn.    

Ram Care – Practical advice!

“Care for your rams, so that they can care for you!!”

Extra care in the two months prior to mating leads to higher fertility.

More lambs, means more money in your pocket, but also leads to a better utilization of the ram`s genetic potential.

Although rams are the most expensive sheep on the sheep farm, they are often neglected.

Various articles have been written on the care and nutrition of rams. Emphasis is placed on ram fitness, and yet very few farmers exercise their rams before the mating season.

Pro-active or preventative medicine requires that certain management procedures are done in advance to ensure that the animals are healthy and in a good “working” condition when peak performance is required. In a ram this is at mating time, or during the breeding season.

It is important to understand the physiological processes taking place in a ram`s body, in order to understand why it is important to do certain procedures well in time.

Spermatogenesis and the maturation of sperm cells in the testes and epididymis is a process that takes roughly 60 days (2 months) to complete.

Sperm are stored in the testes at 32°-34°C – more or less 6°C lower than body temperature.

The warm blood coming from the body is first cooled down by a very intricate mechanism, where the warm blood runs in arteries in close proximity to the veins with cooler blood coming from the testicles. The cooler blood is then cooled down further in small blood vessels running close to the external surface of the scrotum, before moving into the testes to deliver the necessary oxygen and nutrients for spermatogenesis.

Disease and subsequent fever reactions, as well as even the slight fever encountered after vaccinating with live vaccines, can cause the semen to “overheat”, leading to temporary infertility. Conditions like blowfly strike or foot rot might cause a slight fever reaction. The sperm are then not all killed, but undergo certain changes that effect fertility. A proper semen analysis, in which special attention is given to sperm morphology, is necessary to identify the presence or absence of these “abnormalities”.

On the day a farmer introduces the rams to the ewes, he should ask himself the following question:-

“Did I do everything possible to ensure that these rams deposit the best possible sperm cells into these ewes?”
Note to reader: Some of these are repeats of previous two blogs, nevertheless see the repetitions as priorities!

-         Ensure a good spread of young and old rams by replacing 25% of the ram flock yearly. In this way you will always have a good balance between younger, virile rams with a high libido, and older rams with lots of experience.

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-         Shear rams regularly. Preferably every 6 months in wool breeds.

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-         Do proper hoof care. Trim hooves before the mating season and treat cases of foot rot as early as possible.

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-         Give a balanced ration – especially in the two month period prior to mating when sperm cells are formed.

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-         Get rams fit by walking them briskly for a minimum of half an hour early in the morning or during the late afternoon.

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-         Supply adequate shade, especially in the warmer parts of the country.

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-         Give the broadest possible protection against diseases by vaccinating you protect your rams against Pulpy kidney and other Clostridial diseases, Pasteurella, as well as against Corynebacterium infection (“cheesy gland”) - three very important sheep disease complexes.

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-         Additional vaccination against Bluetongue and Brucellosis is also recommended.

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-         Dose / deworm preventatively. A sick or parasitized ram cannot produce top quality semen. It is also necessary to treat animals preventatively before the mating season against nasal bot, as scent plays an important role in feed intake as well as in the detection of the ewes that are on heat.

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-         Rams should be tested for breeding soundness by a qualified veterinarian.

This entails a proper clinical check-up to certify the ram as healthy and free of disease. It should also include a detailed examination of the genital organs, a semen analysis which includes sperm morphology as well as certifying the semen free of infection (the absence of bacteria and white blood cells).

-         Breeding soundness should also include a mating dexterity test. It does not help if a ram has good semen and good genetics, but is unable to carry it on to its progeny because it cannot serve a ewe!!!

It Pays to look after your Rams

More tips on Ram Management

Extra care in the two months prior to mating leads to higher fertility.

Emphasis is placed on ram fitness, and yet very few farmers exercise their rams before the mating season.

Ram Effect

The introduction of rams early in the breeding season stimulates ewes to ovulate within 3–6 days (without showing oestrus, if this is the first ovulation of the breeding season) and show oestrus about 17 days later.

Ewe flocks stimulated by the ram effect are thus likely to be synchronized.

Rams introduced several weeks before normal onset of oestrus may have no effect and late introduction will only stimulate those few ewes, which have not begun cycling.

Reproduction and breeding

1.         Test rams and teaser rams before mating by a Vet (fertility & venereal diseases)

2.         Test serving ability and libido of rams

3.         Use teaser rams 8–10 days before mating

4.         Condition of rams should be good prior to mating and they should be fit

5.         Rams should have short wool during mating Ram Effect

 Pro-active or preventative medicine requires that certain management procedures are done in advance to ensure that the animals are healthy and in a good “working” condition when peak performance is required. In a ram this is at mating time, or during the breeding season.

What does preventative medicine in rams entail?

* Ensure a good spread of young and old rams by replacing 25% of the ram flock yearly.

* Shear rams regularly. Preferably every 6 months in wool breeds.

* Do proper hoof care. Trim hooves before the mating season and treat cases of foot rot as early as possible. 

* Give a balanced ration especially in the two month period prior to mating when sperm cells are formed.

* Get rams fit by walking them briskly for a minimum of half an hour early in the morning or during the late afternoon.

* Supply adequate shade, especially in the warmer parts of the country.

* Additional vaccination against Bluetongue and Brucellosis is also recommended.

*Dose / deworm preventatively. A sick or parasitized ram cannot produce top quality semen.

Ram Management

Keep the following in mind when it comes to rams:

Make sure that your selection strategies are the same as those of your breeder. Where BLUP technology is available it should be used.

Know your breeder and his aims, because your flock’s improvement depends largely on him.  To shop between breeders renounces this principle.

Rams must be active, virile, fertile and physically able to mate with dexterity.  As a buyer you have a right to such mentioned qualities.

Take note:

• The scrotum circumference of a 15 month old ram must at least be between 30cm and 35cm.  There is a positive relationship between testicle size of rams and the pubescence of maiden ewes.
• 
  
• In cases where a twin ram is used it will, over a period of time, result in a more fertile flock.

In order to allow rams to acclimatize, producers are urged to purchase them at least three months before the mating season.  Remember, adaption to an environment can cause temporary infertility.

Avoid rams with soft and flabby testicles as approximately 50% of these rams have poor sperm quality compared to 5% of rams with firm and elastic testicles.

Management practices

Examine rams on a regular basis for foot disease and problems such as fly strike.

Rams must be shorn 8 to 10 weeks before mating. 

Long wool increases heat-tension which in turn is detrimental to libido.

Clip hooves 6 to 8 weeks before mating and have rams tested for fertility.

Rams must be exercised before mating.  Start roughly 6 weeks before mating by gradually increasing chasing rams over distances.

Remember to mate your young ewes with relatively young rams.  Young ewes have shorter heat cycles and young rams are generally able to serve more ewes over a shorter period of time.

A 25% annual ram-replacement is advisable.  The mating tempo declines with age.

Refrain from all activities and handling two weeks before mating.

Make provision for sufficient shade and clean water, especially before and during mating.

Feeding  

It is advisable that rams be kept in a good condition through out the year.  If conditions justify it they may be flushed as from two months before mating. 

A supplement of vitamins A, D, E may have a positive influence on conception rates.

Teaser-rams

Normally it is beneficial to use teaser rams, especially during spring time.

• The use of teaser rams result in more concentrated lambing.
• A better interval can be brought about by dividing the ewes into three groups, teasing with two day intervals.
• Teaser rams must be kept young.
• Teasers should not be used in excess of 11 to 14 days before mating.

Although the senses of sight, smell and hearing can synchronize a ewe, more success is derived from physical contact.

For successful synchronization it must be ensured that teasers have no contact with ewes for a period of at least 43 days, preferably three months before the scheduled mating.  This practice will cut down on possible conception problems.

Important characteristics

The following characteristics with long term advantages should be considered when rams are selected and purchased.

• Genetically better wool length has advantages such as a higher fleece mass, increased breaking strain and reduction in the fibre distribution range.  This characteristic is between 40-50% hereditary.
• Select for finer wool.  Fine wool can be used in a wider range of quality materials.  Producers can easily select for this characteristic because it is highly hereditary.
• Make sure that your ram has evenness of crimp right through the fleece – good quality
• In order to combat flystrike producers should select for whitish wool with a good quality and an even yolk flow.
• Pigmentation on the horn sites, legs or hooves is correlated to the presence of too many pigmentated fibres in the fleece.