Timetable - Cultivated pastures (South Africa)

Sheep on Lucerne - Skape op Lusern

Rooster - Aangeplante Weiding

Die koeie vreet mengsel van groen lusern, groen hawer/ryegrass, mieliemeel, sojaoliekoek, katoensaad en minerale. 57% kragvoer teenoor 43% ruvoer op DM basis bereken. - Gerdie Landman - Mooimelk Koeihotel, Kookhuis, Oos-Kaap. 

Grazing maize – a real champion in winter for ruminants

Whole maize is an excellent proposition as winter grazing for the sheep and cattle farmer. Weaner lambs can be raised on maize, currently with good economic benefits; Use #maize for grazing as a “low cost feedlot”.

 It can also be utilized successfully for over-wintering of ewes with lambs.  Maize fills the winter gap effectively in a fodder flow from autumn until the first spring rains and can be used on its own or in combination with other winter pastures or crop residues or even saved for bridging the difficult August-September period. 

It is a low risk, high potential winter pasture produced with summer rain and kept until winter as forage. It is thus not, as in the case of winter grains, dependent on unreliable autumn rains.  Prior to winter a relative reliable estimate can be made of the amount of fodder available. In case of high grain yields, some rows can even be reaped for grain production; the crop residues of the reaped areas can also contribute to the feed available on the land.

#Cultivation of maize for grazing:

The carrying capacity of maize is determined to a large extent by the grain yield; therefor maize for grazing should be cultivated similar to maize as a cash crop, i.e. a suitable cultivar for the area producing a high grain yield. Normally the cultivar suited for grain and silage production in an area will also be good for grazing. Weed control may be less to lower cultivation cost, because especially grassy weeds are good grazing. 

$Grazing period:

Maize can be grazed from the first frost up to the first spring rains, roughly taken as ±100 days. Some farmers prefer to start grazing it earlier, when the maize are still a bit green and sheep will take in more leafy material and less grain and adapt more easily. As the season proceeds, dry material losses will be unavoidable and maize in the latter part of the grazing season will inevitably be of lower quality than those grazed earlier in the season.

#Adaptation of sheep prior to grazing:

Acidosis (suurpens) because of the high energy content of maize, is a real threat, but proper adaptation of animals prior to grazing combined with buffers in the lick, can successfully control it. A method that is effective is to give sheep each day an increasing amount of whole maize supplementation (or even maize cobs) on veld or whatever pasture they are utilizing at that moment

Some farmers prefer to start grazing maize immediately with restricted grazing periods that increases every following day. Supervision is of the utmost importance. Ensure that internal parasites are under control and inoculate against pulpy kidney.

Grazing of the whole maize plant:

Weaner lambs:

Inoculate against pulpy kidney and adapt as above.

Ewes with lambs:

Lambs should be at least three weeks of age when grazing commences, to ensure that they are strong enough and do not get separated from their mothers. Lambs will gradually, as they start grazing, adapt on the high energy diet and should not be susceptible to acidosis. They will also benefit from the good milk production of their dams on the maize.

The one serious shortcoming of grazing maize is an insufficient protein-content for producing sheep, which should be rectified with a protein lick or a protein-rich companion crop like Japanese radish. Protein supplementation in a lick is very effective and eliminates a lot of practical problems. Ensure enough lick trough space, enough lick intake and supply fresh lick often.

Graze restricted areas at a time to reduce selective grazing habits and tramplng losses.  If not, sheep will at first select a high quality diet that will become poorer with time, and with it animal performance will decline. Temporarily or electric fences may be used to divide in smaller areas. Move to the next camp when the area is well utilized but ± 20% grain is still available. Non-producing animals, like old ewes can be used as scavengers.

Growth:

Pre-weaning growth of lambs should be 180 - 250g per day, with lactating ewes

50-100g/day and weaner lambs between 180-200g/per day and even more.

Natural Pastures - fine wool

It is possible to produce finer wool effectively under natural pastures. It is, however, important that traits such as body weight, wool production and reproduction must be included in the selection objectives in order to improve or maintain these traits.

Livestock depend on natural pastures for their diets, and rainfall is the most important factor determining the quantity and quality of pastures and water.  

Vitamin A and E for cattle and sheep

 Vitamin A is an important nutrient for cattle and sheep.

Cattle uses 8 parts of carotene to develop 1 part vitamin A whereas sheep only need 6 parts of carotene to develop one part of vitamin A.

Vitamin A itself does not occur in plants, but the substance carotene in green plant material is converted by animals with an enzyme in the wall of their intestine to vitamin A. Carotene gives plants their yellowish colour and it is converted into active vitamin A.

  In general, green pasture, hay with good green colour and yellow maize all contain sufficient carotene to allow the animal to produce enough vitamin A to top up the reserves stored in the liver. 

During winter we find a decline in carotene levels in plants with subsequent vitamin A deficiency problems in animals in late winter and spring. Vitamin A requirements increase during growth and pregnancy. It is one of the most important vitamins in the body because it is important for normal: growth, reproduction, sight and protective mucous membranes. Rams that are to be used for breeding ant that have not had access to any green feed for 2 – 6 months should be given vitamin A minimum of 6 – 8 weeks before mating. 

Vitamin A prevents “night blindness”. It has a particular importance in growth, reproduction and the immune system. Vitamin A is important in the resistance to disease and promotion of healing through its effect on the immune system. In breeding sheep a deficiency may lead to infertility and in pregnant animals to abortion, short gestation, retained placenta or to the production of dead, weak or blind lambs. Deficiencies will occur if the sheep have not any green forage available for a prolonged period.

Vitamin E 

The adage that "the ewes are walking away from the lambs" may well be heard for the wrong reason. If your ewes have not had green feed for three or four months, then lambs may be lacking vitamin E. Vitamin E, unlike vitamin A, is not stored in the animal body in large amounts for a length of time and consequently a regular dietary source is important. Green fodders are good sources of Vit E. Cereal grains are also good sources. Animal products are relatively poor sources. 

 Vitamin E plays an important role in the development and function of the immune system. The most frequent form of vitamin E deficiency in farm animals is muscle degeneration. A popular descriptive name for this condition is “white muscle disease”, owing to the presence of pale patches or white streaks in the muscles. The condition is frequently referred to as “stiff lamb disease”. Sheep grazing on green pasture build up some reserves in the liver. 

 Excellent management is to give Vit A and E supplements to ewes a month before lambing and a month before mating.

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.

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).

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.    

Vitamin A and E for sheep and cattle

Vitamin A is an important nutrient for cattle and sheep.

Vitamin A itself does not occur in plants, but the substance carotene in green plant material is converted by animals with an enzyme in the wall of their intestine to vitamin A. Carotene gives plants their yellowish colour and it is converted into active vitamin A.

Cattle uses 8 parts of carotene to develop 1 part vitamin A whereas sheep only need 6 parts of carotene to develop one part of vitamin A.

  In general, green pasture, hay with good green colour and yellow maize all contain sufficient carotene to allow the animal to produce enough vitamin A to top up the reserves stored in the liver.

 During winter we find a decline in carotene levels in plants with subsequent vitamin A deficiency problems in animals in late winter and spring. Vitamin A requirements increase during growth and pregnancy. It is one of the most important vitamins in the body because it is important for normal: growth, reproduction, sight and protective mucous membranes. 

Rams that are to be used for breeding ant that have not had access to any green feed for 2 – 6 months should be given vitamin A minimum of 6 – 8 weeks before mating.  

Vitamin E  

The adage that "the ewes are walking away from the lambs" may well be heard for the wrong

reason. If your ewes have not had green feed for three or four months, then lambs may be lacking vitamin E.

 Vitamin E, unlike vitamin A, is not stored in the animal body in large amounts for a length of time and consequently a regular dietary source is important. 

Green fodders are good sources of Vit E. Cereal grains are also good sources. Animal products are relatively poor sources. 

Vitamin E plays an important role in the development and function of the immune system. The most frequent form of vitamin E deficiency in farm animals is muscle degeneration. A popular descriptive name for this condition is “white muscle disease”, owing to the presence of pale patches or white streaks in the muscles. The condition is frequently referred to as “stiff lamb disease”. 

 Sheep grazing on green pasture build up some reserves in the liver. Vitamin A prevents “night blindness”. It has a particular importance in growth, reproduction and the immune system. Vitamin A is important in the resistance to disease and promotion of healing through its effect on the immune system. In breeding sheep a deficiency may lead to infertility and in pregnant animals to abortion, short gestation, retained placenta or to the production of dead, weak or blind lambs. Deficiencies will occur if the sheep have not any green forage available for a prolonged period. 

Excellent management is to give Vit A and E supplements to ewes a month before lambing and a month before mating.