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.