Rounding off lambs in a feeding pen

When mutton prices are high or grazing is scarce, this practice can be extremely profitable.

If mutton becomes scarce, the price usually goes up. It then becomes profitable to round off lambs in a feeding pen, if the price of feed is affordable. It is also sometimes necessary to round off animals in a feeding pen when grazing is scarce
and lambs cannot reach a desired slaughter weight on veld.

In addition, if you are weaning many multiple lambs, you may find it necessary to round off some of them in a feeding pen.
Lambs weaned early can go into the feeding pen at eight weeks. The younger the lambs, the better the feed conversion rate. However, the longer the lambs are kept on grazing, the lower the total cost of rounding off. Lambs must weigh at least 15kg before they are placed in the feeding pen. Feed conversion drops as a lamb becomes older and heavier, because more fat than meat is deposited in the body.

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Variable marketing age
The ideal marketing age depends on the breed. For example, SA Mutton Merino lambs are usually marketed at about 40kg. Dorper lambs are marketed slightly earlier – at about 38kg – because the carcasses become too fat at a higher weight. When put in a feeding pen animals must be given time to acclimatise (adapt to their new environment). This should take about two weeks. High-quality roughage must always be available to reduce digestive problems.

During the first week, provide enough hay plus 300g concentrate per lamb per day. During the second week, provide enough hay plus 500g concentrate per lamb per day. Thereafter, provide concentrate ad lib.  A diet for young lambs should meet the following requirements:

  • Total digestible nutritive material: 68%
  • Total coarse protein: 16%
  • Roughage: 12% – 16%
  • Calcium: 0,8%
  • Phosphate: 0,3%

Physical form
Milled or processed grain is of limited value to sheep. Keep grain whole to prevent acidosis. Pelleting noticeably improves intake and performance. Roughage can be milled (through a 12mm to 18mm sieve) or chopped to reduce wastage. Add a binding agent to milled rations to prevent dust.

Type of grain
Maize has traditionally served as the source of grain in sheep diets. But certain small grains can also be used. Although the energy content is lower than that of maize, the protein content is higher. Barley, wheat and triticale can be used in a lamb’s diet. Oats has a low-energy content and is not suitable by itself. Rye is almost tasteless, contains anti-nutritional factors, and could be contaminated with ergot, which would limit its value.

Include a high-quality protein (a low-degradable source) in the diet of young lambs. For good results, also add about 4% fish meal. Alternatively, add oilcake meal (from soya beans or cotton seed).

Creep feed
When placing lambs in a feeding pen, provide creep feed during the pre-weaning period to limit acclimatisation problems.

  • Additives & growth stimulants
  • Additives and growth stimulants are available to improve production. These include:
  • Additives that increase intake (such as antioxidants, flavourants and binding agents);
  • Substances that modify digestion and absorption (buffers, enzymes and antibiotics);Substances that affect the metabolism of an animal (such as growth hormone implants with a hormonal effect and sedatives);
  • Substances that improve the health of an animal (fungus inhibitors, antibiotics, coccidiostats, parasiticides and vermicides);
  • Substances that influence rumen function and modify the end products of rumen digestion (ionophores).
  • Growth stimulants and antibiotics commonly used in South Africa are Tauratec, Salocin, Ralgro and Tilosien.