The fattening of lambs for slaughter has been a common practice to add value to feeder lambs. Jano Louw, Beef and Sheep Technical Advisor at Meadow Feeds, explains the fattening process which normally occurs in an intensive system where lambs are stocked in small camps or pens.
The fattening of lambs in feedlot systems consists of two phases: the adaptation period of new arrival animals, and the growth or finishing phase. The basic principles need to be followed to manage a successful and profitable feedlot.
The lambs enter the feedlot with an average body weight of 25-35kg and are slaughtered between 42 to 50 days later.
The adaptation phase (10-17 days) is critical to adapt the lambs for the finishing phase. This phase also contributes to the overall profitability of a feedlot. It is important to know that damages to the rumen of the animal in the early phases are irreparable. Newly arrived lambs must therefore be handled with care to minimise any stress factors.
A feedlot adaption feed programme is developed to transition the lambs from a high roughage diet to a high-energy diet in the growth phase. The main objectives of the adaptation phase are to stimulate maximum feed intake and adjust the rumen microbial population to micro-organisms that can ferment non-fibre carbohydrates.
Thinner and weaker lambs must remain in the adaptation period for an extended time to optimise their growth potential. Clean water and efficient feed bunk space must be available to the lambs at all times. The adaptation camps or pens must be clean and dry and any unnecessary objects must be removed.
Handle with care
Mortalities must be prioritised and limited to 1-2%. Morbidity and mortality have a direct impact on profitability and are the highest in the first two weeks when transport and handling stress account for most of the incidents.
The minimum handling of lambs in the first two weeks can minimise the stress. Low-stress handling techniques and well-trained personnel are needed when lambs are dosed, sheared and moved to different camps.
Feed and water intake are the main factors influencing average daily gains (ADG) and must be monitored regularly. Ad-lib feed and water must be provided to the lambs. Adequate feed intake can only be achieved by good feed bunk management and the right stocking density. When feeding twice per day 30cm/head is sufficient, and 5cm/head when an automated feeder system is used.
The quality of the lambs and type of breed also influence the profitability of a feedlot. Certain breeds have better feed efficiency and growth rates. The target ADG should be between 280-320g/day. Growth rates increase when animals enter the fattening/growth phase.
Good record-keeping, well-trained personnel and effective communication between the feedlot manager, veterinarians and nutritionists are key to a successful feedlot operation.
Important factors that influence the profitability of a feedlot system are:
- Purchase of the required genetic quality animals at the right price.
- Ensure animals are healthy and free of parasites.
- Keep mortality as low as possible.
- Provide cool, clean water and allow sufficient feed bunk space.
- Provide proper and sufficient shading over the feed, as well as for the animals.
- Manage stocking density for optimal conditions.
- Clean camps/pens regularly to minimise energy expenses.
- Follow the correct adaptation programme.
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