Pen Fattening Management

Pen fattening involves the feeding or finishing of beef cattle with a protein and high-energy ration for a period of 70 to 120 days under zero grazing to increase live weights and improve the carcass grade at slaughter.

Reasons for Pen Fattening

Pen Fattening Farming | Feedmix | Zimbabwe

  • To take advantage of seasonally high prices and increase revenue turnover
  • To add extra mass to slaughter stock at a younger age, thereby increasing turnover.
  • To Increase the degree of fatness and fleshiness (finish) of the animal carcass in order to achieve higher grades at a younger age.
  • To maximize output from the beef enterprise.

Distinct factors that influence the profitability of a feedlot

  1. The buying price of weaner calves or store cattle,
  2. The cost of the feed,
  3. The selling price of the finished cattle, and
  4. The performance of the cattle is influenced by management.
Pen Fattening Solutions | Feedmix | Zimbabwe

Solutions for a good economic assessment for pen fattening


  • Time your operations strategically
  • Good prices are normally firm from the end of July to February.  There could be two cycles from July to December.
  • Peak prices are fetched in December.

Selection of animals

  • Select the right animal of the right breed, age, sex, and conformation for optimum performance in pens.
  • Get the price right if purchasing the cattle.
  • Steers or males, in general, are more preferred than females (cows or heifers), as they respond better when feeding.
  • Young animals perform better in feed lots — low feed conversion ratio.
  • Draft power normally responds poorly to feed hence poor meat grades.

Quality and cost of feed

  • Use good quality FeedMix Pen Feeding Meal, as an affordable and highly nutritious feed.
  • Feeding Instructions:  The feed can be used for maintenance purposes at low levels of 4-6 kg of pen feeding meal per animal per day.
  • Induction is key to measuring the performance of the animals during the induction period.

Feed Conversion Efficiency

  • Feed at least 2 – 3 times per day, this measures how much feed was eaten to convert to 1Kg of meat.
  • High Average Daily Gain (ADG) of 1.8 – 2.0kg/animal/day.
  • Low feed conversion ratio of 8:1 to live mass or 11: 1 to Cold Dressed Mass (CDM).

Record keeping

  • Weigh and record the initial weights of the animals before they are inducted.
  • Identify the weighed animals using ear tags.
  • Vaccinate with Vitamin A.
  • Vaccinate against Botulism.
  • Record information on how the animals are responding during induction.

Feeding Cycle

  • Feeding cycle ranges from 70 – 120 days depending on age and breed.

Selecting Animals for Pen Fattening

Pen Fattening Young Bull | Feedmix | Zimbabwe

Age & Size

  • The young stock has better feed conversion efficiency (FCE) than the older stack and tends to finish better.
  • Bulls and short scrotum bulls grow faster these are most efficient and grade better than steers. Provided the fattened bulls are sold at milk tooth.
  • The size at which an animal can be finished is determined by the targeted finishing mass and genetic potential of the breed.

Fattening Periods at Different Ages

Class of AnimalLive WeightFinishing period in pens
Weaners230 kg100 – 120 days
Steers280 kg90 – 100 days
2 Tooth Steers300 – 310 kg80 – 90 days
4 Tooth Steers320 – 325 kg70 – 80 days
6 Tooth Steers340 – 345 kg60 – 70 days
§  The above-quoted figures refer to larger framed improved breeds

Selecting Animals for Pen Fattening


  • Young male animals (steers) grow faster and deposit less fat than older animals.
  • Young animals have better-feed conversion efficiency.
  • These animals have to be slaughtered at milk tooth age. Therefore if an intensive feeding system and management permits, then the finishing of animals before 15 – 18 months of age one should use intact uncastrated animals.
  • heifers respond well enough to finishing but they tend to finish quicker because of their reduced growth potential as compared to steers.
  • Heifers eat less feed per day than steers of the same age hence the reduced growth potential. They deposit more fat than steers during the same feeding period.
  • heifers are as efficient as steers if ted to slaughter weights 10-15% lower than those of steers.
  • Feeding heifers for a shorter period is advisable.

Selecting Animals for Pen Fattening


  • Good genetics especially pure breeds and crosses have the better conformation and perform better in feed lots.
  • Good breeds show high voluntary feed intake (VFI) per day in the pens.
  • Some animals will not adapt to intensive feeding Conditions. Such animals, referred to as non—feeders/non-starters either refuse to eat a high—energy diet or react unfavorably to it.
  • Non-feeders of the exotic breeds cannot be identified until the pre-pen fattening/induction period is done.

Preparation of Pens for Pen Fattening

  • Allow a spicing of 10-14 m² per animal.
    Pens must be strong, Upright poles should be 15 to 20cm in diameter and about 2.75 -3m long. The uprights should be sunk about 800mm into the ground, at a spacing of not exceeding 2.75m apart. Cross rails should be on average 90mm in diameter.
  • Prepare the holding pens with the feed and water troughs
  • Feed troughs allow trough space of about 300mm per head on average.
Yearlings250 – 300mm / head
18 – 24 months300 – 380mm / head
Large animals

380 – 460mm / head

  • Throat height 680mm above hoof level
  • Adequate pen space must be provided singly or grouped, by age, bleed, and sex.
  • When constructing pens, the feed trough should be as far away from the water trough as possible to avoid spoilage of the feed by water which can cause molds.

Preparation of Pens for Pen Fattening

  • With the feeding trough in one corner of the pen, the water trough should be in the corner diagonally across.
  • This is to force cattle to walk the longest possible distance a few times daily to reduce incidences of laminitis, as well as reduce contamination of feed.
  • Drinking water will stay clean for longer periods.
  • Take precaution to make sure that no shortage of water does not occur during the feeding period.
  • Water must be available at all times, allowing for at least 50 liters per head per day.
  • Determine the feed requirement and make sure that enough feed has been bought in or prepared to last for the duration of the feeding period, if using FeedMix 1:4 Beef Concentrate harvest full cobs and store them in maize cribs. Grind the cobs to produce snap corn to mix with FeedMix 1:4 Beef Concentrate.
  • It is essential that sufficient roughage is available to last the whole fattening period.
  • The problem of shy feeders can arise as the animals have probably never consumed concentrates.


  • Dip the animals before they are moved into the pens against ticks.
  • Dose against internal parasites e.g. liver flukes, roundworms, tapeworms, etc.
  • Group the cattle accordingly to see size and breed if possible.
  • Give Vitamin A injection and botulism vaccine.
  • Weigh the animals individually and record the initial weight.
  • Identify the animals with ear tags and record.
  • Keep proper records for monitoring and evaluation of animal performance.


The following are recommended induction (starting) masses in order to achieve a certain target slaughter mass for steers for a medium-sized breed. It is important to adapt animals gradually to high-energy diets over a period of at least 10 -14 days to avoid digestive and metabolic disturbances.
Age at InductionMinimum Induction Mass (kg)Minimum Target Slaughter Mass (kg)Average Weight Gain (kg)
+9 months245425180
+18 months350425175
+25 months300465165
+33 months375540165

Rationing the diet in the initial stages of induction

In this method, the diet is rationed at about 50% of the total intake for two days and each subsequent two days the ration is increased by 1kg until about the 14th day when the diet is fed ad lib.  The following is an example of an adaptation programme for yearlings with a live weight of about 300 kg on 20% roughage.

Adaptation Period in DaysFeedMix Pen FeedMeal (12.1%CP) AM amount (kg)FeedMix Pen FeedMeal (12.1%CP) AM amount (kg)Total feed consumed/day Feedmix Pen Feeding Meal (12.1%CP)
11-145510 to 13kg depending on breed and size of the animal
90 days of pen feedingTotal feed consumed by one1000kg (1 tonne) Feedmix pen Feeding Meal

A loading ramp is a necessity where fattening is practiced for ease of loading and off-loading of animals.  Also required is a scale for monitoring the performance of the penned animal, and a race and/or crush pen for handling the animal.

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