The feedlot finishing phases of cattle must be considered when producers want to add value to their calf-crop. Producers must carefully consider the market conditions and feed prices when a decision is taken to finish cattle, as it will influence the profitability of the operation. Particularly if the producer considers this as a seasonal operation and not a permanent fixture on the farm.
Phase feeding
The fattening of cattle is generally divide in three phases; however, it may be beneficial for some producers to only use one phase (and feed a grower ration), in order to simplify management. Phase feeding is applied to address the nutritional requirements of cattle more accurately and to reduce the quantity of nutrients wasted. These phases will be explained below.
Starter phase
The starter phase usually lasts 14 days in the feedlot. Emphasis is placed on the adaptation of calves, oxen and c-grades to a complete feed. Regarding calves, this ration has a higher protein (and thus also contains bypass protein), which will support frame development and growth. The ration also typically has a higher roughage content than the grower ration, and therefore has a lower energy content, to facilitate adaptation to the feedlot.
Grower phase
In the grower phase, emphasis is placed on the development of the frame potential established previously. Meaning, in this phase, muscle (carcass) development takes centre stage. For calves or oxen, this phase generally lasts 60-100 days, depending on the current mass and the target end live mass. The grower ration typically has a lower protein and fibre content than the starter ration and contains a higher energy content (higher grain component). For C-grades, because they have already achieved mature body mass, they bypass the growth phase and enter a fattening phase upon entry to the feedlot.; this phase can be completed with either a grower or finisher ration. This phase lasts approximately 50-70 days, depending on the body condition score that the cow entered the feedlot on.
Feedlot finishing phase
The finishing ration contains the lowest protein and fibre content, and simultaneously the highest energy content, of all the rations. This ration may also contain Zilpaterol, which promotes carcass gain and increases dressing percentage. The goal is to support fattening and to ensure that the carcass becomes market-ready as soon as possible. Cattle transition to a finisher phase when they have completed a specific number of days in the feedlot or when a desired body condition score is achieved for this phase to start. For calves and oxen, this phase typically lasts 30 – 40 days.
A few tips for the feedlot environment are shared below, including the changes in feed allowance, the feeding of cattle and roughage quality.
Changes in feed allowance
The aim in a beef feedlot is to maximise dry matter intake by feedlot cattle; cattle that eat are cattle that grow. When increasing or decreasing the amount of feed offered to cattle, it is advisable to change it by a standard amount, usually 4 – 6% of dry matter intake, which equates to 250-375g of feed on a dry matter basis for beef calves weighing 250kg. Should a producer have increased or decreased the feed allowance today, wait two to three days before adjusting the feed allowance again.
Feeding of Cattle
A thumb rule is to have a third of the cattle at the bunks when the mixer wagon approaches, a third heading toward the bunk and the remainder showing interest in moving toward the bunk at feeding. If all cattle rush to the bunk at once, it is a clear indication that they are not being fed enough, frequently enough. Another sign of infrequent and/or insufficient feed allowance is feed troughs that have been licked “clean” by cattle. This behaviour may have negative consequences for the digestive system as it leads to digestive disturbances (such as acidosis) and, as a result, causes permanent damage to the rumen.
Roughage in the feedlot
Roughage and or silage quality is of utmost importance in the feedlot. The reason being the low inclusion of these sources in the ration and the importance for rumen and overall cattle health. Roughage or silage must be free of any mould and must be stored and managed properly. The chop length of roughage is also important and must be monitored closely.
The fattening of cattle in the feedlot may be rewarding for the producer, given that it is planned and managed properly.
