by Dale Blasi, Extension Livestock Specialist, and T.J. Spore
Many producers have used limit- or programmed-feeding in the past with success, especially during periods of drought when forage is not adequate. In a nutshell, limit- or program-feeding refers to the practice of limiting calves to two-thirds to three-quarters of the dry matter that they can normally consume. This feeding strategy varies greatly with traditional management where calves generally have free-choice access to forage. Traditionally, limit-fed diets have consisted of 80 to 85% whole shelled corn and the remaining balance as a protein supplement. The total amount of the ration delivered is increased every two weeks or so to account for increased body weight gain based upon the desired level of gain.
Limit-feeding requires additional management and attention to detail. For example, adequate bunk space and maintaining a regular feeding schedule are necessary. Cattle need to be fed the same amount at the same time every day in a pen situation where all calves have an equal chance to get to the bunk. Moreover, the producer must recalculate and adjust the ration DM allowed every couple of weeks to account for cattle growth. Therefore, it is important to have accurate cattle weights before initiation of the feeding period (and during if possible) to ensure proper amounts of feed are being delivered.
Four research feeding trials were conducted during 2016 at the KSU Beef Stocker Unit to evaluate the value of limit-feeding a high-energy diet (NEg = 60 Mcal/100 lb DM) when the energy is derived from highly-digestible fiber from Sweet Bran or distiller’s grains rather than starch from corn. From a ruminal health perspective, minimizing the level of starch in the diet will avoid the potential occurrence of subacute ruminal acidosis that can negatively affect consistent feed intake and potentially jeopardize cattle health.
The 1,444 head of calves used in this research originated from a variety of environments (Montana, Florida, Texas, New Mexico and Tennessee) across the United States. Upon the day of arrival, all calves received long stem prairie hay. The limit-fed diet was introduced to the calves on the following day at a feeding rate of 1 to 1.5% DM on a body weight basis. Results from these trials indicate it is important not to over-fill cattle too quickly and to keep them hungry initially. The desired maximum amount of dry matter intake allowed (2.0 to 2.2% of body weight) was attained within 1 to 2 weeks (as dictated by cattle appetite which can be curbed by limit-feeding).
Results from these trials indicate high-energy diets based on corn by-products can be fed to newly received stocker cattle without negative effects on overall health. In addition, when these diets are limit-fed, advantages in efficiency are evident. Moreover, feeding the highest energy ration in these trials formulated with dry-rolled or whole corn and Sweet Bran or wet distiller’s grains yielded similar performance. These results are beneficial to the growing cattle sector because gain may be targeted by feeding the same diet and only altering intake and, depending on producer location and commodity markets, the choice between by-products. Intake restriction increases digestibility and efficiency, which may contribute to less total manure production, thus a smaller impact on the environment and reduced costs of removal.
In addition to more efficient gains, limit-feeding makes for hungry animals that are more than eager to approach the bunk at feeding. This concept is beneficial in regard to monitoring cattle health because when an animal is not at the bunk to meet the feed wagon it is likely due to a health issue and earlier detection is paramount when dealing with newly-weaned, stressed calves. More research is warranted addressing the effects of limit-feeding high-energy diets based on corn by-products and their effects on performance and carcass characteristics after the finishing phase of production. Nonetheless, the results of these studies introduce a novel programmed-feeding protocol based on corn by-products as the primary energy source that is more efficient than high-roughage growing diets and does not negatively affect health.
|KSU High energy-highly fermentable fiber limit-fed diet|
|Item||Wet distiller’s grains||Sweet Bran|
|Ingredient, % DM|
|Dry rolled corn||36.50||39.50|
|Wet distiller’s grains w/ solubles||40.00||–|
1Diets formulated to supply 60 Mcal NEg/100 lb DM
2Supplement pellet was formulated to contain (DM basis) 10% CP, 8.0% Ca, 0.24% P, 5.0% salt, 0.55% potassium, 0.25% magnesium, 1.67% fat, and 8.03% ADF.