Production

Limited or Driven by Feed Bunk Management

Abstract

Bunk management is a vigorously debated subject in the cattle feeding business. That is where my experience lies. I will readily admit that I do not fully understand the nuances of feeding dairy cows. My goal is to share ideas and principles we have learned while finishing cattle because these principles have some application whenever ruminants are being fed to support high levels of production.

The core of concern when managing bunks in a feedlot is controlling acidosis. High concentrations of highly fermentable carbohydrate create the risk. Ruminants were designed to eat until physical fill triggers satiety. Our diets no longer work within the scope of that intake regulation system. So, we reduce bunkspace to increase competition for feed. We feed 2 to 4 times daily to ensure cattle don't experience prolonged hunger and to limit the amount of feed available at any one time. Monensin, which tends to depress intake or at least the rate of consumption (Birkelo and Lounsbery, 1992) is being used again at higher concentrations to regulate consumption rates and intake variability (Stock and Britton, 1993).

We also manage intake simply by restricting variability in feed deliveries. The most dramatic system involves programmed feeding. In this system feed deliveries are intentionally set at some point less than ad libitum. A summary of these systems (Pritchard, 1995) shows that they generally allow equal rate of gain while requiring less feed. In part, this efficiency response may be due simply to reductions in the variability of daily feed deliveries and subsequent variation of Dry Matter Intake (DMI). Galyean et al (1992) observed that it was variability of deliveries that was crucial when limit feeding. Bierman and Pritchard (1997) noted that stable feed delivery rates enhanced efficiency when not using programmed feeding.