The current dry conditions affecting a large area of North Dakota this year have cattle producers evaluating various management options to reduce the need for herd reduction.  Potential options to consider include early weaning, limit-feeding, and targeted culling.    Consideration should be given to all potential options; however, an immediate strategy may be trying to extend the currently available forage supply through feeding by-product feeds and or grains to grazing cattle.

In situations when forage supply is adequate but quality is suffering, supplementation, especially with protein supplements, can increase dry matter intake of grazed forages.  However, when forage supply is limited, providing alternative feed sources to grazing cattle may cause a substitution response and help extend the forage supply. 

A considerable variety of by-product feedstuffs and grains are produced in North Dakota (https://www.ag.ndsu.edu/publications/livestock/alternative-feeds-for-ruminants).  The cost of these feeds can vary and should be evaluated on a cost per pound of nutrient supplied when deciding which will be the most cost effective (link to Combined Feed Value and Protein and Energy Calculator).  

Ideally, choosing a by-product source low in starch and high in digestible fiber will provide the greatest substitution benefit as starch can negatively impact fiber digestion.  Hand feeding, cake boxes, or grain tanks may be viable options for daily delivery.  If daily delivery is not feasible then a self-feeder can be used.  However, a limiting agent such as salt should be included to prevent over consumption.    

A considerable amount of research has been conducted to evaluate dry distillers grains (DDGS) as a feed option to effectively substitute for forage.  A review of 20 studies utilizing growing steers and heifers determined that as level of DDGS offered increased, the average daily gain linearly increased while forage intake decreased quadratically (figure 1 and 2).  The amount of forage replaced per pound of distillers ranged from .28 to 0.50 lbs forage/lb DDGS. 

Figure 1. Average daily gain response of growing steers and heifers fed increasing levels of DDGS

Adapted from Griffin et. al., The Professional Animal Scientist 28 (2012):306-312.

Figure 2. Forage replacement in diets of growing steers and heifers fed increasing levels of DDGS

Adapted from Griffin et. al., The Professional Animal Scientist 28 (2012):306-312.

When considering your supplemental feed options price should be the greatest decision driver. In general, higher levels of supplemental feed will result in greater forage replacement.

Chanda Engel
chanda.engel@ndsu.edu
Livestock Research Specialist