On the Blog

Effects of Drought on the Beef Cow Nutritional Needs

Much of the U.S. has suffered from drought for several months.  Lack of rain obviously limits the amount of available grass. Under normal conditions, grass is the majority source the daily amounts of energy and protein required by the cow for her maintenance and production needs. Supplemental proteins, minerals, trace minerals and vitamins are fed to make up for nutritional deficiencies, which occur as grass matures.

Drought changes the normal growth curve of grass.  Not only is the quantity of grass less, the grass matures faster. If we normally start supplementing protein in September or October; we might have to start 30-45 days sooner during drought due to lower than expected grass protein levels. The following table is an example of what occurred during the 2002 drought in the Sandhills of Nebraska.

 

 

Average  Crude Protein %

2002 Crude Protein %

June 7

12.3

12.7

July 16

11.0

8.2

July 30

10.3

5.9

August 20

9.3

5.6

September 5

8.6

7.5

October 14

6.7

5.9

2011 Range Beef Cow Symposium, Volesky and Adams, page 206

The plants have reached maturity much earlier in the season. Their July protein analysis is more typical of a mid-September analysis. A plant tries to produce seed in order for the species to survive long term. During a drought, there is less leaf growth (quantity and percent of plant) as the plant uses the available moisture in an attempt to produce seed. So there is not only less grass to eat, the available grass is lower in quality.

 

 

Average TDN %

2002 TDN %

June 7

69

53

July 16

63

49

July 30

60

50

August 20

57

49

September 5

56

48

October 14

54

48

2011 Range Beef Cow Symposium, Volesky and Adams, page 206

As less and less grass is available, producers start to supplement. It is important to remember a protein supplement makes up for the lower protein available when sufficient quantities of the forage are being grazed or hay being fed. It does not replace the lack of forage due to drought. Lowering the protein level in a protein supplement and increasing the fat level will increase the energy in the supplement. However, increasing the fat percentage in a one pound per head per day protein supplement from five to ten percent may sound like a significant increase in energy but the increased fat intake will not replace the energy from one pound of hay. In fact that increase in fat is less than the energy in 0.20 pounds of corn. We need to keep in mind quantities as well as quality.

CRYSTALYX® low moisture blocks are nationally known for predictable controlled consumption. Many producers use this predictability in conjunction with the web-based CRYSTALYX® Supplement Scheduler to manage their supplement delivery schedule. If available forage is severely limited, cows may spend more time consuming self-fed supplements resulting in increased daily intakes. Low moisture blocks like CRYSTALYX,® due to their physical characteristics, are more resistant to over consumption. 

Very hot, persistent temperatures where forage availability is limited are conditions that should prompt you to be monitoring intakes closely. Customer satisfaction is greatest when your cattle consume within normal intake expectations. If consumption is not at normal expected levels, you may need to evaluate the location of where blocks are placed relative to water, shade and standing forage; how much forage is available to graze; how many cattle you have stocked per barrel; etc. As environmental conditions become more stressed, management demands of your supplement program will increase dramatically over more normal conditions.