COWS = GRASS

This month we reach the 10 year milestone of grazing cattle here at DS Family Farm. Since July 2011 we have embraced “Fresh Grass and Move” management with the cattle herd. Prior to the cattle arriving, we spent about 15 years managing the pastures with periodic prescribed burns (fire).

Without cattle to recycle the old forage, fire was the tool we used to remove old grass. Fire is rarely used now that we have the herd available to manage pasture. Recently we did burn a 5 acre patch of Conservation Reserve Program land (see May 2020 blog post).

10 Years of Cows vs. 10 Years of Fire

Curious to know if cows or fire results in more forage production? We turned to the Rangeland Analysis Platform (RAP). RAP gives the ability to investigate “rangelands across space and time” for the western states. We can actually go back in time and compare the past 10 years of managing pasture with cattle versus the previous 10 years of managing with fire.

Managing with cows = more grass produced

For the past ten years we have used a “Fresh Grass And Move” management technique. The cows are constantly on the move. Appropriate animal impact is applied to the land. Cows and grass have a symbiotic relationship. Cattle managed this way ensure that a future harvest of grass will be available. Below we show 10 year accumulated biomass totals for three key points during our growing season.

10 year forage production results

1. June 25th represents about 40% of our growing season.
   1. During the growth period (Jan. 1 to June 25), the pasture accumulated an additional 100 lbs. of forage per acre under cattle grazing versus fire management.
2. August 28th represents about 80% of our growing season.
   1. During the growth period (June 25 to August 28), the pasture, on average accumulated another additional 100 lbs. of forage per acre with cattle grazing vs. no cattle fire management.
3. December ends our growing season (100% accumulated forage production for year).
   1. During the growth period August 28 to the end of the growing season, the pasture, on average accumulated another additional 100 lbs. of forage per acre under cattle grazing vs. no cattle fire management.

Bottom Line: when averaging 10 years of total forage production, cattle grazing management out produced 10 years of total forage production under fire only management by 300 lbs. per acre.

• Fire management only, 10 year average total growing season production = 2,601 lbs. per acre.
• Cattle grazing management, 10 year average total growing season production = 2,899 lbs. per acre.
• 2,899 lbs. per acre – 2,601 lbs. per acre = an additional 298 lbs. per acre production with cattle grazing management.

Additional Considerations

There are many variables that go into each growing season. The only variable that we knew was different between these two 10 year data periods was the addition of cattle grazing and the elimination of fire over the past 10 years.

RAP does include climate data. When we look at temperature and precipitation we find:

• 10 year average precipitation without cattle (fire only management period) = 28.3 inches per year.
• 10 year average precipitation with cattle grazing/no fire management = 31.5 inches per year.
  • Note: the 10 years with cattle management had both the highest and the lowest recorded annual precipitation.
• 10 year average annual temperature without cattle = 51.2 degrees F
• 10 year average annual temperature with cattle = 52.0 degrees F.

Further reading on climate variables

The paper “Annual Range Forage Production“, from the University of California, highlights climate variables on annual range production. Below I try to summarize the findings:

ABOVE average annual production under these conditions:

• Warm, wet fall, with an average winter and spring.
• Average fall, mild winter and average spring.
• Average fall, short winter with an early spring.

BELOW average annual production under these conditions:

• Cold, wet fall, average winter and average spring.
• Dry fall, average winter and average spring.
• Average fall, long winter and late spring

NORMAL average annual production under these conditions:

• Average fall, average winter and average spring
• Average fall, cold winter, average spring.

Note how the fall is used as the starting point when considering a growing season total forage production. Annual production in temperate climates start the fall before the growing season. That is why we take interest in how our water year begins in October. Refer to this past post for more information: Happy New Water Year.

Want to produce more grass? Properly managed cattle appears to produce more grass then when cattle are absent. Does this surprise you, that cattle grazing would stimulate more grass growth?