For most producers it has been a long, cold winter and spring has been a bit stubborn about showing itself.  I was recently traveling from Minnesota to southeastern Kansas about a month ago, and grasslands had not really started greening up at that time.  This is pretty late for that part of the country and because of the cold temperatures, I would say those same delayed spring conditions are the norm with most of the US and Canada.  We are now into late April and cows are stretching the fences as they look at greener pastures on the other side.  Total pasture production can be negatively impacted if pastures are grazed too soon in the spring as carbohydrate reserves become severely reduced.  Rather than storing carbohydrates from actively growing leaves, plant roots are called upon for energy to help support plant growth.

This reminds me of a blog that Jon Albro put together two years ago about this same time.  It dealt with timing of Spring turn out on pastures and the negative impact that going out too early, prior to the 3^rd or 4^th leaf stage, can have on total forage production over the entire grazing season.  It is kind of a pay me now, or pay me later situation.  Back in 2012 spring conditions were very mild and producers were considering turning cattle out early because of the mild conditions.  This year, the same warning is needed but for a different reason.  Tough winter feeding conditions may have put a strain on forage supplies for many producers and the thought of getting cattle out on green grass is very appealing.  Unfortunately going out too soon, before pastures are ready to handle the grazing pressure can have very negative effects on future production of those pastures.

I have pulled out the guidelines from Jon’s blog below and encourage you to recognize the physiological, i.e. growth, stage of the grass plants that he has outlined and how much forage production that is at risk.  North Dakota State University has also looked into some spring grazing guidelines and they recommend waiting until plants have reached the 3^rd  leaf stage for cool season native range species.   If you have tame grass pastures such as crested wheat grass or brome grass, these will generally be ready to graze two weeks or more prior to native grass species.  Winter wheat, rye or triticale are annual crops that can be sown in the fall to produce early spring pastures to help hold cattle off of native grasslands to help manage your overall forage resource.  Please review Jon’s comments below and manager your pastures for optimal forage production. 

Growth and carbohydrate (energy) reserve level of a grass as affected by defoliation. Source: Colorado State University Extension 2006, Fact sheet No. 6.108.

Forage production can be dramatically reduced (35 percent or greater) for the grazing period if native pastures are grazed too early in the spring. Too early is prior to when there are four fully developed leaves (shoots or tillers) that provide surface area for achieving positive energy balance within the grass plant. Grazing too early in the season is basically a form of overgrazing. Too much leaf material grazed (especially at the crown of the plant or below the growing point) will slow plant growth, require the plant to draw on more stored energy in the roots, impair root growth and development and make the plant much more susceptible to drought or competition from non-desirable species, i.e. weeds. Again, the end result is less production and less forage not only for the current grazing season but for subsequent seasons as well.