The Grazing Calendar

Achieving and maintaining cow productivity when using pasture for the primary  forage  source requires constant management.  While  no  single daily  decision is highly critical, the accumulation of  decisions  made will affect pasture quality, quantity, and milk production.

Items like body condition scoring, paddock planning, forage sampling and analysis, and pasture topdressing also need to be kept in mind.  These decisions should be made in the context of a larger forage feeding plan that provides alternatives should pasture be in short  supply  or present in excess.

Just   as  a  weekly  pasture  walk  is  useful  in   planning   current grazing/ harvesting  decisions  for  the coming  week,  a  planning  walk throughout the pasturing season is likewise useful.  The following suggests some items to keep in mind with each decision making period.

These  guides are made in the context of grass management.  The goal  is to  maximize quantity and quality of pasture forage. Recognizing  that grass  growth/day takes place THREE TIMES AS FAST at 4-6" in height  vs. 2"  in  height,  then grazing a  paddock should be avoided until  grass  has reached the grazing height of 6-8". Supplemental forage is  recommended to allow paddocks to reach the desired grazing height.

Nutritionally  and economically this strategy makes the most sense.  If supplemental forage and grain is not fed and paddocks with shorter grass are  grazed,  there is 1) less forage produced from the pasture  and  2) when  the pasture runs out, harvested forage must be fed  anyway.   More supplemental  concentrates and forage will be needed than if the  ration continued  to  contain some pasture with its higher protein  and  energy content.


Calendar of pasturing events:

Last of April: Start cows on some of the pasture land that is early and drained if grass has started to grow.  Hold back some paddocks to be the first  full height plots to be grazed.  These will start the "official" grazing season on your farm. 

Avoid  the pitfall of grazing all the proposed pasture at the  start  in case  there is a cold wet spring (like this year and some  past  years).  Feed  supplemental  forage rather than graze  the  first  "official" paddocks too soon.

Early  May:  Ungrazed paddocks should be coming "on line"  for  grazing.  The start  of the "official"  grazing  period  will  be  very  highly   weather dependent.   Once on schedule, rapidly maturing paddocks  should  remain ungrazed and harvested for later feeding.

Late May:  The "official" grazing season with paddocks at 6-8" in height will have started by now.  Be prepared to harvest any excess growth should  the weather turn warm so that paddocks can be returned to the rotation and  be  part of the "desired" maturity for grazing.  The  abundance  of pasture at this time and its high quality allows for the highest ratio of milk  to grain feeding.  About 7-8# of corn meal/minerals  will  support 60# of 4.0% milk and 14-15# about of 80# milk.

Graze grass plants while still vegetative before they reach reproductive stem elongation.

Early  June:   Paddocks are in full swing with enough  forage  both  for grazing  and harvesting.  Haylage, baleage and hay are the best  options.  That feed may be needed in late summer and the winter.  Clipping and not harvesting should be done if that is the only option.  Begin the process of  topdressing  paddocks most recently grazed.  Take samples  of  early June pasture for forage analysis.

Late June:  The character of grass growth begins to change.  Even at the desired  pasture grazing heights, there may be less energy  and  protein present.  Follow the bulk tank shipments very closely.  Milk shipped may begin to drop.  Cow condition may begin to drop, unnoticeable at  first.  Most  successful  grazers begin to increase the amount of corn  meal  or other  pasture designed concentrates at this time.  Continue to  machine harvest paddocks too mature for grazing.

July:  Summer grasses and clovers are here; the spring grasses have gone dormant.   Paddock recovery is slower; more land is needed for  grazing.  It is a better strategy to allow for full paddock recovery by stretching the available grazing with supplemental forage if the next paddocks  are not ready. 

This strategy best uses the protein and energy of pasture to  supplement the  lower  protein  and  energy content of  harvested  forages.  It  is nutritionally and economically better to keep some pasture in the ration than  to be nearly out of pasture and have to rely almost exclusively  on stored feed.  Sample summer pasture for forage analysis. 

Pasture  may  only  provide a  to ½  of  the  cows'  forage  needs.  Supplemental  forage  and  concentrates containing both  corn  meal  and protein sources will be needed.  Rations for 60# 4.0% milk  supplemented with  corn  silage or low protein hay will need about 15# of  a  14%  CP grain equivalent and for 80# about 25#.  Check cow body condition.

August:  If your land is dry, chances are that you are feeding a lot  of stored feed.  Certainly with the drought we had last year even  normally heavier  lands  were dry and not growing any grass.  Line up  some  corn silage,  hay or haylage for the winter feeding if you have had  to  feed all your stored feed during the summer.  Recheck cow body condition.

September:   With  the  arrival of cooler, wetter  weather,  the  cooler season grasses return and pasture regrowth can be somewhat quicker  than the summer.  Because cool weather is approaching, it may be possible  to begin  to  "stockpile  on the stem" some forage  for  November  grazing.  Because  the weather is cooling and not heating up as it does  in  the spring, grasses will not mature as they did in June and will be higher in available energy.  Recheck body condition.

October:  Cool weather has arrived again and grass growth has slowed and will  essentially stop toward the end of the month.  If rain and  warmth have  been sufficient, stockpiled pasture will be available for the  end-of-the-month grazing.

Forage growth in the Fall is not significant enough to provide a surplus for  harvesting.  All of the Fall growth will be needed for  grazing  on most  farms.  Pasture may only provide 1/3 or less of the  cows'  forage needs during this time.

November:   Grass  is not growing any more in New England,  but  if  any excess  pasture growth has carried over into the month, it  may  provide some  grazing for a couple more weeks.  Quality will be  retained  until cold  weather  starts to kill the grass.  Pasture intake  drops  and  is ended with any significant snow cover.

Grazing does require grass and cow management, timely decision  making, anticipation  of expected and unexpected seasonal changes  and  suitable records for success.  Develop a grazing calendar that is appropriate for your farm.


Sidney J. Lyford, Jr.,

Dept. of  Veterinary and Animal Sciences

University of Massachusetts Amherst

Crops, Dairy, Livestock News. Vol. 1:2, Summer 1996

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