Farmers frequently ask for information regarding the sort of production and stocking rates one can achieve using Holland and New Zealand grasses in combination with Management Intensive Grazing (MIG). One could write a book on the subject and fortunately several good ones have been written. The best books are generally available through The Stockman Grass Farmer monthly publication (Jackson, Mississippi; 800-748-9808).
A short illustration of the potential productivity of improved species and varieties of grasses follows. A farmer called wanting to know just how many 500 lb. heifers he could carry on 800 acres of irrigated pasture. A New Zealand intern working for Modern Forage Systems worked up the information requested and replied:
“Dear Mr. X:
I am a New Zealander on exchange in the U.S.A. working for John Kaye. John asked me to put something together for you. Hope it will help.
Assumptions:
*You know and understand MIG and will apply it.
*800 acres irrigated, good fertility, and drainage.
*You allow a 20 day rotation, that is, the pasture will be ready to graze after 20 days rest, with just 15 days not uncommon.
*The pasture composition is 75% Barenbrug perennial ryegrass and 25% white clover. *You will apply 60unit/ lbs. of supplemental nitrogen per acre in early spring, twice during summer, and once in early fall, for an annual total of at least 240 unit/ lbs.
*After 20 days rest, the pasture will yield 3000 lbs. of dry matter per acre at the 6” height, and will be grazed down to a residual of 1500 lbs., or to a height of 3”, yielding approximately 1500 lbs. of DM/acre.
Therefore, using a 20 day rotation and an average DM yield of 1500 lbs./acre, with 800 acres you will utilize 40 acres per day, and have (40 x 1500=) 60,000 lbs. of DM per day to budget. Using figures from New Zealand’s Lincoln University, a 500 lb. heifer needs 15 lbs. of DM/day to produce an average daily gain of 2.21 lbs.. Therefore, on your 800 acres with 60,000 lbs. of DM/day available, you should be able to feed 4,000, 500 lb. heifers and achieve a target gain of 2.21 lbs./day.”
Recommend you start with 3,000 animals and work up as you gain the needed experience. Also, keep in mind that the stocking rate will decrease as animals gain. Move the animals daily to a new 40 acre paddock for best results. Clean drinking water and free choice minerals are a must in every paddock. Don’t let the 800 acres intimidate you. The same numbers could be applied to 80 or just 8 acres. Most of us aren’t blessed with the resources this farmer had. However, most land will be substantially more productive using MIG and improved species and varieties of grasses.
One frequently asked question is whether or not to use a nurse crop, such as oats planted in companion with the grasses. You have to realize that all plants require space and sunlight to prosper. Oats, for example, are far more aggressive in establishing than grasses, thus delaying the establishment of the permanent pasture. The grasses really don't get the opportunity to grow until after the oats are harvested. If your need is to establish permanent pasture, then don’t use a nurse crop. If you have an economic reason to create a fast food source for your livestock, then a nurse crop can be justified.
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