In NZ and Canada I have seen mixed pastures suitable for the area out
produce single species in pasture density, DM and milk production.
From Animal Net
Scientists study benefits of pasture plant diversity on dairy production
March 3, 2004
ARS News Service
Agricultural Research Service, USDA
Identifying the benefits of grazing dairy cows on pasture having
diverse forage plant mixtures is the objective of a cooperative study
by scientists with the Agricultural Research Service and Pennsylvania
State University (PSU).
One interest is determining whether such pasture can tolerate heavy
grazing better than pasture with only one or two forage plant
species. A second interest is finding out what effect pasture plant
diversity has on herd productivity and production savings to farmers
who practice grass-based dairying, according to Kathy Soder, an
animal scientist in the ARS Pasture Systems and Watershed Management
Research Unit, University Park, Pa.
Since 2001, Soder and colleagues with ARS and PSU have monitored
crude protein content, dry forage yield and other features of eight
pasture plots at PSU's Dairy Research Center as indicators of
productivity. In the Northeast, pasture typically contains a grass
species plus a legume, like clover, according to ARS agronomist Matt
Sanderson. But the dairy center's plots contain various mixtures of
orchard grass, white clover, red clover, chicory, perennial ryegrass,
Kentucky blue grass, birdsfoot trefoil and tall fescue.
Sanderson leads pasture plot evaluation, while Soder oversees the
dairy cows' grazing behavior, physiology and milk production over
four 21-day grazing periods. From 25 pounds of dry forage matter,
plus a grain supplement, the cows produce 10 to 12 gallons of milk
per day. Interestingly, their milk production on mixed pasture has
differed little from control plots having two forage species. But
this isn't necessarily a disadvantage, according to Soder. The main
benefit expected from using mixed pasture is a greater, more
persistent yield of dry forage matter that can support more cows per
area than conventional pasture.
Read more about the research in the March issue of Agricultural
Research magazine, available online at:
http://www.ars.usda.gov/is/AR/archive/mar04/dairy0304.htm
ARS is the U.S. Department of Agriculture's chief scientific research agency.
--
Vaughan Jones
Hamilton
New Zealand
