Improving Farm Profitability by Efficiently Using the Pasture Resource
Permanent pastures in the northeast United States typically have low productivity, producing only about two tons of moderate-to-poor-quality forage per acre during a three- to four-month grazing season. A proven method exists that enables these kinds of pastures to produce four tons or more of excellent-quality dry forage per acre during a six- to seven-month grazing season. The method is controlled grazing management, as described by Andre Voisin in 1959. The Voisin method, also known as short-duration grazing, intensive rotational grazing, and rational grazing, has been used for many years in New Zealand and for nine years in Vermont. New Zealand's highly productive and profitable agriculture depends almost entirely on permanent pastures that are grazed under controlled management. Voisin grazing management is a simple system of controlling grazing by dividing pastures into small areas (paddocks) that are grazed on a rotational basis, minimizing the waste of forage and protecting the plants from overgrazing.
In contrast, many American farmers use a system of zero pasturing or year-round confinement feeding that involves large amounts of purchased feed and supplements, often resulting in low profitability. Feeding of livestock in confinement can cost six times as much as it does on well-managed pastures. First-year costs of materials, maintenance, and labor for controlled grazing management range from $1,500 to $2,000 for a 40-cow herd. Its use has returned $3.75 in benefits for each $1 invested by dairy farmers.
This project proposes to assist farmers in the northeast in using Voisin grazing management and to study and refine the method for this region. It has been developed with the active participation of dairy and sheep farmers, research scientists, Extension personnel, Soil Conservationists, and fencing industry representatives.
Investigators at the University of Vermont determined through work done from 1989-1990 that:
(1) The best method for estimating pasture mass was a bulk density rising plate, which was both inexpensive and easy to use;
(2) Plants recovered from grazing quicker, and net dry forage yield was greater during both years under sheep grazing alone (5,857 kg/na in 1989; 8,777 kg/ha in 1990), compared to cattle-grazed treatments (4,000 in 1989 and 3,117 in 1990);
(3) Sheep grazing increased soil levels of N and K, possibly reflecting more uniform dung distribution by sheep, compared to cows;
(4) Soil compaction was greater under cattle grazing than under sheep, and probably influenced numbers of soil organisms and limited plant growth;
(5) Soil CO2 respiration was lower under cattle than under sheep;
(6) Soil nematode numbers were three times greater under sheep than under cattle;
(7) Cattle rejected forage around dung pats on 34% of the pasture area in 1989, and 40% of the area in 1990.
Results from 1991 and 1992 include the following:
In studies that focused on the optimum grazing conditions for lactating cows, researchers found that in a grass/white clover pasture, cows should go into a fresh paddock when the forage is between six and eight inches tall, preferably after each milking. When the plants get much taller than six to eight inches, nutrients are wasted and taller plants start shading out others.
Post-grazing treatments such as harrowing or soil aeration are not needed if grazing is appropriate and soil texture is not conducive to excess compaction by livestock.
Grazing management can encourage the growth of white clover in the pasture.
Supplements (based on estimates of cows' dry matter consumption on pasture at 1.5 percent to 2.25 percent of body weight) increased milk production, but their cost exceeded the value of the additional milk. Further experiments are planned to determine at what level concentrates would boost milk production without diminishing profits, and whether reduced supplements would affect cows' body condition, breeding and milk production in the long term.
The Hanson farm saved over $12,000 in feed costs by using Voisin-style grazing between late April and early November 1992. Similar savings were achieved at the John and Brent Brigham farm in 1991. The Brighams, of St. Albans, Vermont, were the on-farm cooperators in 1992.
Results of the West Virginia experiments indicate that in general, more cattle are supported with more and better quality forage when the sward is grazed starting at a height of six inches to remove 75% of the available forage.
The above information helps to understand the complex pasture-livestock interrelationship, which is essential for obtaining full potential benefits from feeding livestock on pasture.
In seven additional experiments concerning supplemental protein feeding of cows grazing pasture at the University of Vermont, total milk production was 11% higher during feeding periods of a high rumen undegradable intake protein (UIP), compared to the low UIP feeding period. Milk protein production also increased during these periods, but milk fat percent did not change. If an inexpensive ration adjustment in UIP produces an 11% increase in milk production from cows on pasture, a major economic benefit is possible, making use of pastures by dairy farmers much more attractive.
The financial effects of incorporating well-managed pastures into farm feeding programs are being studied using a representative sample of ten dairy farmers who are using controlled grazing management. Preliminary results indicate that net return to farmers' labor, management, and interest is about six times greater for medium size Jersey herds on pasture and purchased winter feed ($47,628), compared to similar size herds under year-round confinement feeding with no pasture and all feed produced on the farm ($7,729).
Two videos of approximately 30 minutes each have been produced by Perceptions, Inc., of Charlotte, VT, with introductions by Dr. Bill Murphy from the University of Vermont. The first one introduces pasture management and strives to motivate farmers to at least consider incorporating well-managed pastures into their feeding programs. The second video focuses on pasture forage utilization and controlling livestock with electric fencing.
Topics under continuing investigation are the social organization and grazing behavior of cows in a well-managed pasture system; the actual amount of forage that cows eat on well-managed pasture; soil organisms in well-managed pastures; and the long-term effects of Voisin-style grazing on overall farm profitability.
(1) Determine sward dynamics, light relationships, net forage production, seasonal distribution, and effects of postgrazing grooming (harrowing, clipping, soil aeration) and manuring on white clover-grass swards, under various frequencies and intensities of dairy or beef cattle grazing.
(2) Determine effects of supplementing high levels of rumen undegradable intake protein and additional energy on milk production of cows receiving all roughage from pasture.
(3) Determine soil biota populations, microcommunity structure, fertility levels, and compaction under controlled-grazed pasture.
(4) Determine economics of incorporating well-developed, controlled-grazed pastures into dairy and beef farm feeding programs.