Evaluation of Low-Input, No-Till, No-Herbicide Continuous Grazing System for Dairy Cows

Evaluation of Low-Input, No-Till, No-Herbicide Continuous Grazing System for Dairy Cows

Summary

Objectives
1.) Develop a planting scheme which would provide year-round grazing based on annual crops, which provide much higher level of nutrients than perennial grasses in the Southeast.
2.) Grow crops using sustainable agriculture methods. This includes using manure as the primary fertilizer, using no-till planting methods, and minimizing the use of chemicals.
3.) Maximize the use of grazing small grains, sorghum and alfalfa to high producing dairy cows and to reduce the amount of silage and grain fed.
4.) Economically evaluate this method compared to a system of feeding stored forages only.

Approach
This project was conducted by Clemson University at the Tom Trantham Dairy, located 35 miles from campus in Pelzer, SC. Mr. Trantham milks approximately 74 Holstein cows twice per day. Mr. Trantham farmed conventionally for many years but began to convert to a grazing-based dairy several years before becoming involved in this project.

Mr. Trantham is enrolled in the Dairy Herd Improvement Association (DHIA) and his Rolling Herd Average was 17,463 pounds of milk. This fluctuated during the course of the project and at one time was nearly 19,000 pounds. His somatic cell count was 280,000. The average pounds of milk produced during the 3-year study was 53.9 pounds per cow per day. Average milk price was $15.10/cwt. A feeding program for a 70 cow dairy herd was designed to maximize the use of grazing.

Basal ration
In addition to forage obtained from grazing, the feeding program during the project consisted of purchased corn silage and purchased grain concentrates. The amount fed depended on availability of pasture, milk production level, body weight, season of year, days in milk and milk fat percent, but in general, 25-80 pounds of corn silage and 17-25 pounds of grain were fed per cow per day.

The concentrate portion of the ration consisted of 12 pounds per cow per day of a pellet fed in the milking parlor (approximately 20% crude protein) and a custom mixture (approximately 22% crude protein) blended with silage and fed as a total mixed ration twice daily. In general, 5 to 12 pounds of the custom mixture were fed per cow per day and consisted of corn, corn distilled grain, soybean oil meal, wheat midds, soybean hulls, whole cottonseed, minerals and vitamins. In order to maximize dry matter intake from grazing, the amounts of silage and custom grain were reduced prior to placing the cows in each paddock. The amount could be lowered additionally while grazing a paddock if milk production remained steady or was increasing. If however, milk production dropped, the amount of grain and/or silage would be increased accordingly. Balancing the available grazing with grain and silage was a critical daily management decision.

The purchased corn silage was delivered to the farm and ranged in price from $36 to $42 dollars per ton. Both the pellets and the custom grain mixture were booked at various times throughout the project for various prices. The pellets ranged from $158 to $186 per ton and the custom mixture ranged from $151 to $228 per ton. It should be noted that the higher feed prices reflected the tremendous increase in feed prices during late 1995 and 1996.

Grazing
Mr. Trantham’s dairy farm consists of 95 acres, 50 of which were available for grazing the milking string. These 50 acres were divided into 8 permanent pastures for the cow herd plus one pasture for heifers. Movable fence was used to further subdivide each pasture into smaller paddocks. The size of the paddocks was dependent on the amount of forage available. This farmstead was ideal for converting to a pasture system because of its layout. The farm buildings were centrally located and the pastures were on the perimeter of the farm. No pasture was more than a 10-15 minute walk from the barn. Cows have access to woods from all pastures except 1 and 8. Cows were not left in pastures 1 and 8 for extended time periods during hot weather since they did not have access to shade. Sustainable agriculture techniques are utilized including no-till planting and manure is the main source of fertilizer. Use of herbicides and chemical fertilizers was been minimized. The paddocks were rotationally grazed.

A system was designed with the goal of utilizing grazing during as much of the year as possible. Rye, ryegrass, clovers, wheat, and triticale were planted in the fall and provided fall, winter and spring grazing. Several varieties of millet and sorghum were planted during late spring and early summer and provided summer and fall grazing. One pasture was planted in grazing alfalfa after the first year and was grazed during the spring, summer and fall of 1995 and 1996.

The amount of forage available varied considerably. Irregular rainfall throughout the project was a major factor contributing to the varying amount of forages produced. When a field was ready for grazing, cross fencing was used to subdivide the field into smaller paddocks if warranted. The amount of days each paddock was grazed varied from as few as 2 days up to 12 days.

Results
Results showed that the cows grazed the most nutritious parts of the plants. The neutral detergent fiber (NDF) of the crop offered (whole plant) averaged 59.41% but the portions that the cow ate were only 54.1%. This same trend was true for acid detergent fiber (ADF); the ADF content of the feed offered to the animals was 31.9% but the ADF content of what they actually ate was 29.0%.

This indicates that the cows ate the least fibrous portions of the plant. Conversely, the cows ate portions of the plant higher in crude protein (CP) than the whole plant contained, 24.4% versus 20.0%. These data illustrate one of the unique advantages of grazing. Had the cows been fed the same crops as harvested feed, they would have been fed a much lower quality product and would have had to expend energy digesting lower quality forage.

On days that cows grazed, they consumed an average of 9.6 pounds of dry matter per cow per day, which is approximately 25% of their dry matter requirement. When all costs associated with grazing were calculated, data for the three years of this study showed that grazing saved an average of $.31 per cow per day on days when cows grazed when all costs including fixed costs are included.

Since the cows grazed a total of 689 days out of 945 (73%), the total savings from grazing was $15,805.66 for an average of 74 cows. If only variable costs are included, grazing saved an average of $0.63 per cow per day over what it would have cost to feed this herd harvested feeds only. This might be the proper scenario for someone to consider if they already have all the necessary equipment and want to know how converting to a grazing system would affect their operating expenses.

Grazing winter annuals was shown to have an economic advantage of grazing summer annuals. This is not surprising since the weather in our region is much more consistent and desirable in the winter. The economic advantage of grazing winter annuals averaged $0.41 per cow per day whereas the economic advantage of grazing summer annuals was $0.21 per cow per day. There was also less fluctuation in the savings realized from winter annuals. For summer annuals, cost savings ranged from -$0.48 per cow per day in 1995 to $0.75 per cow per day in 1994 whereas the range in savings for winter annuals was from $0.23 in 1994 to $0.59 per cow per day in 1995.

Overall, it was financially advantageous to graze cows instead of feeding stored forages. There was, however, a wide range in results, and there were several times when the costs associated with establishing the crops were not recovered. This was usually due to adverse weather conditions.

The major problem associated with this project was unfavorable weather conditions. We did not have the capacity to irrigate pastures, so we often lost summer crops due to droughts. However, this is what farmers must live with, so the data is very realistic.

Impact of results
This project has received a lot of publicity and notoriety. We have received calls from dairy farmers all over the southeast interested in the project. The results clearly demonstrated that a low-input grazing system can be cost effective, especially when winter annuals were used. This type of system could be the key for survival for small family dairy farms in the southeast.

December 1997