Figure 1.1. Aggregate milk price earned according to month of freshening. The returns are based on a 305-day lactation with 85% persistence of the lactation curve, representing 1981-87 prices in Federal Order 33.
Intensive grazing and seasonal dairying have not been well understood by dairy operators in North America. Yet, these are the fundamentals of dairying in other nations such as New Zealand where milk is produced at very competitive costs. Even though some U.S. dairy operators allow their cattle to be on pasture part-time, the feed acquired there is not regarded as significant to the total ration over the long term. The general pattern is to feed each cow individually with a ration balanced to her particular needs. That is improbable with grazing because the forage intake cannot be measured. Also, the nutritional quality of the pasture changes with varying stages of maturity and climate.
Overlooked in the above pattern are the advantages derived from intensive grazing of forages. These advantages can be both economic and ecological. Emphasis is placed on the intensive aspect of grazing. Through modern fencing technology, it is now relatively easy to partition larger pastures into small segments that provide 12 to 24 hours of forage requirement. Fencing difficulty has been one of the barriers to adoption of intensive grazing in the past. Lately, cost, efficiency, and portability of electrified fencing have become highly acceptable.
Seasonal dairying is a management plan that may enhance seasonal advantages of milk production or milk price (Figure 1.1). The basis of seasonal dairying is a 12-month calving interval with all the cows calving together in a brief time frame, such as eight weeks. Thus, with all cows calving together, ten months later, all cows can be turned dry together resulting in a closure of the milking facility for about seven weeks each year. The basic decision to be made is the choice of season to initiate the lactation period. If the advantages of grazing forages are to be maximized, calving should occur three to four weeks ahead of the onset of the grazing season. Then, every cow will be peaking in production just when the forage is most abundant and also most nutritious. Where land is best used for production of pastures, and when these pastures are to be used to greatest advantage, late winter freshening maximizes the conversion of forages to milk. Intensive grazing accomplishes the best harvesting at least cost.
There are other virtues for seasonal dairying. Most importantly, duties of the manager are arranged sequentially rather than simultaneously. This facilitates greater concentration on execution of management tasks, resulting in better management for the herd. The lifestyle is markedly more versatile for the dairy family and employees. Feed purchasing advantages are possible. Cows can sometimes be culled at better prices, depending on the season chosen. Summer heat slump and fertility problems can be reduced or eliminated under some models of management. Operating costs and housing requirements can also be reduced. The inherent 12-month calving interval may contribute to profitability.
The Mahoning Dairy Program was developed around the two fundamentals of intensive grazing and seasonal dairying. Because of the fragile tendency of the soil in that rolling terrain, it is best suited to forage production rather than tillage agriculture, which suggests the preference of late winter freshening for the Mahoning dairy. Forage management by intensive grazing was chosen for the following expectations:
The project site was formerly a beef production unit. An old bank barn with an attached silo and an open-sided shed were available. Forty-two acres (17 hectares) of poor pasture which had not been intensively grazed were included in the project. The pastures were fenced into paddocks of about five acres (two hectares) in size. The daily allocation of pasture was controlled with electrified polywire which was relocated every afternoon for a 24-hour rotation. A milk house was built within the bank barn alongside a six-stanchion milking area. The milking system included three milking machines, a pipeline, and a 600 gal (3,271 L) bulk tank.
To broaden the base of data interpretation, Holstein and Jersey breeds were equally represented in the 30 head of springing heifers assembled to construct the herd. These heifers were generally commercial in value, many resulting from natural service by home bulls. There was plenty of opportunity for genetic improvement during the five-year project.
Figure 1.1. Aggregate milk price earned according to month of
freshening. The returns are based on a 305-day lactation with 85%
persistence of the lactation curve, representing 1981-87 prices in
Federal Order 33.
Because the cows in the first year were all two year-olds, the herd health was more controlled and the performance of the two breeds was more understandable as the herd aged over the course of the five year project. Since no yearlings were on site the first year, it was decided to improve half of the pasture not needed by the herd through a minimum tillage alfalfa seeding. That pasture was to be switched for the utilized half during the second year to accomplish the improvement of the other half. However, the intensive grazing effect was so favorable, it was not deemed prudent to invest in the overfeeding process the second year. Meanwhile, the residual pesticide levels in certain pastures were monitored closely as reported later in this Bulletin (Chapter 11). Consequently, the alfalfa-incorporated pastures were taken out of the project after one year of use because of the pesticide levels in the soil.
The program was initially for Grade B milk production. There is substantial demand in Ohio for milk to be used in cheese production and the requirements for physical facilities of such a dairy are not as expensive as for Grade A. After three years of Grade B operation, following a relatively minor investment in barn improvements, the dairy was upgraded to Grade A status. This improved the blend price for milk about $1.50/cwt.
Compartmentalization of the program into modules helped define the areas of responsibility of the several scientists on the project. Also, portions of the overall project could thus be extracted and reported separately for various purposes. The modules were:
The dominant goal was to define a new dairy management program for
greater profitability in Ohio agriculture while remaining faithful to
environmental principles. Service goals were: (1) to develop and
evaluate the 24-hour rotation plan for pasture management, (2) to
design a nutritional program around grazing, (3) to operate the dairy
with a 12-month calving interval at an economically acceptable
involuntary culling rate, (4) to evaluate mastitis control under
grazing management, and (5) to understand the problems of
contaminated soil used for grazing.