Forage Production for Cow and Calf Operations
Most cattle producers in Tennessee realize that a solid forage program is key to having a profitable beef cattle operation. Providing forage for grazing for as many days of the year as practical will reduce feed costs, as well as the costs of producing a weaned calf. There are many opinions on forage production practices, and many alternatives with respect to forage species, fertilization, weed control, and grazing management. Developing a plan for the species and practices that will be used will make decisions easier during the year.
What are the basics of forage production for Cow and Calf?
Forage for growth and quality?
What are the basics of forage production?
There seems to be a constant flow of new forages, herbicides or fertilizers on the market that are going to “solve” all the problems in pastures. New solutions seem to be popping up every few years, apparently because the others didn’t work as well as advertised. Producers who have successful forage programs generally have one thing in common. They understand the basics of forage production, and put those basics into practice each day. It is not that they don’t try anything new, but they make sure the basics are covered first. This is an important lesson for all forage producers to understand.
There are a few basic management practices that all beef cattle producers in Tennessee should be incorporating into their farming practices. Following are brief discussions of these basic practices.
(1) Fertilize according to soil test. If forage is to be produced, the nutrient level in the soil is the starting point. Plants need large amounts of nitrogen (N), phosphate (P) and potassium (K) to produce at the greatest level. If the available supply of one or more of these major nutrients is lacking, forage production will be limited. If too much fertilizer is applied, costs will be increased without improving forage growth. The only way to know the amount of N, P and K to apply on a field is to take a soil test and follow the recommendations
Another piece of information a soil test provides is the pH, which indicate the acidity of the soil. As the pH of a soil decreases, several elements that are toxic to the roots get released from the soil particles, while some of the nutrients that are needed for plant growth get bound to the soil, limiting their availability to the plants. A soil test will determine the pH of the soil, and amount of lime needed to raise the pH and improve growing conditions in the soil.
(2) Control weeds in pastures and hayfields. Weeds in pastures and hayfields can reduce forage quality, as well as using fertilizer intended for the forage plants. An important part of a forage program is minimizing the negative effect of weeds. A good fertility program and periodic clipping will help, but some weeds cannot normally be controlled without the periodic use of herbicides. Scout fields to determine which weeds are present, and then use the appropriate herbicide(s) when needed.
Several weeds are easily controlled if sprayed at the correct time. Buttercup and musk thistle are two examples of winter weeds that can be controlled with a low rate of 2,4-D if they are sprayed before they bloom or bolt (in the case of musk thistle) (Table 6-1). If the herbicide is applied after bloom or bolting, control will be greatly reduced. Weed plants that produce seed early and the surviving plants will provide adequate seed for next year’s weed crop. When using herbicides, be sure to read and follow all label instructions.
Table 6-1. Control of Buttercup with Two Herbicide Application Dates.
| Application Dates | |||
| Application | March 17 (before bloom) | 25-Apr | |
| Herbicide | rate/acre | (after bloom) | |
| ----- pints ----- | ----- % of buttercup controlled ----- | ||
| 2,4-D | 2 | 99 | 70 |
| 2,4-D | 4 | 99 | 85 |
(3) Add clovers to grass pastures and hayfields. Adding red and white clover to grasses can improve forage quality, which will improve the performance of the animals. Since clovers produce nitrogen, a tall fescue/clover mixture will produce the same yield as a tall fescue stand fertilized with 60 lb N per acre. Broadcast 2 lb white clover and 4 lb red clover per acre in mid to late February. This should be done every three years to maintain adequate stands of clovers in tall fescue pastures and hayfields.
(4) Stockpile tall fescue in fall. One of the greatest expenses for a cow/calf operation is winter feed. Stockpiling the fall growth of tall fescue is a way to lengthen the fall grazing season and reduce winter feed costs. Stockpiling means setting aside up to one acre per cow in early September, fertilizing with 180 lb ammonium nitrate per acre then letting growth accumulate until after frost. For fields that weren’t fertilized in spring, potash and phosphate can be added at the same time to correct any nutrient deficiencies. This growth can then be grazed during the remainder of the fall and into the winter. Forage produced by tall fescue in the fall does not drop in quality as fast as forage produced in spring. Research has shown that the forage can stay above 10 percent crude protein all the way into February (Figure 6-1). With normal rainfall, stockpiling can add an extra two months to the grazing season, for about half the cost of hay.
Figure 6-1. Crude protein (CP) and digestibility changes of fall-stockpiled tall fescue.
(5) Minimize hay storage losses. Round bales are the most popular form of packaging hay for winter feeding. Producing round bales has made it much easier to handle hay, compared to square bales. However, many of the round bales are stored outside, unprotected from rain and snow during the winter. Round bales will shed this moisture better than square bales will, but rotting still occurs. Research has shown that the outside six inches of a round bale can be lost to rot if stored outside, uncovered. The outside six inches contains 30 percent of the hay that is in the bale. Storing bales unprotected from the elements result in a loss of one-third of the hay produced (Table 6-2). If a round bale is worth $15, then for every bale stored outside, uncovered, $5 is lost. Store bales in a barn if possible. This will result in the least loss. If this is not possible, cover bales with a hay tarp. Losses will also be decreased if the bales can be gotten off the ground, by placing bales on a rock pad, or on tires, pallets, etc.
Table 6-2. Effect of Storage Method on Hay Loss
| Storage Method | Percent Loss |
| barn | 6 |
| hay tarp | 12 |
| uncovered, on ground | 35 |
The points listed above are five basic practices that every producer should have in the program. Before trying to move on to what is considered to be more intense management practices, be sure that the basics are covered. The points listed above can do more to improve the profitability of a forage program than any others.
Forage for growth and quality?
When trying to design a forage program, producers often try to consider so many factors that it becomes mind-boggling. If basic plant physiology, how and when a forage plant grows is considered, improving a forage program will usually become easier, especially in developing a controlled grazing system. The purpose of a controlled grazing system should be to improve the utilization of the high quality forage produced on the farm. In order to improve this utilization, it is helpful to understand plant growth and quality, and the factors that affect them.
Forage Quality
For this discussion, forage quality is defined as the relative amounts of protein, total digestible nutrients (TDN), and fiber that are present in the plant. The goal is to have a plant high in protein and TDN, and low in fiber. The result will be a forage that is nutritious, highly digestible, and will provide good animal performance.
In general, as a plant becomes more mature, fiber levels will increase, and protein and TDN levels will decrease. As leaves mature, fiber is laid down in the leaves, so quality will drop. Also, as a plant switches from vegetative growth (leaf production) to reproductive growth (seedhead or bloom production) the quality of the forage will decrease. This is because there is more fiber in the reproductive structures than in leaves, so the quality of the overall plant will be lower.
Quality vs. Quantity
For the best quality possible, forage should be cut when it is very young. This will provide young leaves that contain very little fiber and are very high in protein and TDN. The problem is that the yield will be very low. To produce the largest quantity of forage possible wait for the forage to get old and mature, with as many seedheads as possible. The problem here is that the quality will be very low. For the most efficient forage production, a mid-point should be desired.
The goal is to produce a good tonnage of a high quality forage. Maybe not the highest quality or quantity, but acceptable levels of both. Figure 6-2 illustrates forage accumulation over time. During phase 1, forage quality is high, but tonnage is low. During phase 3, tonnage is high but quality is low. Harvesting during phase 2 should be the goal.
Figure 6-2. The three phases of forage growth
Managing Leaf Area
One of the most important factors influencing forage growth is the amount of light that is absorbed by the plant. Because plants need sunlight to carry on photosynthesis, growth depends on sunlight, as long as the other nutrients are available (water, fertilizer, etc.). Because of this, the management of a plant’s leaf area will influence yield. Look again at Figure 6-2. Early as the plant begins to grow, there is not much leaf area available to capture sunlight. Most of the light is falling on the soil around the plant. Because of this, the growth rate during phase 1 is slow. Since the plant can’t produce the energy it needs to grow, its growth is dependent on stored energy from the roots. As the leaves begin to develop, more sunlight is captured, more energy from photosynthesis is produced, and less root carbohydrates are needed. This cycle begins to build on itself. More energy means more leaf growth, which captures more sunlight, which means more energy, producing more growth, and so on. Phase 2 is characterized by a very rapid growth rate. As the plant moves into phase 3, the leaves produced during phase 2 get older, are less efficient at photosynthesis, and growth rate slows. The amount of forage accumulated comes to a halt.
Overgrazing vs. Undergrazing
Figure 6-2 is the basis for the benefit for rotational grazing. In phase 1, the forage quality is high, but quantity is low. The plant is depending on stored energy for its growth. If a plant is forced, through overgrazing to stay in phase 1, forage quality may be high, but eventually the plant may run out of energy in the roots, and will die. Some species are more sensitive to overgrazing than others. It is easy to kill alfalfa and orchardgrass by overgrazing, while bermudagrass and tall fescue are harder to kill.
If plants go into phase 3 before grazing, they are able to keep high levels of root carbohydrates, but a lot of forage matures before harvest, so efficiency is reduced. The best management is to let the plants get into phase 2, then graze and force them back into phase 1. Then after they grow back into phase 2, graze again into phase 1.
As difficult as we would like to think rotational grazing is, it boils down to this simple point. Rotational grazing is used to manage the forage growth curve shown in Figure 6.2.
FORAGE PRODUCTION FOR COW AND CALF OPERATIONS
Gary Bates, Professor and Extension Coordinator, Forage Specialist, The University of Tennessee
