Grazing management has a greater effect on the pasture than any other part of the pasture management program. Poor grazing management can lead to profit loss for farm businesses that depend on pasture as a key source of feed for their farm animals.

Overgrazing

What causes overgrazing: allowing animals to regraze plants before they are able to replace root reserves used for regrowth. Overgrazing reduces root reserves, which leads to fewer leaves and a weakened root system. Although juicy and tasty to grazing animals, these young, recovering plants must be protected. Also, overgrazing can lead to the loss of some plant species in the pasture and the loss of forage yield.

Table 1. Leaf Removal and Its Effect on Root Growth

Amount of Leaf Volume Removed (by percentage)	Amount of Root Growth Stoppage (by percentage)
10-40	0
50	2-4
60	50
70	78
80-90	100

All root growth stops for 12 days with 80% leaf removal and for 18 days with 90% leaf removal. Source: Dietz 1989.

Overgrazing also causes plants in the pasture to recover slowly. The rule of thumb for how long to keep animals in a pasture is to "take half and leave half." This means: noting the height of plants whenever you put animals to pasture for grazing; and removing the animals from grazing when they have eaten the forage down to about half its height.

This management tool allows plants in the pasture to regrow more rapidly. Table 1 shows how the percentage of leaf removal affects plant regrowth.

The effect of frequent, severe grazing on root growth. If the plant is not allowed to recover, the shallower root system could make it more susceptible to environmental stresses like drouth.

When pastures are grazed heavily and continuously, the forage plants are weakened. If this management persists, production will be lowered and desired plants may be eliminated and replaced by weeds. This will result in forage shortage and in increased need for supplemental feeding. In the beef cattle industry, the cost per day of feeding hay is generally considered double the cost of grazing. Extra feed cost because of poor pasture has a large impact on profitability of the herd.

Have a safe summer and we look forward to seeing you at these important educational programs.

• The US cow-calf or breeding sector is characterized by 830,670 beef producers, with the majority being small producers.
• Ninety two percent of the producers have less than 100 cows but account for 48 percent of the 33 million head beef cow inventory. The remaining 10% of the operations have 52% of the cows.
• The group of producers with more than 500 cows account for 0.7% of the beef cow operations and 15% of the cattle inventory.
• The producers with larger herds are the most likely group to participate in an alliance that requires retaining ownership of the cattle beyond breeding.
• The actual number of producer participants in alliances is not known. There are approximately 30 production and marketing alliance organizations in the US in 2002.

(Source: Texas A&M University, Department of Ag Economics).