Here is some Coker 227 oats grown for seed but are also grazed. A critical decision that is make this time of year is when to stop cows from grazing so plants can produce seed. This decision is somewhat influenced by planting date but mostly by growth stage.
Small grains germinate and grow as seedlings before tillering. Following the tiller stage, the plant will begin the stem elongation phase. During this phase, the a node, or joint, will form at the base of the stem. This is a thickened area on the stem and is the growing point. If cows graze below the joint (growing point), this plant will not produce seed.
The first thing we want to do is look for joints. The decision to remove cows is based on grazing height and joint position on the stem. If joints are seen on stems but low to the ground and below the grazing height, cows do not need to come off the field yet. If joints are higher position and grazing is lower than joints, it is time to remove the cows. It would be a good idea to avoid grazing on a small area to observe growth the growth stage.
This field was planted in mid-November and is still in the tiller stage. Plants are 4-5 inches in height. We only found a joint on one stem, so this field can be grazed much longer removing cows.