On mixed farms it is common for sheep or cattle to graze cereal stubbles over the summer. At first sight it might seem that GrazFeed is not designed to help you with the nutrition of these animals. With some practice, however, it should not be difficult to adapt your estimates of the available feed to the stubble situation, and thus obtaining predictions of the animal production.

 

For the first few weeks after harvest, stubbles present a mixture of feeds; straw, fallen grain, and green feed. The values that you enter as your “pasture” description will include some or all of these components but the last two of the three will be by far the the most important for the nutrition of the grazing animals.

 

If this is present in abundance, say 2-6 tonnes of dry matter per hectare, a precise estimate of its weight (to be entered in the dead herbage field under pasture in the program) is not important. However, the quality of the straw will vary with the proportion of dead leaf, so that the estimate of digestibility may range from 50% for leafy straw to 40% when most leaf has disappeared. The digestibility of oat straw is usually higher than wheat straw, with barley straw of intermediate quality.

 

Animals with access to straw only will almost certainly lose weight; maintenance or gain of weight will depend on the presence of fallen grain or green feed in the stubble.

 

For a short period after harvest, fallen grain may provide a useful amount of high quality feed (80% digestible). As a guide to estimating the weight of fallen grain, a count of 400 grains of wheat per square metre represents about 100 kg of dry matter/ha. Estimates should be entered in the green herbage fields under Pasture so that GrazFeed can assess its contribution to the animals diet. If fallen grain is present but green feed is absent, ignore the field that is concerned with the height of green herbage.

 

Under moist summer conditions, weeds and germinating grain may provide green herbage for grazing animals. Estimate the weight and digestibility of this material as you would for a green pasture and enter estimates as ‘green herbage’ in the pasture dialogue box. However, in most stubbles this material is distributed quite sparsely and the average height estimate of green herbage may need to be increased over the default value suggested by GrazFeed.

Very often, fallen grain will have been eaten before much green feed emerges but if both sources of feed are present, your estimate of ‘green herbage’ will be made up of both components.

 

Testing the effect of supplements for stubble grazed animals can be described in the usual way within the same GrazFeed run.