- Short term ryegrass should be sown in autumn to ensure rapid establishment with warm soil temperatures. In certain parts of New Zealand there is the opportunity to spring sow.
- If barley grass is likely to be a problem, wait for a germination of this weed and spray before sowing.
- Annual broadleaf weeds can easily be addressed after sowing maximising pasture yield.
- Ideally sow with starter fertiliser.
- If broadcasting, lightly harrow or roll to ensure good seed soil contact. If moisture is marginal rolling will help germination.
- If drilling, ideally sow into moisture at around 10 -- 15 mm depth.
Post emergent weeds and pests
- Consider the use of selected seed treatments for early insect control in high pressure areas.
- Be vigilant over the first few weeks for any signs of insect pest damage. Identify broadleaf weeds early and control them whilst they are small. Ensure that you observe any stock withholding periods after spraying.
Graze early and feed your pasture
- New pasture should be grazed as soon as plants will withstand pulling. This early grazing will encourage rapid tillering and tiller density per square metre will influence early feed production.
- If legumes are sown in the mix, it is important that they are not crowded out by allowing the pasture canopy to close over and block sunlight to the clover.
- Pastures should be continually grazed at the three leaf stage to best balance feed quality, recovery after grazing and total feed production.
- To get the most out of a short term pasture, ensure good plant nutrition. It will respond to applications of nitrogen in particular (and any other nutrient that may be limiting).
- Application of nitrogen will be most efficient under cool moist conditions, but not under consistent frosts. Time the application to grow quick feed going into winter and to provide an early spring flush.
- Late applications of nitrogen can extend the growing season and provide increased quantity, and help maintain quality.
- Ensure that pasture is eaten down well and evenly prior to lock up for fodder conservation. If necessary top any remaining patches from last grazing.
- Apply a balanced topdressing of nutrients to ensure maximum yield and quality and balance nutrient removal.
- For maximum quality and to obtain multiple cuts lock up 4 - 6 weeks before cutting.
- Where multiple cuts are desired, remove cut fodder quickly and re-apply further fertiliser to ensure rapid regrowth and best quality.
Megajoules of metabolisable energy (MJME)
MJME is a calculated value that indicates the energy rating of a pasture. The higher the MJME value of a pasture, the more likely that stock will perform well on it. MJME is a useful, general guide to probable animal performance from a pasture.
Some limitations of MJME are:
- MJME is a calculated value only.
- MJME values for pasture should not be compared between different laboratories because labs often use different equations to calculate MJME values.
Increasingly we are using other measures of pasture quality to predict probable animal performance, including neutral detergent fibre (NDF), crude protein and non-structural carbohydrates.
Neutral detergent fibre (NDF)
NDF is a measure of the amount of cell wall (or fibre) in a pasture sample. The higher the NDF, the more fibrous the pasture. NDF is a useful indictor of probable feed intake. Often lower NDF pastures also digest more rapidly in the rumen which equates to more energy available to the animal.
- Very low NDF diets (e.g. very lush pasture plus high rates of cereal grains) are linked with low feed intakes because there's not enough fibre for normal rumen function = risk of rumen acidosis.
- Moderate NDF diets are ideal for good feed intakes - a pasture with an NDF of 35% supports good feed intakes by cattle.
- High NDF diets can limit intake because stock find harvesting this fibrous feed difficult and high NDF feeds break down too slowly in the rumen.
Sometimes pastures don't contain enough NDF for normal rumen function. New pastures at their first grazing, pastures after the first autumn rains and pastures during peak growth in the spring are sometimes characterised by low NDF.
A supplementary fibre source may be required occasionally.
Crude protein (CP)
CP is the amount of nitrogen in the feed x 6.25.
CP gives us a measure of how much protein is available to feed both the rumen microbes and the animal. Too much pasture CP is common during parts of the year (autumn, winter and spring).
Not enough pasture CP can be a problem when:
- Late spring/summer when ryegrass is heading and/or moisture stress causes loss of leaf.
- Severe frosting of pasture causes loss of leaf.
- Stock are being supplemented with considerable quantities of low protein supplements.
Non-structural carbohydrates (NSC)
NSC include simple sugars and water soluble carbohydrate complexes including fructosan. NSC are 'fuel' for rumen microbes.