Forage harvest has started

Gary Sliworsky
Ag. Rep.

Forage harvest has started in some parts of the district with some reports of slightly reduced yields. Forages in the area are about a week to a week and a half behind normal depending upon the amount of rainfall received, which has been quite variable.

For a dairy producer forages are probably the most important crop grown. They are the cheapest protein and energy feed grown for cattle while also benefitting any crop rotations with additional soil structure and self producing nitrogen.

Quality of forages is based on stage of maturity of both alfalfa and grasses, combined with harvest moisture and harvest losses. Alfalfa-grass mixes and timing of harvest decisions are also influenced by what other feeds are used in ration balancing.

Producers know that the ideal high quality forage has 20% crude protein (CP), 30% acid detergent fibre (ADF) (a measure of digestibility) and 40% neutral detergent fibre (NDF) (a measure of intake). Studies conducted on alfalfa forages revealed that these three main components in forages are affected by delayed harvesting. Crude protein content declines by 0.5%, ADF increases by 0.7% and NDF increases by 0.9% for each day past the peak harvest time.

A 6 day delay in cutting forage from the “ideal” can increase feed costs by up to 30 cents per cow per day - or over $5,000 per year for a 50 cow herd - depending upon which products are used to replace protein and energy lost in the forage. If the lost protein and energy is not replaced forages cut 6 days ‘late’ can cause a loss in milk production of 0.45 kg per day.

Ideally, alfalfa should be harvested at the early bud stage at a time when the physical development of the plant is used as a gauge of maturity and quality. Harvesting early allows the producer to get several cuttings in a year, increase level of production and improve quality of forage.

Once the first cut is taken, the second cut should be made 35 days later. Any additional cut should take into consideration the time required to build plant reserves for the winter. The first three weeks of growth is used to drain the root system and the next two weeks builds the reserve. A fall cutting should have either no regrowth or five weeks of growth.