Feed quality is a critical factor affecting milk production responses and profitability on a dairy farm. While the quality of all dietary components is paramount, grain and concentrate are generally nearly always of high feed quality. Variation in milk production between different batches of wheat or barley, for example, can still be observed.
The most important thing when considering feed quality is usually the forage component of the diet. Massive variation in forage quality can be evident between paddocks, different batches of feed and different seasons. This has a dramatic impact on milk production and also profitability.
Forage quality is affected by the level of structural carbohydrates in it, or the neutral detergent fibre (NDF) component. Young leafy plants are always more digestible, lower in NDF and higher in metabolisable energy (ME), which will provide greater milk production responses.
Cows eating more high-quality forages than poor-quality forages allows for more profitable diets and better milk production responses.
Conserved forages in particular can decline significantly in quality during the ensiling process, which leads to much poorer milk production responses. Grazed pasture, if not managed correctly, can also decline significantly in quality.
The following pages provide more detail on the importance of feed testing to more accurately formulate balanced rations, as well as the variation in the quality of perennial ryegrass pasture that can be expected in different seasons and between different cultivars throughout Victoria.