Any grass mixture has the potential to make into hay. Unfortunately, what is growing in the field and the result in the barn can be vast, in terms of quality and quantity. There are several factors which influence the final hay crop, the main being the weather window, which certainly provides its challenges in the UK.

At one time hay was the most common method of conserving grass for winter feeding, and mainly due to the wet summers its place as a winter feed has been taken over by silage. Hay making involves the reduction of the grass dry matter to 13- 18% from 70 to 80%, at this moisture content, hay is fit to store. As you would expect the feeding value of hay is determined by the D value of the grass crop when it is cut, the earlier in the grass growth curve, the higher the D value.

Hay quality is also influenced by weather and degree of mechanical treatment it receives during drying in the field. The best hay is made in conditions that encourage rapid drying. In the early stages of drying plant cells continue to respire, resulting in the loss of soluble carbohydrate to carbon dioxide and water. The faster drying proceeds the sooner this process is stopped.

Another source of nutrient loss is the use of excessive working with machinery, as the leaf dries more quickly than stem, shattering of the leaf is increased and loss of plant material will occur.

Rainfall during the hay making operation not only delays harvesting but causes loss of soluble nutrients by leaching. Even sunshine, although essential for drying of the grass to hay, also causes substantial loss of carotene by bleaching. Incidentally carotene loss also occurs when the hay is stored.

Any grass mixture can be made into hay, but due to the process of turning grass into hay, mixtures containing red and white clover should be avoided, unless losses from leaf shattering are accepted.