Factors which affect hay quality
A quality hay starts with the soil in which the grass and wild plants or herbs are grown. The variety of grass and other plants used is also important. Even they are not enough without the right climate for the grass to grow and be harvested at the right time.
1st cut Timothy hay tends to be coarser, stalkier, higher in fibre and lower in protein than the softer, leafier 2nd cut Timothy hay.
In the UK it is not always possible to get the 1st cut hay cut in time if the weather is bad. When this happens the grass does not grow long enough to produce a 2nd cut. The resulting late cut hay lies somewhere in-between 1st and 2nd cut with a higher protein content than regular 1st cut and a lower protein content than 2nd cut.
Which is the best hay?
High fibre hay such as 1st cut Timothy hay is ideal for obese animals, helps to prevent boredom and is fed as a complementary feed (ad lib). Hay which is higher in protein, such as 2nd cut Timothy, Mountain or Alpine meadow hay, can replace some of the regular diet as well as being a source of fibre.
As a general rule, the greener, leafier or softer the hay, the higher it is in protein, calcium, vitamin C & chlorophyll; the stalkier and more golden the hay, the higher it is in fibre and vitamin D.
Grass and other plants take up minerals from the soil they are grown in. Hay made from grass grown in poor or heavily cultivated soil tends to be lower than naturally grown or organic hay in essential minerals and trace elements.
Clover, alfalfa and other legume related forages, help to fix nitrogen to the soil reducing the need for nitrogen based fertilisers.
Cutting and baling hay
The optimum stage at which Timothy grass or perennial ryegrass should be first cut for hay is at the Early Heading stage. This is where the flower head is visible but still green, before the seeds have matured. Grasses grown in hotter climates, such as Bermuda grass or Orchard grass, should ideally be harvested in the Boot Stage where the head just appears beyond the leaf roll.
If the grass is too wet to cut at this stage, the grass may be too stalky and lacking in leaf by the time it can be cut. The resulting hay would be lower in protein, higher in fibre and subsequently lower in feed value than desired. Grass which is allowed to become too dry before cutting has an obvious golden colour. If the grass is too mature, golden seed heads will be visible in the hay and the seeds will fall out easily.
The period between cutting and baling, known as Curing, is an important stage in hay making. The grass must lose enough moisture in this time so that it is no more than 18% – 22% moisture when baled. Raking the hay to encourage it to lose moisture during the curing period helps. However if the grass is too dry when it is raked, leaf loss, known as ‘leaf shatter’ will occur and affect the protein content and food value of the hay. If the hay gets rained on during the curing phase, nutrients will leach away from the hay, detracting from its food value.
Crushing the stems of the grass during mowing is known as ‘conditioning’ and helps the stalks to dry out at a similar rate to the leafy material. This helps ensure that when the hay is baled, the moisture content is the same throughout. Hay continues to lose moisture once it is baled so freshly baled hay should not be stored tightly together. This is one reason why you will see baled hay left in the field to cure further before storage.
Storing hay & identifying hay quality
If the hay is baled at the correct level of moisture, after proper curing, it will keep well if stored properly. Good hay can be identified by it’s green or green-gold colour, sweet odour and flexibility of the stems even in coarse hay.
Hay which has been baled at too high a moisture content is at risk of excessive heating, (sometimes to the extent where it will spontaneously combust), and the development of mold spores. The classic ‘exploding bale’ is one which has been baled damp. Brown areas on the bale are an indicator of this. Dark brown to black areas indicate rain damage. Sun-bleached hay with a straw blonde colour will have lost a lot of it’s nutritional value. Bad hay is brittle, the stems cracking easily when bent. The stems of good but coarse hay will bend and break into segments which remain connected.
One of the best ways of checking for good hay is to use your nose. Good hay has a classic aroma which comes from a plant chemical called coumarin. Poor hay on the other hand often has a musty or similar ‘off’ smell to it. Hay which has been infected with mould can cause sneezing even if the obvious black or white puffs of spores are not visible.
Throughout the country, hay is visible stored in fields. The cost to the farmer of moving and storing they hay is weighed up against the loss of quality or feed value that outside storage entails. Hay that is in contact with the soil, wicks moisture from the soil and is at risk of mould and overheating. Rain damage can cause discolouration and lack of nutrients whilst, on the other hand, wrapping hay that is already too damp can cause further deterioration because the moisture cannot evaporate.
Hay should be stored off the ground, protected from sources of moisture and with adequate ventilation. Correctly cured and baled hay can be wrapped in plastic to prevent moisture getting to it but poor hay would worsen under such conditions.
Purdue University’s pages on Forage Identification