Paddock Talk
When to cut hay and silage – Quantity vs Quality
With the warm weather upon us many producers are in the midst of cutting or waiting to cut
pastures and/or crops for hay and silage. The million dollar question is ‘When do I cut?’ and
the honest answer is ‘It depends’.
To elaborate on that answer a bit further, it depends on what you are wanting to do with that
feed later on. Fodder conservation is all about maximising the quantity and quality of feed in
the bale or stack.
If you are looking to finish animals or feed lactating ewes or cows later on you will need the
highest quality feed possible, if you are simply looking for a forage for maintenance of dry
ewes or cows then you can afford to give up a little quality for more tonnes of dry matter.
Similarly, if you are producing fodder to sell then think about your potential market and what
they might be looking for.
In terms of good quality I am referring to high levels of digestibility, metabolisable energy
(ME) and protein.
In general, the earlier we cut the higher the quality but potentially lower the yield, the later we
cut the higher the yield but lower the quality. Silage will often produce higher quality feed
than hay from the same cut.
The key message about time of cutting is that the quality and quantity of forage will never be
any better than the day you cut it. Poor quality crop or pasture will make poor quality hay or
silage, high quality crop or pasture has the ‘potential’ to make good quality hay or silage. I
say potential because from the day we cut it to the day it is stored we are trying to minimise
the losses in quality.
Things that impact on yield and feed quality are:
Crop or pasture type – The quality of the parent forage sets an upper limit on the quality of
silage or hay conserved. Young temperate grasses and legumes such as ryegrass, lucerne
and clover have a high forage quality potential but maybe not as higher yield as cereal
crops. Mature grasses or crops such as phalaris or cereals will have a lower quality
potential.
Soil fertility – Soil nutrition can not only effect yield through lower growth rates but also feed
quality. A grass pasture or crop that is nitrogen deficient will have lower protein and ME
levels as nitrogen is a key component of amino acid and protein structure in the plant as well
as chlorophyll which is used to photosynthesise and produce sugars in the plant.
Weeds, pests and diseases – Quality and yield may decline with infestations of weeds,
pests and diseases. For example barley grass and silver which goes to head a lot quicker
than clovers and ryegrasses will significantly reduce the average quality of your fodder.
Select paddocks free from weeds or identify patches in a paddock and bale them separately
from the rest. Be careful then where this feed is distributed later on as it may spread seeds.
Growth stage at harvest – Forage quality is highest when the plants are in the early
vegetative stage. As grasses mature they become more fibrous and their forage quality
drops rapidly. Legumes will decline slower than grasses but run the risk of collapsing or
slumping as the weather warms up, making them hard to physically cut. Cereals, such as
wheat and oats, are of highest digestibility and protein content when young and leafy. As
they mature, energy is mobilised and becomes concentrated in the grain, stems become
more fibrous and less digestible, and some leaves die off.
In summary, the earlier you cut the higher potential for making good quality hay and silage.
In finding that balance between quality and quantity some general rules of thumb would be:

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For temperate grasses and legumes before flowering and even better before head
emergence.
For cereals either flag leaf or booting (early ear emergence) for quality or at the milky
dough stage if you’re looking for quantity.
References: Successful silage manual, Top Fodder course, NSW Department of Primary
Industries.
Ashley Paech
Farming Systems Officer, Holbrook Landcare Network.