Kingshay Good Grass Guide 2007 Results

Kingshay has been testing and reporting on the effectiveness of additives for over 10 years. They give the results, good or bad, completely independent of commercial bias.

The Trial:

· All the additives were tested alongside a no additive control
· All additives were applied at the recommended rates
· Four mini-silos of silage were made for each of the treatments
· The grass was tested for quality and contamination before ensiling
· The silos were sealed and left for 12 weeks
· On opening, the silages were tested for quality and contamination
· The silages were exposed to air and aerobic spoilage was monitored
· The results were statistically analysed to highlight any significant differences betwen the treatments

GRASS QUALITY
These additives were applied to a crop of perennial ryegrass from a 4 year old sward with approximately 10% clover. The grass was cut at Bridge Farm, Glastonbury during late morning on the 31st May 2006. The crop was wilted, then picked up by a trailed forage harvester on the 1st June. The weather and a delayed cutting date meant mature material was harvested which affected protein quality but good sugar levels and dry matter was achieved. More mature crops carry a heavier yeast and mould count, analysis of the grass at ensiling including lactobacillus count and yeast & mould count is given in the table below:-

Quality of grass entering the silos

Out of the additives tested Optimize was said to be an inoculant and enzyme combination which is designed to maximize stability of the silage at feed out, whilst improving the digestibility of the fibre fraction.

RESULTS:

The consequences of using an additives compared to the no additive control, on aerobic stability were assessed.
The results of Optimize verses the no additive control are summarised in the table below.  The full trial shows Optimize showed significantly better stability than all others tested.  For further details contact liz@envirosystems.co.uk or telephone +44 (0)1772 860085.  

Aerobic Stability

Aerobic stability is an important factor to consider in assessing the production capability of silage. Often silage heats behind the silage face up to 1m back  and when this occurs the silage is already spoiled long before you feed it to your cows. If the silage is spoiling faster than you can feed it, then significant feed value is lost. The presence of mould may also lead to lower feed intakes and lower utilisation of the silage. In addition the silage can loose volume in the pit and in the trough meaning the as the winter progresses the silage volume reduces faster than it should and can mean a shortage of silage around or before turn-out.  In the trial the different innoculant types affected the aerobic stability of the silage in different ways.

• The no additive control increased in temperature over time. Silage treated with Optimize stayed cooler than the no additive control.  
• The trial proved there was plenty of naturally occurring lactobacillus on the forage to ensile and acidify the crop to the required 4.00 pH 
• The yeast and mould stabilising properties of the Optimize bacillus used in conjunction with lactobacillus already available on the crop (see chart above) means stable forage which  easier to handle at feed out with little or no heating and does not reduce in volume in the pit.

Conclusion:

Optimize was the only silage innoculant that did not contain Lactobacillus. Lactic acid production in the Optimize treated silage was entirely derived from the naturally occurring lactobacillus. This was sufficient to reduce the pH to 4.00 - the desired pH for high intakes.   Lactobacillus convert plant sugars into lactic acid.  Plant sugar is a perfect energy source for a dairy cow  and it is beneficial to the stability and digestability to limit lactic acid production whilst achieving stability.  Higher levels of lactic acid can lead to instability and inhibit intakes. It can be seen below that the quality of grass entering the silo in this experiment shows grass alone contains  large numbers of lactobacillus and yeast and mould spores:

cfu/g = colony forming units per gramme of grass

The above findings show that spoilage caused though yeast and and moulds is a greater threat to the feeding quality and nutrient value of your silage than the risk of insufficient lactic acid to achieve a successful fermentation.  The primary function of the Optimize bacillus is to eliminate spoilage organisms such as yeast and mould and soil born pathogens such as clostridia and listeria. Stability is the main aim meaning your cows want to eat more, achieving a healthy digestion which offers higher production and milk quality.  In the trial the high aerobic stability achieved by Optimize meant that the silage stayed cooler for longer than with the no additive control and the other inoculants tested even when air was deliberately introduced. It shows farmers can rely on Optimize to achieve palatable silage with less waste even when conditions are  not perfect.  In the best conditions the quality of the silage which you can produce achieves competition winning silage and importantly, money making silage.