Timing really is everything with silage quality
Published 03/06/2015 | 02:30
Many dairy farmers around the country will have their first cut silage in the pit at this stage. Others may find themselves checking every weather forecast available in a bid to find a window of opportunity start cutting.
In Kerry, last week required a snatch and grab approach as mowers and harvesters tried to work around the intermittent showers. It was either this or wait and take a chance on the weather improving. However, every week you wait, the silage crop ages and the quality declines.
The quality of the grass at harvesting determines the quality of the silage. High quality silage depends on the stage of grass growth, which is inversely related to yield.
For example, one study has shown that a cut of silage, taken in early May resulted in high grass quality with 25pc crude protein (CP) and 75pc digestibility (D-value). Unfortunately, however, the yield was only 3t of dry matter (DM).
By waiting two weeks the yield increased to 6t DM, but quality was now 18pc crude protein and 68pc digestibility.
By the end of May the yield had increased further to 8t DM, but grass only had 12pc crude protein and 60pc digestibility. A similar study compares yield against dry matter digestibility (DMD) as outlined in the table, and sees a huge 5.4pc fall in DMD between May 29 and June 5. So, in essence, timing is everything.
My renewed interest in silage quality is actually driven by the abolition of milk quota. This will be the first autumn with no restrictions on milk production except for the price being paid. Many farmers will use this opportunity to create decent incomes for later on in the year.
However, will milking on and exploiting the opportunity to increase the herd's days in milk come at a cost?
Within the last two weeks many farmers have reached their 21-day submission rate. This was a good breeding season overall and, for once, the 90pc submission rate target seems to have been widely achieved rather than being the preserve of just the top 10pc of operators.
Which then leads me to wondering why the 2015 mating season has been so good?
It comes off the back of a good 2014 mating season. In breeding terms, success generally breeds success, so a tight calving spread one year helps you achieve a tight calving spread the following year as most cows get sufficient time from calving to the start of mating.
Secondly, while it might have had a few sticky moments generally it was a good spring, with cows being fed well at grass.
More importantly, however, cows were in good condition at calving, and as a consequence they were in good condition at mating.
I can't help thinking that this condition score was driven by the early drying off of cows as a consequence of milk quota and the heightened risk of superlevy last spring.
For some farmers this was also the case in 2013.
Because body condition score is not commonly measured on farm I cannot definitively prove that increased condition score improved mating this year but I do believe it was a significant factor.
So my concerns are that cows will potentially milk longer in 2015 and with a greater use of silage to produce this milk. Where this is the case, the importance of harvesting high quality silage will be critical, and body condition score will have to be actively managed using staggered drying off.
The positive effects of 2014's long dry period on breeding could be lost in one or two seasons if we don't actively manage the gains.
It is therefore essential that farmers check the quality of their first-cut and second-cut silage, and all baled silage, to assess its potential to feed both the milking and dry cow.
Mary Kinston is a discussion group facilitator and consultant, and farms with her husband in County Kerry.