GrassWatch 30 July 2020

30 Jul 2020

Wendy Hutton, one of our dairy specialists gives us an insight into current grass performance (29 June)

Acid load

The grass watch testing this week has highlighted the increase in the acid load figures (changes to the pH in the rumen) which has a knock on effect on butterfat production. 

From spring throughout summer, grass is readily fermentable and can also cause high Polyunsaturated Fatty acids (PUFAs).  These factors contribute to acid load in the rumen and are prerequisites for Milk Fat depressions. A high acid load, this week’s figure 37, can cause a reduction in ruminal pH (more acidic) this in turn has an effect of the microbial populations and reduces the production of butterfat within the milk. 

There are a number of ways we can help to balance this:

  • Yea-sacc

Yea-sacc is a live yeast culture that will assist to remove the oxygen from the rumen environment.  The removal of this oxygen will be of benefit to the fibre digesting bacteria within the rumen, which can increase the fibre digestibility and in turn increase the potential butterfat yields.  Yea-sacc has also shown to benefit rumen efficiency, improve fertility and is certified with the Carbon Trust.

  • Buffer feeds

Buffer feeds in the form of a straw or fibrous forages help to promote rumination (cudding) and stimulate saliva production.  The addition of these buffers will improve the rumen conditions required for the production of the mirobes which assist in butterfat production.

  • Rumen buffers

Rumen buffers such as Alkacid are another option.  Alkacid is a product that helps to maintain the optional pH for the microflora to work at their optimum levels.



The increased rainfall has resulted in less favourable growing conditions for grass.  Overall the average grass growth in the UK has fallen by 4kg/DM/ha/day on the previous week to 56kg DM/ha/day.  Scotland has been an exception and seen a slight increase of 2kg from 62kg to 64kg/DM/ha/day.  With the reduction of grass growth the average Milk Yield From Grazing (MYFG) has decreased to M+ 8.43 litres/day, compared to M+13.48 litres/day on the previous week across the UK but Scotland has recorded M+18.6litres/day.

Copyright Trouw GrassWatch


Speak to your dairy specialist for advice about strategies to help you balance and maximise performance from grass and which Harbro products will help to complement your system.

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