As the summer has finally arrived and grass growth has increased significantly over the last few weeks, we are approaching in some cases drought conditions with soil moisture deficits prominent throughout the country of Ireland. Breeding programs are in full swing now and the excellent weather is very beneficial at this stage of the season. Despite the positivity in the air it is important to be mindful of where things can slip and become problematic.
Good advice is to keep mineral & vitamin supplementation elevated going right through the breeding season and to maintain body condition of calved cows.
The main aim for all dairy farmers must be to produce milk with a high solids concentration that attracts a higher price for milk; this is of particular importance when we will have extreme volatility in milk markets. I am seeing some problems that occur on an annual basis in terms of low milk solids produced per cow and there are many factors that contribute to low milk solids for dairy cows at grass:
- Insufficient herbage intake at grass which limits energy and the dairy cow will not reach her genetic potential for milk yield.
- Energy is the limitation of potential milk yield at grass and dairy cows must be supplemented with high density concentrates to bridge this shortfall.
- An energy shortage in the diet of the dairy cow is diagnosed when the milk protein is <3.0%
- High protein feeds can depress milk protein percentage when energy is the real root problem.
- The content of lush grass can have an effect on milk solids in terms of low butterfat percentages; lush grass can be very digestible with very low fibre levels.
In order to avoid such problems, it must initiate from the start of the lifecycle of the dairy cow. Dairy replacements must be selected for their high genetic merit for milk solids focusing particularly on milk protein and butterfat.
The genetic merit of milk protein explains 60% of the difference in milk protein between herds and over 80% of the difference between cows within a herd.
There are many other factors that will affect milk protein, for example, bull selection, replacement rate, calving pattern and soil fertility.
In order to counteract low butterfat levels at grass, I advise all customers to provide some digestible sources of fibre either in the form of hay/straw after milking. I have seen considerable success with chopped straw and molasses to increase palatability for spring cows post-milking. Alternatively, other digestible sources such as beet pulp or soya hulls work effectively to slow the rate of digestion. Rumen buffers will also act as an aid in stabilizing milk solids at grass, but will not single handily maintain butterfat values.
To increase the overall milk solids content of your herd, it may take time to achieve but seasonal effects in terms of grass quality and composition can be prevented with monitoring of herbage intake, providing cows with straw/hay and offering concentrates high in energy content.