We are frequently asked by our grass based dairy farmers clients ‘what is the milk response to feeding concentrates at grass?’  These are businesses that focus on maximising the use of grazed grass, typically concentrates are fed when grass availability is limiting.  We have however seen a movement towards increased concentrate feeding rates, this has often been tied in with stocking rates that have been purposely increased to maximise grass utilisation during the peak spring and summer growth months.  We are therefore now seeing a large variation in stocking rates and supplementary feeding levels within spring calving systems.

The below scatter graph shows the range in feeding rates expressed in kgs of concentrate per cow and the yield per cow in both litres and kgs of milk solids.  This data is for 70 spring calving businesses all located in Wales and covers the 2017 grazing season.

Concentrate feeding levels in the data set range from 200 kgs to over 2,000 kgs per cow, with yield ranging from 3,700 litres to 7,300 litres per cow.  The above scatter graph shows an average response rate to feeding was 1.4 litres per 1 kg of concentrate fed, when expressed in kgs of fat & protein this equated to 107 grams of fat & protein per kg of concentrate fed.  These figures are consistent with analysis we have completed for previous years.  From the above it would suggest there is a good response to feeding concentrates at grass, however these figures differ significantly from the data that’s available in Ireland and New Zealand.  The data therefore needs to be looked at with an understanding of why these variances occur.  It also needs to be noted that there is a significant variance within the data set i.e. each side of the trend line.

Typically, with increased supplementation it would be expected that it would have a negative effect on grazing residuals and grass quality.  In addition to the cost of supplement there will be the other costs in your business, i.e. possibly more silage on the platform plus cost of dealing with poor residuals.  It would be expected that the latter would increase the costs of production.

The below table groups the same data set into three feeding level categories.  The data shows that the higher stocking rate farms which by default have higher feeding rates have achieved a higher Comparable Farm Profit per ha while still maintaining a comparable cost of production i.e. a comparable margin per litre, but over more litres.

As a policy on simple grass-based systems, this intensification does go against the grain, but again an understanding of the data is important.  There a several factors that need to be taken into consideration.

• Typically, the grass growth curve in wet Wales means that to maximise the % of grass grown on the platform as grazed grass, a high stocking rate is required on the grazing block.  This is due to the growing season having relatively high growth over the spring and summer period.  Although this means that the % of grass in a cow’s diet may decrease, the % of grass grown on the platform that is harvested through grazing increases.
• Grazing platforms are often a limiting factor on the farms we deal with, however off-lying land for additional forage is easier to source therefore increasing the stocking rate on the platform can be done without the worry of winter forage.
• Feeding in the early part of the season does have a positive effect on increasing milk yield through the season and into the autumn, increasing autumn milk sales and the average milk price.
• Good feeding resources are required on the shoulder months, however on wet challenging farms this is an essential resource.

The correct stocking rate and level of supplementation will vary subject to your farm, but it is interesting to note that ‘standard’ grazing recommendations relating to stocking rates and low levels of supplementation don’t have to be followed to maximise profits on grass-based systems.

To discuss this further please contact Cled at cledrichards@fcgagric.com or your local FCG office.