Many modern concentrate feeding systems, both in-parlour and out-of-parlour systems, allow concentrates to be allocated to individual cows based on their milk yield. While these feeding systems represent a considerable financial investment, they also require regular checking to ensure that the planned concentrate feed levels are actually being offered. Given the cost of concentrate feeds, it is important that concentrate feeding systems are accurate. This need for checking feeding systems was highlighted recently as a result of a larger project being conducted by the Agri-Food and Biosciences Institute (AFBI) on 31 local dairy farms. This larger project, which was co-funded by DAERA (Research Challenge Fund) and AgriSearch, examined the effect of feed-to-yield systems on milk production, milk composition and economic performance. The full results from this larger study will be released by AFBI in the autumn but in the meantime some fundamentally important findings from the work are highlighted here.

Examining feeder accuracy

Within the work, feeder accuracy was examined on 16 of the 31 farms, with a total of 490 individual feeders tested (between 16 - 48 feeders tested per farm). The test involved a pre-programmed quantity of concentrates (normally between 0.5 – 2.0 kg, depending on the feeder calibration setting) to be dropped from each feeder into a plastic bucket which was then weighed. The difference between the actual weight of concentrate dropped from the feeder, and the target weight that should have been dropped (percent deviation from target), was then calculated. The information on the actual weight of concentrate that was dropped was then used to recalibrate the weigh-cell in each feeder using the inbuilt computer software.



The average deviation of all feeders on each of the 16 farms from the target concentrate feeding level is shown in Figure 1. On average, the feeders on Farms 1 - 7 underfed cows (i.e. the feeders dropped less concentrates than they were supposed to), while feeders on Farms 8 - 16 overfed cows. In the extreme cases (i.e. Farms 1 and 2) the feeders dropped approximately 13 – 14% less concentrate than planned, while on Farm 16 on average the feeders dropped 15% more concentrate than planned. 


On most of the remaining farms the average error across all feeders was plus or minus 5%, which most producers would consider to be acceptable. However, even on these ‘better’ farms the average values ‘hide’ problems with individual feeder variations. For example, on Farm 11 one feeder was overfeeding by 100% (i.e. dropping 2 kg instead of 1 kg), while on Farm 4 one feeder was underfeeding by 70% (i.e. dropping 0.3 kg instead of 1 kg). 


Figure 1. Average deviation from the target of all feeders tested on each of the 16 farms.


The impact that these inaccuracies can have on the amount of concentrates offered on a farm can be considerable. For example, for a 100-cow herd offered an average of 6.0 kg concentrate/cow/day through in-parlour feeders over a 180 day winter period, the total target concentrate usage is 108 tonnes over the winter. However, based on the feeder inaccuracies observed, Farm 1 would actually feed only 93 tonnes concentrate, while Farm 16 would actually feed 125 tonnes concentrate, representing underfeeding and overfeeding of 15 tonnes and 17 tonnes respectively (Figure 2).

Figure 2. Impact of inaccurate feeders on the total quantity of concentrates that would be fed over a 180-day winter period (100 cows at 6 kg/cow/day)



Unfortunately, poorly calibrated feeders are common on many local dairy farms, and as a result, underfeeding or overfeeding of concentrates is likely to be a significant problem, especially given the cost of concentrates and the need to optimise efficiency on farm. As such it is recommended that farmers adopt a feeder calibration check at least once a month. In addition, different types of concentrates have different densities, and feeders should be recalibrated for each new type of concentrate being fed. Your feeder supplier should be able to advise you on how to calibrate your feeding system, but in general, a simple weigh-scale, plastic bucket and some of your time is all that is required. However, this is likely to be time well spent, especially if you wish to bring more accuracy and precision into your feeding systems, and increase profit.