Max Sealy (Chippenham)

A common question asked by nutritionist when doing rations is how much do your cows weigh?  Often, as farmers we have a stab at this basing it on judgement, or cull cow weights (with an estimate for deadweight where appropriate), our general knowledge of cows, or just sheer luck.

This question becomes even more important when considering carbon footprint, as one of the biggest drivers of carbon footprint is methane.  In most carbon footprint models, methane is derived from an equation using cow weight and dry matter intake.  Dry matter intake is reasonably easy to monitor in a lot of systems where there is good measurement and recording.  

On our own farm, we have been crossbreeding the cows for five years now, with most being a two way cross between Holstein and Norwegian Red.  We have been shut down with TB for a long time and this has meant buying in replacements, often older cows to keep milk income up when TB losses have hit hard.  We continue this policy as we move into our new unit where we have a lot of youngstock coming forward.  This inevitably means that we finish up with quite a range of cows.

Last week we weighed every single cow.  We weigh all of our youngstock periodically at birth, weaning, throughout their first winter, at turnout, mid grazing season and pre bulling.   (One of the few advantages I can ever think about being consistently shut down with TB is that you have to handle you cows every 60 days, so you might as well weigh them!).

We have a true test weighing platform put underneath the crush and it is a simple and easy process.

We used this on the cows and simply weighed every cow as they came out of the race.  With our autumn calving system, we thought now was probably a good time to do this as cows are pregnant and in good working condition. 

The answer?  The average cow is 631kg and the median is 630kg.  The lightest cow in the herd was 447kg and the heaviest a massive 870kg. 

We will consider what to do with this data going forward but will certainly be using it as part of our carbon footprinting.  Particularly now in our new parlour, we have more yield recording data, so we will be able to more accurately match output to cow size. 

It is a worthwhile and interesting exercise and gives us more information to fine tune our system.   How are you using your data and are you making profitable decisions based on the data?  Does all this data confuse and overwhelm?  Why not contact Max at maxsealy@fcgagric.com or your local FCG Office, for an outside fresh look at what is relevant and how to make best use of your data.