DEAR SIR: I had lots of feedback on the Greenfield herd article (p32) last week describing the March and April milk solids production of the herd. The nub of the article related to the fact that the Greenfield herd in March produced milk with higher fat and protein percentage than the average Glanbia fat and protein percentage figures for the same month.

I did a calculation showing the difference if the Greenfield herd had produced the same volume of March milk (192,000 litres) at the average Glanbia figures.

The net result was the Greenfield herd produced 1,815kg of milk solids extra and if you put a value of €4.24 per kilo milk solids (taken from the Glanbia milk statement) there was a value of €7,700 on that for the month.

Some farmers queried what numbers to divide that figure by to get the per-cow figure. I divided by 150 – the number of cows calved by the start of March delivering milk to the tank. Some suggested you should divide by 300 or 330, the number of cows going to be milked on the farm for the year. If you do that it’s the €7,700 divided by 330, so it’s €23 per cow extra.

Some queried the value of fat relative to protein. Yes, the herd produced more fat than protein (0.72% fat extra versus 0.20% protein in comparison with the Glanbia average figures). However, there is still a value on the extra fat. Contrary to what many milk traders thought five years ago, butter is driving global milk markets at the moment. The euro-per-kilo milk solids figure factors in the relative value difference in fat and protein (as described in the monthly milk league on p18 last week from €4.33 to €4.10/kg MS).

The meal figure of 80kg of meal fed per cow was also queried by some farmers relative to average feed input. The National Farm Survey (2013 to 2015) data suggests 1,003kg of meal fed per cow per year and I’m making the assumption 50 to 60% is fed in the spring. We will feature these issues again in future Greenfield articles.