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Do you know how much your cows are eating?

By Lorna MacPherson, Senior Dairy Consultant, SAC Consulting

With dairy cows settled on winter rations, now is the time to consider accurately measuring dry matter intakes. Measuring intakes is not common practice on many dairy farms, as this takes into account refusals which are not often weighed. However, monitoring and improving intakes can greatly impact on feed efficiency, reduce waste and increase milk output.

Feed conversion efficiency (FCE) can be calculated from milk yield (kg) divided by dry matter intake (kg), with the target being around 1.5. It varies according to stage of lactation, and will be highest in early lactation, as milk yield peaks before dry matter intake peaks. In early lactation, once maintenance requirements are met, every extra 1kg dry matter consumed, will support on average an extra 2kg of milk.

Feed space is very important, especially for newly calved cows and 1st lactation heifers. They are most susceptible to low feed intake and most negatively affected by it. A minimum 24 inches of feed space is commonly recommended but fresh cows will benefit from more, with 36 inches being optimal.

FCE is driven by forage quality, with higher NDF silages lowering FCE. To some extent, feed additives such as yeasts, plant extracts and rumen buffers can help improve FCE. Management practices can also play a huge role. Consider the following: more regular pushing up of feed, moving from once a day to twice a day feed out, proper mixing of the TMR and adequate processing of forages. All these things can help reduce wastage and encourage intakes.

Aim to feed for no more than 3 to 5% refusals for the milking herd and weigh leftovers to accurately assess dry matter intake and FCE. What is the dry matter of the TMR? If too wet, mixing and feed presentation will be poor and if too dry, spoilage and sorting may occur, reducing intakes and FCE. If the ration is greater than 45% dry matter, consider adding water to target a dry matter around 40 to 45%.

This article from Farming for a Better Climate was funded by the Scottish Government as part of Scotland’s Farm Advisory Service and first published in the Farming Scotland Magazine in November 2020.