Key points of summer nutrition:

• A 10% increase in the digestibility of pasture (equivalent to an increase of about 1.5 MJME/kgDM) will increase milksolids production by 0.3-0.45 kg MS/cow/day
• As the dry matter content (DM %) increases in summer pasture (even under irrigation) there is more dry matter available for the cows to eat compared to pasture at the same height in spring
• Feeding an energy supplement in summer can be profitable, if it has been sourced and fed at a reasonable cost, pasture is not wasted and that it will keep more cows milking for longer lactations
• For most farms, protein will not be limiting production as crude protein content in pastures is rarely less than 16%. Protein may be limiting where a low protein supplement is fed, for example where more than 4 kg of maize silage/cow/day is being fed. Whether a protein supplement will be necessary will be dependent on the average protein content of the cow's diet
• When air temperatures exceed 27°C in the day and 15°C at night, even with low humidity, the effective temperature is above the comfort zone for high producing dairy cows (and farmers!).