Back Maize grain for more milk protein

Date: 25 June 2014

During the last few years there has been a rise in the number of in-shed feeders being used on NZ dairy farms. This method of feeding cows has a number of advantages in terms of convenience, low wastage and the ability to control per-cow intake of concentrates. Feeding the right supplement through your in-shed feeding system will ensure that you maximise milk returns and supplementary feeding profitability.

Processed maize grain is an excellent choice. Maize has a higher energy content than other grains and many other commonly available concentrates. It can be used to increase cow energy intakes, delivering more milk or faster condition score gains.

Information published by DairyNZ shows that milk production is determined by the amount of energy a cow eats but the composition of the milksolids she produces is affected by the type of supplement fed.3

• When cows are fed a starch or sugar-based supplement, they product more milk protein.

• When cows are fed a fibre based supplement, they produce more milk fat.

Figure 1: Typical Concentrate Energy Content 1,2

Since milk protein is worth two to three times more than milk fat, starch and sugar based supplements will deliver more milk revenue than fibre-based supplements

Table 1: Estimated milk revenue from feeding 1 tDM of different supplements fed through an in-shed feeding system3

As well as containing more energy than other concentrates (e.g. dairy meal, other grains), maize grain has advantages for rumen health.

• It has a high starch content but virtually no soluble sugar.
• Maize starch is less rapidly broken down in the rumen than other starch types.

This means there is a lower risk of acidosis (grain overload) when feeding maize grain compared to other grains (e.g. wheat) or high sugar feeds (e.g. molasses.)

Feeding rates
Maize grain feeding rates will vary depending on the age and production level of livestock and the amount and type of other feeds in the diet. General recommendations for cows are:

• Feed a maximum of 30% of the total drymatter intake as maize grain.
• Start at lower rates (e.g 1 kg maize grain per cow per day and increase feeding rates gradually over 7-10 days).
• Feed a maximum of 2.5 kgDM maize grain in a single feed.

Feeding rates will be lower in diets that contain other sources of carbohydrate (e.g other grains or meals, molasses or high sugar or starch byproducts).

Maize grain is an ideal supplement for pasture-fed calves and young-stock promoting rapid rumen development and excellent liveweight gains. Processed maize grain can be purchased as required from most local grain companies.


Ian Williams
Forage and Farm System Specialist