Balancing Dairy Cow Diets

Minor Ingredients But Major Impact!

The functions of minerals, trace elements and vitamins in dairy cow animal performance are of considerable economic importance.  While major deficiencies may not be seen, lesser subclinical problems still may be serious.  Meeting the needs of the dairy cow requires knowledge of her requirements.  Also, it is important to consider factors that may affect the availability of these nutrients.  Adequate long-term supplementation is essential to maintain normal cellular activity, which in turn affects milk production, reproductive function, growth, development and udder and hoof health.

The diet of a dairy cow needs to include a supply of at least 15 different minerals for proper growth, milk production, health and reproductive performance.  Without these minerals, the ability of the cow to use other nutrients (protein, carbohydrate and fat) efficiently is compromised.  The major or macro minerals are needed in relatively large amounts (1 - 7 grams per kilogram of the diet), whereas the micro minerals or trace elements are required in small but vital quantities (0.1 - 80 milligrams per kilogram of the diet).

All nutrients within the diet relate to each other and this is particularly true for minerals.  For example, pasture is generally a poor source of minerals for lactating cows; it is often adequate in potassium, iron and manganese, but is low in phosphorus, chlorine, zinc, copper, iodine and selenium.  Mineral levels vary between pasture species, with ryegrass having lower concentrations of trace elements compared with clover.

Further complications are the varying effects of soil type, geographical location and fertiliser policy on the level and availability of minerals in pasture.  Soil pH has a bigger effect than fertilisers and is of major importance in determining the mineral status of pasture-fed animals.  Major minerals are more available under alkaline soil conditions, whilst trace elements are more available under acidic conditions.  The exception is molybdenum, which has higher uptake from alkaline soils at a time when copper uptake and/or availability is reduced.  Phosphorus fertiliser can depress the level of copper and zinc in grass.  In contrast, nitrogen fertiliser has little effect on copper, molybdenum or zinc but a combination of nitrogen and potassium fertiliser increases molybdenum and suppresses zinc.

All these factors lead to an enormous variation in the mineral and trace element content of grazed pasture, crops and conserved forages.  In order to optimise dairy cow performance it is important to be aware of these variations and ensure cows receive adequate supplementation to allow the diet to be balanced for all the nutrients she requires.  Rather than just looking at dry matter, energy, protein and fibre constraints, take into account minerals and trace elements as well.

Part of the service provided by the Ridley team of dairy specialists is to assess where you can make the best return on your feed inputs to help increase the profitability of your dairy business.  A correctly balanced diet is essential to ensure rumen function is optimised.  This allows the milk response to feed inputs to be maximised and reduces overall feed costs.

The Barastoc range of feeds is designed to suit all types of dairy production systems.  The pelleted feeds ensure superior digestibility, even distribution of minerals, trace elements and vitamins and ease of handling.  Similarly, pelleted concentrates are also available that are designed to balance grains and grain mixes with protein, minerals, trace elements and vitamins.

All the major minerals and trace elements mentioned above are balanced according to the cows' requirements in Barastoc feeds.  In addition, if particular deficiencies or imbalances have been identified in your homegrown feeds, additional supplementation of pellets with minerals and trace elements is a simple way of addressing these issues.

Tim Harrington
Ruminant Technical Manager

This information and advice has been prepared specifically and exclusively for the use of the Company's customers.  The company believes the information and advice in it is accurate, but subject to those terms implied by statute which cannot lawfully be excluded, restricted or modified, no warranty of accuracy or reliability is given and no responsibility to the customer or any other person is accepted for errors or omissions howsoever arising, including matters arising through negligence by the Company, it's Directors, employees or agents.