NorFor Update: vitamins and minerals (April 2022)

What's in the new release?

NorFor’s update improves mineral and vitamin recommendations as follows:

Macrominerals: Relatively small changes in the daily needs of macrominerals.

  • Phosphorus is marginally reduced by 1%,
  • Sodium for lactating cows is reduced by 10% (equivalent to about 5 g/day).
  • For high yielding cows:
    • Calcium is raised by 6% (corresponds to about 10 g/day),
    • Magnesium is raised by about 9% (corresponds to about 4 g/day),
    • Potassium is raised by 6% (corresponds to about 12 g/day),
    • Sodium requirement for dry cows is doubled (equivalent to 8 grams per day),
    • Chlorine is raised by 6% (equivalent to 4 g/day).
  • Sulphur remains unchanged.

Microminerals: The changes are relatively large.

  • Iron demand is halved for dairy cows (equivalent to about 700 mg/day), while it remains unchanged to other cattle categories.
  • Manganese demand is reduced to lactating cows by 20% (equivalent to 200 mg/day), while to dry cows it is unchanged.
  • Zinc demand has been raised to high-yielding cows by 23% (equivalent to 270 mg/day), while the need is reduced to dry cows by 43% (equivalent to 270 mg/day).
  • Copper demand is reduced to lactating cows by 5% (equivalent to 13 mg/day) and raised to dry cows by 68% (equivalent to 88 mg/day).
  • In DMS (Danish and international client), copper demand is reduced by 25% for all cattle, these recommendations are based on Danish field studies.
  • Cobalt demand is doubled.
  • The recommendation for selenium has not been changed.
  • The recommendation for iodine has not been changed

Absorbed copper: There is a special feature in the calculation of copper requirements in areas with known problems with copper deficiency. High levels of molybdenum and sulfur in homegrown feed reduce the uptake of copper, and are factors that should be taken into account and increased copper in the diet. Therefore, there is now a new parameter that shows the absorbed amount of copper.

Vitamins:

  • Vitamin A is elevated to high-yielding cows, otherwise unchanged.
  • Vitamin D for lactating cows is raised, unchanged to dry cows.
  • Vitamin E is raised to sinuses in the "close-up" period, otherwise unchanged.

The minimum limits apply to added vitamins found in compound feed and mineral feed.

Keep an eye on the units:

  • Minerals: The minimum limit for sulfur, cobalt, selenium and iodine (nd for DMS also copper) is presented as a constant concentration in the diets, are
  • The other mineral recommendations indicate the daily need in total quantity. The needs are based on factors such as body weight, estimated feed intake, milk quantity, fetuses and growth.
  • The news in this release is the optimization for total amount for the microminerals iron, zinc, manganese and copper. (In DMS, the copper requirement is indicated as a concentration.)

Maximum limits: In this release the presentation of maximum limits on the concentrations of microminerals in the rations changes (according to EU and NRC, 2006). One-day feeding control shows the maximum limit for both macro- and micromineral concentrations.

Differences between breeds: the recommendations of minerals and vitamins distinguish between dairy breeds and meat breeds.

References

NASEM, 2021. Nutrient Requirements of Dairy Cattle: Eighth Revised Edition. National Academies of Sciences, Engineering, and Medicine, Washington, DC: The National Academies Press. https://doi.org/10.17226/25806.

NASEM, 2016. Nutrient Requirements of Beef Cattle: Eighth Revised Edition. National Academies of Sciences, Engineering, and Medicine. Washington, DC: The National Academies Press.https://doi.org/10.17226/19014.