Double check the mineral nutrition of your cows

In a recent webinar, Dr. Bill Weiss from The Ohio State University provided some updates on mineral nutrition of dairy cows. Below are a few slides and key points from the webinar:

1. Feed phosphorus a little bit above NRC requirement. Research reported decrease in milk production when phosphorus level is fed at 85% of the NRC guidance. Feeding 0.35 to 0.65% of DM is generally acceptable.

2. In most situations, feeding at 1.2 to 1.4% of DM potassium is recommended. Higher potassium level than required may help boost milk fat and help cows cope with summer heat stress, but too high can increase manure potassium loss and reduce the absorption efficiency of magnesium.

3. Magnesium is generally recommended at 0.2 to 0.3% of DM. In case of high dietary potassium, greater amounts of magnesium should be fed because potassium inhibits the absorption of magnesium. In addition, there are huge variations on magnesium availability to the animals due to the differences in chemical forms and product quality. It is important to save feed costs, but the cheapest option is often times not the best.

#mineral