Importance of silage mineral analysis

Calving is a stressful period for the dairy cow. This leads to a challenged immune system and a cow with a poorer ability to fight off infection.

Through correct mineral and energy nutrition you can boost the cow’s immune system. This will lead to lower levels of metritis, mastitis, SCC, lameness and will over-all lead to better fertility performance. Prevention of these issues occurring.

Avoiding metabolic problems and improving general health and disease resistance of both the cow and new born calf next spring, starts during the dry cow period. This is best achieved through following a quality Dry Cow Mineral Programme. Milk fever is considered as a gateway disease and predisposes the cow to various metabolic and infectious disorders in early

It is well established that calcium plays a major role when it comes to milk fever. The sudden increase in demand for Calcium at the onset of lactation, presents a major challenge to a cow’s homeostatic control mechanism. The onset of lactation increases the demand for Calcium. Each litre of milk requires circa 2 grams of Calcium.

However, other minerals are essential to prevent milk fever. The role of magnesium cannot be understated. This switch from storing to drawing calcium requires a hormonal change, which is controlled by the cows’ magnesium and vitamin D nutrition. Magnesium stored in the soft tissues and bone of the cow is unavailable to the cow and so she requires a continuous dietary supply to meet her requirements.

An excess of potassium limits magnesium absorption, delaying the release of calcium and increasing the incidence of milk fever. High levels of dietary potassium are common in Irish grass silages (range from 0.6%-5.6%) potassium particularly second and third cut silage, which may have received high levels of manure, and which is typically fed to dry cows and young stock. The recommended level of dietary potassium is less than 1.8% of dry matter.

High phosphorus can compromise the ability of the cow to produce the hormone necessary for the activation of intestinal Ca transport, which will impair the Ca homeostasis of the cow.

Trace elements play an important role in disease resistance, immunity and reproductive performance. Irish Forage (grass based) has been shown in many surveys to contain categorical deficiencies of key trace elements (Selenium, Copper, Zinc, Cobalt and Iodine) and an excess of Iron & Molybdenum.

This highlights the importance of silage mineral analysis to identify the deficient and excessive mineral to be able to match the requirements of the dry cow in preparation for calving and early lactation to minimise challenges in early lactation.

First Published: 19 October 2021