Choline helps cut metabolic disease in dairy cows

Introducing rumen-protected choline into the diets of cows in the run-up to calving and early lactation has increased milk yields and decreased metabolic disorders on a farm near Dromore, Northern Ireland.

Darren and Stuart McMurran, milk 300 Holstein cows and feed rumen-protected choline to the close-to-calving group, continuing for three weeks after calving. They say the impact has been huge.

“Average daily yield across first and second monthly milk recordings has increased by 7 litres/cow, and we see much fewer cows suffering from metabolic disorders during the transition into milk,” says Darren.

Before feeding rumen-protected choline the McMurrans were treating about 20% of cows for high temperatures post-calving caused by metabolic disorders, but it is now typically less than 10% of cows in early lactation.

See also: Guide to preventing metabolic diseases

Choline is a nutrient that’s essential to the processing of body fat by the liver when rising energy demand during early lactation outstrips supply from the ration.

Important in all cows, regardless of condition, inadequate choline levels can cause fat to accumulate in the liver, impairing its function and leading to fatty liver syndrome and sub-clinical or clinical ketosis.

All can significantly reduce early lactation yields, with impaired immune function also common.

The challenge is that choline in the ration is destroyed in the rumen, so the cow’s requirements need to be supplied in a protected form that bypasses rumen fermentation.

In order to target cow nutrition dry cows are split into far-off and close-up groups. Spending 21 days in each group, cows are fed separate forage made from mature swards that receive no slurry to keep potash levels low.

A low energy density, high bulk ration (table 1) conditions the rumen well for lactation, whilst a calcium binder helps minimise the risk of milk fever – just ten cases from over 280 cows calved in the last year.