A dairy consultant at Kite Consulting has said that checking mineral levels in transition cow diets has never been so important.
Maimie Sloan said that, with the ongoing effects of last year’s unique weather and straw and forage stocks disappearing quickly, many dairy producers have struggled with rationing their herds, and transition cow diets are at the highest risk.
Farmers cannot afford to let this impact transition diets and the health of dry cows, she said.
“Last year’s harvest conditions resulted in increased levels of potassium in straw and grass silages across the UK, putting many dry cow rations at risk of causing problems with rising milk fever cases,” she said.
“Many farmers operating transition under dietary cation anion difference (DCAD) conditions need to ensure they are regularly testing forages, as many dry cow diets currently aren’t achieving the correct acidity, potentially leaving cows vulnerable to problems with milk fever.
“The hot weather of summer 2022 led to many drought stressed crops and we’ve seen straw samples with more than double the usual amount of potassium in.”
Sloan said, similarly, farmers who optimised slurry applications as a result of high fertiliser prices last year may be feeding forages with high potassium levels resulting in the risk of rising milk fever cases.
Mineral sampling
Sloan said mineral sampling of straw and forages is extremely important to check exactly what level of DCAD is being fed versus cow requirements.
“Without knowing the base level of minerals, standard book values for typical mineral contents could be very different to the actual diet being fed, especially when we experienced a non-typical season last year,” she said.
“It’s difficult to achieve a low enough DCAD by just controlling the base forages, made more challenging by forage availability and continuity of diets.
“Even if clinical cases of milk fever aren’t presenting themselves, higher rates of retained cleansings, metritis and poor fertility are warning signs of sub-clinical milk fever and a thorough diet check should be conducted.”
Sloan said, when managed correctly, a DCAD diet in the dry period has “fantastic results in transition cows”, with very low metabolic disease incidence, and a typical increase in milk yields across the lactation.
