Paying closer attention to milk test results, and using the data to adjust feeding strategies, is critical if feed efficiency and milk income are to be maintained during the grazing season.
So says KW nutritionist Anna Sutcliffe, who adds that milk fat content and milk urea levels are both key indicators for herds looking to maximise utilisation of grazed grass. “Responding to changes in either can produce relatively quick returns.”
Butterfats drop-off through spring and early summer can exceed 0.2% – equivalent to losing 0.7ppl on some milk contracts. Higher milk ureas can indicate poor utilisation of grass rumen degradable protein (RDP), with lower levels also linked to reductions in early embryo loss of up to 20%.
“If butterfats are dropping then focus on maximising fibre digestion in the rumen to boost the supply of the acetate needed for milk fat synthesis,” says Dr Sutcliffe.
“Swap rapidly fermentable starch for more rumen-friendly options, like sodawheat, increase the supply of digestible fibre from feeds, such as soya hulls, and consider adding a rumen-conditioner, like Acid Buf, to reduce acidosis.”
She adds that milk urea levels above 0.030% (30mg/l, 300mg/dl) suggest that more rumen fermentable energy is needed. “Traffordgold wheat-gluten moist feed and low-protein liquid feeds, like Lactoboost, are good options that also improve ration palatability.
If more rumen-bypass protein is needed to balance high grass RDP levels, Dr Sutcliffe suggests feeding the heat-treated rapeseed expeller NovaPro. “It’s a better option than soyabean meal – both in terms or DUP:RDP ratio and cost per tonne.”