ARINI research dispels costly feeding myths
FEEDING concentrates and costly protein straights such as fishmeal to dry cows is a waste of money.
It is also a myth that bulky forages such as straw stimulate intake post-calving, according to Agricultural Research Institute of Northern Ireland, Hillsborough research.
Speaking at a ruminant research seminar last week, Hillsborough researcher Tim Keady disputed work which showed supplementing dry cows with undegradable protein increased milk and protein yield in their subsequent lactations.
"This is a popular feeding method, but differences shown in the study are likely to be due to differences in cow condition score rather than feeding. Supplementing with undegradable protein in late pregnancy has no effect on milk yield and fat, and it may even have a slightly negative effect on milk protein."
Maintaining a high level of intake immediately before calving or feeding high fibre diets and bulky forages – such as straw – also have no effect on post-calving intakes, believes Dr Keady.
"Our studies compared cows in the last four weeks of pregnancy with differences in dry matter intake of 4.3kg a cow a day. But when cows from all treatments were offered the same diet after calving, feed intakes were similar."
Achieving and maintaining a condition score of 2.5-3 between drying off and calving is critical and should usually be possible without concentrates, he added. "It is a waste of time and money feeding high protein concentrates to dry cows; they do not stimulate intakes post-calving.
"A good quality silage of 11ME or poorer quality silages supplemented with barley or maize gluten to achieve this level of ME should suffice. With cows at grass, dont let them put on too much condition."
Although straw is often fed to dry cows in the belief that it will stimulate the rumen, increasing intakes in early lactation, this is untrue, said Dr Keady. "Straw is more expensive than many other feeds when expressed in terms of cost/unit of ME.
"Studies show that including straw decreases intake during late pregnancy and has no beneficial effects on feed intake or performance in the subsequent lactation. There is evidence that it actually decreases milk protein content for the first eight weeks of lactation." *