More energy feed key for calved cows
Calved cows need more energy feed. This is according to Edmond Daughton of Teagasc.
In terms of cow intakes, in the final two months of pregnancy the energy requirement of the dairy cow increases by up to 30 per cent, he said.
“However once the cow calves and begins to produce milk the energy demand increases even more dramatically to a level significantly greater than demand immediately pre-calving.
He continued: “In fact a cow producing 27 litres of milk requires staggering 130 per cent plus more energy than she did in the weeks pre-calving. This surge in nutritional requirements occurs at a stage when the appetite of the cow is at its minimum. Intake will have fallen to 6.5-7.0 Kgs of dry matter at this stage. It will take six to eight weeks before full intake of 18 – 18.5kgs of dry matter is achieved.”
He noted while some of the energy deficit can be made up through the cow mobilising body fat reserves, it is obvious that the energy density of the diet must be increased from the typical low energy pre- calving diet.
“Poor post-calving nutrition leads to excessive weight loss with a multiplicity of side effects among which are Ketosis, fatty liver disease and fertility problems, including significantly delayed conception dates and lower conception rates.”
Daughton stressed the best solution is to get cows to grass as soon as possible after calving, but noted where this is not possible the feeding of concentrates is essential.
The following data, from Teagasc, gives an outline of the recommended feeding levels for a cow with a potential yield of 6,000 litres. The level of supplement is influenced by the quality of silage fed, it notes.
Recommended feeding levels (Indoors)
Silage DMD 75% 70% 65% 60%
Kgs of Ration Supplement 6.5 7.5 8.5 9.5
According to Daughton, where silage dry matter is low – under 15 per cent and/ or preservation is poor these feeding levels may need to be increased.
“At very high feeding levels the inclusion of alternative forages such as maize silage or whole or wet feeds such as brewers grains, fodder beet may be useful. Rations should be of good quality ranging from 18 to 20 per cent crude protein with an energy content of 0.95 UFL.”
In terms of cows on grass, the Teagasc expert said once cows have access to grass, meal levels can be reduced.
“Even at low levels of grass intake – eg 4Kgs of grass dry matter per day – feed can be reduced by 1.5 to 2 Kgs. At 8 Kgs of dry matter, typical of cows out by day and on silage by night, feed 4-5 Kgs of ration at 14-16 per cent crude protein. Once cows go on grass full time, eating 13-15 Kgs of grass dry matter, an economic response can be realised by feeding up to 3.5–4.0 Kgs of ration. This includes the immediate benefit of the supplement and the carry over effect into the rest of the lactation.”
In terms of milk quota management, he advised that the above assumes that milk quota restrictions do not apply.
“However this year in particular, the quota situation needs to be closely monitored. Kerry agribusiness was close to four million litres over quota at the end of 2013. If problems appear likely steps should be taken to contain potential risks. When reducing the feeding levels be cautious about cows losing condition especially with high potential cows. Reducing ration protein levels, once a day milking where SCC is low or feeding extra milk to calves can help to contain the situation,” he concluded.
Calves on grass. Photo O’Gorman Photography