Dairy Notes January 2010

Using a feeder wagon to produce a Total Mixed Ration (TMR) can produce a significant increase in feed utilisation compared to feeding blocks of silage and concentrates twice daily in the parlour provided it is well managed.  There should be less digestive and metabolic problems and milk production usually increases.  If the ration is not planned and monitored, TMR can be an expensive feeding system, especially if all the milking cows are run as one group.

Offering a TMR which meets the feed requirements of the average yielding/top 25 percent of cows in the herd means a large proportion of the herd are fed more concentrates than they need.

Such a rationing system could be particularly expensive this winter with many herds having more stale cows milking in January-April, as a result of poor fertility with last year’s spring calvers.  Overfeeding could also mean a number of these cows putting on too much condition, leading to calving difficulties and low appetite/excessive weight loss after calving.

To ensure stale cows and lower yielders are not overfed, set the concentrate level in the TMR to meet the lowest reasonable yield in the group.  In-parlour feeding can be used to offer up to 5 kg of concentrates at each milking, supplying sufficient energy to produce up to 22 litres of milk.  If the top 10 percent of cows in your herd are producing 45-50 litres, you could adjust the TMR to provide for Maintenance (M) plus 28 litres with the rest of the cows concentrate requirement fed in the parlour.  Stale cows would still be overfed although not as severely if they were fed a TMR for M plus 35 litres.  Running a second group for stale cows and low yielders would be the ideal option.

As you are relying on the cows actually eating the ration you plan, TMR intake needs to be monitored throughout the winter.  Check the dry matter intake of the herd monthly.  If it is not within five per cent of the expected value reformulate the ration.  Low intakes may indicate that forage quality and/or dry matter content have changed and may be limiting intakes.

Test silage dry matters several times during the winter.  If part of the pit was filled with grass that only received 12 hours wilt instead of the normal 24hours the difference in dry matter content will have a significant effect on energy intake.  

For example, 50 kg of an 11.0 ME silage at 27 percent dry matter supplies 148.5 MJ – sufficient energy to supply almost Maintenance plus 15 litres.  If the dry matter is only 22 percent, energy supply is only 121 MJ – sufficient for only Maintenance plus 9.5 litres.  Concentrate levels would have to be increased by over two kg to meet the cows feed requirements.

The TMR should be available to the herd for 22-24 hours daily.  To maximise intake allow for a five percent surplus of feed in the daily mix – this can be fed to other stock.  Check the feed passage an hour before feeding.  There should be edible feed of the same appearance as the original mix left.  If it is licked clean or contains only nosed out stale remnants then you are restricting your cows potential intake.

Diet Feeders differ in preparation of the TMR, so follow the manufacturers’ recommendations.  Over mixing can cause serious problems by grinding the feed into a mush, reducing forage particle length and reducing intakes.  Under mixing can cause less effective feed utilisation as cows can select out and eat more of the fine material or reject the longer more fibrous material.  The ideal mix is open and fluffy – a double handful will compress into a ball and spring open when the pressure is released.

Regularly calibrate the wagon’s weigh cell to ensure mixes are accurate.  Use big fertiliser bags or other known weights.

Consider putting down a smooth surface such as tiles or power floated concrete on the feeding area/trough base.   The smoother surface is less abrasive on the cow’s tongue encouraging her to eat more.  The extra intake easily justifies the expense.