Avoid TMR rejection:

31th October 2011

Rejection of TMR can be a problem at any time of the year but as we move towards winter rations it often becomes more prevalent.

When rations are left uneaten this is a clear signal something is wrong. Frequent causes include overfeeding, contamination or clamp spoilage, which can cause the constituents to become unpalatable.

Another possible cause is that the TMR has over-heated after mixing.

This was the situation encountered by ruminant nutritionist Warwick Bastard working on behalf of Lillico Attlee at the dairy unit of Holmbush Farm, Haywards Heath, part of Heaselands Estate.

The unit is situated on weald clay interspersed with banks of gravel. The closed dairy herd consists of 450 mainly Holstein cows plus another 275 followers.

They calve throughout the year and achieve 9000 litres per cow at 3.8% BF and 3.2% protein.

Silage is made from 2 cuts of grass, forage maize and whole crop oats. A TMR with added brewer’s grains, maize-gluten, wheat, and molasses is fed throughout the year.

A problem was initially noticed when a proportion of TMR spread after evening milking remained uneaten the next morning. After a thorough investigation and working with dairy manager Steven Barbour it was found that the TMR was overheating with steam visible after midnight. This caused reduced intake resulting in a loss of milk production.

Warwick advised adding a TMR stabiliser – called Profresh Plus - manufactured by Micron Bio-Systems.

In a matter of days, the problem was solved with the ration eaten; intake improving and milk yield increasing by 2 litres per cow per day.

Profresh Plus is a dry granular form of propionic acid that inhibits the growth of spoilage yeasts and moulds that cause a rise in temperature, degrading the constituents and spoiling the forage.

Profresh Plus was added at the rate of at 1.5kg per tonne to the TMR in the mixer wagon - a 22 cubic metre Shelbourne Powermix holding approximately 5.5 tonnes.

The cows are divided into groups:

Group 1 - the milking cows receive 56kg TMR and fed once per day
Group 2 - the freshly calved cows are fed 45kg TMR plus 10kg of whole crop
Group 3 - the heifers receive 50kg of TMR

All of the groups are fed once a day at 105% of their daily requirements.

The last group consisting of dry cows that are kept at grass during the summer – receive 50kg TMR per day. As they are fed only every other day the use of Profresh Plus, to keep the ration palatable, is a necessity.

Steven explained, “Since we started using Profresh Plus we have encountered no problems with over-heated TMR or rejection by the cows due to spoilage. It’s an excellent result for us.”

Another innovative introduction by Warwick is that during the summer months the milking cows are kept housed during the day and only fed TMR and allowed to graze outside at night. This has shown remarkable benefits with total feed intake remaining high; the cows avoid the daytime heat and flies and graze contentedly during the cooler nights.