TMR less efficient than feeding to yield – survey
By Jessica Buss
DAIRY producers offering total mixed rations are overfeeding concentrate which is less efficient than parlour-feeding to yield.
According to compounders Dugdales, 8000-litre herds on TMR are fed up to 20% more concentrate compared with those fed to yield, yet performance is similar.
Dugdales says a survey of 13 farms on TMR and 17 feeding to yield shows that true TMR-fed herds use 0.39kg of concentrate a litre and herds fed to yield 0.32kg/ litre. TMR, which doesnt allow individual feeding, results in overfeeding concentrates, it concludes.
Axient senior consultant Diana Allen agrees that there is a real risk that TMR-fed herds overfeed concentrate to lower yielders within a herd, and margins are lower than expected.
This inefficient use of concentrates often results from a wide range of genetics. When heifers are entering the herd at £60 PIN and older cows are below £0 PIN, cows must be split into at least three groups, she advises.
However, Dugdales nutritionist John Runnalls maintains that there is a wide range of yields -between 35 and 50 litres/day – even when cows are grouped.
He advises that most producers formulate a TMR for the first 25-30 litres of milk, then feed to yield. By using parlour compound to supply half the herds concentrate instead of feeding one TMR, its possible to cut concentrate use and still achieve the same margin even if the compound costs £40/t more.
Mrs Allen agrees that it may be more efficient to feed an outside ration and top-up cows in the parlour. The outside ration should provide sufficient concentrate for the lower yielders without overfeeding. But cheaper straights can be fed in the parlour instead of a compound – the difference in price between the two is typically £15-£20/t.
True TMR feeding suits block calving herds, herds where cows are all of similar genetics or when there are facilities to split cows into three groups, she says. Milk quality and, therefore, milk price may also be higher with TMR.
Independent nutritionist David Jacklin, who specialises in TMR diets for high yielders, admits care is needed to avoid overfeeding cows.
"In herds with more moderate yields – 7000 litres or less – group cows or consider feeding limited parlour cake – up to of about 4kg a cow a day."
TOTAL MIXED RATIONS
• Can overfeed concentrate.
• Group or feed in parlour.
• Use cheaper straights.