Farm Ireland

Wednesday 21 March 2018

What makes a good dairy herd turn bad?

SCC monitoring, parlour maintenance, and cubicle management are essential in optimising winter milk quality

Dairy herd
Dairy herd

Don Crowley

What factors can optimise milk quality as we face into the autumn with prices in a slump?

The following are some of the issues that dairy farmers should be paying close attention to over the autumn and winter.

Lactose Level

Lactose is a natural sugar in milk which gives it its sweet taste. It is a good indicator of quality of milk and it declines with stage of lactation and with milk yield.

Dr Bernie O'Brien and Dr Siobhan Kavanagh have carried out significant work identifying areas to address. Low lactose milk, that is milk with levels below 4.2pc has poor characteristics for quality cheese manufacture.

The main areas to help manage low lactose milk include strategic drying off, somatic cell count (SCC) management and appropriate feeding regime. Milk recording is an important tool to manage lactose as yield, SCC and lactose levels of individual cows are measured.

Cows milking under 6.5 litres per day should be dried off and when a herd average drops below 8 litres, the herd should be dried off.

When lactose levels drop it is difficult to increase it with diet, so it is important to prevent a drop in the first place, maintaining good quality grass in the diet with 2 to 3kgs of ration is the main way to maintain lactose levels.

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Concentrate supplementation studies at Moorepark have consistently shown lactose content to be high for supplemented animals in comparisons with animals fed on a grass-only diet.

Alternative forages such as forage maize or whole-crop cereal silage appear to do little to maintain lactose levels.

The decision to supplement in the autumn must be based on the economic response to supplementation and keeping the feed budget on target.


This is a crucial aspect to attend to at this time of year, and significant financial costs are incurred due to mismanagement in late lactation.

The costs can vary from early drying off, resulting in a loss of income that affects cashflow during the months of November, December, January and February.

Elevated SCC results in financial penalties, and reduced potential yield, that equates to a 2pc loss for every 100,000 over the 100,000 SCC mark.

It also gives a greater probability of lower lactose below 4.2pc which incurs a significant financial penalty of up to 6c/l.

High SCC is associated with changes in the mammary gland, resulting in low lactose content

The Infected Cow

A common cause is under estimating the impact a clinically infected cow can have on a low SCC herd. There can be a dramatic rise in SCC from September onwards due to neglecting these cows.

These cows can be time bombs and should be treated with care. One cow can often represent up to 30pc of bulk tank SCC.

Always disinfect cluster after a problem cow or milk her last. Remember a cow with clinical mastitis, was probably shedding bacteria for the two previous milkings, and she can infect the next eight cows during milking.

Cluster dipping the entire herd for three to five days helps greatly in preventing spread of contagious mastitis when a number of clinical cases occur together.

It is crucial to change solution after 10 cows. These cows should be culled immediately or at very minimum dry off the problem quarter.

Cubicle management

Teat ends of cows remain open for 30 minutes post milking; in many yards cows have access to cubicles post milking before turn out to grass.

They should be restricted from lying on cubicles post milking as this is a common cause of environmental mastitis during the summer months.

A significant number of mastitis cases arise during the summer/autumn for this reason. All too often scrapers are turned off and hygiene is poor in these sheds.

Run a rope along the opening of the cubicles to prevent cows from lying up on them.

Parlour maintenance

"This is the heart beat of any dairy enterprise," is how Dan Connolly of Dairymaster sums up the importance of a good parlour - and how true this is. Poor maintenance is still an on-going issue.

I have opened a number of old liners and cultured them on agar plates and I will consistently grow colonies of Staph aureus - a contagious bacteria and very sophisticated bacteria.

The liner is the only part of the parlour to come in contact with the cow. New liners will ensure less bacteria and better milk out especially in heifers. You must change liners every six months, or after 2,000 milkings.

Change at the start of January and start of July. Vacuum settings should constantly be monitored, and pulsation should be monitored by inserting your thumb in the liner to measure pulsation rate, should be checked on a weekly basis.

If you find cases are difficult to cure this usually indicates a problem with the milking parlour.

Don Crowley is a dairy advisor and milk quality specialist with Teagasc, Clonakilty, Co Cork

The cows with no homes to go to

A shortage of housing is a significant problem with expansion. Many dairy units are over-stocked - for example 120 cows on 100 cubicles. This poses a significant environmental mastitis challenge and creates a lot of stress for cows.

A plan needs to be put in place for housing the herd indoors. For example if you are milking 80 cows and have 60 cubicles available then turn out 20 cows to grass. This will minimise poaching and reduce the challenge in the housing period.

There may be a cheap and cost effective conversion available, but it needs to be addressed and planned through very carefully.

More frequent running of scrapers in these buildings is paramount, with a run every three hours the minimum recommended.

In-calf heifers often suffer most due to lack of facilities, so make sure they're not overlooked.

Indo Farming

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