July 2019 Monthly Management

CellCheck Time for a Change; Gate Promotion 2019; Simple Steps to Reduce Thermodurics

23 July 2019

CellCheck Time for a Change

CellCheck from Animal Health Ireland Assuming you started the spring with a new set of liners, then it’s definitely time to change them now if you haven’t already done so. To help prevent mastitis, CellCheck recommends that liners are changed every 2,000 milkings, or every 6 months whichever comes first. For example, for the average Irish milk recording herd of 79 cows, if the full herd has been milking since March 1st in a 10-unit swing over parlour, the milking liners will have clocked up over 2,800 milkings by 31st August. These liners had completed 2,000 milkings by July 4th!

Cluster liners are designed to flex and squeeze the teat during each pulsation cycle, ensuring even blood supply and efficient milking. Over a prolonged period working, liners begin to lose tension and quality. Worn liners will hinder speed and completeness of milking, resulting in a loss of milk yield and risk of teat end damage. Fatigued rubber can also hold bacteria, and this can increase the total bacterial count (TBC) if dirt is being trapped. In severe cases, liners may be prone to absorbing fat and hold bacteria. Mastitis cases will also increase due to the irregular pulsation and pathogenic bacteria building up in cracked liners.

To calculate how often you should change your liners, based on the number of rows you’re milking, the following formula can be used:

2,000 x number of milking units
Herd size x Number of milkings per day
= Number of
days in between
liner changes

e.g. a herd of 80 cows milked twice a day in a 10-unit parlour would allow a liner life of 125 days.

Many herds have increased cow numbers while the parlour size has not. This effectively means more cows are being milked through the same number of liners as before; so liners will have to be changed more frequently than in the past.

Although changing liners can be expensive it will more than pay for itself in the long run if it means your cows are going to be milked fully and the incidences of mastitis are less.

Simple Steps to Reduce Thermodurics

What are Thermodurics

ThermoduricsPasteurisation is effective at reducing the microbial risk of milk but some bacteria can survive this process and subsequently grow in the pasteurised milk, these bacteria are called Thermodurics. These micro-organisms can carry over into cheesemaking and subsequently through the ingredient manufacturing process causing quality defects. These defects cause significant problems for food manufacturers, in particular the production of ingredients for infant nutrition. It is very difficult to remove thermoduric bacteria at processing level due to the severity of treatment required and the risk of further quality losses. Invariably, attention is drawn back to the stages of primary milk production, where the problem first arises and where control steps can be more effectively applied.

Source and Growth of Thermoduric Bacteria

Thermoduric bacteria have their origin in the environment and are widely distributed, occurring in animal feeds, faeces, bedding and soil. Levels can be higher in wet or extremely dry weather. Poor milking parlour hygiene, cracked or old rubberware, etc. are ideal conditions for bacteria to harbour and spread on equipment. With inadequate cleaning, contamination will build-up, particularly in hard to clean areas, such as pipeline joints and dead ends.

A Biofilm forms on pipelines from extensive thermoduric growth and this residual contamination can contribute to high bacterial counts in subsequent milkings, if it is not removed by proper washing of the equipment. Exposure of rubberware to chlorine for long periods will cause rubber to deteriorate faster allowing residues to build up.These sources are critical in determining levels of thermodurics in milk, and lack of attention in this regard can result in milk in the bulk tank containing substantially higher thermoduric bacteria/ml, rendering it unsuitable for processing.

Transfer of Thermoduric Bacteria into Milk

These mico-organisms are readily transferred from environmental sources into the milk when cows are milked. As previously mentioned, dirty cow teat surfaces, poor parlour hygiene and residues on milking machine equipment all contribute to elevated thermoduric readings. Risk of transfer is far greater whilst cows are housed, however soil contamination also contributes to the problem from cows resting on bare or poached paddocks.

Management of Thermoduric Bacteria

Greater care is required to ensure hygienic milking conditions to obtain thermoduric numbers within the processor specifications. The following measures can be applied at farm level:

Cow Cleanliness Udders and teats should be clean and dry before milking, if they look dirty then there is a higher risk of contamination. Keep udders and tails neatly trimmed as dirt can get trapped in the hair leading to increased thermoduric readings. Cubicles & bedding should be clean and dry. Tracks/Gateways to and from milking parlour should be maintained in a clean manner to avoid contamination.

Milking Parlour Best practice in wash routine and detergent usage must be adopted to reduce risk. Check water volume and hot wash temperature when washing the milking plant. Hot wash needs to be 70-80°C. Ensure length of wash & contact time is adequate to remove residues. Check water quality (recent water tests). Visual inspection of bulk tank, pump, lines, liners, etc...

Refrigeration & Wash Check that the bulk tank cooling system is working effectively. Visually check if tank is washing correctly (water temperature and detergent uptake is adequate).