The feasibility of switching to a once a day milking system.

Image Credit: Image by pixabay

Research states the benefits in the reduction of production diseases such as mastitis, all while maintaining high margins and a minimised workload – if it is so promising, what is holding us back?- Laura Thompson tells us more.

As the national dairy herd continues to increase, the dairy sector will need to attract new entrants as both famers and employees, to maintain production. Milking once a day (OAD) could potentially improve uptake in this field of work due to decreased labour times as well as the potential benefits for the animals themselves. 

Once a day milking is an alternative to the common twice a day milking method. However, its uptake in Ireland is low with only around 200 farms milking OAD continuously over the lactation period. This means milk yield per cow per day is lower but there are added benefits that help bridge the gap between this consequent drop in milk and profitability. Cows milked once a day have been shown to have a reduced chance of mastitis, which is inflammation of the mammary gland. This disease is extremely common in dairy cows and can be caused by inadequate milking procedures in the parlour. Teat canals close after milking however the time taken for this to occur fully can be extended if the mechanical action of milking itself causes damage to the teat canal. If the compression of the liners is not optimised this can lead to pathogenic bacteria being able to enter the mammary gland and cause infection much more easily. If cows are only being milked once a day, and good parlour hygiene is maintained such as removing clusters gently and cleaning each teat thoroughly, then mastitis should decline in the herd due to better teat condition. Mastitis levels in the herd is also measured by milk processors through somatic cell count which is an indicator of the cleanliness of the milk. Cows with high cell counts are penalised by the processor, further reducing profits, highlighting the importance of reducing this production disease in the herd. 

Another, possibly unexpected, benefit of OAD milking is greater reproductive efficiency. Milking once a day reduces the metabolic demand for production on the animal meaning they put on more condition. OAD cows average a body condition score (BCS) of 0.5 above their twice a day counterparts during lactation. This has seen these animals come into the correct BCS for mating quicker and resume cyclicity quicker after calving. All of these reproductive traits help reduce the calving interval and increase the lactation length which ultimately drives profitability. There is also a reduced empty rate at the end of the breeding season which decreases the need for culling. This is an especially important factor as farmers considering moving from twice a day milking to once a day will need to be efficient at culling cows from the herd that are unsuitable for this new system. Cows must be culled if they are high SCC animals or do not produce enough milk to justify their keep when only being milked once a day. 

Once a day milking at the start of lactation will help reduce the effects of negative energy balance and therefore the likelihood of production diseases such as acidosis.

Certain breeds such as Jersey cows are more suited to this OAD system while also giving good solids which is what farmers are paid on in Ireland. However, OAD milking may still not be a good match for all farms. Farm location is also a considering factor to farmers considering the switch. To maximise production and minimise input costs, especially with once a day milking, cows should be at pasture for as long as possible. Technically efficient grassland management is required which increases labour input, an important factor if decreasing labour was the main reason for switching systems. Herd management is also crucial. Heifers will give less milk in a OAD routine so although culling should be effective, a herd with too high of a culling rate will see further reductions in herd milk yield if additional heifers have to be kept.  

Short term OAD milking may be the happy medium for both the farmer and the dairy industry as a whole. Once a day milking at the start of lactation will help reduce the effects of negative energy balance and therefore the likelihood of production diseases such as acidosis. Returning to twice a day milking after this period will increase peak yield and decrease SCC levels overall through dilution. It could also help reduce greenhouse gas emissions as cows are not being as intensively fed to meet high production targets. This could be a key benefit as the continued expansion of the dairy herd has caused some concern for environmental bodies. Regardless of the timing of OAD milking, whether it be throughout lactation or for a certain period, this system needs to be technically efficient in order to reap the associated benefits.