Is Once-a-day milking regime a tactical short-term response to feed shortage in grass-fed dairy herds?

Once-a-day (OAD) milking is the practice of milking cows only once during a 24 hour period. This differs from the traditional Twice-a-day (TAD) system, more widely used around the world.

It might surprise readers outside New Zealand that a Once-a-day (OAD) milking regime is fairly common to Kiwi dairy farmers. In fact, it is estimated that 10% of the national dairy herd is OAD full time. In New Zealand OAD is used either as the overall farming system or as a tactical, short-term response to adverse seasonal conditions.

As OAD milking becomes more and more popular, farmers note the following benefits:

• It can save time — more time for other jobs on the farm
• It can save money on labour and feed costs
• It can improve herd body condition
• It can improve reproduction, making it easier to get cows in calf quickly
• It can reduce lameness by forcing less walking each day
• It tends to be more forgiving to a wider selection of farm layouts, contours and infrastructures

Versatile feeding equipment remains the key!

OAD milking in early lactation is often used as a method to boost body condition score immediately after calving and alleviate body condition score (BCS) loss during feed shortages.

Richard Owens, a New Zealand dairy farmer utilising a year-round OAD milking system, employs a Hustler bale feeder to quickly and efficiently feed his herd. This type of small bale unroller is particularly suited for small- to medium-size operations and can be single-man operated.

Bigger operations tend to need more versatile and voluminous feedout equipment such as combination wagons. Adam Atkinson, a dairy farmer in South Devon, UK appreciates being able to feed clamp silage, whole crop silage, bales, hay, straw or fodder beet … and appreciates that his combination wagon removes all restrictions on what he can grow and then feed out – giving him the freedom to plan his crops and feedout schedule with maximum economy. “If we had a season with paddocks to close up, we can make bales. Or we can make clamp silage or grow fodder beet,” Adam explained.

A long period on OAD milking is needed to have a positive effect

Research by DairyNZ senior scientists Jane Kay and Claire Phyn provides valuable insights on what to expect for farmers considering once-a-day (OAD) milking over summer and early autumn/fall.

“One of the key points is that the longer the cows are on OAD, the greater the improvement,” Phyn said. “In early lactation, cows lose BCS immediately postpartum which is difficult to change. However, “there are no differences in BCS loss in the first couple of weeks of lactation, regardless of OAD or TAD milking.”

Research showed that BCS loss was the same in underfed cows on OAD and TAD for the three week period following calving, supporting the idea that OAD as a strategy for improved BCS isn’t suited for short periods (such as the colostrum period) with the benefits greatly increasing the longer cows are on OAD.

“Even though there’s a decrease in milk production on OAD, the cows don’t eat much less so coupled with a better energy status, over time they will have an improved BCS, usually detectable from about five weeks onwards,” Phyn explained. A longer period of 10 plus weeks on OAD is needed to have a positive effect.

A better Body Condition Scoring (BCS) with less feed intake, but a significant loss in production 

However, Kay and Phyn’s research found that the decline in feed intake by the OAD herd doesn’t seem to be significant. Cows milked OAD ate about three percent less than cows milked TAD. This small decrease in intake needs to be considered if milking OAD during a dry summer. With similar intake levels, but with less energy being put into milk production, the OAD herd was in a better energetic state. This resulted in OAD cows being on average a quarter of a BCS unit more at dry off than the TAD cows. 

More research from Whareroa Research Centre considers that during adverse events such as flooding or snowstorms, OAD milking may be the only practical option and has some farm system advantages. It allows more time to be spent on non-milking activities such as feeding supplements and pasture management.

Additionally, it can reduce stress on people during a difficult period, and if supplementary feeds are delayed or unavailable, OAD milking may reduce the risk of metabolic disorders, improve cow energy status and potentially improve reproduction.

However, comparing once-a-day and twice-a-day production differences, in the first season once-a-day production decreased 11% on average.

So, is Once-a-day (OAD) milking for you? 

While the OAD milking system may not be for everyone depending on a wide variety of factors, we found it interesting to explore what experts and farmers think about this system as a tactical response to feed shortage in grass-fed dairy herds.

According to the available research, it seems that the system can save a little feed. However, all the other benefits of OAD milking are definitely more effective in the long-term farm strategic plan than in the short-term. 

Whether one switches to OAD from TAD should depend primarily on their goals and how long they can afford the ramp up time. In any case, it is very important to make a well-considered decision before taking the plunge as the operation will irremediably face a drop in production, particularly in the short term. Consider seeking advice from your regular vet as well, who would know and assess the current BCS of your herd.