Milking order plays a major role in the amount of milk produced from pasture-based dairy cows.
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New research from the Dairy Feedbase program at the Ellinbank SmartFarm has revealed a substantial difference in milk production between cows that return to a paddock early after milking and those that are milked and return to the paddock later.
"We were interested in, firstly, clarifying what the actual variation in within-herd milk yield was, based on the order of milking, and then to investigate some strategies to address the disparity in milk yield between cows in the herd," said Dr Meaghan Douglas, who together with fellow Agriculture Victoria research scientist Dr Marlie Wright, led the research.
READ MORE: Helping all cows get a fair share of feed
The research team found a daily difference of five to six litres per cow between early lactation cows that arrive at the dairy first versus cows that arrived towards the tail end of milking. While this effect is likely to be greater for larger herds, the issue is not just related to herd size, but time away from the paddock.
"Smaller herds with inefficient dairies where the herd takes a long time to be milked can be affected as much as larger herds," Dr Douglas said.
Testing the theory
In 2022, Jindivick farmer Chris Bagot partnered with the project team to assess whether the results they had observed in the research environment were also evident on his larger scale commercial farm.
Mr Bagot milks 550 cows in a predominantly spring-calving, pasture-based system.
"I'm a big believer in supporting this type of industry research to help bridge the pathway from research to adoption," he said.
Preliminary results from Mr Bagot's herd were similar to results found on the Ellinbank SmartFarm: the was a difference of more than three litres in daily milk yield for cows in the first and last quarters of the herd during late lactation.
Better allocation of resources can lift milk production
The research team at Ellinbank SmartFarm investigated how changing the allocation of the same total resource available on farm (pasture and supplementary feeds) across the herd could improve overall milk production.
Importantly, no additional resources were purchased to overcome the disparity in milk production across the herd due to milking order.
To counteract the lack of available ungrazed pasture for cows milked later in the milking order, paddocks were divided into segments, reserving fresh pasture for the later cows.
The fresh breaks were opened to the second and final third of the herd at 1.5 hours and 3 hours after milking start time. This allowed cows that were later back to the paddock access to fresh pasture.
The cows that returned to the paddock first could not access this fresh pasture. When tested with cows in early lactation, this approach showed an increase in daily average herd milk yield of 1.1 litres per cow when compared with offering one break to all cows.
So, for the Ellinbank SmartFarm, which has 450 cows in the milking herd, this meant approximately 500 additional litres per day would be produced without adding any extra feed to the system.
The research team also tested an alternative mitigation strategy: allocating the same amount of grain to the herd overall but providing more grain to the cows at the end of milking and less grain to the cows at the start of milking.
For example, early cows would receive 4 kilograms of dry matter of grain, late cows would receive 8kg DM of grain, and cows in the middle receive 6kg DM of grain.
When compared with feeding a flat rate of 6kg DM grain to all cows, the altered grain allocation showed an overall increase in daily average herd milk production of 0.8L per cow in early lactation cows. Across the whole Ellinbank Smart Farm herd of 450 cows, this would amount to about 360 additional litres per day.
On-farm application of research
The results of this research are promising, especially for larger herds or herds where the overall duration of milking is long.
"We are now looking to further fine tune these strategies to optimise milk production at a herd level and working with more commercial farms to make sure that the strategies will work in different settings," Dr Douglas said.
Mr Bagot said he was encouraged by the results of the research.
"If I can feed the same amount of grain and achieve my target post-grazing residuals, while producing more milk through manipulating the way the herd accesses the paddock, or the amount of grain each cow gets, it's an attractive proposition," he said.
For more information on this and other research outcomes from Dairy Feedbase, contact Dairy Australia or local Regional Development Program.
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