The results from two DairyNZ surveys held in 2008 and 2013 on milking technologies have been compared to look at industry trends and the change in how technologies are being used on NZ dairy farms.
Milking technologies generally fit into two categories; those that are labour-saving and those that provide decision support, assisting farmers managing large herds who have little contact with individual cows.
Labour-saving technologies are the most widely used. The latest survey found in herringbone dairies the most common technologies were automatic vat washing (63%), yard washing (14%), plant washing (13%) and in-bail feeding (22%).
When farmers were asked what technology they would like in the dairy, automatic drafting was the most popular, with 43% of surveyed farmers wanting this technology. Automatic teat spraying was on the wish list for 21% of farmers. Both allow the milking of more cows an hour. Automatic cluster removers (ACR), which prevent overmilking but generally don’t increase throughput, were wanted by 22% of farmers.
The use of technology is more widespread in rotary dairies, the most common being ACRs (70%) and automatic teat sprayers (66%). More than 80% of farmers with rotary dairies either had or wanted ACRs and automatic teat spraying and drafting. The combination of these three technologies means the cups-off operator isn’t needed, allowing an average of 344 cows an operator in the 2013 survey, compared with 251 for those without all three.
In the past decade, 54% of new-build dairies have been rotaries, which now represent 27% of dairies, milking 44% of the national herd.
In the 2013 survey more than 45% of farmers said they were waiting for slow milking cows. The aim of maximum milking time (MaxT) is to shorten the milking time of the slowest 20% of cows, resulting in a greater amount of residual milk. But this is deferred to the next milking, where it is harvested at a faster milk flow rate. This means MaxT can be used without affecting milk production or somatic cell counts (SCC) when implemented correctly.
To think of it practically, in a herringbone when you are down to the last 20% of the row, or eight clusters in a 40-aside, swing these remaining clusters over without waiting. In a rotary, set an appropriate rotation time using the MaxT table. For those with ACRs some models can apply a MaxT time or it may be more appropriate to increase your ACR threshold to achieve a similar effect. Aim to optimise your milking routine first before considering investment in labour-saving milking technologies.
It can be more challenging to detect animal health problems as the number of cows managed by each person increases and the contact time for each cow decreases. To help with this, farmers can use animal monitoring or decision support technologies. Most provide a systemised approach which can minimise issues with staff-to-staff variation in skill and operator fatigue on large farms.
Activity meters can be used for automatic heat detection, where the spike in a cow’s activity, relative to the previous few days and the rest of the herd, indicates the cow is likely to be in heat. The automatic reading of heat-mount patches by camera is another method used.
Mastitis can be automatically detected using the electrical properties of milk, where an increase in conductivity is a sign the cow is fighting infection. Alternatively, some systems estimate a SCC level as an indicator for mastitis.
The most important aspect is that any technology needs to meet the needs of an individual farm and system as they require significant capital investment. Before investing in automatic heat detection systems farmers should identify their current rate of heat detection from your InCalf fertility focus report. If they’re achieving good results they have less to gain from automatic heat detection and it will be more difficult to justify the investment.
Also consider the expected performance of the system. Achieving a good six-week in-calf rate is essential, so if you plan to rely on the heat detection system it will need to have a detection rate greater than 90% with a manageable level of false alerts – those cows the system drafts that are not actually on heat. Performance varies significantly from system to system and farm to farm, so request robust numbers from your technology supplier.
In the case of automatic mastitis detection systems farmers need to consider whether their goal is to detect clinical mastitis or to manage their bulk milk SCC. Typically, systems are good at detecting one or the other, not both.
Like heat detection systems, ask technology providers to supply robust performance data as well as considering how you will use the system. If looking for a mastitis cow in a herd of 1000, a slightly higher false alert rate may be tolerable because you’ll only need to strip a hundred cows instead of a thousand. Weigh up the potential benefits to your farm system and compare it with the investment cost.
Informed investment decisions are critical. The more that can be learned about the performance of existing and emerging technologies and the keys for successful integration, the faster the dairy industry can identify and adopt those that are beneficial, leading to more efficient farm businesses that are good for both cows and people.
For more information on MaxT or increasing your ACR threshold visit www.dairynz.co.nz/shorter-milkings. Find your DairyNZ InCalf fertility focus report at www.dairynz.co.nz/fertilityfocus
Paul Edwards is a DairyNZ post-doctoral scientist with its feed and farm systems team.
