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23rd February, 2019

The Challenges of Dairy Herd Expansion

Dairy herd size in grass based milk production systems has increased significantly in the past five years. This expansion has brought with it many unforeseen challenges.

Milk quota, farm fragmentation and structure of grazing platforms have in the past restricted the opportunity to increase herd size. Land sales and age of inter generation transfers are poor in Ireland. The cost of land is prohibitive for most farmers with a business plan presented to lending agencies.

Tax incentive to encourage long term leases have had a significant impact on the opportunity to increase dairy herd size. Frequently, this has meant the installation of underpasses through public roads. These cost approximately €45,000.

Walking distance has increased. The risk of lameness has increased with distance walked. This becomes an animal welfare issue aside from the financial cost of lameness to the business. One client with a 400 cow dairy herd noted that milk production stopped by 2.5 litres per day when cows had to walk 2 kilometres to the furthest paddock on the grazing platform. The cumulative stress reduces reproductive performance. The intensity and duration of heats decrease, later embryonic mortality increases.

An alternative to increasing walking distance has been the uptake of zero grazing. This requires additional costs of machinery and time on a daily basis to harvest grass. A number of contractors now provide this service. Zero grazing will increase the risk of stomach fluke infestation and neospora relative to cows grazing the same grass.

The availability of skilled labour is now the primary constraint on optimal management of dairy herds. The stockmanship skills required cannot be taught over a short time period. It is difficult to attract people into the industry. Salaries and working conditions are not attractive relative to a rejuvenated building industry.

Employing unskilled staff will cover menial tasks but will result in significant financial losses when tasks associated with animal welfare are compromised. An example of this is best described in a recent case study. A Dairy farmer with 320 cows needed additional help. He employed a man from Poland who previously worked in the building industry. The owner showed him the basics of calving cows and devoted his time to office management. Two weeks after starting his new job he came to the office beckoning the boss that a serious problem had arisen with a cow. “Big problem, the calf has gone back into the cow”. The farmer went out to address the situation to find that the calf was coming backwards!

A structured training programme for stockmen is required. This will take time with a defined career path. Farm managers on large dairy units need stockmen with defined skillsets to optimise animal welfare and thereby the financial performance of the business.

Dairy health issues have increased as herd size increases. The risk of mastitis infection and measures to prevent same have placed an additional burden on milking routines and maintenance of milking parlour equipment.

As environmental stresses increase, the risk of IBR infections increase. The questions being debated on many farms regarding IBR are the choice between live and dead vaccines and the need for a second booster vaccine on a yearly basis to maintain antibody titres.

Stomach and liverfluke infections are causing significant problems on many dairy farms. Treatment requires milk withdrawal from the food chain for a defined period. Farmers are reluctant to treat animals when milk sales are decimated. The industry needs to establish better guidelines in preventative health management for these diseases.

Finally, lung worm infections have caused a significant increase in later embryonic mortality this year. Lungworm infections are frequently confused with IBR. Treatment can cause serious health setbacks where a heavy lung worm infection pertains. I have encountered cases of foetal death between 40 and 50 days following treatment for lungworm.

There is a greater use of stock bulls on large dairy units after a 3 to 4 week period of AI. The bulls used are frequently too young and break down after a short period of use. Fertility testing of bulls is only useful on the day of testing and is no guarantee that cows or heifers will go in calf. I have encountered several cases of infertile bulls this year which were previously classified as fertile using semen evaluation.

Finally, there are significant social issues: Rural depopulation and social isolation as fewer people work on larger dairy units with increased workloads. Increased mental health problems cannot be an acceptable outcome to dairy herd expansion.

Dr. Dan Ryan is a bovine reproductive physiologist and can be contacted at

Article written by Dr. Dan Ryan for the Farming Independent  1st August 2017.