Le Producteur de Lait Québécois MagazineVolume 2019Number SeptembreSeptember 3, 2019
Isabelle MorinD.M.V., Cert. LAM

Six reasons why udder health and sustainable dairy production go hand in hand

Six raisons de favoriser la santé du pis

During the closing session of the recent Mastitis Conference organized by the International Dairy Federation, Norwegian researcher Dr. Olav Østerås spoke about the role of mastitis prevention and therapy in promoting worldwide sustainable dairy production. His presentation underlined six key points.

1.  Mastitis prevention is essential for the sustainable and efficient development of milk production

Milk is a high-quality source of protein, which is particularly important in developing countries (such as Africa) where dairy production is a central component of sustainable development. Sustainable development involves more than the fight against climate change; it also means ensuring that the population is healthy and has access to a healthy diet. This in turn requires a sustainable supply of nutritious and safe milk that is both affordable and culturally acceptable.

Of the 7.5 billion humans on Earth, 1 billion are involved in dairy production, from farming to processing and marketing, in order to supply the world’s 6 billion consumers of dairy products.


2.  Producers and processors rank mastitis as the most important disease affecting dairy production

In its 2018 Annual Report, the International Dairy Federation ranked dairy diseases in order of importance according to the results of a survey conducted among dairy producers and processors in a dozen countries. Presented in the graphs below, the results show that producers and processors alike consider mastitis to be of utmost importance.

Adapted from the International Dairy Foundation Annual Report on Animal Health, 2018

3.  Inadequate management of udder health can present a threat to human health

Only a few animal bacteria are transmissible to humans, and nearly all bacteria found in milk are destroyed by pasteurization. In some countries, such as India, however, the consumption of raw, unpasteurized milk remains common. When milk contains antibiotic- and zoonotic-resistant bacteria, which are transmissible from animals to humans and vice versa and are able to adapt to different environments, there is a risk to human health.

Moreover, bacteria that have developed a resistance to antibiotics can transmit that resistance to other bacteria in their environment. For example, a bacterium that has developed a resistance to antibiotics and is present in milk discarded in a manure pit could transmit that resistance to other bacteria.

To address this type of risk, the Wildlife Conservation Society developed the One World One Health policy in 2004. The approach involves collaboration across sectors and disciplines and is implemented at local, regional, national and global levels. The aim is to improve public health throughout the world by highlighting the relationships between animal health, human health and their shared environment. Still, the good news is that, despite all, there appears to be no emerging resistance to antibiotics among mammary pathogens.


4.  A made-to-measure plan for each country and each herd should to be put in place

The types of bacteria that cause mastitis vary greatly across countries and across regions within the same country. For example, in the case of staphylococci other than the aureus types (referred to as Staph spp. on milk bacteriology reports), there is a wide variation not only between countries, but also between regions, and even between farms. Hence it is important that the protocols for mastitis treatment be adapted to each herd and that regional guidelines be established. 

5.  Judicious use of antibiotics at dry off, a practice that needs improvement in Canada

Nearly 75 per cent of respondents to a worldwide survey conducted in 27 countries use selective treatments at dry off. This means that the majority of producers do a milk culture before dry off and then choose a treatment (including non-antibiotic treatment) based on the result. Basically, cows with a negative milk culture receive no antibiotics at dry off while those testing positive receive an antibiotic appropriate to the milk bacteriology result. For comparison purposes, the National Dairy Study (Bauman and others, 2015) conducted in Canada in 2015 revealed that 85 per cent of the farms sampled use a blanket dry cow treatment, meaning that all cows receive a long-acting antibiotic treatment at dry off. In Quebec, selective dry-off therapy has been the recommended practice for many years now, but some habits will need to be changed before we can come up to the world average.

6.  Effective mastitis prevention reduces the dairy sector’s carbon footprint

One of the main effects of mastitis is of course milk loss. The results of a global survey indicate that about 0.7 to 2.0 per cent of the world’s milk production is discarded due to mastitis. This is a concern, particularly in terms of reduced efficiency, because it means more CO­2 is produced per litre of milk marketed. The SCC also has a negative effect on dairy production when it exceeds 200 000 SCC/ml. Average losses are estimated to be between 170 and 520 litres of milk for a 305-day lactation.

In conclusion, while udder health has improved considerably over the past decades, new challenges continue to emerge and there will be no lack of opportunities for improvement.