Proactively managing milk quality by monitoring Herd Test data.

Keeping udders healthy; a challenge every dairy farmer faces almost daily. Somatic cell count (SCC) is a good parameter for udder health. How can an abnormal value appear on a Herd Test (HT)? A HT periodically collects animal-specific data for dairy farmers. HT SCC data are part of a farmer’s milk quality assessment. What do these data tell you and how can you best use them to manage udder health?

Keep clean, be healthy

The HT is a highly effective tool to manage udder health. Many dairy farmers already use these HT data to implement protocols when it comes to udder health: dry-off management,  milking technique and identifying cows that need support with elevated SCC. The importance of a healthy udder is well known. Bradley and Green (2004) (Figure 1) showed that 60% of visible udder health challenges within the first 100 days after calving are due to invading bacteria, arising during dry-off or calving. Cows with a milk yield of 12.5 litres or 1 kg MS or higher at drying off have a significantly higher risk of new udder health challenges early in a new lactation. With every additional five litres of milk or 0.4 kg MS at dry-off, this risk increases significantly (Rajala-Schultz et al., 2005). New infiltrations usually arise from bacteria gaining access to the udder through the teat canal. Because the pressure on the udder can be  high after dry-off, the teat canal may open and leak milk. This is an opportunity for bacteria to penetrate the teat canal and colonize the udder. Around calving, this process repeats. The calving paddock can be  a reservoir of bacteria that can invade the cow’s udders.

Figure 1. A schematic illustration of the rate of new intramammary infiltrations during the lactation cycle. The peak in new infiltration rate, after drying off, is considerably higher in cows not receiving any form of dry cow therapy (Bradley and Green, 2004).

Pro reactive is better than reactive

HT data are often the trigger for dairy farmers to tackle invisible udder health challenges. An increased SCC shows that the cow’s immune system is battling an invader. If unfavourable bacteria invade the udder of a cow that is immune compromised (ie in a challenging situation and/or in low energy), they only need 24-48 hours to multiply and protect itself from the cow’s immune system via biofilm production. Once in the biofilm, the cow’s immune system can’t see nor remove them, and traditional methods can’t penetrate the biofilm.  As this process of biofilm production is repeated every time a cow is immune compromised, the udder will be classified as persistent. Because a proactive approach is better than a reactive one, many dairy farmers understand the importance of HT data. How quickly and when do you react to an HT attention? Typically a SCC value over 200K will indicate a quarter needing attention (as three quarters are likely to be under 50K and one well over 500 to get to an average SCC of 200K). An adequate proactive approach reduces the number of cows that end up with severe udder health challenges. Research by Buiting (2012) shows that udder health in dairy cattle is number two reason for culling cows.  By reducing sources of contamination and by reacting to SCC attentions from the HT early, proactive action on udder health can be taken. Acting proactively on udder health with the right combination of measures will ensure the need to  cull cows because of udder health challenges is  reduced. This will extend the longevity of your dairy cows. Extending lifespan will lower the replacement rate.

How can AHV help optimise udder health on your farm?

To support and optimise udder health on farms, AHV has developed the Udder Health Program. This approach focuses on early identification and addressing abnormalities. Here, we look at data such as HT data and robot data. Abnormal values can be an indication of (upcoming) udder health challenges. At AHV, we distinguish four categories; UDR-C, UDR-L, UDR-P and UDR-R. These categories take your animal’s udder condition and history into account and base the advice on that. Would you like to know which advice we recommend for your cow? Our Territory Managers will be happy to discuss this with you and provide advice free of charge based on your farm’s specific data to minimise permanent udder damage and the associated costs.

Sources:

• Bradley, A. J., & Green, M. J. (2004). The importance of the nonlactating period in the epidemiology of intramammary infection and strategies for prevention. Veterinary Clinics: Food Animal Practice, 20(3), 547-568.
• Rajala-Schultz, P. J., Hogan, J. S., & Smith, K. L. (2005). Association between milk yield at dry-off and probability of intramammary infections at calving. Journal of Dairy Science, 88(2), 577-579.
• Boer, M., Zijlstra, J., Buiting, J., Colombijn-van der Wende, K., & Andringa, E. A. (2013). Routekaart Levensduur; eindrapport van het project” Verlenging levensduur melkvee” (No. 668). Wageningen UR Livestock Research.

About AHV

AHV (Animal Health Vision) is the global leader in quorum sensing-powered animal health solutions and advisory services, giving #PowerToTheFarmer to optimise their animal health. Since opening in New Zealand February 2022, AHV has tailored a range of protocols to New Zealand farming challenges to power herd longevity, productivity and profitability. Reach out to your local Territory Manager or call AHV New Zealand at 0800 424 869 to learn more about how AHV can support your farm.