Temperatures Are Rising - Make Sure Your SCC Doesn't Follow

You've reached the Virginia Cooperative Extension Newsletter Archive. These files cover more than ten years of newsletters posted on our old website (through April/May 2009), and are provided for historical purposes only. As such, they may contain out-of-date references and broken links.

To see our latest newsletters and current information, visit our website at http://www.ext.vt.edu/news/.

Newsletter Archive index: http://sites.ext.vt.edu/newsletter-archive/

Christina Petersson-Wolfe, Extension Dairy Scientist, Milk Quality & Milking Management
(540) 231-4767; cspw@vt.edu

We are coming into the summer months when the incidence of mastitis and the bulk tank somatic cell count tend to rise. These are due, in part, to the additional stressors placed on the cows. However, there are steps we can take to reduce the impact these summer months have on milk quality. Of paramount importance is maintaining a clean and dry environment for all cows. New mastitis infections predominantly occur in the early dry period, around the time of calving and into early lactation. For this reason, we cannot forget about dry cow housing or the calving pens. Freestalls should be raked out at each milking, calving pens should be cleaned out between each birth, and loose housing should be maintained on a daily basis. Additionally, animals on pasture must be fenced out of bodies of water. For those producers using sawdust as a bedding material, consider purchasing kiln-dried sawdust and adding hydrated lime as a conditioner. The general rule of thumb for the application of lime is 2 lbs/stall/day or 2 parts bedding to 1 part lime for loose housing. Skimping on the application rate can render the conditioner ineffective. Therefore, it is important to apply in adequate quantity and frequency to maximize effectiveness.

Aside from bedding, we also have tools at our disposal that help to improve milk quality. Fly control will help reduce the spread of certain mastitis pathogens, including Arcanobacterium pyogenes, also known as ‘Summer Mastitis’. This type of mastitis is very difficult, if not impossible, to treat and therefore, much easier to prevent. Secondly, the use of an internal teat sealant during the dry period has been shown in research studies to reduce new mastitis infections seen at calving. Although this may not be necessary in all herds, it is something to consider if your herd historically has an environmental mastitis problem at calving.

Lastly, the J5 vaccines help to reduce the severity of clinical coliform mastitis. The summer months are known to be particularly problematic when it comes to coliform infections. Therefore, some veterinarians have started recommending wholeherd vaccinations prior to the heat of the summer. If your herd has had problems with coliform mastitis during the summer in the past, discuss this option with your veterinarian.

The summer months continue to bring about concern related to milk quality. However, in most instances it is easier to prevent mastitis than it is to treat. Therefore, our focus needs to turn to the management tools we have at our disposal and maintaining a clean, cool and comfortable environment for our cows to live in.