Amber Yutzy, dairy extension educator of Huntingdon County, Pennsylvania, recently held a webinar titled “Earning More Milk Quality Premiums.” Yutzy outlined the keys to maximizing premiums for milk quality through SCC and mastitis control. “It takes many different factors to make sure cows are operating at their highest production level,” she said.
Somatic cell count
It is imperative dairy producers aim to keep a low SCC. The SCC a dairy producer has on-farm affects the quality of the product sold to consumers. On average, milk has a shelf life of 17 days when SCC is below 200,000 cells per milliliter. If SCC is higher than 200,000, the shelf life of milk can decrease rapidly. Picture this: A consumer purchases a gallon of milk with a 17-day shelf life. On day nine, the consumer must throw out half of the gallon because the milk has spoiled and, on the next purchasing trip, the consumer only purchases a half-gallon. This is most likely because the SCC of the milk is too high, and now the consumer is buying less product.
On-farm, a higher SCC means lower production levels. In a cow’s first lactation, a SCC of 200,000 can mean the cow will produce 1.3 pounds less milk per day than if the cow had less than 200,000. This totals out to 400 pounds of milk lost for the lactation. Multiply 400 by the amount of cows in the herd, and there goes thousands of pounds of milk from the tank and dollars not in your pocket. For mature cows, this figure doubles, and cows produce 800 fewer pounds during that lactation than with a lower SCC. Herds with lower SCC have lower treatment costs, less discarded milk and more milk in the bulk tank.
Mastitis control
Proper diagnosis of mastitis is vital. Mastitis can be clinical or subclinical. Clinical mastitis is shown through visible abnormalities in the milk such as flakes or chunks. With early detection, clinical mastitis is easy to treat. Effective detection is done through the use of a strip cup with a black plate in order to see any signs of mastitis in the milk. Forestripping onto a boot or bedding is not effective. Every cow must be forestripped in every quarter during every milking because clinical mastitis lives in the teat cistern.
Milking from a quarter bucket alone will not solve the problem. Subclinical mastitis does not show visible signs but rather decreases milk quality silently. Cows may produce less milk or stand more during the day if they have subclinical mastitis. It is incredibly important to realize subclinical mastitis causes chronic cows, which are cows with a SCC higher than 350,000 for three months or more. Mastitis cannot be managed without individual cow somatic cell counts.
Determining whether mastitis is environmental or contagious is a key factor in determining how to treat. Contagious mastitis is often caused during milking and can be nearly eradicated. Environmental mastitis is everywhere on the farm, and exposure happens between milkings. Effective pre-dipping protocols will reduce environmental mastitis cases. Bulk tank cultures, CMT tests, individual cow DHIA tests and on-farm cultures can help determine what to treat and how to treat it, with consultation from a veterinarian. If a cow is chronic, treatment is most likely not cost-effective. Options for chronic cows are: treat, segregate (milk these cows last or have a separate milking unit for only chronic, high-SCC cows), dry the cow off, dry off a quarter or cull the cow.
Treatment must be done appropriately whether the cow has clinical or subclinical mastitis. Antibiotics are often used to treat clinical mastitis and are usually unnecessary and not cost-effective. Unnecessary antibiotic use leads to profit loss. Just as doctors diagnose different antibiotics for different illnesses in humans, different mastitis-causing bacteria need different antibiotic treatments.
In order to solve mastitis problems, keep bacteria away from the teats as much as possible. Find infected cows in the herd and make a decision to either treat them or cull them. Again, it is incredibly important to determine where the infection came from, why the cow was affected and to decide how to prevent new infections.
Keys to mastitis control:
- Dip teats effectively, meaning three-fourths of the teat must be covered all the way around.
- Appropriately treat clinical cases. Record all cases of mastitis and monitor outcomes.
- Cull chronic cows.
- Monitor fresh cows for signs of mastitis.
- Conduct regular milking machine maintenance including changing inflations, cleaning pulsators and replacing rotted hoses.
Make a milk quality plan
No two milk quality plans will be exactly the same. Find a practice that works with your farm and practices. In order to stay under 200,000 SCC, goals must be set, including 80% of the herd must have an SCC less than 100,000. First-lactation heifers should all be under 100,000 SCC. All cows over 200,000 SCC must be monitored and tested in each individual quarter to determine problem areas. Identify chronic cows and review options surrounding chronic cows.
At-home tests:
1. Check the milk filter for cleanliness, signs of mastitis, dirt, manure or bedding.
2. Alcohol teat-end tests: Right before attaching the milking unit, swab the bottom of the teat. If any dirt or manure appear, the cow is not ready to milk.
3. Knee test: Kneel in the bedding. When you stand up, you should have clean, dry knees.
4. Culture for bacteria: Bedding, towels, cows and the bulk tank can be problem areas.
5. Visually inspect: Look at the cows, floors and milking units to determine if they are clean.
The development of a chronic cow is an indication of failure. Prevent, detect, treat (when necessary) to lower SCC and, when available, receive a higher premium on your farm. 
Rachel Coyne is a freelance writer and a student at the University of Minnesota – Twin Cities.
