Improving Milk Quality

Many of you have done a great job at lowering cell counts and clinical mastitis in recent seasons, while reducing antibiotic use as well. As management and systems have improved, the opportunities to make further gains have become fewer. Getting to that next level can be challenging and we will need to find new innovations to achieve this.

One untapped area of the cow is the immune system. A better immune system means the cow is better equipped to combat mastitis. We have seen this in calves; A Multimin injection at birth can half death and disease in calves.

If we think a dose of Multimin helps the immune system in calves, could we then also use it in our cows, to make the immune system more robust before calving? A recent study performed by Virbac in New Zealand looked at this exact situation.

What did they do?

• 1700 cows, half of which were given 5mL of Multimin 2 – 4 weeks before calving.

• Clinical and subclinical* mastitis rates were recorded in the first 30 days after calving.

• Bloods were taken at the time of injection for selenium and copper evaluation.

  *Subclinical mastitis = more than 150,000 ISCC at the first herd test

What did they find?

• Selenium and copper levels were at the upper end of normal, reflecting that these were herds that already had very good trace element management. This included dry period long-acting selenium injections and oral mineral mixes during lactation.

• Clinical mastitis was reduced from 4.2% to 2.0%. Even from this low baseline, in a well managed herd, Multimin halved clinical mastitis in the first 30 days post calving.

• Subclinical mastitis was also significantly affected. 17.1% of untreated cows were above 150,000 at the first herd test, and Multimin treatment lowered this to 12.9% - a reduction of about a quarter.

Why is this relevant?

The response to a Multimin injection was very significant, even on farms with good mastitis management and trace element supplementation. It means that we potentially have another tool in the kit, to make gains in milk quality and animal health on even the best performing farms. Why do we see such a dramatic immune response to supplementing trace elements, when animals are not in the deficient range? The graphic below helps to explain this effect:

The left-hand side of the graph is more relevant to modern farming. This shows that even a small dip in trace element levels will affect immunity first. The huge demand for trace elements at stressful times like calving, mean that it is almost inevitable that even well-managed herds will drop into this zone temporarily. Supplementing with Multimin prior to these times is a pre-emptive strike to reduce this immune suppression.

Is it worth the investment?

Using the SmartSAMM Gap Calculator, we can estimate the return in an average 800 cow North Canterbury herd (if the same results seen in the trial are achieved).

Assuming 400kgMS/cow and a conservative $6.50 payout, the benefit is over $18,000 - a return on investment of about 4:1.