Impact of MULTIMIN^® on Mastitis Reduction and Immune Support in Dairy Cows

In particular, two studies by Bates et al.^1,2 have shown halving of morbidity and mortality in calves, with greater white blood cell function after treatment.

First principles would suggest that increased white blood cell activity should also have a positive effect in adult cattle, particularly in diseases where we know this is a major component of the immune response, such as mastitis and endometritis. Previous research has suggested this is the case³ and now also this New Zealand study.

Study Outline

1,700 cows across four South Canterbury herds were enrolled, with half of each herd randomly allocated based on SCC, breed and age) treated with 5 ml of MULTIMIN^®. Treatment was administered when cows were vaccinated with an anti-scours vaccine 14-28 days before the planned start of calving.
All herds were fully supplemented with oral trace element mixes, and copper and selenium levels were within normal reference ranges on the day of treatment, as seen in Table 1. 

Table 1: Average serum trace element concentrations at day of pre-calving injection.

Clinical mastitis was recorded from 7 days before to 100 days after calving, and SCC at first herd test of above 150,000 cells/ml was used to define subclinical mastitis. All cows were also Metrichecked^® 14-28 days after calving, and colostrum samples were collected from a subset on the day of calving to compare Brix readings between groups.

Results

There was an approximate halving of clinical mastitis cases between 7 days before and 30 days after calving, from 4.2% to 2.0%. As can be seen in Figure 1 below, this effect is present throughout the first 100 days of lactation, however it is only significant in the first 30 days.

Figure 1: Kaplan-Meier survival curves for the percentage of quarters without clinical mastitis in the period 7 days before to 100 days after calving for treated (red) and control (grey) cows.

The proportion of cows with subclinical mastitis (>150,000 cells/ml on herd test) was reduced from 17.1% to 12.9%, an approximate 25% reduction. Figure 2 illustrates the effect on the respective treated and untreated groups.

Figure 2: Distribution of estimated probability of subclinical mastitis at the first herd test after calving in treatment (red) cows and control (grey) cows.

There was no significant difference in colostrum quality between groups, with median Brix values of 21 in both treated and untreated groups. There was also no difference in the
proportion of Metricheck^® positive cows, with 12% in the untreated group and 11% in the MULTIMIN^® treated group.

Discussion

This study adds to the research with MULTIMIN^® and is relatively consistent with other research on pre-calving use, where significant reductions in both clinical and subclinical mastitis were observed. Interestingly, the halving of clinical disease is a similar magnitude to the reduction in morbidity seen after MULTIMIN^® injection in neonatal calves in New Zealand conditions.

There was a low level of disease in these herds, and trace element levels were within normal ranges, reflecting that these were well managed farms. This reinforces the importance of trace elements in supporting the immune system when stressful events increase demand, even where disease is well controlled and no deficiencies are apparent.

An estimate of the financial benefits on-farm can be made using the SmartSAMM^® Gap Calculator. For an average 400 cow farm at a $6.50 payout, and using conservative figures of 9 less clinical mastitis cases (in line with the numbers in the study for the first 30 days) and a reduction in bulk tank SCC from 175,000 to 150,000 (a 14% decrease), the potential financial gain is $6,550. This financial analysis has limitations and makes some assumptions about SCC in particular, however it suggests that there is substantial return on investment for dairy farmers, alongside the benefits of reduced antibiotic use.

References:
1. Bates A, Wells M, Laven R, Ferriman L, Heiser A, Fitzpatrick C. Effect of an injectable trace mineral supplement on the immune response of dairy calves. Res. Vet. Sci. 130, 1–10, 2020
2. Bates A, Wells M, Laven RA, Simpson M. Reduction in morbidity and mortality of dairy calves from an injectable trace mineral supplement. Vet. Rec.(April 25, 2019). doi: 10.1136/vr.105082
3. Machado VS, et al. Effect of an injectable trace mineral supplement containing selenium, copper, zinc, and manganese on the health and production of lactating Holstein cows. Vet J. 2013;197(2):451-6.