The evaluation of the BMSCC of 31 farms applying selective dry cow treatment and participating in the Pir Dap management program showed an increase and decrease on 12 farms (39 %) and remained stable on 7 farms (22 %). Half of the farms showed an increase of the average cow SCC of culled cows and the other half a decrease. The culling percentage of 21 farms reduced on 11 farms, increased on 7 farms and remained the same on 3 farms during the 3 year period. The analysis of farms not using selective dry cow treatment (n = 6) showed that BMSCC showed the same trend as farms using selective dry cow treatment (2 increased, 2 decreased, 2 remained the same), less farms had an increased cow SCC of culled cows (17 % versus 48 %) and more farms had a reduced culling percentage (67 % versus 52 %), compared to the farms using selective dry cow treatment (table 2).

CONCLUSIONS AND DISCUSSION

By the number of dry cow and mastitis injectors sold we could conclude that selective dry cow treatment does not have a negative impact on mastitis. It is difficult to draw conclusions from the culling percentage since 2 factors played an import role. Due to the end of the quotum system in 2014 less cows were culled. And in 2015 more cows were sold due to the low milk price. We can conclude that farmers not using selective dry cow treatment seem to have a lower cow SCC at culling and a reduced culling percentage.

INTRODUCTION

In this case study a retrospective analysis was performed to investigate the effect of selective dry cow treatment on mastitis incidence measured by mastitis injectors sold by a practice in The Netherlands. Also the effect on several udder health parameters was analyzed.

MATERIALS AND METHODS

The data presented here result from a veterinary practice in the south of The Netherlands. For the retrospective analysis three periods were compared: September 2012 to Sept 2013 (period 1), Sept 2013 to Sept 2014 (period 2) and Sept 2014 to Sept 2015 (period 3). For each period the following parameters were calculated on farms using selective dry cow treatment:

1. Total number of dry cow antibiotic injectors and internal teat sealers

2. Total number of mastitis injectors sold3. Average bulk milk somatic cell count (BMSCC) in September 4. Average cow somatic cell count (SCC) of culled cows 5. Culling percentage of farms

Selective dry cow treatment means that only cows with a cell count over 50,000 and heifers over 150,000 cells/ml receive antibiotic dry cow treatment. Farms not using selective dry cow treatment are using dry cow antibiotics on every cow entering the dry period. The first two parameters were available from the practice management system. The last three parameters were available from farms participating in a specific farm management program in The Netherlands, called Pir Dap. This data is also available for veterinarians with permission from the farmer.

RESULTS

During the 3 year period a gradual decrease up to 10 % in the number of dry cow antibiotic injectors sold was observed. Also a decrease of 14 % was seen in the number of mastitis injectors sold. An increase of 27 % in the number of teat sealers was noticed, but was less obvious in period 3 (table 1).

H. Caron1, M. Driesse2

1Veterinary practice ’t Leijdal, Chaam,The Netherlands; 2Boehringer Ingelheim Vetmedica, Alkmaar, The Netherlands

In practice case study to investigate the effect of selective dry cow treatment

on mastitis incidence

TABLE 2: DIFFERENCE IN CULLING (%), AVERAGE COW SCC AT CULLING ANDBMSCC OVER THREE YEAR PERIOD

Number of farms

Culling % increase decrease similiar

Selective DCT (n = 21 farms) 7 11 (52 %) 3

No selective DCT (n = 6 farms) 2 4 (67%) 0

Average Cow SCC at culling

Selective DCT (n = 31 farms) 15 (48 %) 16 0

No selective DCT (n = 6 farms) 1 (17 %) 3 2

Average BMSCC in September

Selective DCT (n = 31 farms) 12 (39 %) 12 (39 %) 7 (22 %)

No selective DCT (n = 6 farms) 2 (33 %) 2 (33 %) 2 (33 %)

TABLE 1: TOTAL NUMBER OF INJECTORS SOLD IN PRACTICE

period 1 period 2 period 3 difference (%)

dry cow antibiotic injectors

23144 22824 20912 -10 %

mastitis injectors

16132 14396 13912 -14 %

teat sealers 17136 21264 21756 27 %

Presented at World Buiatrics Congress 2016 in Dublin ABCD