It was also found that disease control and prevention practices did not 

 differ on farms with only raised cows and farms with both raised and 

 purchased cows which were in the sample of 62 farms in the field survey. 

 Table 10 shows the percentage of farmers who said they used specified 

 practices to control disease and to prevent mastitis and brucellosis • — two 

 of the more costly diseases. The proportions of farmers with only raised 

 cows and those with both raised and purchased cows who adopted health 

 practices differed very little. If there was any difference, the farmers with 

 both raised and purchased cows adopted more of the practices that are 

 generally recommended by veterinarians. 



This conclusion can be substantiated by further reference to Table 9. 

 Average age at disposal for each reason was consistently higher for the 

 groups of purchased cows. This reflects the fact that the purchased cows 

 spent some time in other herds as raised cows before sale for dairy purposes. 

 For all reasons of removal, the average age at disposal of raised cows was 

 5.52 years while that of purchased cows was 6.74 years. Excluding animals 

 sold for dairy purposes, the average age at disposal for raised cows was 

 5.74 years and for purchased cows 7.06 years. The average age at disposal 

 differs considerably for raised and purchased cows, but the average years 

 in the herd for these two groups of cows was about the same ■ — 3.34 years 

 for raised cows removed for all reasons and 3.17 years for purchased cows. 

 For cows removed for reasons other than sale for dairy purposes, raised 

 cows averaged 3.55 years and purchased cows 3.43 years in the milking 



Table 10. Percentage of 62 Sample New Hampshire Commercial Dairy 

 Farmers Who Used Specified Disease Control or Prevention Practices 



Disease and Control or Prevention Practice 



Mastitis 



Use of strip cup 



Wash udders before milking 



Inflaters rinsed between cows 



Infiaters boiled 1 time each week 



Recommended milking machine vacuum 



Recommended milking machine pulsations 



Infected cows milked last 



Medication given by owner 



Brucellosis 



1 blood test each year 



2 blood tests each year 

 12 blood tests each year 

 Calves vaccinated 



Isolation of newly acquired livestock 

 Check with State Veterinarian before 



making final payment 

 Blood test new cattle before they enter herd 

 Separate freshening cows from herd 

 Disinfect calving areas 

 Destroy afterbirth 

 Isolate suspects or reactors 

 Use disinfectant pans at doorways 



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