Discussion and Conclusion 



It appears that the experimental serum preservation methods used were superior to the standard preservation 

 method. This conclusion is drawn because in each case the antibody titers were higher following the experimental 

 treatments and there was no significant increase in false positives, false negatives or suspects. The one false negative 

 subsample appeared to be due to an error in preparing the subsamples. 



Perhaps a weakness of this study was the fact that no low titered (1:5) serum was included among the known 

 positive samples. Animals with such titers have been proven to be carriers of J A naplasma marginale. However, one 

 would logically expect that low titered serums would show the same effect from the experimental treatments as the 

 serums used in the study. This would possibly enhance the ability of the test to detect low titered carriers. 



The degree of variation observed in titers following the different treatments was greater than expected and the 

 comparisons made indicate that one or more influential factors were not controlled. The information obtained was 

 not sufficient to determine definitely the identity of these factors. However, two variables were noted which could 

 have been involved. First, samples in treatment groups A and B were less hemolyzed than those in groups C and D. 

 Second, the technique for mixing serum and phenol was different for samples in treatment groups B and C. Samples 

 in treatment group C were cold (approximately 4 C.) and the phenol was added to the serum. For treatment group 

 C, the serum was at room temperature and was added to the phenol. 



There is no evidence from the results obtained that phenol preservation of serum samples is necessary or even 

 desirable. 



