BS in Dairy Science
Dairy Science Department
The objective was to determine the quality and quantity of DNA collected via nasal swab in Holstein and Jersey cows compared to the time taken to collect the samples through a person inexperienced with the Performagene™ LIVESTOCK product. DNA was collected from 100 cows at the California Polytechnic State University San Luis Obispo Dairy. Holsteins (n=47) and Jerseys (n=53) were collected and samples were shipped to Iowa State University where DNA was extracted by Dr. Jim Reecy’s lab. Results were compiled into a spreadsheet based on DNA quantity in ng/ul, and protein to DNA ratios (A260/A280). Extracted DNA was sent to GeneSeek to be genotyping where the BovineSNP50 Bead Chip was used to determine single nucleotide polymorphisms (SNPs). Data were analyzed by comparing mean, median, standard deviation, minimum, and maximum numbers within the data set. Numbers were observed based on “pass” or “fail” percentage for call rate (>80%=pass), and were compared by breed. Data showed significant signs of reliability compared to blood and hair sampling resulting in a 92% pass rate. Average DNA quantity was significantly higher than blood sampling (n=108.18ng/ul). There may have been some behavioral differences between Holsteins and Jerseys that cause a few animals to be more difficult to sample. However, this was not an important issue in this study. If used on a larger sample of animals a higher call rates could be better represented as well as a DNA average that better summarized results from a larger population . This would result in more accurate characterization of the new technology. Possible follow-up work should include testing animals in different conditions. Another suggestion for testing would be to sample a lot more animals and breeds to make comparisons across breeds. Next research steps should test if longer nasal passage time results in greater quantity DNA.