Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Thesis. LarsenPDF.pdf (1004.67 KB)

ETD Abstract Container

Abstract Header

Detection and Prevention of Intramammary Infections in Primigravid Dairy Heifers

Larsen, Lindsay
http://orcid.org/0000-0001-9983-4483
http://rave.ohiolink.edu/etdc/view?acc_num=osu1626638139653464

Abstract Details

2021, Master of Science, Ohio State University, Animal Sciences.
Mastitis is a key challenge for the dairy industry. Defined as inflammation of the mammary gland, mastitis is most commonly caused by a bacterial intramammary infection (IMI). A large proportion of dairy heifers have an IMI prior to calving and beginning their first lactation. An infection during this time is expected to be deleterious to the growth and development of the mammary gland (quarter), diminishing future milk production and producer profitability. The objectives of these works were to describe the effects an IMI has on primigravid heifer mammary secretions, determine if prepartum administration of an internal teat sealant (ITS) in heifers reduced the odds of IMI at calving, and determine if administration of ITS earlier (75 vs 35 days prepartum) differentially affected the odds of IMI at calving. A total of 270 heifers were utilized. Aseptic secretion samples were obtained from one quarter of every heifer at 75 days prepartum and another quarter of every heifer at 35 days prepartum. Immediately following sampling, the designated quarter was administered ITS. The other 2 quarters of every heifer were not interfered with prior to calving. After calving, each quarter of every heifer was sampled. Both prepartum secretion as well as colostrum samples were bacterially cultured to determine quarter infection status and the somatic cell count (SCC) was enumerated. Prepartum secretion samples were scored based on viscosity as thick or thin. At 75 days prepartum, 26% of quarters had an IMI, and 28% were infected at 35 days prepartum. Uninfected secretion samples were 133.2 (95% confidence interval (CI): 16.8 - > 999.9) times more likely to be thick compared to samples infected with a major pathogen, and 14.3 (95% CI: 8.5 - 24.1) times more likely to be thick compared to samples infected with non-aureus staphylococci (NAS). Secretion SCC was elevated when an IMI was present within the quarter; quarters with an IMI caused by a major pathogen had the highest SCC, and uninfected quarters had the lowest SCC (6.73 ± 0.08 and 6.04 ± 0.03 log₁₀ cells/mL, respectively). Postpartum, quarters that did not receive ITS prepartum were 3 times (95% CI: 1.4 – 6.3) and 2.5 times (95% CI: 1.2 – 4.9) iv more likely to be infected with a pathogen other than NAS at calving than quarters that received ITS at 75 or 35 days prepartum, respectively. Quarters that did not receive ITS were 5.8 (95% CI: 3.2 – 10.5) and 6.4 (95% CI: 3.4 – 12.0) times more likely to be infected with NAS than those that received ITS at 75 and 35 days. The odds of IMI at calving was similar for quarters that received ITS at either 75 or 35 days prepartum for both NAS (odds ratio (OR) = 0.9) and other pathogens (OR = 1.2). Given there were no adverse effects from administering ITS earlier at 75 days prepartum, it may be recommended that earlier administration of ITS could be preferred as it may provide a longer time period for IMI prevention. Using detection tools such as secretion viscosity and SCC, and control practices, like early prepartum ITS administration, can allow producers to mitigate some of the negative effects of primigravid heifer IMI and increase herd production efficiency and profitability.
Benjamin Enger (Advisor)
Jessica Pempek (Committee Member)
Craig Zimmerly (Committee Member)
99 p.
Animal Sciences
mastitis; viscosity; internal teat sealant; heifer mastitis; heifer IMI; somatic cell count; SCC; IMI; heifer mammary secretions; mammary secretions

Recommended Citations

Citations

  • Larsen, L. (2021). Detection and Prevention of Intramammary Infections in Primigravid Dairy Heifers [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1626638139653464

    APA Style (7th edition)

  • Larsen, Lindsay. Detection and Prevention of Intramammary Infections in Primigravid Dairy Heifers. 2021. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1626638139653464.

    MLA Style (8th edition)

  • Larsen, Lindsay. "Detection and Prevention of Intramammary Infections in Primigravid Dairy Heifers." Master's thesis, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1626638139653464

    Chicago Manual of Style (17th edition)

osu1626638139653464
167
© 2021, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.
Release 3.2.12