The Use of Protective AI Cover Sheaths Improved Fertility in Lactating Dairy Cows

Abstract

The objectives of this study were to evaluate the effectiveness of using a disposable sheath protector (SP) on top of the regular artificial insemination (AI) sheath to minimize contamination of the AI gun and to assess pregnancies per AI (PAI) in lactating dairy cattle inseminated with or without the use of SP. Services (n = 2843) during spring (67%) and summer (33%) from lactating Holstein cows in three commercial herds were included in this study. Animals were presynchronized with two injections of prostaglandin F2α (PGF) given 14 d apart (starting at 26 ± 3 DIM) followed by Ovsynch (gonadotropin releasing hormone [GnRH]-7d-PG-56 h-GnRH-16 h-timed AI) or Cosynch (GnRH-7d-PG-72 h- GnRH+timed AI) 12 d later. At the time of AI, services were randomly assigned to 1 of the 2 groups: 1) with (TRT; n = 1405) or 2) without (CON; n = 1438) the use of SP. Sterile cotton swab samples were collected from the tip of the AI gun (n = 102) immediately after AI (from TRT and CON) for bacteriology. Pregnancy diagnosis was determined by ultrasonography 40 ± 5 d after AI. Swab samples revealed that the use of SP was effective in minimizing contamination of the AI gun at the time of AI in TRT (51.9%) compared with CON cows (98%; P < 0.05). Overall, PAI was greater (P = 0.01) for cows in TRT (30.1 ± 1.7%) than in CON (25.4 ± 1.9%). Results from this study suggested that the use of SP reduced contamination of the AI gun at the time of AI and improved PAI in lactating dairy cows. [...]