Individual and Combined Effects of Diseases and Cytological Endometritis on Reproductive Performance and Culling of Dairy Cows: Preliminary Results

Abstract

The objective of this study was to evaluate the effect of calving-related disorders/clinical diseases (DIS) and cytological endometritis (CYTO) on the reproductive performance and culling of dairy cows. In a total of 119 multiparous Holstein cows, DIS were recorded and CYTO was diagnosed at 40 ± 2 d in milk. Onset of luteal activity was defined as the first postpartum measurement of milk progesterone >5 ng/mL. A dummy variable containing all four possible permutations between DIS and CYTO statuses was created. The pregnancy rates after first artificial insemination were 57.7, 42.9, 23.0 and 15.8% for the DIS−/CYTO−, DIS+/CYTO−, DIS−/CYTO+ and DIS+/CYTO+ groups, respectively. The hazard of pregnancy was affected by DIS−/CYTO+ and DIS+/CYTO+ health statuses (hazard ratio (HR) = 0.43 and 0.29, respectively), whereas DIS+/CYTO− and DIS−/CYTO− cows had a similar hazard to pregnancy. The hazard of onset of luteal activity was affected by DIS+/CYTO+ health status (HR = 0.45), but not by DIS+/CYTO− and DIS−/CYTO+ health statuses. Compared with DIS−/CYTO− cows, DIS−/CYTO+ and DIS+/CYTO+ cows had 4.24 and 5.57 times the odds of being culled, respectively. Culling was not affected by DIS+/CYTO− health status. In conclusion, CYTO+ status, irrespective of DIS status, decreased the pregnancy rate. When DIS+ and CYTO+ were combined, they had an additive negative effect. Our preliminary findings suggest that the far-reaching consequences of clinical diseases on fertility and culling can be mediated through the development of CYTO. Further investigations including a larger number of cows are required to confirm these results.

Investigation of Uterine Fluid Extracellular Vesicles’ Proteomic Profiles Provides Novel Diagnostic Biomarkers of Bovine Endometritis

“…The evaluation of uterine health was based on vaginal discharge characteristics (colour, proportion, and volume of pus) [ 41 ] and cytological evaluation [ 42 ] of cell pellet acquired from the UF. Details of the evaluation protocol and classification of the cow’s uterine health are provided in Supplementary File S2 .…”

Uterine Fluid Extracellular Vesicles Proteome Is Altered During the Estrous Cycle

“…The cytological evaluation of uteri was performed 5 days before the end of Double-Ovsynch using cytobrush technique ( 31 ). Briefly, endometrial brush (Uterobrush; Medscand Medical) was assembled to the stainless-steel device ( https://worldwide.espacenet.com/publicationDetails/originalDocument?FT=D&date=20151202&DB=EPODOC&locale=en_EP&CC=EP&NR=2029026B1&KC=B1&ND=4 ) and autoclaved.…”

“…The cytology slides were prepared, stained, and counted according to Valdmann et al. ( 31 ). Briefly, two cytological examination slides were prepared by rolling the cytobrush with cells on glass slides.…”

General and comparative aspects of endometritis in domestic species: A review

“…Importantly, endometritis causes no direct loss of milk production or mortality. Although the impact of endometritis on culling is not well studied, recent preliminary data showed that poorer reproductive performance associated with SCE may be linked with a greater culling risk (Valdmann et al, 2022).…”