Using vaginal discharge score (VDS) grading system to evaluate the effect of clinical endometritis on reproductive performance of dairy cows in China.

Yubing Wei,Xiaohu Wu,Xingxu Zhao,Zuoting Yan,Yong Zhang,Hongsheng Wang

doi:10.1590/1984-3143-ar2020-0228

Abstract

Clinical endometritis (CE) is a major cause in affecting the reproductive performance of dairy cows. The objectives of this study were to ascertain the prevalence of CE and to evaluate the effect of CE on reproductive performance in dairy cows using vaginal discharge score (VDS) grading system. 803 dairy cows were examined by vaginoscope with 4-point VDS at 26 ± 3 days in milk (DIM) and classified into six groups: non-endometritis with VDS 0 (control; CON), endometritis with VDS 1 (MEM), non-treated endometritis with VDS 2 (NTME), treated endometritis with VDS 2 (TME), non-treated endometritis with VDS 3 (NTPE), and treated endometritis with VDS 3 (TPE). Cows in TME and TPE groups were treated with 200 mL of 50% dextrose solution by intrauterine infusion. The prevalence of CE was 33% at 26 ± 3 DIM. Binary logistic regression analysis revealed cows in MEM, NTME and NTPE groups had a less likelihood of first artificial insemination (AI) pregnancy than those in CON group (P < 0.05). Kaplan-Meier survival curves for days open were statistically different (P = 0.004). In Cox regression model, cows in NTME and NTPE groups had a reduced pregnancy rate than those in CON group (P < 0.05). The hazard of pregnancy in NTME group was lower than that in TME group (P = 0.044). Similarly, it was lower for the hazard of pregnancy in NTPE group than in TPE group (P = 0.048). Cows in MEM, NTME, and NTPE groups required more services per pregnancy than those in CON group (P < 0.05). In conclusion, CE examined by the VDS grading system impaired reproductive performance, and mild endometritis with VDS 1 should be treated in the early postpartum period to ameliorate fertility in dairy herds.

Highlights

Reproductive performance is a key factor in determining the profitability of dairy production management (Fourichon et al, 2000; LeBlanc et al, 2002a)
803 enrolled dairy cows were screened for Clinical endometritis (CE) at 26 ± 3 days in milk (DIM), and data from 42 cows were excluded from the analysis because cows were culled or died from other causes of illness (n = 31), or any other incomplete information that may influence the results (n = 11) during the study period
761 enrolled dairy cows were available for further statistical analysis of reproductive performance, with 506 (66.5%) being classified as CON group, 99 (13%) as MEM group, 39 (5.1%) as non-treated endometritis with VDS 2 (NTME) group, 45 (5.9%) as treated endometritis with VDS 2 (TME) group, 34 (4.5%) as NTPE group, and 38 (5%) as TPE group; 268 for primiparous cows and 493 for multiparous cows; 264 for cows with body condition score (BCS) ≤ 2.75 and 497 for cows with BCS ≥ 3.0

Summary

Introduction

Reproductive performance is a key factor in determining the profitability of dairy production management (Fourichon et al, 2000; LeBlanc et al, 2002a). Clinical endometritis (CE) is a common cause of reduced reproductive efficiency in dairy cows, which is characterized by the presence of mucopurulent or purulent uterine exudate in the vagina for 21 days or more post partum, and without systemic signs (Sheldon et al, 2006; Dubuc et al, 2010a).

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