Abstract
Aim of study: The aim of this study was to determine the relationship between spontaneous recovery from subclinical endometritis (SE), body condition score (BCS), serum concentrations of non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) in grazing dairy cows. Area of study: In the southern province of Santa Fe, Argentina. Material and methods: A total of 56 multiparous Holstein cows were evaluated at -9 (prepartum), 27 and 45 (postpartum) days relative to calving (DC). Serum levels of NEFA and BHB, along with BCS (scale 1-5), were measured. The experimental groups included: cows with spontaneous recovery (SRC) (n= 31), sick cows (SC) (n = 17), and cows with healthy uterus (HC) (n = 8). Main results: A spontaneous recovery rate from SE of 64.6% was observed. A moderate positive correlation (r = 0.302, p < 0.05) between NEFA and DC during the prepartum period, and a significant negative correlation (r = -0.408, p < 0.001) between percentage of polymorphonuclear neutrophils and DC postpartum were identified. Plasma concentrations of BHB and NEFA exhibited similar patterns in all groups. The HC group maintained higher BCS scores at both postpartum evaluations (p < 0.05). At 45 days postpartum, HC cows showed the least reduction in BCS, followed by SRC cows, which preserved their fat reserves relative to the SC group. Research highlights: This study demonstrates a high rate of spontaneous recovery (64.6%) from SE when evaluated during the fourth week postpartum. While the ability to spontaneously resolve SE was not directly linked to specific serum thresholds of NEFA, BHB, or overall BCS, the data reaffirm that minimizing the loss of body reserves during the transition period is fundamental for maintaining a healthy uterine status.