Effect of intrauterine dextrose or antibiotic therapy on reproductive performance of lactating dairy cows diagnosed with clinical endometritis

摘要

The objectives of this study were to assess the responses to treatments (clinical cure and cow survival 14 d posttherapy) of cows with clinical endometritis (CE) that received intrauterine infusion of a hypertonic solution of 50% dextrose (DEX) or subcutaneous ceftiofur crystalline free acid (CCFA) and subsequent pregnancy per artificial insemination (P/AI) in cows with CE compared with cows without CE. Cows (n = 760) from 2 dairy herds were screened for CE using vaginoscopy and measurement of cervix diameters [exam 1; 26 ± 3 d in milk (DIM)]. Cows with vaginal discharge scores of 2 or 3 (scale 0-3) were stratified by parity and randomly allocated into 1 of 3 treatment groups: (1) intrauterine infusion (～200 mL) of 50% DEX solution (n = 79); (2) 6.6 mg/kg single-dose of subcutaneous administration of CCFA (n = 75); or (3) untreated control animals (CON, n = 83). Fourteen days posttherapy (at 40 ± 3 DIM), cows with CE were re-examined (exam 2; 40 ± 3 DIM) to assess the response to treatments. All cows were presynchronized with 2 injections of PGF_(2α) given 14 d apart (starting at 26 ± 3 DIM) followed by Ovsynch (OV; GnRH-7 d-PGF-56 h-GnRH 16 h-timed-AI) 12 to 14 d later. Cows displaying signs of standing estrus any time during the protocol were inseminated, whereas the remaining cows were subjected to timed AI 16 h after the second GnRH of OV. Pregnancy diagnosis was performed via transrectal ultrasonography at 39 ± 3 d post-AI followed by pregnancy reconfirmation 30 d after the first pregnancy diagnosis. Uterine swabs revealed that Arcanobacterium pyogenes and Escherichia coli were the most predominant bacteria isolated at the time of treatments. Mortality within 14 d posttherapy was not different among treatment groups. Cows with CE had greater cervical diameter at exam 1 and decreased P/AI compared with cows without CE. Treatment with CCFA or DEX increased the proportion of cows with clear vaginal discharge (score 0; clinical cure) 14 d posttherapy compared with CON cows. Pregnancy per AI from DEX (29.8 ± 4%) cows tended to differ from that of CON (21.1 ± 4%) or CCFA cows (19.7 ± 4%), but it resulted in similar P/AI as those cows without CE (39.1 ± 2%). The use of intrauterine DEX alone or as an adjunct of antibiotic therapy for the treatment of CE needs further investigation.