Prevalence of clinical endometritis and its impact on reproductive performance in grazing dairy cattle in Argentina

The objective of this study was to evaluate the prevalence of clinical endometritis and its impact on reproductive performance in grazing dairy cattle in Argentina to compare data with previous reports from herds kept in confinement housing systems. A total of 243 Holstein dairy cows from three commercial dairy farms in Buenos Aires Province (Argentina) were examined for the signs of clinical endometritis 18-38 days postpartum (dpp) by external inspection and manual vaginal examination. Vaginal discharge was scored into the categories VDS 0 (transparent, clear mucus), VDS 1 (mucupurulent discharge), VDS 2 (purulent discharge) and VDS 3 (purulent discharge with fetid odour). Cows diagnosed with VDS 1 to VDS 3 were regarded as affected with clinical endometritis and cows with VDS 0 as free of clinical endometritis. All cows were re-examined 14 days later following the same examination protocol. Prevalence of clinical endometritis 18-38 dpp was 35% and decreased to 18% at re-examination. Cows with no palpable ovarian structures or periparturient disorders were at higher risk for clinical endometritis. Hazard for pregnancy was significantly lower in cows with purulent or fetid odour discharge compared with reference cows with no discharge (HR=0.49; p=0.01), resulting in a lower proportion of cows pregnant by 360 dpp (66% vs 78%). Furthermore, the number of services per pregnancy was higher for cows with clinical endometritis than for cows without clinical endometritis (4.4 vs 3.1; p=0.04). Cows with clinical endometritis were 1.6 times as likely to be culled as cows with no signs of clinical endometritis. In conclusion, the prevalence and the impact of clinical endometritis in a pasture-based, extensive dairy production system in Argentina were similar to previously published data from dairy farms with confinement production systems.     

Effects of the intensity of a post partum examination on the fertility performance of high yielding dairy cows

Two methods for a scheduled post partum examination were compared on a commercial dairy farm. In Group 1, all cows (n = 601) were examined by rectal palpation between day 20 and 26 post partum for signs of endometritis (vaginal discharge, enlarged uterus). In Group 2, all cows (n = 652) were examined by external inspection for vaginal discharge as a sign for endometritis. In both groups all cows with endometritis were treated twice with prostaglandin F2 alpha (25 mg of dinoprost) in a 14-day interval. The proportion of cows with signs of endometritis was 33.3% and 17.2% in Group 1 and Group 2, respectively (p < 0.05). In Group 1, the conception rate (39.0% vs 49.3%) and the proportion of cows pregnant (60.5% vs 72.6%) were lower for cows with endometritis than for cows without endometritis. In Group 2, no significant differences were found in reproductive performance for cows with and without signs of endometritis. No significant differences in reproductive performance were found for cows with endometritis between the two groups. Also, for cows without endometritis no significant differences in reproductive performance were found between the groups. It is concluded that the post partum examination by rectal palpation was more sensitive in finding cows with endometritis. However, with regard to the reproductive performance the more sensitive method was not more effective than the method based on systematic external inspection.     

Evaluation of Subclinical Endometritis and Consequences on Fertility in Piedmontese Beef Cows

Subclinical endometritis (SEM) is poorly investigated in beef cows, as stated in the literature. This project aims to evaluate the rate and the consequences of SEM in Piedmontese cows, with a focus on bacteriological findings and fertility parameters. Uterine cytology was performed for 97 subjects; a total of 31% of the cows were diagnosed as being positive for SEM and as having an 8% neutrophil (PMN) presence on the slide, which is considered as the best cut‐off to diagnose the pathology. Only 13% of the cows positive for SEM were pregnant within 130 dpp and generally showed increases of 40 days in the partum to conception interval compared with the negative cows (142 vs 182, p = 0.01). Cows positive for both bacteriology and cytology showed a lower fertility than cows with only inflammation or only a bacterial presence (p = 0.0004). Bacterial isolation detected different species, but no difference in regard to the impact of these bacteria on SEM was shown. Parity, presence of calves, hygiene condition, age and number of service did not affect whether a cow was positive for subclinical endometritis (p < 0.05). The housing system (free stalls vs tie stalls) used seems to affect the SEM rate in Piedmontese cows; cows bred in tie stalls were more likely to be positive for SEM (OR = 2.2; p = 0.04). In conclusion, cytology seems to be a good technique for the diagnosis of subclinical endometritis in beef cows, and as in dairy cows, subclinical endometritis has a detrimental effect on fertility, causing an increase in partum to conception and a decrease in the rate of cows who become pregnant within 130 dpp, particularly for those cows housed in a tie stall.     

Supplementing rumen‐protected methionine to lactating multiparous dairy cows did not improve reproductive performance

There is evidence that supplementing methionine has positive effects on uterine environment, oocyte quality and embryo development in cattle. Thus, the objective of this study was to evaluate reproductive traits of cows supplemented with rumen‐protected methionine (RPM) during early to mid‐lactation in comparison with an untreated control group (CON). An additional focus was on the effect of puerperal diseases on reproductive performance parameters in RPM‐supplemented group MET and in CON. A total of 1,709 multiparous Holstein‐Friesian cows were enrolled in this field trial conducted on a commercial dairy farm in Slovakia. Cows were allocated at approximately 12 days post‐partum (dpp) to either CON or MET, the latter supplemented with 25.0 g–27.2 g RPM per cow per day incorporated into the total mixed ration (TMR) until leaving the study pen at approximately 140 dpp. The amount of RPM was calculated based on individual feed ingredients analysis and adjusted during the study period when TMR changed. Cows were monitored during the post‐partum period by vaginal examination (day 5 pp), measuring of beta‐hydroxybutyrate in blood (3, 5, and 8 dpp) and by vaginal examination, uterine cytology and measuring of back fat thickness by ultrasound (all at 31 ± 3 dpp). Compared with CON, cows supplemented with RPM did not show better reproduction performance parameters (first service submission rate, days to first service, conception risk, days open 140). Results from binary logistic regression model for the risk of conception showed that metritis had a significant effect, but the supplementation of methionine had not. Results of Cox regression analysis for the odds of conception within 140 dpp revealed only metritis and clinical endometritis as significant factors. In conclusion, supplementation of RPM had no beneficial effect on reproductive performance in this study farm compared with an untreated control group.     

Strategies for the treatment of dairy cows at high risk for postpartum metritis and for the treatment of clinical endometritis in Argentina

The objectives of this study were to evaluate the efficacy of (1) administering ceftiofur hydrochloride in dairy cows with calving-related disorders to prevent metritis and (2) a combination of GnRH and PGF_2α for the treatment of clinical endometritis, under Argentinean dairy farming conditions. Cows at high risk (HRC) for metritis (dystocia, RFM >12 h postpartum, hypocalcaemia, twins, or stillbirth) were randomly assigned to receive either 1.1 mg/Kg of ceftiofur hydrochloride on three consecutive days (HRC treated group HRCT, n?=?110) or remained untreated (HRC control group HRCC, n?=?126). Cows with low risk (LRC, no calving-related disorders, n?=?868) did not receive any treatment (LRC group, n?=?868). All cows were examined for metritis between days 4 and 10 and for clinical endometritis between 24 and 30 days postpartum. The body condition score (BCS) was recorded at both examinations. Cows with endometritis at days 24 to 30 postpartum received either 1.5 mg of D-cloprostenol (PGF; n?=?129) or 100 μg of GnRH followed by D-cloprostenol after 7 days (GnRH+PGF, n?=?119). There was no overall effect of treatment on the incidence of metritis or on time to pregnancy. Treatment, however, reduced the incidence of metritis in cows with high BCS (HRCT?=?24.0 %, HRCC?=?38.5 %) but had no effect in cows with low BCS (HRCT?=?38.7 %, HRCC?=?37.5 %). The proportion of pregnant cows by days in milk was greater (P?<?0.01) in LRC group compared with that of the HRCT and HRCC groups. No significant differences were found between groups PG and PG+GNRH. GnRH+PGF treatment, however, tended (P?=?0.06) to increase pregnancy rate in cows with a moderate loss of BCS (76.5 vs 65.2 %) but tended to reduce pregnancy rate (54.5 vs 76.0 %) in cows with a more pronounced loss in BCS (>0.75 points).     

Serum progesterone levels in post-partum dairy cows after repeated application of the prostaglandin F2 alpha analogue D (+) cloprostenol sodium

Reproductive management programmes based on strategic use of prostaglandin F2 alpha (PGF2 alpha) to induce and synchronize oestrus in post-partum dairy cows are widespread. Repeated shortening of the oestrous cycle during early lactation in high-yielding dairy cows, however, could impair corpus luteum function and thus decrease fertility. The objective of this study was to analyse the effect of repeated treatments with the prostaglandin F2 alpha analogue D (+) cloprostenol sodium on progesterone concentrations indicative of a functional corpus luteum in post-partum dairy cows. Furthermore, the influence of milk production, parity and endometritis on progesterone concentrations under these circumstances were studied. Eighty-four cows of a commercial dairy operation were treated three to four times with D (+) cloprostenol sodium (Preloban; Hoechst Roussel Vet, Wiesbaden, Germany) at 14-day intervals, starting 22-28 days post-partum. Blood samples were collected prior to treatment 1 (sample 1) and 14 days after treatments 1, 2 and 3 (samples 2-4) and serum progesterone (P4) levels were determined. The percentage of cows with P4 levels < 1 ng/ml decreased from 51% in sample 1 to 23% in samples 3 and 4. More primiparous cows had low P4 levels 14 days after the second treatment than older cows (P < 0.05). Cows with low progesterone levels in sample 3 or 4 had lower protein contents in milk on the second milk test day post-partum and in their cumulative milk yield of the first 100 days of lactation. Clinical endometritis at post-partum examination did not influence progesterone levels after treatment with PGF2 alpha. Repeated application of PGF2 alpha (more than twice) in the post-partum period does not influence serum progesterone levels 14 days after treatment. Failure to develop luteal tissue after treatment contributed to the conception failures after first service.     

Hormonal treatments for fertility disorders in cattle

In dairy cows, hormonal treatments are commonly implemented for acyclicity, silent heat and endometritis. Before treatment, causes of infertility need to be detected and severe failures in housing, feeding or other diseases must be eliminated. Without sustainable improvement of herd management, the use of intensive hormonal treatments will not improve reproductive performance. The most common cause of anoestrous is silent heat. In cows with a palpable corpus luteum, injection of prostaglandin F2α (PGF) reliably induces oestrous. A satisfactory treatment for acyclicity (ovarian dystrophy, ovarian cysts) does not exist. Combinations of different hormones have greater treatment success than a single use of gonadotrophin releasing hormone (GnRH) or human chorionic gonadotrophin (hCG). Strategic use of PGF during the early postpartum period cannot be recommended because positive effects on uterus involution and resumption of the oestrous cycle after calving have not been verified. In contrast, application of GnRH combined with PGF in the puerperal phase appeared to have positive effects on fertility of cows with endometritis. The same applies to PGF for cows with chronic endometritis. Cases of endometritis with fetid odour of vaginal mucus or isolation of Trueperella pyogenes should be treated with antibiotics. Treatment before the 27th day post partum is not advisable. In conclusion, hormonal treatments can be used to treat fertility disorders. Nevertheless, in order to enhance the reproductive performance at the herd level, a sustainable improvement of the general conditions (housing, feeding, animal health, management) is a prerequisite.     

Effect of a 10 day postpartum administration of a PGF2 alpha analog at different concentrations on the course of the puerperium and fertility in dairy cows

In this double-blind Study 72 dairy cows were treated with injections of Luprostiol (Reprodin). 32 cows served as control. Gynaecological examinations in 10-day intervals up to day 40 post partum and determination of progesterone levels in milk samples taken in 3-day intervals up to day 73 p. p. were performed. The administration of PGF2 alpha did not improve the early onset of ovarian activity in cows with uncomplicated or complicated delivery. Ovaries without detectable function up to day 73 p. p. only occurred in the placebo group, representing a significant (p < 0.05) difference to the control group. In cows after uncomplicated as well as in animals after complicated delivery involution of the uterus up to day 20 p. p. progressed faster in the verum group compared to the control group. Cervical diameters were highest in the placebo group up to day 20 p. p. Until day 40 p. p. the cervical diameters of the probands equaled those of the control animals. In contrary to cows after uncomplicated delivery the injection of PGF2 alpha after complicated parturition lead to a significant (p < 0.05) reduction of puerperal endometritis. Neither in cows with uncomplicated nor complicated delivery the administration of PGF2 alpha resulted in an improved conception rate. There were no significant positive effects on fertility parameters to be detected in general. Partial results observed were not dose dependent.     

Effect of three programmes for the treatment of endometritis on the reproductive performance of a dairy herd

Three management programmes to improve the reproductive performance of a dairy herd were compared in a prospective controlled field study on one commercial farm. A total of 542 cows were examined for endometritis 22 to 28 days postpartum and assigned to one of three treatment groups: in group 1 the cows with signs of endometritis were treated with an intrauterine infusion of 100 ml of a 2 per cent polycondensated m-cresolsulphuric acid formaldehyde solution; in group 2 the cows with signs of endometritis were treated with an intrauterine infusion of 125 ml of a 20 per cent eucalyptus compositum solution; and in group 3 all the cows were injected intramuscularly with 0.75 mg of tiaprost, an analogue of prostaglandin F2alpha (PGF2alpha) at two-week intervals, starting on day 43, until they were inseminated. Thirty-four per cent of the cows showed signs of endometritis. In group 3, oestrus detection efficiency was significantly higher than in groups 1 and 2 (P<0.05), the interval to first service was shorter, and the cows had fewer days open than the cows in groups 1 and 2 (P<0.05). The results indicate that management programmes based on the strategic use of PGF2alpha are an effective alternative to traditional programmes based on rectal palpations and intrauterine infusions to control endometritis at a herd level.     

Clinical and Bacteriological Aspects on the Use of Oxytetracycline and Flunixin in Primiparous Cows with Induced Retained Placenta and Post-partal Endometritis

Retention of the fetal membranes and post‐partal endometritis (RFM) are common problems in dairy cows. Treatment often includes manual removal of the placenta in combination with antibiotic treatment. Earlier studies have shown that cows with endometritis post‐partum have a strong tendency to recover spontaneously. The present study focused on treatments of post‐partal endometritis with the prostaglandin synthesis inhibitor, flunixin (F) either alone or combined with oxytetracycline (T). The study was conducted in two experiments, using 12 primiparous cows in each. As a model for RFM, premature parturition was induced in late pregnant heifers by injecting PGF_2α (25 mg i.m.) twice with a 24 h interval. In each experiment the cows were set into four groups and treated with either T (10 mg/kg BW i.m. once daily), F (2.2 mg/kg BW p.o. twice daily), a combination of T and F (dosage, as above) or conservatively (group 0, no drugs). The treatment periods lasted from days 11–14 post‐partum in experiment 1 (groups T1, F1, TF1 and 0) and from days 3–6 post‐partum in experiment 2 (groups T2, F2, TF2 and 0). Jugular vein blood samples were collected for analyses of flunixin and total white blood cells. Uterine biopsies were collected twice weekly for investigation of endometrial microbiology. Rectal palpation and ultrasonographic examinations were performed three times weekly for investigations of uterine involution and ovarian activity. No attempts were made to remove the placentas manually. The experiment lasted until day 56 post‐partum. The induction of parturition was successful in all heifers and 22 of 24 animals had RFM. All RFM cows had bacterial endometritis. The predominant bacteria were Escherichia coliα‐haemolytic streptococci, Fusobacterium necrophorum, Arcanobacterium (Actinomyces) pyogenes, Bacteroides spp., Pasteurella spp. and Proteus spp. Fusobacterium necrophorum and A. pyogenes could be isolated for 3–5 weeks post‐partum and E. coli, Pasteurella and Proteus could be isolated for 2–3 weeks post‐partum. Animals treated with tetracycline after placental shedding (T1 and TF1) had a more rapid recovery from infections with A. pyogenes and F. necrophorum than animals that were not treated with tetracycline. No other genera were affected. Antibiotic treatment before placental shedding (T2 and TF2) did not shorten the uterine infection but altered the bacterial flora, seen as an overgrowth of Proteus spp. (p < 0.05) and increased frequency of Pasteurella (p < 0.05). The α‐haemolytic streptococci were less common in T2 and TF2 than in other groups (NS). Antibiotic treatment of cows before placental shedding (T2 or TF2, n=6) postponed detachment of placenta compared to cows were no antibiotics were administered before placental shedding (T1, TF1, F1, F2 and 0, n=16, 9.8 days pp (median) versus 11.8, p=0.004). Neither treatment shortened uterine involution. Flunixin treatments did not seem to influence recovery from infection or uterine involution. It was concluded that early oxytetracycline treatment of retained fetal membranes in the cow did not shorten the uterine involution or uterine infection but it did slow down the detachment process of the retained placenta. Oxytetracycline treatment after placental shedding might shorten the uterine infection but otherwise did not affect the clinical results. Flunixin treatment had no influence on the clinical outcome of the disease.     

Reproductive effects of estradiol cypionate in postparturient dairy cows

OBJECTIVE: To determine the effects of estradiol cypionate (ECP) on measures of reproductive efficiency in postparturient dairy cows. DESIGN: Randomized clinical trial. ANIMALS: 273 cows in a single herd in California. PROCEDURE: Twenty-four hours after parturition, 122 cows were treated with ECP (4 mg, IM); the remaining 151 cows were untreated controls. Percentages of cattle with abnormal findings during uterine palpation 27 to 40 days after parturition were compared between groups, along with days to first artificial insemination (AI), percentages of cows that were not pregnant after the first AI, and days to pregnancy. RESULTS: Treatment with ECP did not have a significant effect on whether results of uterine palpation 27 to 40 days after parturition were abnormal, days to first AI, or odds that a cow would be pregnant after the first AI. Treatment with ECP appeared to have a negative effect on days to pregnancy (hazard ratio, 0.72) CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that prophylactic administration of ECP during the early postparturient period in dairy cows did not have measurable beneficial effects on reproductive efficiency.     

A clinical trial using a regimen which includes a norgestomet implant and norgestomet plus oestradiol valerate injection as a treatment for anoestrus in dairy cows

In seasonally calving dairy herds in the Macalister Irrigation Area of Gippsland, Victoria, cows that had not been observed in oestrus by the start of the mating season and which had inactive ovaries based on rectal palpation and progesterone assay were treated with a hormonal treatment (n = 49). Mature cows had calved at least 40 days previously and 2-year-olds had been calved at least 60 days. The treatment consisted of a norgestomet implant and a norgestomet and oestradiol injection on day 1; prostaglandin analogue Prosolvin) on day 8; withdrawal of implant on day 10 and an injection of PMSG; and fixed time artificial insemination 54 to 56 h after implant withdrawal. This treatment was called the Syncro-mate regimen. Control cows (n = 46) were injected with water on days 1, 8 and 10 and artificially inseminated or served by a bull when seen on heat. Forty seven percent of the treated cows became pregnant within 14 days from the start of treatment compared with 20% of control cows (P less than 0.01). There was an effect of age group on the response to treatment. A greater proportion of 2-year-old cows than mature cows became pregnant within 14 days of treatment (79% of 19 v. 27% of 20; Chi square interaction, treatment by age, 6.4, P less than 0.05). In the younger cows there was also a gain of 22 days in the treatment to conception interval over the control cows (P less than 0.001). It was concluded that the Syncro-mate regimen can be an effective treatment for post partum anoestrus in dairy cows under certain conditions.     

Relationship between postpartum changes in 13, 14-dihydro-15-keto-PGF2alpha concentrations in Holstein cows and their susceptibility to endometritis

Uterine infections (i.e., endometritis) can have a major economic impact on dairy production. Identifying cows that are susceptible to endometritis and improving the diagnosis of endometritis could lead to a reduction in the impact of such infections. Thus, we used Holstein cows to determine whether postpartum changes in 13, 14-dihydro-15-keto-PGF2alpha (PGFM), a metabolite of PGF2alpha, could be used to identify cows that are susceptible to endometritis and to improve the diagnosis of endometritis. Cows were assigned to three treatments. 1) Control (n = 10) had no clinical or bacteriological signs of endometritis during the study. 2) Treated (n = 11) developed endometritis spontaneously and were treated i.m. with 25 mg of PGF2alpha immediately after clinical diagnosis (d 17.6 +/- 0.8 postpartum; mean +/- SEM). 3) Untreated (n = 10) developed endometritis spontaneously and were not treated after diagnosis (d 20.0 +/- 0.5). Examinations of external and internal genitalia and bacteriological data were used to diagnose endometritis. From d 0 (calving) until approximately d 63 postpartum, jugular blood was collected three times weekly. Progesterone and PGFM were quantified in plasma. For PGFM, the treatment x day interaction was significant (P < 0.01). Overall PGFM profiles for Control and Treated differed (P < 0.05), but the Untreated profile did not differ from either Control or Treated. To better understand the interaction, PGFM data from d 0 to 35 postpartum were partitioned into consecutive 7-d periods, and d-36 and greater data were partitioned into one period. Effects of treatment, day, and the treatment x day interaction were then evaluated within period. Except for the d-15 to -21 period, PGFM was greater (P < 0.03) in Control than in Treated and Untreated. In Treated and Untreated, PGFM increased during the d-15 to -21 period. For progesterone, treatment did not affect the profiles, but day was significant (P < 0.001). Progesterone concentrations were basal from d 0 until approximately d 12, and they generally increased after d 12. Onset of endometritis was associated with increased progesterone concentrations. Treatment did not affect the interval from calving to first detected estrus (29.5 +/- 4.9 d) or from calving to AI (73.3 +/- 8.7 d). We conclude that PGFM measures have the potential to be used to identify cows that are more likely to develop endometritis and that PGFM may aid in the diagnosis of endometritis.     

重组溶葡萄球菌酶对奶牛子宫内膜炎的疗效研究

为研究重组溶葡萄球菌酶对奶牛子宫内膜炎的疗效,以青霉素钠、土霉素为对照药物,子宫内灌注给药,分别在河北、内蒙古、广州、上海奶牛场试验,共治疗急、慢性子宫内膜炎病例359头,抽检249头奶牛子宫分泌物进行细菌学分离鉴定与统计分析。结果表明,大肠杆菌、金黄色葡萄球菌、链球菌、化脓棒状杆菌是4种检出率较高的病原菌。重组溶葡萄球菌酶治疗组与土霉素、青霉素钠比较,按400、800、1200U／次的三个浓度剂量治疗,隔日投药1次,连续用药3次,800、1200U／次的浓度剂量显效率超过80％,显著优于青霉素钠的疗效（P〈0．01）,与土霉素注射液组相当。追加用药次数可进一步提高奶牛子宫内膜炎的痊愈率。重组溶葡萄球菌酶能有效治疗由金黄色葡菌球菌、链球菌、化脓棒状杆菌等革兰氏阳性菌感染的子宫内膜炎,治愈后受孕率在70％左右。尤其是对抗生素治疗无效的慢性子宫内膜炎同样具有很好的疗效。因此,用重组溶葡萄球菌酶治疗奶牛子宫内膜炎安全、高效。     

Retention of a functional corpus luteum and peripheral concentrations of 13,14-dihydro-15-keto-prostaglandin F2alpha following metestrus administration of Syncro-Mate-B.

This study was conducted to examine the effects of metestrus administration of SyncroMate-B (SMB) on PGF2alpha secretion and corpus luteum (CL) development. In a study replicated over 2 yr, cows were observed for spontaneous estrus in yr 1, and cows received an injection of 25 mg of PGF2alpha and were observed for subsequent estrus in yr 2. At standing estrus (estrus = d 1), cows were randomly allotted to receive either the standard SMB regimen (n = 40) on d 3 of the estrous cycle or no treatment (n = 8). Fifty percent (n = 20) of SMB-treated cows were administered PGF2alpha on d 10 of the estrous cycle 48 h prior to implant removal. Twice-daily blood samples were collected in the morning (AM) and evening (PM) from d 2 AM through d 14 AM of the treated estrous cycle and subsequently analyzed for progesterone (P4) and PGF2alpha metabolite (PGFM). Prior to statistical analysis, SMB- and SMB/PGF2alpha-treated cows were sorted according to P4 concentration at d 10 of the treated estrous cycle to either a CL functional group (P4 > or = 1 ng/mL; n = 20) or a CL nonfunctional group (P4 < 1 ng/mL; n = 17). Following d 10 AM administration of PGF2alpha, functional and nonfunctional groups were further subdivided based on treatment. The groups were as follows: untreated control cows (n = 8); SMB-treated cows retaining a functional CL (SMB-F; n = 8); SMB-treated cows with a nonfunctional CL (SMB-N; n = 11); SMB/PGF2alpha-treated cows retaining a functional CL (SMB/PG-F; n = 12); and SMB/PGF2alpha-treated cows with a nonfunctional CL (SMB/PG-N; n = 6). Of all SMB-treated cows, 54% retained a functional CL through d 10 AM of the treated estrous cycle. Mean serum P4 concentrations increased for cows in all groups until d 7, after which P4 concentrations increased for cows in SMB/PG-F, SMB-F, and control groups and decreased for cows in SMB/PG-N and SMB-N groups. Following PGF2alpha administration on d 10, mean serum P4 concentrations remained < 1 ng/mL for cows in SMB/PG-N and SMB-N groups, decreased to < 1 ng/mL for cows in the SMB/ PG-F group, and remained > 1 ng/mL for cows in SMB-F and control groups. Mean serum PGFM concentrations tended (P = .06) to increase in cows with nonfunctional CL compared with control cows on d 8 AM and were greater (P < .05) in cows with functional CL on d 8 PM through d 9 PM. These results indicate that retention of a functional rather than a nonfunctional CL following metestrus administration of SMB is dependent on a premature release of uterine PGF2alpha.     

Treatment of Unobserved Oestrus in a Dairy Cattle Herd with Low Oestrous Detection Rate up to 60 days Post-partum

The efficiency of treatments for unobserved oestrus and their effect on the reproductive performance of a dairy cattle herd with low oestrous detection rate till 60 days post‐partum (dpp), attributed to the declivous and slippery concrete floor were investigated. The herdsman requested advice in order to improve the mean days open of the herd, but no investments were allowed because a new unit was about to be built. Due to the low oestrus detection rate of the herd, the breeding policy was to inseminate at the first detected post‐partum oestrus. Cows were examined at 20–30 dpp to assess uterine involution, ovarian activity and prevalence of reproductive disorders and, at 60 dpp if no previous oestrus was detected. Each examination included palpation per rectum, ultrasound scanning and collection of a blood sample for plasma progesterone (P4) measurement. Cows with unobserved oestrus till 60 dpp were allocated either to a treatment group (n=139) or to a control group (n=139). Three treatments were used: (a) injection of PGF_2α (PG) upon detection of a corpus luteum (CL; n = 30), cows not observed in oestrus being re‐injected 11–12 days later. AI was at oestrus; (b) PRID (n=35) or Crestar (n=74) devices kept in situ for 12 and 9 days, respectively, were associated to an injection of PG and of equine chorionic gonadotrophin (eCG) at device removal. Cows were double‐fixed time‐inseminated at 48 and 72 h after device removal. All treated cows were examined at 48–72 h after treatment to confirm oestrus. The percentage of cows detected in oestrus up to 60 dpp remained unchanged through the trial (35 and 47% for years before intervention: 1994–95; 51 and 48% for years of intervention: 1996–97). In contrast, the oestrous detection rate was high both in treated (93%) and control (100%) cows. This possibly resulted from an improvement in the oestrous detection efficiency of the herd's personnel and from examination of cows at 48–72 h after treatment. Treated and control cows had identical conception rate (CR; 36 and 37%, respectively) and reproductive performance. However, the mean days open of the herd in 1996 was significantly improved in comparison with previous years (mean ± SEM: 134 ± 6, 126 ± 5, 110 ± 4 and 114 ± 5 days, for years 1994, 1995, 1996 and 1997, respectively, p < 0.05, ANOVA ). Conception rate to AI up to 40 dpp was significantly reduced, compared with the period between 60 and 100 dpp but, mean days open were significantly improved in cows inseminated up to 60 dpp, compared with thereafter (p < 0.05).     

Role of oxytocin and/or PGF2 alpha on breeding efficiency in buffaloes

A study was conducted on 40 buffalo-cows, assigned randomly, immediately after calving into three groups: group I (n = 10) injected with saline and taken as control; group II (n = 15) received 25 mg PGF2 alpha/animal (Lutalyse); group III (n = 15) received 25 mg PGF2 alpha + 25 i.u. oxytocin/animal (Syntocinon), single i.m. dose. Oxytocin and/or PGF2 alpha significantly (P less than 0.01) shortened the interval from calving to first service (38.33 and 31.53 days for groups II and III respectively, versus 91.60 days for controls). The treatment reduced the service period (38.29 and 35.87 days for groups II and III respectively, versus 45.40 days for controls). Concomitantly a significant (P less than 0.01) decrease in the open-days post partum was achieved (76.62 and 67.40 days for groups II and III respectively, versus 137.00 days for controls). In addition, the treated buffaloes needed significantly (P less than 0.01) fewer services per conception (1.67 and 1.20 S/C for groups II and III respectively) than the untreated ones (2.70 S/C), besides a substantial improvement (P less than 0.01) in their conception rate either at 60 or 85 days post partum. Significantly improved (P less than 0.05) results were obtained in the oxytocin and PGF2 alpha treated animals, than in those receiving PGF2 alpha alone for all the previous parameters, except for the service period. Buffaloes therefore seemed to respond better to such treatment than dairy cows.     

Ovarian and endocrine responses associated with the treatment of cystic ovarian follicles in dairy cows with gonadotropin releasing hormone and prostaglandin F2alpha, with or without exogenous progesterone

The objectives of this observational study were to document ovarian and endocrine responses associated with the treatment of cystic ovarian follicles (COFs) in dairy cows, using gonadotropin releasing hormone (GnRH) and prostaglandin F2alpha (PGF) with or without exogenous progesterone. A secondary objective was to determine pregnancy establishment following synchronization of ovulation and timed insemination in cows diagnosed with COFs. In trial I, 18 Holstein cows diagnosed with COFs received 2 injections of 100 microg GnRH, 9 d apart, with 25 mg PGF given 7 d after the 1st GnRH. A new follicle developed in all 18 cows after the 1st GnRH, and 83% of cows ovulated following the 2nd GnRH. Cows were inseminated 16 h after the 2nd GnRH. Of the 17 cows available for pregnancy diagnosis, 7 were confirmed pregnant. In trial II, 8 cows with COFs received GnRH and an intravaginal progesterone device (CIDR) concurrently, then PGF 7 d later. The CIDR was removed 2 d after PGF administration. Plasma estradiol concentrations declined following CIDR insertion. In all cows, a new follicle developed following GnRH treatment; estradiol-surge and estrus occurred spontaneously after CIDR-removal. Seven of 8 cows ovulated the new follicle. In dairy cows diagnosed with COFs, treatment with GnRH followed by PGF 7 d later, with or without exogenous progesterone, resulted in the recruitment of a healthy new follicle; synchronization of ovulation and timed insemination resulted in a 41% pregnancy rate.     

Effect of intrauterine treatment with cephapirin on the reproductive performance of seasonally calving dairy cows at risk of endometritis following periparturient disease

OBJECTIVE: To determine the effect of intrauterine cephapirin (0.5 g) treatment on the reproductive performance of cows diagnosed as at risk of developing endometritis. METHODS: Cows (n = 1325) from 17 seasonal calving dairy herds were enrolled if they had been calved for more than 6 days and had a condition that placed them at risk of endometritis. Half were treated with intrauterine cephapirin at an examination performed 28-37 days prior to mating start date (MSD). Cows were scored for body condition, their vaginal discharge was scored using vaginoscopy (VV), and the uterus and ovaries were assessed by rectal palpation. RESULTS: Overall, there was no significant treatment effect on reproductive performance. In 945 modified at risk (MAR) cows the effect of treatment varied with the calving to treatment interval (CTI) and VV status. For the subset of 229 MAR cows with CTI < or = 28 days, treatment improved the proportions of first-service conception (OR 3.1; P < 0.01) and 6-week in-calf (OR 2.1; P < 0.05), and reduced the mean MSD to conception interval by 20 days (P < 0.05). The difference was greater in cows with a positive VV score (1-3). Treated VV-negative cows with CTI > 48 days had a reduced proportion of cows in-calf by 6 weeks (OR 0.58; P = 0.056) compared with untreated cows. CONCLUSION: Intrauterine cephapirin infusion of MAR cows improved reproductive performance, depending on CTI. The greater treatment effect in VV-positive cows suggests that VV scoring is a useful tool for the diagnosis of endometritis.     

Estimating prevalence of endometritis in smallholder zero-grazed dairy cows in Rwanda

Endometritis is a postpartum uterine disease of cows that interrupts reproductive cycles resulting in suboptimal fertility, reduced performance and profitability of the dairy herd. The objective of the study was to estimate the perceived and observed prevalence of endometritis among zero-grazed dairy cows in smallholder farms in Rwanda. A snowball sampling method was applied in cross-sectional survey to obtain data from 370 farms on 466 cows within their 21–60 days postpartum (dpp). The survey, conducted from September 2018 to March 2019, simultaneously examined cows using the Metricheck Device (MED) to determine the presence and type of vaginal mucus (VMC) based on a score scale of 0 to 3. Cows scoring VMC ≥ 1 were recorded as clinical endometritis (CLE)–positive. Cytotape (CYT) was used to determine the percentages of polymorphonuclear cells (PMN) in endometrial cytology sample. Cows with ≥ 5% PMN were recorded subclinical endometritis (SCLE)–positive, whereas cows with VMC-0 and < 5% PMN were considered healthy cows. At cow-level, endometritis prevalence was 70.2% with 67.2% CLE and 31.8% SCLE while at the herd-level, prevalence was 71.1% with 68.1% CLE and 34.4% SCLE. The differences between the diagnostic performance of the MED and CYT were significant (p < 0.001). Perceived prevalence by farmers was much lower (3.2%) and without agreement with the observed prevalence (kappa = − 0.02, p > 0.05). The highly observed prevalence and farmer underestimation of endometritis prevalence indicate knowledge gaps about endometritis. The extension service therefore needs to increase awareness and education among smallholder farmers about detection and management of endometritis.