Influences of metabolic traits on subclinical endometritis at different intervals postpartum in high milking cows

Seventy pluriparous high‐yielding cows were used to investigate the impact of metabolic traits and body condition score (BCS) during early lactation on subclinical endometritis diagnosed at weeks 5, 6 and 7 postpartum (pp). Blood samples were collected from animals with no peripartum problems from the second (W2) to seventh (W7) weeks pp to estimate some blood metabolites including non‐esterified fatty acids (NEFA), β‐hydroxybutyric acid (BHBA), blood glucose, total cholesterol (T‐chol) and blood urea nitrogen (BUN). Reproductive tract examination was carried out at weeks 5, 6 and 7 pp by endometrial cytology (percentage of polymorphonuclear cells; PMN%). Based on PMN%, animals having <5% were defined as subclinical endometritis group (ENDM group) while animals unaffected by endometritis were defined as no subclinical endometritis group (NOENDM group). Animals with endometritis during week 5 were identified as ENDM5, during week 6 identified as ENDM6 and during week 7 identified as ENDM7 or animals with no endometritis during weeks 5 (NOENDM5), 6 (NOENDM6) and 7 (NOENDM7) pp. Animals diagnosed at week 5; BUN and BCS were lower p < 0.05 in ENDM 5 than NOENDM5 group at W2, W4, W6 and W7. Cows diagnosed at week 6; T‐chol was significantly higher (p = 0.05) in ENDM6 group (279.2 ± 12.5 mg/dl) than NOENDM6 group (246 ± 9.5 mg/dl) at W7. Moreover, blood glucose was significantly low (p < 0.05) in ENDM6 group when compared to NOENDM group at W4 pp (49.2 ± 1.8 vs 53.8 ± 1.3 mg/dl). BCS was significantly lower (p < 0.001) in animals suffered from endometritis during week 7 when compared to NOENDM7 cows at W3, W4, W5, W6 and W7. In conclusion, lower blood glucose, BUN and BCS could be a risk factor for cytologically diagnosed endometritis at weeks 5, 6 and 7 pp.     

Immune responses during the peripartum period in dairy cows with postpartum endometritis

Determining the immune responses to the development of endometritis during the peripartum period may assist in the development of more efficient reproductive management regimens for dairy herds. In this study, we compared the peripartum immune responses of dairy cows that develop endometritis by 4 weeks postpartum (n = 11) to cows that did not develop this disease (n = 19). Blood samples were collected 1 week before calving, just after or during calving, and then at weeks 1, 2, 3, and 4 postpartum. Cows that developed endometriris had significantly higher total leukocyte, neutrophil, lymphocyte, and monocyte counts than the control cows (P < 0.05) at all time points. The leukocytes from cows that developed endometritis were significantly less phagocytic than those from control cows at all sampling time points (P < 0.01). The serum TNFalpha concentrations of the control cows decreased linearly from the prepartum time point (P = 0.0029), but the endometritis cows showed a different profile (P > 0.05). As a result, the serum TNFalpha concentrations were greater in the endometritis group (P < 0.01) than in the control group during the third and fourth weeks postpartum. The greater total leukocyte numbers and neutrophil, lymphocyte and monocyte counts, and the maintenance of elevated serum TNFalpha levels in the cows with endometritis may be due to infection in the postpartum period. Furthermore, the decreased phagocytic capacity of leukocytes during the peripartum period, including at the prepartum time point, makes cows more susceptible to postpartum endometritis.     

Blood and Intrauterine Leukocyte Profile and Function in Dairy Cows that Spontaneously Recovered from Postpartum Endometritis

The profile and function of blood and uterine leukocytes were evaluated in 14 dairy cows that spontaneously recovered from postpartum endometritis (mild, n=6 and heavy, n=8; general health not affected). From a minimum of 2 weeks before parturition until 6 weeks postpartum, blood samples were obtained twice weekly for leukocyte counts and leukogram determination and once weekly for flow cytometry assessment of polimorphonuclear neutrophils (PMN) phagocytic capacity and oxidative burst activity. Uterine fluid‐stained smears, obtained twice weekly from parturition until fluid was present in the uterus, were used for determination of the percentage of PMN, of phagocytizing PMN (phago‐PMN) and of the mean number of phagocyted bacteria per phagocytizing PMN (phagocytic index; PI). Uterine swabs were obtained twice weekly from parturition until 35 days postpartum for bacteriological examination. The time of endometritis diagnosis was similar in cows with mild or heavy endometritis but the latter cows had a significantly longer persistence of the infection and of the isolation of Gram‐negative anaerobes from the uterus. However, the effect of group (mild versus heavy) was not significant for all the blood and uterine parameters analysed. The effect of sampling day (within group effect) was significant (p<0.01 to p<0.00001) for all parameters, except for the blood monocyte count and the blood PMN phagocytic capacity, in which only a tendency for significance was observed (p<0.1). The effect of the interaction group × sampling day was significant only for the blood monocyte count. The phago‐PMN and the PI were significantly correlated (r=0.70, p<0.001). A significant correlation was also observed between the uterine fluid phago‐PMN and the blood PMN oxidative burst activity (r=?0.41, p<0.05). At the spontaneous recovery, the blood PMN oxidative burst activity was significantly higher (p<0.05) and the percentage of intrauterine phago‐PMN and the PI were significantly lower (p<0.001 and p<0.01, respectively) than at diagnosis of endometritis. These results suggest that a decrease in blood PMN oxidative burst activity until the first week postpartum could be associated with an increased susceptibility to early postpartum endometritis. The later increase in this parameter as well as the increase in the intrauterine fluid phago‐PMN and PI, might favour the spontaneous resolution of endometritis.     

Influence of Puerperal Uterine Infection on Uterine Involution and Postpartum Ovarian Activity in Dairy Cows

This article presents the results of a clinical trial designed to study the effect of puerperal uterine infection on uterine involution and on ovarian activity in dairy cows, monitored twice weekly from parturition until the sixth week postpartum (wpp). Infection significantly retarded uterine involution assessed by the uterine body diameter and a score of intrauterine fluid volume (IUFV). By the sixth wpp, cows with normal puerperium (controls) and cows that showed mild puerperal endometritis had similar uterine body diameter and IUFV, indicating spontaneous recovery within the postpartum voluntary waiting period. However, in cows with severe puerperal endometritis, although uterine body diameter had regressed to pregravid size, IUFV remained significantly higher than in control and mild endometritis cows, indicating that chronic endometritis was established. The IUFV score was positively and significantly correlated with uterine swab bacterial growth density and allowed diagnosis of endometritis after the third wpp. Cows with mild or severe endometritis had a significantly higher prevalence and persistence of pathogenic bacteria ( Escherichia coli , Actinomyces pyogenes , Gram-negative anaerobes – GNA) than controls. Actinomyces pyogenes was associated to GNA in 74% of isolations. Ovarian activity measured by ultrasound scanning of the ovaries and plasma progesterone (P4) concentrations was more abnormal (prolonged anoestrus, prolonged luteal phases and ovarian cysts) in cows with severe endometritis than in controls.     

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.     

Predisposing factors,diagnostic and therapeutic aspects of persistent endometritis in postpartum cows

A certain level of endometrial bacterial infection and inflammation is involved in bovine uterine involution during the puerperal period. Factors that hamper normal uterine involution expose the uterine environment to pathological conditions, causing different endometritis levels. The lack of proper diagnostic tools extends the time to conception. Efforts have been made to elucidate the postpartum uterine environment, including bacterial flora, changes in transient endometrial inflammation, and the pathophysiology of endometritis, to improve bovine reproductive performance. E. coli and Trueperella pyogenes in the uterus are likely to cause persistent infection, and Mycoplasma bovigenitalium infection is associated with dystocia and cytological endometritis in postpartum dairy cows. Due to the widespread use of cytobrush as a diagnostic tool for bovine subclinical endometritis (SE) that enables quantification of the degree of inflammation, we found that endometritis at week 5 postpartum was associated with delayed first ovulation. Approximately 30% of open cows have SE during the postpartum period, and cows with low blood glucose during prepartum have a high risk of developing SE. Additionally, cows with purulent vaginal discharge do not always have endometritis but only vaginitis and/or cervicitis. Intrauterine infusion of polyvinylpyrrolidone-iodine (PVP-I) improves fertility and promotes endometrial epithelial cell regeneration after inducing transient uterine inflammation, suggesting that PVP-I could be a good alternative to antibiotics. In conclusion, prepartum management to prevent glucose deficiency, prompt diagnosis to identify causative agents and intrauterine inflammation levels, and appropriate treatment to minimize antimicrobial resistance is beneficial for tackling endometritis and improving reproductive performance in bovine herds.     

Uterine bacteriology, histology, resumption of ovarian activity and granulocyte function of the postpartum cow in different milking frequencies

The postpartum uterine bacteriology, histology, resumption of ovarian activity and polymorphonuclear granulocyte (PMN) number and function in 18 Swedish dairy cows were studied. Cows were milked either 2x (n = 9) or 3x per day (n = 9). Endometrial biopsy samples for bacteriological and histological investigations were collected during 8 weeks postpartum, starting within one week after calving. Milk samples for progesterone determination were collected twice a week until the cows had shown normal reproductive cyclicity. Blood samples for granulocyte function (phagocytic capacity and total number) were collected from each animal on the same days as when the biopsies were obtained. All animals in both groups were free from bacteria at the latest after 6 weeks post-partum and there was no difference regarding bacterial elimination and bacterial species between milking groups. No difference regarding uterine histology between milking groups was seen. In both groups, 8 cows had normal to slight infiltration of leukocytes in the endometrium at the end of sample collection. No changes in granulocyte function could be seen in the 2 milking groups. Resumption of ovarian activity was detected on day 45.6 +/- 9.3 (mean +/- SD) postpartum in the 2x milking group and 36.6 +/- 9.0 (mean +/- SD) post-partum in the 3x milking group (p = 0.05). Based on our findings, an increased milking frequency from 2 to 3 times a day did not influence the uterine function postpartum.     

Body Condition Change Ante- and Postpartum, Health and Reproductive Performance in German Holstein Cows

The effects of body condition score (BCS) change and status ante‐ and postpartum (pp) on health and reproductive performance in 234 German Holstein cows from eight dairy farms were evaluated. BCS was determined from 6 weeks antepartum until 20 weeks pp in 2‐week intervals. Three and 5 weeks pp progesterone concentrations in blood serum were determined to detect the presence of luteal tissue as an indicator of cyclicity. The incidence of various diseases, percent cycling cows, reproductive measures and culling rate were assessed. Data were subjected to logistic regression to account for possible herd and lactation number effects. Cows with a low BCS status (<3.0) at calving and during early lactation (4–10 weeks pp) were at a higher risk of suffering from lameness (OR 2.9–9.4), not being cycling at 3 and/or 5 weeks pp (OR 2.24–3.99) and being culled (OR 2.56–2.79) than cows in better body condition (≥3.0) In addition, cows with a low BCS status at parturition were at a higher risk of developing endometritis (OR 2.95) and becoming pregnant later than 105 days pp (OR 5.92) than cows with a BCS ≥ 3.0. At 10 weeks pp, the risk of dystocia (OR 4.10) or retained placenta (OR 2.78) at the preceding calving and not being pregnant at 200 days pp (OR 2.42) was higher in cows with a BCS < 3.0 than with a BCS ≥ 3.0. Cows with no BCS loss antepartum were more likely to have an interval from calving to first artificial insemination of <80 days and <105 days open, to be cycling at 3 and 5 weeks pp and to be pregnant at 200 days pp than cows with a BCS loss of >0.25 (OR 2.44–6.67). Furthermore, cows with no BCS loss from calving to 4 weeks pp had a lower risk of suffering from displaced abomasum than cows with a slight or a severe BCS loss (OR 0.09–0.07 respectively). In conclusion, our results suggest that body condition loss during the antepartal period affected BCS status at parturition and to a certain extent during lactation which was linked to a higher incidence of reproductive disorders and lameness, a higher culling rate and lower reproductive performance.     

Postpartum uterine disease and dairy herd reproductive performance: a review

This paper reviews the causes, impact, treatment, and prevention of retained placenta (RP), metritis, and endometritis in dairy cows. The occurrence of each of these diseases largely depends on immune function in the transition period. Retained placenta affects 5-10% of calvings and greatly increases the risk of metritis and endometritis. More field studies are needed to validate criteria for treatment of metritis, but cows with at least two of RP, fever, dullness, and fetid uterine discharge appear to merit treatment with systemic antibiotics. Clinical endometritis affects 15-20% of cows at 4-6 weeks postpartum; an additional 30-35% have subclinical endometritis between 4 and 9 weeks postpartum. Under specific conditions, treatment of cows with endometritis improved pregnancy rate. Systematic use of prostaglandin F(2alpha) at 5 and 7 weeks postpartum may improve pregnancy rate. The economic benefit of efforts to identify and treat endometritis is herd-specific.     

15-Ketodihydro-PGF2α, Progesterone and Uterine Involution in Primiparous Cows with Induced Retained Placenta and Post-partal Endometritis Treated with Oxytetracycline and Flunixin

Retention of the foetal membranes (RFM) and post‐partal endometritis are common problems in dairy cows. Among other things, the disease is characterized by a bacterial endometritis with aerobic as well as anaerobic bacteria. From an endocrine perspective, cows with RFM have high levels of 15‐ketodihydro‐PGF_2α (PG‐metabolite) immediately after parturition but these levels fall rapidly within 2 weeks post‐partum (early PG‐metabolite elevation). After this decline, the PG‐metabolite levels increase again and the levels (at this time of a lower magnitude) remain elevated during the period of uterine infection (late PG‐metabolite elevation). The aim of this study was to investigate the PG‐metabolite profiles in cows with retained placenta and post‐partal endometritis treated with the prostaglandin synthesis inhibitor flunixin (F), either alone or in combination with oxytetracycline (T). The study was accomplished over 2 years with 12 primiparous cows in each experiment. As a model for RFM, preterm 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 divided into four groups and treated with either T (10 mg/kg b.w. i.m. once daily), F (2.2 mg/kg b.w. p.o. twice per day), a combination of T and F (dosage, as above), or conservatively (0). The treatment periods lasted from day 11 to day 14 post‐partum (pp) in experiment 1 (after placental shedding, groups T1, F1, TF1 and 0) and from day 3 to day 6 pp in experiment 2 (before placental shedding, groups T2, F2, TF2 and 0). Jugular vein blood samples were collected for analyses of PG‐metabolite and flunixin. Uterine biopsies were collected twice weekly for investigation of endometrial microbiology. Rectal palpation and ultrasonographic examinations were performed three times per week for investigations of uterine and cervical involution and ovarian activity. No attempts were made to remove the placentas manually. The experiment lasted until day 56 pp. The induction of parturition was successful in all heifers and 22 of 24 animals had RFM. All RFM cows had bacterial endometritis, based on bacteriological examinations. Flunixin treatment (F1, TF1, F2 and TF2) suppressed PG‐metabolite levels significantly (p=0.006) during the period of treatment in both experiments. However, the early flunixin treatment only suppressed PG synthesis partially. Late oxytetracycline treatment (T1) did not influence the PG‐metabolite levels but oxytetracycline treatment (T2 and TF2) before placental shedding significantly altered the kinetics of the early PG‐metabolite elevation compared with other treatments. Late PG‐metabolite elevation was significantly correlated to duration of uterine infection and cervical involution. In conclusion, flunixin treatment of cows with retained placenta either before or after placental shedding suppresses prostaglandin synthesis. However, early treatment, when the release of prostaglandins is high, might need more intensive treatment in order to prevent the PG synthesis effectively. Oxytetracycline treatment during the period immediately after parturition before placental shedding might influence the PG‐metabolite profile and suggests a bacteriological contribution to the high levels of PG‐metabolite seen during the first 2 weeks pp in cows with retained placenta. In this study, a correlation between prostaglandin release, the final cervical involution and the end of infection was found. This suggests a link between uterine endocrinology, bacteriology and involution in cows with retained placenta.     

Impact of ovarian and uterine conditions on some diagnostic tests output of endometritis in postpartum high-yielding dairy cows

The effect of ovarian predominating structures and uterine condition on the result of some diagnostic tools for the evaluation of endometritis was studied in postpartum (pp) Holstein-Friesian dairy cows (n = 58). Endometrial cytology (EC) and the evaluation of vaginal mucus by vaginoscopy or Metricheck were performed weekly from week 3 to 7 pp. The ovarian studies involved the predominating structures including cystic follicles with plasma progesterone (P(4) ; more or <1 ng/ml; >23 mm), corpus luteum (CL), pre-ovulatory follicles (10-23 mm) and small follicles (<10 mm). The uterine conditions comprised uterine involution, tonicity and fluid in uterus (FIU) regarding echogenicity extent. During week 5, the percentage of polymorphonuclear neutrophils (PMN%) was higher (p < 0.05) in animals with pre-ovulatory follicles (mean ± SEM, 26.3 ± 7.6%) than animals having CL (11.0 ± 3.6%). In cystic ovaries, during week 5, PMN% was higher (p < 0.05) in follicular cysts with low progesterone (P(4) < 1 ng/ml; 9.3 ± 2.6%) than those with high P(4) (P(4) ≥ 1 ng/ml; 1.5 ± 1.1%). Moreover, PMN% was higher (p < 0.01) in animals with non-involuted uterus (11.5 ± 7.4%) than those with involuted uterus (2.7 ± 0.6%) during week 7 pp. The animals that had abnormal mucus determined by Metricheck was higher in animals with atonic uterus than those with tonic uterus during week 6 (82.6% vs 51.5%; p < 0.05) and 7 (71.4% vs 25.7%; p < 0.01) pp. In addition, by vaginoscopy, the prevalence of animals with abnormal discharge showing small follicles (100%, 5/5) during week 3 pp and pre-ovulatory follicles (40.0%, 8/20) during week 5 pp was higher (p < 0.05) when compared to those having CL during week 3 (33.3%; 1/3) and week 5 pp (7.7%; 2/26), respectively. In conclusion, endometrial cytology, Metricheck and vaginoscopy were influenced by the predominating various ovarian structures and uterine condition in early pp high-yielding dairy cows.     

Subclinical endometritis in Zebu x Friesian crossbred dairy cows: its risk factors,association with subclinical mastitis and effect on reproductive performance

A study was carried out on 59 clinically healthy Zebu x Friesian crossbred cows to determine the prevalence of subclinical endometritis, associated factors and its effect on the reproductive performance. Subclinical endometritis was diagnosed by endometrial cytology using uterine lavege technique and subclinical mastitis using CMT. The clinical, management and reproductive data were obtained from a weekly follow up visit of each cow for a period of 6 months after calving. The prevalence of subclinical endometritis, with ≥5% neutrophil count, was 47.5% and 30.5% at week 4 and 8, significantly decreasing (P = 0.002) as postpartum period advanced. Body condition score at week 4 postpartum (OR = 4.5, P = 0.017) and regular cow exercise (OR = 4.8, P = 0.026) were the significant risk factors while post-calving hygiene (P = 0.06) was poorly associated. Subclinical endometritis was also directly associated with subclinical mastitis at both week 4 (OR = 4.5, P = 0.012) and 8 (OR = 3.6, P = 0.031) postpartum. The risk of first service pregnancy (OR = 5.1, P = 0.004) was higher in cows negative for subclinical endometritis at week 8 postpartum and the proportion of cows that required more than 3 services was higher in cows with uterine inflammation. Also the proportion of cows diagnosed pregnant within 180 DIM was higher in cows with normal uterus at both week 4 (OR = 10.3, P = 0.001) and week 8(OR = 21.8, P = 0.001). These results indicated that subclinical endometritis was directly associated with poor body condition and subclinical mastitis and that it had negative effect on reproductive traits of dairy cows. This association may also reflect the possibility of translocation of bacteria/bacterial products from the uterus to the udder or vic-versa or else the presence of common cause for both endometritis and mastitis.     

Onset and duration of luteal activity postpartum and their effect on first insemination conception rate in lactating dairy cows

The incidence of different types of luteal activity postpartum and their effect on reproductive performance were studied in 21 postpartum dairy cows. Progesterone concentrations in defatted milk collected 3 times a week were determined by EIA. Reproductive tract examination was undertaken every other week postpartum. Body weight and body condition score (BCS) were measured before and after calving and the average 100-day milk yield was calculated. Nine (42.9%) cows had normal ovarian activity (first luteal activity < or = 50 days postpartum followed by regular cycles), 5 (23.8%) had prolonged luteal phase (PLP; ovarian cycle with luteal activity > or = 20 days pre-service) and in 7 (33.3%) cows the first luteal activity was shown later than 50 days postpartum (DOV). When compared with normal cows, both PLP and DOV had longer interval to first insemination (63.1 +/- 22.0 days versus 77.6 +/- 21.6 and 93.0 +/- 22.3 days, P<0.05 and P<0.01, respectively), lower first insemination conception rate (88.9% versus 0.0% and 57.1%, P<0.01 and P<0.05, respectively) and greater BCS loss (0.81 +/- 0.2 versus 1.05 +/- 0.21 and 1.04 +/- 0.10, respectively, P<0.01). Cows with PLP showed longer interval to uterine involution than normal and DOV groups (54.0 +/- 8.3 days versus 42.4 +/- 5.5 and 43.3 +/- 8.3 days, respectively, P<0.01) and higher 100-day milk yield (38.8 +/- 2.7 kg versus 33.6 +/- 4.7 and 29.9 +/- 6.1 kg, respectively, P<0.01). In conclusion, more than half of the cows had abnormal luteal activity postpartum, which adversely affected reproductive performance.     

Associations of prepartum body condition score with occurrence of clinical endometritis and resumption of postpartum ovarian activity in dairy cattle

This study was performed to investigate the effect of periparturient body condition score on the occurrence of clinical endometritis and postpartum resumption of ovarian activity in dairy cows. Eighty-seven lactating Holstein cows, fed with a total mixed ration diet, were included into the study. Body condition scoring (using a 5-point scale with quarter-point divisions) was performed by the same investigator using the visual technique every 2 weeks, from 2 weeks before until 6 weeks after calving. Palpation of the reproductive tract and ultrasonographic assessment of ovaries for detection of corpus luteum using a rectal linear probe was also performed at 2, 4, and 6 weeks after calving. Cows with clinical endometritis had significantly lower body condition score (BCS) than normal cows at all weeks pre- and postcalving, and cows that did not ovulate until 45 days after calving had a significantly lower BCS pre- and postpartum. Cows that did not ovulate until 45 days after calving also lost more BCS from 2 weeks before to 4 weeks after calving. Besides, first ovulation after calving take occurred later in cows with clinical endometritis compared to normal cows (P?<?0.05). In conclusion, low BCS is a risk factor for postpartum endometritis and delayed cyclicity in dairy cows. BCS loss from dry-off to early lactation and occurrence of clinical endometritis can significantly affect postpartum ovarian activity.     

Bacteriological and cytological findings during the late puerperal period after two different treatments of retained placenta followed by acute puerperal metritis

The aim of the study was to compare the effect of two acute puerperal metritis (APM) treatment protocols on uterine condition during the late puerperal period (5^th to 7^th week). Late gestation healthy cows (n = 21) were divided randomly in three equal groups. Parturitions were induced. Treatments of APM were started on the third day postpartum (PP). Group A was treated with an oxytocin analogue carbetocin for three days and intrauterine administration of cephapirin between days 15 and 17. Group B was given intramuscular injection of ceftiofur for five days followed by two injections of prostaglandin F_2α, at an interval of 12 h, on the eighth day PP. Group C served as the control group with no treatment. Body temperature was recorded daily for 14 days PP. Uterine biopsies for bacteriology, and uterobrush samples for cytology, were taken once a week from the 5^th to 7^th week postpartum. No differences were found in body temperature on day 14 PP, presence of bacteriological infections and disappearance of uterine inflammatory signs diagnosed by cytological examination between experimental groups.     

Pituitary concentrations of gonadotropins and receptors for GnRH in suckled beef cows at various intervals after calving

Mature beef cows were slaughtered at 5 (n = 6), 10 (n = 6), 20 (n = 6) or 30 (n = 5) d after calving to identify endocrine events that may affect the duration of postpartum anestrus. Additional cows (n = 6) were slaughtered 12 to 14 d after their first postpartum estrus (luteal phase cows). Anterior pituitary concentrations of luteinizing hormone (LH) were low at d 5 (383 +/- 69 micrograms/g), averaged 445 +/- 103 and 682 +/- 207 micrograms/g at d 10 and 20, respectively, and were elevated (P less than .05) by d 30 (1,097 +/- 174 micrograms) to a concentration similar to luteal phase cows (1,208 +/- 148 micrograms/g). Concentrations of follicle-stimulating hormone (FSH) averaged 12.4 +/- 1.1, 9.6 +/- 2, 8.6 +/- 1.8 and 7.4 +/- 3.3 mg/g at d 5, 10, 20 and 30, respectively. Affinity (1.6 +/- .2 X 10(9) M-1) of anterior pituitary receptors for the GnRH (gonadotropin-releasing hormone) analog (DAla6; des-Gly10, [D-Ala6]-LH-RH ethylamide) and weights (2.1 +/- .1 g) of the anterior pituitaries did not differ among groups (P greater than .05). Number of receptors for GnRH averaged 37 +/- 7, 39 +/- 9, 25 +/- 5 and 23 +/- 5 X 10(-14) M/mg protein at d 5, 10, 20 and 30, respectively. Anterior pituitaries from luteal phase cows contained 22 +/- 2 X 10(-14) M/mg protein of receptors for GnRH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Relationship between the first ovulation within three weeks postpartum and subsequent ovarian cycles and fertility in high producing dairy cows

The aim of this study was to investigate the relationship between the first ovulation within 3 weeks postpartum and subsequent ovarian cycles and fertility in high producing dairy cattle in Hokkaido, Japan. In Experiment 1, 110 cows (44 primiparous and 66 multiparous) were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent ovarian cycles. Milk samples were collected twice weekly from 7 to 100 days postpartum. The first ovulation was identified by an increase in milk progesterone (P4) to more than 1 ng/ml within 3 weeks postpartum. The numbers of cows showing ovulation and anovulation within 3 weeks postpartum were 31 (70.5%) and 13 (29.5%) in the primiparous cows and 35 (53.0%) and 31 (47.0%) in the multiparous cows, respectively. The patterns of ovarian resumption after calving were classified into two types (normal ovarian cycles and abnormal ovarian cycles) on the basis of milk P4 concentrations. Initiation of normal ovarian function in cows ovulated within 3 weeks postpartum occurred earlier than in anovulated cows regardless of the number of calvings (primiparous, 27.8 days vs. 44.4 days; multiparous, 30.6 days vs. 55.7 days; P<0.01). Out of the multiparous cows that ovulated within 3 weeks postpartum, initiation of normal ovarian function followed by a normal luteal phase was earlier than when it was followed by an abnormal luteal phase (25.5 days vs. 40.4 days; P<0.05). Milk P4 concentrations after the first ovulation were lower than those after the second ovulation in both the primiparous and multiparous cows (P<0.05). In Experiment 2, 22 multiparous cows were used to determine the effects of the first ovulation within 3 weeks postpartum on subsequent fertility. Blood samples were collected once a week from 0 to 3 weeks postpartum. The interval from parturition to first service in ovulated cows was shorter than in anovulated cows (68.4 days vs. 94.8 days; P<0.05). The conception rate by 100 days after calving tended to be higher in ovulated cows than in anovulated cows (50.0% vs. 16.7%, P=0.09). In conclusion, our data strongly suggests that ovulation within 3 weeks postpartum is a crucial phenomenon for subsequent resumption of ovarian function and conception, and thus it can be used as an index of subsequent reproductive performance.     

Influence of time of initiation of a prostaglandin F2alpha protocol in dairy cows with puerperal endometritis

A field trial was conducted to elucidate the effect of the time of initiation of a repeated PGF2alpha-application in a 14 day interval for treatment of endometritis in dairy cows. On a commercial dairy farm in Brandenburg, Germany, a total of 494 dairy cows were examined by rectal palpation and adspection for signs of endometritis (vaginal discharge, enlarged uterus) between day 20 to 26 post partum (dpp). We performed two further examinations by rectal palpation and external adspection to monitor the puerperal phase (34.-40. dpp, 55.-61. dpp). All cows with symptoms of an endometritis were treated with PGF2alpha (0.15 mg R-Cloprostenol, Preloban, Intervet Deutschland GmbH Unterschleissheim) twice in a 14-day interval. In the group "Early" (n = 146) the first injection of Cloprostenol was administered at time of the 1st examination. In the group "Late" (n = 129) an identical treatment was administered in cows with endometritis, however it was started 14 days later (34.-40. dpp). The incidence of endometritis was 57.7% in the group "Early" and 53.5% in the group "Late" at the first time of examination. The 1st service conception rates for treated cows were 34% in the group "Early" vs. 37% in the group "Late". In the group "Early" differences were found in days open between treated cows with endometritis and untreated controls without symptoms of endometritis (99.1 d vs. 110.8 d, p > 0.05). In the group "Late", days open for treated (106.8 d) and untreated cows (108.0 d) were similar. The severity of endometritis influenced the percentage of cows pregnant at 200 dpp. Regarding cows with a severe endometritis (E2 and E3) the percentage of pregnant cows 200 dpp was higher in the group treated early (E2: 78.4%; E3: 80.0%) than in the group with the late initiation of the treatment (E2: 68.6%; E3: 54.5%, p < 0.05). Cows with a moderate endometritis (E1) had a similar percentage of pregnant cows (200 dpp) as the untreated cows without endometritis. It is concluded that application of PGF2alpha in the 4th and 6th week post partum in a 14 day interval in cases of severe endometritis is more effective than the application of the same treatment two weeks later.     

Risk factors and the economic impact of ovarian cysts on reproductive performance of dairy cows in Korea

The objectives of this study were to determine the risk factors for development of postpartum ovarian cysts by evaluating several reproductive factors in individual cows, and to determine the economic impact of ovarian cysts on subsequent reproductive performance in dairy herds in Korea. The data, including cow parity, abnormal puerperium, endometritis, body condition score (BCS), and breeding status were collected from 634 cows in 9 dairy herds. We used logistic regression to evaluate the effects of these factors on ovarian cysts. A stepwise procedure, used to obtain the appropriate model with alpha=0.05, revealed that cow parity was the most important risk factor for ovarian cyst development within 8 weeks postpartum, while development of endometritis and BCS loss>or=1 from the dry period to 8 weeks postpartum were the most important risk factors for ovarian cyst development beyond 8 weeks postpartum. The occurrence of ovarian cysts beyond 8 weeks postpartum prolonged (P<0.01) the mean intervals from calving to first service (27 days) and conception (77 days), and increased (P<0.05) the culling rate (7.8%), while ovarian cyst development within 8 weeks postpartum did not affect (P>0.05) the mean intervals from calving to first service and conception or the culling rate. The economic loss resulting from the occurrence of ovarian cysts was estimated at approximately 823,996 won ($687) due to effects on the cost of nutrition, average growth of calves, labor and medical costs, and culling. These results suggest that cow parity is correlated with the development of ovarian cysts within 8 weeks postpartum, and endometritis and BCS loss>or=1 from the dry period to 8 weeks postpartum are correlated with the development of ovarian cysts after 8 weeks postpartum, which decreases reproductive performance and results in economic loss in dairy herds in Korea.     

Comparison of cholesterol levels among lipoprotein fractions separated by anion-exchange high-performance liquid chromatography in periparturient Holstein–Friesian dairy cows

Changes in lipoprotein profiles occur in dairy cows during the periparturient period and in cows with transition cow disease. Here, the lipoprotein profiles of Holstein–Friesian dairy cows during the periparturient period were obtained by anion-exchange, high-performance liquid chromatography to evaluate the usefulness of lipoprotein profile evaluation during the periparturient period and in cows with fatty liver and milk fever. Lipoprotein levels (including total and high- (HDL-C) and low-density lipoprotein (LDL-C) cholesterol) in 10 healthy cows were low 4 weeks prepartum, with the lowest values at calving or within 1 week of calving; the values increased at 8 weeks postpartum. The lipoprotein levels were measured in 16 cows diagnosed with fatty liver (n=10) or milk fever (n=6) and compared to 10 healthy dairy cows. A significant difference was observed in HDL-C between healthy cows (at calving and 1 week postpartum), and the fatty liver and milk fever cows. Cows with fatty liver and milk fever had a lower mean HDL-C than the 10 healthy dairy cows at calving and 1 week postpartum. HDL-C might be a good indicator of energy balance for differentiating healthy cows from those with transition cow disease.