Induction of parturition in cattle: effect of triamcinolone pretreatment on the incidence of retained placenta.

Two experiments were designed to determine whether pretreatment with triamcinolone acetonide (TRI) prior to induction of parturition with dexamethasone (DEX) and cloprostenol (CLO) would reduce the incidence of retained placenta. Experiment 1 was conducted to determine the optimum dosage of TRI and to approximate the optimum interval from TRI to induction with DEX + CLO. All cows received TRI on day 270 of gestation. Cows in group I received 1 mg/30 kg of body weight (BW) of TRI and were induced to calve with DEX + CLO on day 276. Cows in groups II and III received 1 mg/45 kg BW and were induced on days 276 or 277, respectively. Cows in groups IV and V received 1 mg/60 kg BW and were induced on days 277 or 278, respectively. Group VI cows served as untreated controls. There was no difference in the incidence of retained placenta among the treated and control groups. Experiment 2 was conducted to more precisely determine the optimum interval from pretreatment to induction treatment with the chosen dose of TRI. All cows in groups I, II, and III were pretreated with 1 mg/60 kg BW of TRI on day 270 of gestation and received DEX + CLO on days 275, 276 or 277, respectively. Group IV cows served as untreated controls. The incidence of retained placenta was higher (p < 0.05) in groups I and II than in the control group, with group III intermediate and not different from the others.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of inbreeding on the incidence of retained placenta in Friesian horses

This study was motivated by the hypothesis that the incidence of retained placenta (RP) in Friesian horses is associated with inbreeding. The objectives were to 1) calculate the inbreeding rate in the total registered Friesian horse population; 2) study the association of the inbreeding coefficient of the foal and the mare with the incidence of RP; and 3) study the heritability of RP in Friesian mares after normal foalings. Data from the total registered Friesian horse population from 1879 to 2000 (52,392 individuals) were collected from the registration files of the Friesian Horse Studbook. In 1999 and 2000, 495 parturitions in 436 mares were studied. From 1979 to 2000, the inbreeding rate of the total population was 1.9% per generation. The regression coefficients for the regression of the incidence of RP on inbreeding coefficients of the foal and the mare were 0.12 +/- 0.052 and -0.016 +/- 0.019, respectively. Mean heritability estimates of RP as a foal trait and as a mare trait were 0.046 +/- 0.088 and 0.105 +/- 0.123, respectively. It was concluded that, in order to avoid a further increase in the incidence of RP in Friesian mares, a decrease in the inbreeding rate by increasing the effective breeding population is required. Furthermore, the findings indicate that the high incidence of RP in Friesian horses is at least partly a result of inbreeding.     

The relationship between bovine clinical mastitis at the time of parturition and retained placenta]

868 parturitions were examined to determine the relation between the clinical mastitis around partition and the loosening process of the placenta in the bovine. The occurrence of mastitis in heifers and cows around parturition was 18.7%. The frequency of retained placenta in animals with mastitis was significantly higher (p less than 0.01) than that in animals without mastitis influenced the loosening process of the afterbirth. The results support an hypothesis, that mastitis and retentio secundinarum can regard as signs of the decrease in the activity of the immune system.     

The effects of induced parturition in dairy cows on the incidence of mortality in calves from commercial herds in south-western Victoria

SUMMARY The effects of induced parturition on calf mortality rates were studied in 24 winter-calving, pasture-fed, dairy herds in south-western Victoria. Parturition was induced when most cows were between 27 and 35 weeks of pregnancy. Control groups were selected from cows in the same herds in which calving was not induced. The incidence of mortality within 7 days of birth was much higher among calves from cows in induced groups relative to those in control groups (estimated median herd mortality incidence 72% and 7%, respectively). The incidence of calf mortality was high among groups induced at all stages of pregnancy that were investigated. However, differences in calf mortality incidence, relative to controls, were increased among groups induced at earlier stages of pregnancy.     

Luteal and clinical response following administration of dinoprost tromethamine or cloprostenol at standard intramuscular sites or at the lumbosacral acupuncture point in mares

OBJECTIVE: To determine whether administration of a microdose of prostaglandin at the BAI HUI acupuncture point offers any advantage over IM injections for luteolysis, ovulatory interval, or systemic response in mares. ANIMALS: 17 mature cycling mares, 3 to 20 years of age and weighing 400 to 500 kg. PROCEDURE: Conventional and microdoses of the prostaglandin dinoprost tromethamine (PGF2alpha), the analogue cloprostenol, or sterile water (control) were administered to mares in 7 treatment groups. Treatments were assigned by dose, administration site (semimembranosus, semitendinosus, or lumbosacral region), and treatment type (PGF2alpha, analogue, or sterile water). Mares were observed for ovulatory interval and systemic response to treatment, including heart, and respiratory rates, rectal temperature, and sweat score. Plasma progesterone concentrations were also determined at the time of treatment and at 24-hour intervals for 96 hours following treatment. RESULTS: Ovulatory interval was shortened and progesterone concentrations decreased in prostaglandin-treated mares, compared with control mares, regardless of dose or treatment site. However, no differences in ovulatory interval were observed among prostaglandin-treated mares. Mares treated with conventional doses of PGF2alpha had greater systemic responses than mares treated with microdoses of PGF2alpha or sterile water. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of prostaglandins at the BAI HUI acupuncture point does not appear to offer any advantage over administration at standard IM injection sites for induction of luteolysis or to shorten the ovulatory interval. However, administration of a microdose of the analogue cloprostenol was effective at inducing luteolysis and shortening ovulatory interval regardless of administration site.     

The effects of induced parturition on the incidence of clinical disease and mortality in dairy cows from commercial herds in south-western Victoria

SUMMARY The effects of induced parturition on clinical disease and mortality of cows were studied in 51 winter-calving, pasture-fed, dairy herds in south-western Victoria. Parturition was induced when most cows were between 27 and 35 weeks of pregnancy. Control groups were selected from herdmates that were not induced to calve. The incidence of retained placenta was much greater among induced cows of all ages. The proportion of cows affected by any clinical disease other than retained placenta, and the incidence of mortality were much greater after induction among cows aged over 6 years but not among cows aged 3 to 6 years.     

Retained placenta in cattle: the effect of treatment or nontreatment on puerperal diseases and subsequent fertility

In order to examine the effect of treated and untreated retained placenta (RP) on fertility and on the occurrence of puerperal and fertility diseases, the records of 248 cows with RP were examined: 199 cows were treated with intrauterine tetracycline or systemic therapeutics, and 49 were left untreated. One hundred and ninety-six herd mates without RP served as controls. The fertility of the cows with RP was lower than that of the controls. The effect of treatment on fertility was neither beneficial nor harmful. The untreated cows with RP seemed to be treated more often for endometritis and repeat breeding than either the treated animals or the controls. Mastitis within 1 week after calving was more common in both groups of RP cows than in the controls. Most cases of mastitis in the treated RP group could be diagnosed at the time of RP treatment.     

Rationale for treatment of retained placenta in cows with neomycin and metronidazole.

A combination of neomycin and metronidazole was compared with oxytetracycline for its activity against the intrauterine flora of 10 cows with retained placenta. In vitro the metronidazole/neomycin combination reduced the numbers of aerobic and obligately anaerobic bacteria much more effectively than did oxytetracycline.     

Activity of selected glycosidases and availability of their substrates in bovine placenta during pregnancy and parturition with and without retained foetal membranes

The activity of glycosidases is crucial for the function and biological activity of proteins conjugated with sugar moieties, which play an important role in adhesion of cells during attachment and detachment of the foetal membranes. The aim of study was to describe the ability of bovine placental tissues to break down O-glycosidic bonds in different glycoproteins by the determination of activity of β-galactosidase, α-l-fucosidase, β-N-acetyl-hexosaminidase and sialidase in early–mid-pregnancy as well as at parturition with released and retained foetal membranes. Moreover, the availability of substrates for these glycosidases in placental homogenates was evaluated. Placental samples were collected from pregnant (2–4 months) cows in slaughterhouse (n = 8) as well as during Caesarean section and divided into released foetal membranes (n = 8) and retained foetal membranes (n = 8). Tissue homogenates were subjected to spectrofluorimetric and spectrophotometric determinations of enzyme activities as well as electrophoretic separations. Enzyme activities expressed changes within examined time with significant (p < .05) differences between pregnancy and physiological parturition in β-N-acetyl-hexosaminidase and α-l-fucosidase in foetal part of placenta while in maternal part only in the latter one. Decreasing tendency in enzyme activity was noticed in foetal part of retained samples in comparison with released ones with significant (p < .05) differences in α-l-fucosidase activity. The analysis of staining of sugar moieties attached to selected proteins depicted availability of sugar molecules in examined tissues, but their patterns differed between samples. In conclusion, sugar moieties in conjugated proteins express changes in the course of pregnancy which is reflected by the alterations in activities of placental glycosidases.     

The use of milk progesterone profiles for assessing the response to cloprostenol treatment of non-detected oestrus in dairy cattle

Post-partum milk progesterone profiles from 1400 dairy cows were used to identify 296 animals which had ovulated 50 or more days post partum without being observed in oestrus. Of these, 165 cows were left as untreated controls, being inseminated at any observed oestrus after 60 days post partum. Fixed time insemination three and four days after a single cloprostenol injection (74 cows) resulted in a short calving-to-conception interval and a lower culling rate than in control cows, while insemination at observed oestrus after cloprostenol (57 cows) resulted in an even greater improvement in these parameters. The fixed-time insemination group required significantly more services per conception than either of the other groups (P < 0.005). A study of the profiles suggested that not all of the cows had ovulated within four days of injection and that those ovulating later had a greater chance of being observed in oestrus and becoming pregnant if insemination was carried out only at observed oestrus after cloprostenol injection.     

Strategy for the treatment of puerperal metritis and improvement of reproductive efficiency in cows with retained placenta

The objective of this study was to improve the reproductive efficiency of dairy cows with puerperal metritis (PM) subsequent to retained placenta (RP) using a two-step treatment strategy. A total of 188 postpartum cows, aged from 2 to 8 years, were utilised for 2 experiments. In Experiment 1, cows affected with RP/PM were randomly assigned to two treatment groups. Cows in Group A (n = 17) were treated with 600 mg of ceftiofur intramuscularly for 3 days followed by intrauterine lavage with 0.1% chlorhexidine and infusion with 0.5% povidoneiodine, while cows in Group B (n = 16) received two intrauterine infusions, first with 5 g of oxytetracycline and then with 0.5% povidone-iodine. Cows with normal postpartum findings were regarded as the healthy control group (n = 26). Ultrasonographic examination revealed that the ovarian activities including the appearance of a dominant follicle and days to first ovulation of the cows in Group A during the early postpartum period differed from those of Group B (P < 0.05), which coincided with the results of uterine swabbing for bacteriology. In Experiment 2, cows with normal postpartum findings were allocated to Group D (n = 78), which received an ovulation protocol (GnRH - 7 d PGF2α - 48 h hCG - 24 h AI) on day 50 ± 2 postpartum. Cows affected with PM were randomly divided into two groups, Group E (n = 25) combined the treatments applied in Groups A and D, while Group F (n = 26) repeated the treatment administered in Group E except for uterine lavage. The results indicated that the pregnancy rate within 150 days postpartum and the mean days open in Group E (76.0% and 106.3 ± 4.6 days, respectively) were significantly different from those in Group F (38.5% and 137.9 ± 10.9 days, respectively) (P < 0.05). This study suggests that reproductive efficiency could be improved by using the two-step treatment to regulate uterine involution and an early resumption of ovarian function in cows with RP/PM.     

The effect of intramuscular injection of dinoprost or gonadotropin-releasing hormone in dairy cows on beef quality

Intramuscular injections of drugs and vaccines cause tissue damage and subsequent effects on tenderness and consumer acceptability of beef. In the 2007 National Market Cow and Bull Beef Quality Audit, 100% of plants reported fabricating subprimal cuts such as rib eyes and tenderloins from cow and bull carcasses. Dairy beef quality should therefore be a consideration when injections are given to dairy animals. The discussion about injection site reactions and tenderness has focused on vaccines and antimicrobial drugs with little concern for the effects of reproductive hormones. The objective of this study was to quantify antemortem the effects of semimembranosis/semitendinosis muscle injection of dinoprost and GnRH in lactating dairy cows by estimating the weight of tissue damaged and comparing that with a drug known to cause extensive tissue damage, flunixin meglumine. Tissue damage was estimated from previously reported equations for grams of muscle tissue damage based on area under the curve of serum concentrations of the muscle enzyme creatine kinase over time. Dinoprost and flunixin injection both caused a significantly increased estimate of muscle tissue damaged compared with needle only (P = 0.0351 and 0.0355, respectively). Dinoprost and flunixin caused a marginally significant increased muscle tissue damage compared with GnRH (P = 0.1394 and 0.1475, respectively). No statistically significant difference was found between the estimated weight of muscle tissue damaged by flunixin compared with dinoprost (P = 1.0000), or by saline compared with GnRH (P = 0.7736) or needle only (P = 0.4902). The assumption that reproductive hormones are less damaging than vaccines and antimicrobial drugs should be examined more closely, including postmortem evaluation of injection site lesions and effects on tenderness.     

Lactation and fertility in goats after the induction of parturition with an analogue of prostaglandin F2 alpha, cloprostenol

Cloprostenol, 100 micrograms, given intramuscularly to the nanny, with 50 micrograms 10 hours later, precipitated parturition in goats after 36 +/- 1 hours (mean +/- SEM), when administered at 137 +/- 0.5 days gestation. All kids were born alive and survived to weaning. Milk yield over 40 weeks post partum was not significantly different from that after spontaneous parturition. Three hundred micrograms cloprostenol (200 micrograms with 100 micrograms 10 hours later) also initiated parturition at 137 +/- 0.5 days gestation but caused a significant (P less than 0.01) suppression of lactation. Cloprostenol-induced parturition in more than one pregnancy had no adverse effects except for an increased incidence of placental retention, which was treated successfully with intrauterine pessaries containing oestrogen. During the first eight days after spontaneous parturition efficiency of milk secretion was inversely related to udder mass, suggesting a gradual maturation of the secretory alveolar epithelium over this time. When parturition was induced by cloprostenol there was a four to eight day delay before the establishment of this relationship which appeared essential for a successful lactation. Cloprostenol proved to be a useful tool for the control of parturition in goats, having applications to both general animal husbandry and for the study of mammary development and secretory competence.     

The use of cloprostenol for the termination of pregnancy and the expulsion of mummified fetus in cattle

Misalliance and mummification are two indications for treatment with cloprostenol. Of 56 animals mated accidentally that were treated with 0-5 mg cloprostenol, 12 were more than 150 days pregnant and of those, nine required more than one treatment. The animals treated early in pregnancy aborted promptly and completely whereas two, considered to be 200 days pregnant at the first treatment, failed to respond at all. There were no reports of retained fetal membranes or any adverse side effects. Eight cases of fetal mummification were also submitted for treatment. All aborted within three to five days, the fetus being removed manually per vaginam in each case. Serial blood progesterone assays indicated that successful treatment was associated with leutolysis in all cases. It was concluded that cloprostenol may successfully be used for the treatment of misalliance and mummification of the fetus.     

归芎益母散治疗奶牛血瘀型胎衣不下的扩大临床试验研究

在实验性临床研究基础上,进一步验证归芎益母散推荐有效剂量400 g/头治疗奶牛血瘀型胎衣不下的临床疗效。将纳入研究的193头血瘀型奶牛随机分为2组,其中药物对照组96头和归芎益母散组97头,以滞留胎衣排出为主要疗效评价指标,以受试奶牛产褥期子宫炎继发感染率和产后180 d内繁育性能为次要疗效评价指标,综合评价归芎益母散的临床效果。与阳性药物对照组比较,归芎益母散组中受试奶牛的首次给药72 h内滞留胎衣排出率提高(89.7%vs. 72.9%,P0.01),一次给药滞留胎衣排出率提高(70.7%vs. 50.0%,P=0.013),而给药次数减少(1.7±0.9 vs. 2.0±1.4,P0.05);产褥期子宫炎感染率降低(15.5%vs.24.0%,P0.01),同时可提高受试奶牛的繁育性能,包括产后首次配种时间提前(66.6±19.1 d vs. 78.7±25.6 d,P0.01),首次配种怀孕率提高(70.6%vs. 26.4%,P0.01),配种次数降低(1.8±1.3 vs.2.6±1.3,P0.01),产后180 d内总怀孕率提高(90.6%vs. 71.9%,P0.01),同时空怀时间缩短(87.3±42.7 d vs. 120.9±47.3 d,P0.01)。试验期间未发现药物相关不良反应。以归芎益母散推荐有效剂量(400 g/头)治疗奶牛血瘀型胎衣不下,可有效促进滞留胎衣排出,降低产褥期子宫炎的发生风险,并能有效改善患牛的繁育性能,临床疗效确切,安全性好。     

Influence of feeding regime on timing of parturition in beef cattle and the relationship of vaginal temperature to parturition

The timing of parturition was recorded for a total of 56 beef cattle (Japanese Black × Holstein Friesian) on different dietary treatments. The rate of calving during daylight hours in cows night‐fed (18.00 hours) with a roughage diet was significantly higher than that in cows night‐fed with a high concentrate diet (79.2% vs 38.5%, P < 0.05). Subsequently, the vaginal temperature (VT) of these cows was analyzed using a cosinor method. When the feeding schedule was changed from twice daily (08.30 and 15.30 hours) to night feeding, the periodicity, the acrophase and the bathyphase, which were the parameters of the cosine curve, were unstable from the first day of night feeding until after day 6 (P < 0.05). Prior to parturition, the midline‐estimating statistic of rhythm (MESOR) and the amplitude for the cows that were fed a high‐roughage diet at night and that calved at night‐time were lower and larger, respectively, than that for the other treatments (P < 0.01). Based on these results, the time of parturition in most of the beef cows was influenced by feeding time and diet composition. Those cows that calved at night‐time in spite of night feeding had lower vaginal temperatures.