Termination of Pregnancy with Cloprostenol and Dexamethasone in Intact or Ovariectomized Cows

Termination of pregnancy in cows was investigated using sham-operated (SH) or ovariectomized (OV) cows treated with either a saline vehicle (V), cloprostenol (PG), dexamethasone (DEX) or dexamethasone and cloprostenol (DEX+PG). Surgery was done at 210 days of pregnancy and treatment was administered 72 hours later.

Days (mean±S.E.) from treatment to termination of pregnancy for the treatment groups were: sham-operated +vehicle (SH+V): 61.5±11.3; ovariectomized+vehicle (OV+V): 53.4±15.7; sham-operated+cloprostenol (SH+PG): 61.8±1.7; ovariectomized+cloprostenol (OV+PG): 54.5±13.1; shamoperated+dexamethasone (SH+DEX): 74.8±4.8; ovariectomized+dexamethasone (OV+DEX): 2.8±0.4; shamoperated+dexamethasone+cloprostenol (SH+DEX+PG) 26.0±23.0; ovariectomized+dexamethasone+cloprostenol (OV+DEX+PG): 7.2±4.9. Pregnancies in the OV+DEX and OV+DEX+PG groups were terminated significantly earlier than in all other groups (P<0.05) except the SH+DEX+PG group. These findings suggest that dexamethasone will terminate pregnancy in cows near seven months of gestation after the ovarian source of progesterone has been removed by either an injection of prostaglandin or by ovariectomy.

     

The isolation of a cytopathogenic agent resembling the virus of infectious bovine rhinotracheitis from an outbreak of pustular vulvovaginitis in cattle

Two hundred and twenty seven dairy cows and heifers which had conceived at least 245 days previously were treated with dexamethasone alone (20 mg i/m), cloprostenol alone (500 µg s/c) or both drugs at different time-combinations in order to study the effect in terms of induction of parturition.

Results showed that cloprostenol alone, or 8–11 days after dexamethasone, caused 81% and 96% of animals respectively to calve within 1–4 days of the cloprostenol treatment.

Dexamethasone alone or injected on the same day as cloprostenol also advanced the day of calving but both spread and delay were longer than with the othertreatments.

Animals treated with cloprostenol alone, or cloprostenol 8–11 days after dexamethasone, showed oestrous behaviour 24 hours before calving, though without adverse results. Calf survival was similar for all treated groups. Cloprostenol treatments were associated with a higher incidence of retained foetal membranes (28.2–5.7%) but also with a shorter interval from parturition to resumption of cyclicity.     

The effects of treatment with cloprostenol or dinoprost within one hour of induced parturition on the incidence of retained placenta in cattle

Two experiments were designed to determine whether prostaglandin treatment within one hour postpartum would reduce the incidence of retained placentas after induction of parturition in beef cattle. In the first experiment, 70 cows were induced on day 276-278 of gestation with the combination of 500 μg cloprostenol and 25 mg dexamethasone (CP + Dex). Within one hour after parturition, cows received either 500 μg CP or 25 mg of dinoprost (DI). The incidence of retained placenta (RP) was 64.3% in induced groups and 0% in noninduced control cows and postpartum treatment with either CP or DI had no effect on placental retention.

A second experiment, utilizing 132 cows and heifers, was conducted to determine whether induction with Dex alone, rather than with CP + Dex, would influence the rate of placental retention after postpartum treatment with either CP or DI. The incidence of retained placenta ranged from 28.5 to 58.3% in induced females but was 0% in noninduced control females. As in the first experiment, postpartum prostaglandin treatment had no effect on placental retention.

The results of these experiments do not support the use of prostaglandins within one hour of induced parturition to reduce the incidence of retained placentas.

     

Induction of parturition in dairy cows with dexamethasone.

Sixty Holstein cows were paired by parity and sire, and one of each pair was allocated at random to treatment or control; 17 cows were injected with 7.5 mg/100 kg dexamethasone trioxa undecanoate 14 days before the predicted date of calving, 13 cows received the same dose five days before term and 30 cows were left untreated. The treatment significantly advanced parturition and 29 of the 30 induced cows calved within 72 hours of the injection. Induction at day 14 before term was safe for calf and dam, the calves were 3.2 kg lighter than control calves and there was a high incidence of retained placenta. Treatment for this condition resulted in increased veterinary costs of 14.50 pounds per cow exclusive of dexamethasone treatment. Treatment at this stage was also associated with low pregnancy rates in the next breeding season. Calves born after induction at five days before term were not significantly lighter than calves from control cows, the problem of retained placenta was less marked and there were no subsequent effects on fertility. There were no significant effects of induction on milk yield or milk quality up to 200 days of lactation.     

Factors influencing time of parturition in range beef cattle

A total of 2434 calving records from seven calving seasons were analyzed by the least-squares and chi-square procedures to study the influences of breeding group, age of dam, sex and birth weight of calf and dam weight at calving on the time of day of parturition. Frequency of day calving (0630 ± 030 to 1900 h) was slightly but not significantly higher than night calving (1900 h to 630 ± 030). The frequency of night calving was higher among heifers compared with the older cows. The cows which calved after May 15 (the last one third period of pregnancy) had higher frequency of day calving compared with those that calved earlier. The frequency of daytime calving was higher among the cows that weighed at most one standard deviation below the average compared to heavier cows of comparable age.     

Induced termination of the calving season in a large dairy herd

The calving season of a 550-cow dairy herd was shortened by the induction of premature parturition in 231 cows and heifers, using the synthetic or natural prostaglandins cloprostenol or PGF₂ alpha as the sole treatment, or these agents 8 and 12 days after dexamethasone trimethyl acetate (DTMA), depending on estimated prematurity at the time of first injection. A series of synchronised batch-calvings was produced in the cows, with 85% of the PG group calving within 96 hours of treatment, 97% of the DTMA — 8 days — PG group calving within 48 hours, and 100% of the DTMA — 12 days — PG group calving within 72 hours. PGF₂ alpha was associated with very rapid deliveries and dystocia due to incomplete cervical dilation. Cow and calf survival was high. Eighty-three percent of those mated conceived, 78% of them in the first 8 weeks of mating, despite an incidence of incomplete membrane-expulsion that exceeded 40%. Some conceptions to first service did not progress beyond 6–7 weeks of gestation. In nearly all these cases, the animals conceived at a later service, usually at the first oestrus after expulsion.

The results indicate that acceptable results can be obtained in cows within 2 weeks of term using cloprostenol alone. Treatment regimes that allow a priming dose of depot corticosteroid to precede cloprostenol should be used for terminating less advanced pregnancies.     

Detection of rotavirus and coronavirus shedding in two beef cow herds in Idaho

Fecal samples were taken at the time of pregnancy examinations and at parturition from two beef herds. They were also taken from sick calves at the onset of disease, and from 25% of the healthy calves at 15 days of age. All fecal samples were examined by electron microscopy for viruses.

Four cows in herd A were detected excreting coronavirus, one at the time of the pregnancy examinations and three at parturition. The first cow was removed from the herd and the others calved at the end of the season. There were no sick calves.

No cows in herd B were detected excreting virus at the time of pregnancy checks, but fourteen coronavirus and two rotavirus carrier cows were found at parturition. All but two calves sampled had large numbers of virus particles in their feces. Clinical illness was associated with dams shedding virus and with nightly low temperatures.

     

Betamethasone alcohol suspensions for the induction of parturition in dairy cows: a comparison with dexamethasone trimethyl acetate

A field trial was conducted to compare the efficacy suspensions of betamethasone alcohol with dexamethasone trimethyl acetate on the induction of parturition before term in dairy cows. Initial treatment consisted of a subcutaneous injection of either 20 mg of betamethasone as a 10 mg/ml suspension (Group A), 30 mg of a 15 mg/ml suspension (Group B), or 20 mg of dexamethasone TMA (Group C). Those cows not calving within 10 days received a further 25 mg of betamethasone alcohol as a 2 mg/ml suspension. Data were collected from 619 cows on 41 farms. A marked difference between groups was noted in the proportion of animals calving to the initial injection (55.0, 61.4 and 26.4% calved to first injection in Groups A, B and C respectively); the differences between the groups receiving the betamethasone suspensions and the group receiving dexamethasone trimethyl acetate were highly significant (P<0.001). Of the animals treated 6.9, 3.6 and 10.2% failed to calve within 17 days of the initial treatment in Groups A, B and C respectively (Group B significantly different from Group C (0.02 > P> 0.01). Nevertheless, the response-time (mean of 7.5 days for all those calving to the first injection, and of 12.4 days for all those calving to the second injection) was not significantly different between the three treatment groups. Calf mortality over all treatments was 15.2% at birth and 26.6% by 4 days old. The incidence of metabolic disease was 5.9%, and 203% of cows had retained foetal membranes 24 hours after calving. No differences were observed between groups in the incidence of dystocia and cow mortality. Four cases of mastitis were recorded in Group A and 12 cases in Group C. No cases were recorded in Group B.     

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)     

Cholinesterase Levels in Blood Plasma and Erythrocytes from Calves,Normal Delivering Cows and Cows Suffering from Parturient Paresis

Plasma cholinesterase (pChE) levels and erythrocyte acetylcholinesterase (eAChE) levels were studied in 6 cows before, during and after parturition (Group I), their calves (Group II), 38 cows suffering from parturient paresis (Group III) and 14 newly delivered non-paretic cows (Group IV).The mean of the pChE level in Group I was 1.5 μkat/1 ± 0.20 before parturition and decreased significantly (P ≦ 0.05) to 1.2 ukat/1 ± 0.16 after parturition. The eAChE level was before parturition ≅ 140 ukat/1 and decreased to ≅ 130 μkat/1 4–5 weeks after parturition.At birth the pChE level was 12.8 ukat/1 ± 5.9 in Group II. After 4 weeks the level had decreased to 2.3 ukat/1 ±0.3. In the bull calves the pChE level started to increase when they were 6 weeks old and reached a level of 5.7 μkat/1 ± 0.6 before slaughter at 6 months of age. The heifers did not show this increase. They had a level of around 2 μkat/1 throughout the investigation. The eAChE level at birth was 119 μkat/1 and increased slowly to a level of 145 μkat/1 at 6 months. No differences between the sexes were found.The cows suffering from parturient paresis had a pChE level of 1.80 μkat/1 ± 0.30 before treatment with calcium (Ca). The level decreased significantly (P ≦ 0.001) after Ca-infusion to a level of 1.67 ukat/1 ±0.29. Group IV had a pChE level of 1.65 μkat/1 ± 0.42 at parturition. Two to 4 months later the cows that had recovered from milk fever had a level of 1.61 μkat/1 ± 0.31 and the control cows 1.66 ukat/1 ± 0.48. No differences between the groups were found for the eAChE level.The findings show that parturition influences the pChE level in cows and that sex influences the pChE level in calves between 6 weeks to at least 6 months of age. Furthermore the elevated pChE level found in the cows suffering from parturient paresis before Ca infusion may be a further sign of a disturbance in the cholinergic system with a special preference to the neuromuscular junctions.     

Concentration and heritability of immunoglobulin G and natural antibody immunoglobulin M in dairy and beef colostrum along with serum total protein in their calves

Immunoglobulin (Ig) G and natural antibody (NAb) IgM are passively transferred to the neonatal calf through bovine colostrum. Maternal IgG provides pathogen- or vaccine-specific protection and comprises about 85% of colostral Ig. NAb-IgM is less abundant but provides broad and nonspecific reactivity, potentially contributing to protection against the dissemination of pathogens in the blood (septicemia) in a calf’s first days of life. In the dairy and beef industries, failure of passive transfer (FPT) of colostral Ig (serum total protein [STP] <5.2 g/dL) is still a common concern. The objectives of this study were to: (1) compare colostral IgG concentrations and NAb-IgM titers between dairy and beef cows; (2) assess the effect of beef breed on colostral IgG; (3) compare passive transfer of colostral Ig in dairy and beef calves; and (4) estimate the heritability of colostral IgG and NAb-IgM. Colostrum was collected from Holstein dairy (n = 282) and crossbred beef (n = 168) cows at the University of Guelph dairy and beef research centers. Colostral IgG was quantified by radial immunodiffusion and NAb-IgM was quantified by an enzyme-linked immunosorbent assay. In dairy (n = 308) and beef (n = 169) calves, STP was estimated by digital refractometry. Beef cows had significantly greater colostral IgG (146.5 ± 9.5 standard error of the mean [SEM] g/L) than dairy cows (92.4 ± 5.2 g/L, P <0.01). Beef cows with a higher proportion of Angus ancestry had significantly lower colostral IgG (125.5 ± 5.8 g/L) than cows grouped as “Other” (142.5 ± 4.9 g/L, P = 0.02). Using the FPT cutoff, 13% of dairy and 16% of beef calves had FPT; still, beef calves had a significantly larger proportion with excellent passive transfer (STP ≥6.2 g/dL, P <0.01). The heritability of colostral IgG was 0.04 (±0.14) in dairy and 0.14 (±0.32) in beef. Colostral NAb-IgM titers in dairy (12.12 ± 0.22, log₂ [reciprocal of titer]) and beef cows (12.03 ± 0.19) did not differ significantly (P = 0.71). The range of NAb-IgM titers was 9.18–14.60, equivalent to a 42-fold range in antibody concentration. The heritability of colostral NAb was 0.24 (±0.16) in dairy and 0.11 (±0.19) in beef cows. This study is the first to compare colostral NAb-IgM between dairy and beef cows. Based on the range in NAb-IgM titers and the heritability, selective breeding may improve colostrum quality and protection for neonatal calves in the early days of life.     

Observations on Uterine Prolapse in Beef Cattle

Serum samples were obtained from 26 beef cows with uterine prolapse and from 15 with minor dystocia (controls). The serum of animals with uterine prolapse had significantly lower calcium concentration (mean ± S.D. = 8,22 ± 0,69 mg/dL, P≤0,01), higher phosphorus concentration (mean ± S.D. = 4,78 ± 1,75 mg/dL, P≤0,05) and lower calcium to phosphorus ratios (mean ± S.D. = 1,99 ± 0,88, P≤0,01) than for the control animals (means ± S.D. = 8,91 ± 0,75 mg/dL, 3,54 ± 1,41 mg/dL and 2,99 ± 1,41 respectively). Mild hypocalcemia (6,9 mg/dL-7,9 mg/dL) was present in 11 (42,3%) of the cows with prolapse as compared to only one (6,7%) of the controls. Hypophosphatemia was present in 11 (42,3%) of the animals with prolapse and in ten (66,7%) of the controls.

Eighteen (69,2%) of the animals with prolapse were alert and ambulatory when treated and 15 (57,7%) were known to have required help to deliver the calf. Of the cattle group with uterine prolapse, 14 (53,8%) were two years old, six (23,1%) were three years old, and six (23,1%) were four years of age or older.

It was concluded that mild hypocalcemia and some degree of dystocia were associated with the uterine prolapses. The phosphorus results were equivocal but the high incidence of hypophosphatemia may reflect a phosphorus deficient diet.

     

Pulmonary Clearance of Bacillus subtilis Spores in Pigs

The pulmonary clearance rate of Bacillus subtilis was determined in ten pigs (23-39 kg) exposed simultaneously for 15 minutes to an aerosol generated by an ultrasonic nebulizer. Two pigs were killed at each interval of zero, two, four, eight and 12 hours and the concentrations of B. subtilis in lungs (all lobes), dorsal and ventral nasal turbinates, trachea, pharyngeal and bronchial lymph nodes were determined. The mean percent (± standard error) pulmonary clearance of B.subtilis was 54.2±11.7, 53.0±11.8, 77.4±5.2 and 88.1±3.7 at two, four, eight and 12 hours, respectively. The numbers of B. subtilis retained in the posterior (caudal and accessory) lobes at zero time were significantly greater than those in the anterior (cranial and middle) lobes (P<0.05). However, by 12 hours postinoculation the numbers of organisms retained in the two regions did not differ significantly (P>0.05). The mean percentage of B. subtilis retained by the turbinates, trachea, pharyngeal and bronchial lymph nodes varied between pigs at each time interval, but was usually less than that retained by the lungs.

It was concluded that deposition of B. subtilis spores took place in all parts of the respiratory tract when pigs were exposed to aerosols and that the spores were progressively cleared by the normal lung.

     

The Postpartum Reproductive Status of Dairy Cows in Two Areas in Iceland*

The paper describes the postpartum (pp) reproductive performance of 252 dairy cows in 2 areas in Iceland, in the north (Eyjafjörður) and in the south (Skeið), during a 12 months period.First pp ovulation occurred significantly earlier in primiparous cows, in cows in Skeið and in cows that calved in September—November.The average time of first pp artificial insemination (ai) was 72 days in both areas. Conception rate to first ai in these cows was 58 % in Eyjafjörður and 53 % in Skeið and the number of ai per conception was 1.6 and 1.8, respectively. In Eyjafjörður, 23 % of the cows were inseminated at the time of first pp ovulation. Sixtytwo percent of these cows conceived. In Skeið, 20 cows were inseminated at the time of first pp ovulation, and 9 or 45 % of these cows conceived. The interval from calving to conception was, on the average, 92 days in Eyjafjörður and 100 days in Skeið.Comparison of results from individual farms showed increase in number of conceptions to first pp ai (35–72 %) and decrease in number of services per conception (2.0–1.3) with increased mean number of days from calving to first ai (62–82 days).     

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.     

The yield of colostrum and colostral gammaglobulins in beef cows and the absorption of colostral gammaglobulins by beef calves

The details of a small study on the volume of colostrum and colostral gammaglobulins produced by beef cows at the first milking immediately after calving and the serum concentrations of passively acquired colostral gammaglobulins attained by beef calves are reported. The mean volume of colostrum and colostral gammaglobulins produced were 2990 ± 2100 (SD) mL and 314.75 ± 211.8 (SD) g respectively. The mean serum concentrations of passively acquired colostral gammaglobulins were 29.9 ± 10.1 (SD) ZST units (n = 40, Ranch A) and 19.2 ± 7.5 (SD) ZST units (n = 42, Ranch B). The main reason for this difference appeared to be nutritional; the cows on ranch B being in much poorer condition and almost certainly producing less colostrum than those on ranch A.     

Pregnancy and peripheral plasma progesterone levels in cows inseminated after synchronization of estrus with prostaglandin F2 alpha

Fifteen Holstein cows were treated with two doses of 25 mg of a prostaglandin F₂α (PGF₂α as dinoprost tromethamine) administered intramuscularly 11 days apart. The cows were then divided into three groups and inseminated either at 72, 80 or 72 and 96 hours after the second dose of PGF₂α. Thirteen cows ovulated after the second prostaglandin treatment. Eight cows were diagnosed pregnant by rectal palpation 42 days after insemination but only five calved. PGF₂α induced luteolysis in cows with active corpora lutea as evidenced by the dramatic decreases in the plasma progesterone concentrations after treatment. In contrast, following PGF₂α administration to cows in follicular or late luteal phase the concentrations of plasma progesterone either increased gradually or remained low for several days before increasing to maximal levels. The ovulatory rate after the two doses of PGF₂α11 days apart was high. However, the pregnancy rate after this treatment was influenced by other factors including abnormal ovarian function.     

Days to calving in artificially inseminated beef cows: Comparison of potential traits

Four fertility traits were compared for artificially inseminated (AI) beef cows: A) for cows that calved to the AI sire (from either the initial or follow-up inseminations that season), the number days from initial AI to calving; B) for cows calving either by AI or to a backup bull, the number days from initial AI to calving; C) As trait B for cows that calved, otherwise the maximum of trait B for the contemporary group plus a penalty of 21 days; D) Define the ‘start date’ for a contemporary group as the date the first cow in the group was AI'd. For cows that calved, trait D was the number of days from the ‘start date’ to calving, otherwise the maximum of trait D for cows in the group that calved plus a penalty of 21 days.The vast majority of cows received only one insemination in a season, so trait A resembled gestation length and had estimated heritability of 12%. Traits B, C and D had estimated heritabilities of 3.2%, 3.5% and 5.2% respectively; estimated genetic correlations of traits A–D with naturally mated days to calving were 0.48, 0.60, 0.80 and 0.74 respectively. Trait D is therefore the recommended female fertility trait for AI cows. It has a similar frequency distribution to days to calving from natural mating and should be included in a joint analysis with days to calving of naturally mated cows.     

Evaluation of biological and economic efficiency of the All Heifer,No Cow beef production system using a system dynamics model based on 6 yr of demonstration herd data

Alternative management strategies with no cows and all heifers may improve biological and economic efficiency of beef production. The All Heifer, No Cow (AHNC) beef production system involves insemination of nulliparous heifers with female sex-selected semen (FSS) to produce primarily female calves that are early weaned at 3 mo of age. Dams are finished on a high concentrate diet and harvested before 30 mo of age. The objectives of this research were to: 1) build a dynamic model of an AHNC beef production system to quantify system biological and economic efficiency; 2) compare effects of utilizing FSS vs. conventional semen on biological and economic efficiency; 3) evaluate what-if scenarios to determine the effects on biological and economic efficiency of changing variables ±5%, 10%, 15%, and 20% from initial observed values; and 4) evaluate the effects on biological and economic efficiency of changing variables ±10% from initial observed values. A model was built over a 21-yr horizon using Stella Architect. Biological parameter values in the model were based on the 6 yr of data collected from the management of an AHNC demonstration herd. In the model animal, total digestible nutrients (TDN) intake, hot carcass weight (HCW), and age at harvest were randomized. Feed, animal, and carcass prices included in the model were based on 10 yr of historical U.S. price data. Key response variables were biological and economic efficiency (mean ± SD). Biological efficiency was defined as the ratio of output (kilograms of HCW produced) to input (lifetime kilograms of feed TDN consumed), and economic efficiency was measured using a benefit–cost ratio (BCR) and unit variable cost (UVC). Over 40 simulation runs, the predicted mean biological efficiency was 0.0714 ± 0.0008. Economic efficiency was 0.95 ± 0.02 and US $445.41 ± 0.06 for BCR and UVC, respectively. Biological and economic efficiency was improved in the conventional semen scenario; biological efficiency was 0.0738 ± 0.0008, and BCR and UVC were 0.99 ± 0.04 and US $407.24 ± 0.006, respectively. Under this parameterization and market conditions, the AHNC beef production system failed to achieve profitability under any scenario that was evaluated. However, this review did not account for the potential increased genetic benefit from a decreased generation interval and the reduction in feed energy in comparison to a conventional cow/calf system.     

Effect of dosage of cloprostenol on induction of farrowing and body temperature of sows

In an experiment involving 161 farrowings, cloprostenol was injected on day 112 or 113 of gestation at the recommended dosage (175 μg) or a lower dosage (125 μg). Cloprostenol treatment did not result in abnormally high body temperatures of sows at parturition. Farrowing began within 29 hours of injection in 94% and 88% of the sows treated with 175 μg and 125 μg cloprostenol respectively, as compared to 15% of saline-injected controls. The duration of farrowing and number stillborn were not affected by treatment. Sows farrowing within 19 hours of treatment tended to have a large number of piglets and a higher body temperature postpartum.