Oregano improves reproductive performance of sows

Natural herbs are being explored as alternatives to antimicrobials. The objective of the present study was to determine the effect of strategic addition of oregano to prefarrowing and lactation diets of sows under field conditions. Alternate farrowing groups were given diets containing 1000 ppm oregano (dried leaf and flower of Origanum vulgare, enriched with 500 g/kg of cold-pressed essential oils of O. vulgare) in prefarrowing and lactation diets. Overall, 801 oregano-treated sows, including 601 primiparous and 1200 multiparous (parity 2.99 +/- 0.43, mean +/- S.E.) and 1809 untreated control sows (705 primiparous and 1104 multiparous; parity 3.04 +/- 0.38), were used. Sows fed oregano had lower annual sow mortality rate (4.02 +/- 0.4% versus 6.92 +/- 1.11%, mean +/- S.E.; P = 0.003), lower sow culling rate during lactation (8.01 +/- 1.11% versus 14.02 +/- 1.33%, P = 0.02), increased farrowing rate (77.02 +/- 2.31% versus 69.91 +/- 2.32%, P = 0.01), increased number of liveborn piglets per litter (10.49 +/- 1.5 versus 9.95 +/- 1.22, P < 0.05), and decreased stillbirth rate (0.909 +/- 0.01 versus 0.807 +/- 0.01, P = 0.05). In addition, multiparous sows fed oregano had higher (P = 0.04) daily voluntary feed intake compared to non-treated sows (7.7 +/- 0.32 kg versus 7.0 +/- 0.42 kg, P = 0.04). Additional studies are needed to elucidate the effects of oregano on the gastrointestinal, immune and urogenital system in swine and to determine if it has any adverse effects.     

Exogenous prostaglandin F(2)alpha at time of ovulation improves reproductive efficiency in repeat breeder sows

In order to determine if PGF(2)alpha could improve fertility in repeat breeder females when added to semen used for artificial insemination (AI) the following trial was performed. In a large indoor Hungarian production unit of 2000 sows, 667 repeat breeding females were assigned to two groups and were treated as follows: Group 1 (n=322), received PGF(2)alpha, added to the semen immediately before AI; Group 2 (n=345), received AI with untreated semen. Conception rate, farrowing rate, subsequent total and live born litter size and subsequent weaning to estrus intervals were evaluated. Conception and farrowing rates revealed highly significant differences between the PGF(2)alpha-treated and nontreated animals (P<0.001). Subsequent total born (P<0.07), and live born litter size (P<0.13), and subsequent weaning to estrus intervals (P<0.23) showed no significant differences. It is reasonable to suggest that exogenous PGF(2)alpha added to AI semen improves conception and farrowing rates.     

Fertility in bitches artificially inseminated with extended, chilled semen

Sixteen bitches were artificially inseminated with either fresh, 24 h-chilled or 48 h-chilled extended semen over 38 estrous cycles. A commercial system for extending, chilling and transporting semen commonly used in the equine industry was used Pregnancy rates and litter sizes of the bitches inseminated with extended, chilled semen (19/20, 95%; litter size = 7.1) were not significantly different from those observed in bitches inseminated with fresh semen (17/18, 94%; litter size = 7.2; P > or = 0.89). These results show that a commercial system for extending, chilling and transporting equine semen is an attractive and efficient method of shipping canine extended chilled semen.     

Sources of variation in the reproductive performance of ewes inseminated with frozen-thawed ram semen by laparoscopy

Fertility data from 8 artificial insemination programs, involving more than 5000 ewes and 110 rams in 3 flocks, were analyzed to determine variation due to individual AI program and ram in the reproductive performance of ewes inseminated with frozen-thawed semen by laparoscopy. The semen had been previously frozen by commercial AI centers in either pellets or straws. Both AI program and individual ram affected the proportion of ewes pregnant and the number of fetuses per ewe inseminated, but not the number of fetuses per pregnant ewe. Semen samples from 97 of the rams used were analyzed on a Hamilton Thorn HTM 2000 image analyzer for sperm concentration, percentage of motile and progressively motile spermatozoa, mean progressive velocity, and mean linear index. The correlations between these traits and reproductive performance obtained after insemination were calculated. There was large variation in the quantity and quality of the frozen semen, but only the number of total and motile spermatozoa inseminated per ewe was correlated with fertility (0.25 and 0.26, respectively). Regression analysis showed that none of the traits measured were useful for predicting fertility.     

Prostaglandin F2alpha specific binding in equine corpora lutea

Preliminary studies indicate the presence of PGF2alpha specific binding sites in membrane fractions prepared from equine corpora lutea. The equilibrium binding data indicate an apparent dissociation constant of 3.2 X 10(-9)M and the concentration of binding sites of -0.1 pmoles/mg membrane protein. Competition of several natural prostaglandins for equine luteal PGF2alpha specific binding sites indicates specificity for the 9alpha-hydroxyl moiety and the 5,6-cis doublebond. Significant increases in relative binding affinities were demonstrated for PGF2alpha analogs with a phenyl ring introduced at carbons 16 or 17. Specific PGF2alpha binding was demonstrated in corpora lutea collected at known stages of the estrous cycle. There was no pattern in these values based on the stage of the cycle. While specific 3H-PGE1 binding could be demonstrated, no high affinity sites could be quantitated. 3H-PGE1 binding appeared unaffected by changes in temperature or time of incubation, whereas PGF2alpha specific binding was significantly modified by both these factors.     

Prostaglandin F2alpha (PGF2alpha) and prolactin secretion in rats.

Plasma prolactin and F-prostaglandins (PGF) were measured anesthetized male Sprague-Dawley rats before and at 15, 30, 45 and 60 minutes following i.v. injection of either PGF2alpha (4 mg/kg), chlorpromazine, 1 mg/kg or chlorpormazine (1 mg/kg) after pretreatment with i.p. indomethacin (2 mg/kg). Following PGF2alpha administration, plasma prolactin levels increased significantly only at 15 and 30 minutes in spite of extremely high PGF levels throughout 60 minutes. Besides the expected rise in plasma prolactin, chlorpromazine caused a transient but statistically significant increase in PGF. Indomethacin blocked the chlorpormazine-induced PGF rise but not prolactin increase. Animals stressed with ether anesthesia showed elevation of plasma prolactin, which was not blocked by indomethacin although PGF concentration fell. Theese results indicate that PGF2alpha can stimulate prolactin release. This effect does not appear to be physiologic since very high PGF levels are required. Furthermore, blockade of prostaglandin synthesis by indomethacin does not prevent the release of prolactin in response to chlorpormazine or stress. Our findings do not support a possible role of PGFs as intermediaries in prolactin release. However, it is possible that PGFs may work through other mechanisms not investigated in our study.     

Progesterone levels and litter performance of sows following postpartum administration of prostaglandin F(2alpha)

A total of 101 sows was used to examine postpartum progesterone levels and litter performance following administration of 15 mg prostaglandins F(2alpha) (PGF(2alpha) n = 48) given within 12 h after farrowing. Daily blood samples and rectal temperatures were taken from all sows during the first 3 d post partum. Plasma progesterone (P(4)) concentrations were determined by radioimmunoassay (RIA). Regardless of treatment, plasma P(4) levels for all sows decreased in a similar fashion over the 3 d sampled. Mean (+/- SEM) P(4) on Day 2 (0.55 +/- 0.06 ng/ml) and Day 3 (0.38 +/- 0.04 ng/ml) were lower (P<0.01) than on Day 1 (0.98 +/- 0.08 ng/ml). Rectal temperature did not differ between PGF(2alpha) treated and nontreated sows nor was it different over the days measured. Litter characteristics, including survival rates on Day 7 and at weaning, and body weight on Days 3 and 35, were not affected by treatment. It was concluded that PGF(2alpha) administration to sows within 12 h post farrowing had no affect on the rate of luteal regression, as determined by P(4) concentration, nor on subsequent litter performance.     

Prostaglandin F2 alpha increases responsiveness of pulmonary airways in dogs

We studied the effect of prostaglandin F2 alpha (PGF2 alpha) on the responsiveness of pulmonary airways in dogs. Airway responsiveness was assessed by determining the bronchoconstrictor response to increasing concentrations of acetylcholine aerosol delivered to the airways. In each of five dogs, we determined responsiveness during treatment with physiologic saline, histamine, or PGF2 alpha aerosols. The doses of histamine and PGF2 alpha were determined by establishing the largest dose of each which could be given to the dog without causing bronchoconstriction (subthreshold doses). We found that airway responsiveness was not significantly different during histamine treatment than after saline, however, responsiveness increased during treatment with PGF2 alpha. In addition, the hyperresponsiveness induced by PGF2 alpha was prevented by pretreatment with the ganglion blocking drug hexamethonium (5 mg/kg given intravenously). The results show that PGF2 alpha specifically increases the responsiveness of pulmonary airways in doses that do not cause bronchoconstriction, and suggest that the hyperresponsiveness involves a neural mechanism such as increased responsiveness of airway sensory nerves.     

Prostaglandin F2alpha added to extended boar semen at processing elicits in vitro myometrial contractility after 72 hours of storage.

Improved fertility will maximize productivity of the swine industry. Myometrial contractility is an essential component in the fertilization process because it is the mechanism by which spermatozoa are transported to the site of fertilization. In the present study, we evaluated the potential use of PGF2alpha supplementation to the extended pig semen in regard to inducing myometrial contractility of sows. Extended boar semen (80 mL) was supplemented with PGF2alpha (5 mg) for 72 h at 17 +/- 1 degrees C. Cumulative doses of 0.1, 1, 10 and 100 microL of the mixture were tested on uterine strips obtained from diestrus sows. An increase in myometrial contractility was recorded with PGF2alpha supplementation when compared to extended semen or extender treatment alone after 72 h of incubation. Addition of PGF2alpha to the extended boar semen at the time of the experiment did not differ from the 72 h treated group. The results from this study support that PGF2alpha preparations can be added to extended doses of boar semen at processing to enhance myometrial contractility at the time of insemination for up to 72 h.     

Prostaglandin F2alpha and human prostatic affinity for testosterone.

Earlier work had shown that the lactogen, LTH and HPL, foster testosterone binding by the prostate. This study was undertaken to see if prostaglandin F2alpha would oppose the effect of the lactogen on the prostate as it does the luteotrophic action of the hormone on the corpus luteum. When it was found instead that the PGF increases steroid binding and that its interaction with lactogen was neither antagonistic nor additive, attention was directed to further characterization of prostaglandin's effect. A dosage/response study of F2alpha alone showed that concentrations of 4 ng/ml and 40 ng/ml increased binding but that 400 ng/ml did not. Glands with stromal hyperplasia and/or inflammation were not responsive than those with epithelial hyperplasia. Assays of water extracts of the tissue revealed concentrations of about 340 ng of F2alpha per gram fresh weight and that the concentration varied inversely as the beta-glucuronidase activity. If the enzyme level is considered an index of the epithelial cell density within the specimen, the inverse relationship suggest a non-epithelial (stromal) site of prostaglandin concentration.     

Prostaglandin E2 and F2 alpha in mid-pregnant rat uterus and at parturition

Prostaglandin E2 (PGE2) and F2 alpha (PGF2 alpha) produced by 15 days pregnant rat myometrium, by parturient rat myometrium and myometrium plus endometrium were measured in vitro. The results showed that the PGs produced by parturient myometrium were higher than these obtained during mid-pregnancy. Myometrium with endometrium released more PGs than myometrium alone, and the addition of arachidonic acid (AA) at 10 DM did not show any significant effect. Exogenous progesterone or estradiol-17b at a concentration of 1 Dmol had no effect on parturient uterine PG secretions.     

Influence of leptospirosis on reproductive performance of sows in Brazil

The purpose of this study was to investigate the association between seropositivity for the most frequent Leptospira serovars and reproductive losses in sows in Brazil. Serum samples from 351 sows from 18 herds (in the state of Rio de Janeiro, Brazil) with low reproductive efficiency were tested (microscopic agglutination) for antibodies against serovars of Leptospira. Antibodies were detected in serum samples of 66.1% of all sows, most frequently serovar icterohaemorrhagiae (43.1%), followed by pomona (18.1%) and tarassovi (9.9%). Seroreactivity to icterohaemorrhagiae and pomona were associated (P<0.05) with impaired reproductive performance (and substantial economic loss). Seroreactivity for pomona was associated (P<0.05) with stillborn piglets and mummified fetuses, whereas seroreactivity to icterohaemorrhagiae was associated (P<0.05) with the number of piglets born dead.     

Concentrations of endogenous prostaglandin F2alpha in boar semen and effect of a 72-h incubation period on exogenous prostaglandin F2alpha concentration in extended boar semen

PGF2alpha in semen has been shown to induce uterine contractions, thereby, facilitating sperm transport during fertilization. Previously, we demonstrated that extended boar semen used in artificial insemination does not increase myometrial contractility, but PGF2alpha supplementation did. In this study, we determined the concentrations of endogenous PGF2alpha in pre-sperm and sperm-rich fractions of the boar ejaculate and examined whether changes in the concentration of exogenous PGF2alpha occurred when added to extended boar semen after 72-h incubation at a 17 degrees C storage temperature. Concentrations of endogenous PGF2alpha (n = 10 boars) in pre-sperm and sperm-rich fractions were 69.6 +/- 7.6 and 58.9 +/- 4.4 pg/ml, respectively. No differences were observed in the concentrations of exogenous PGF2alpha in the extended boar semen at 0 h (59.3 +/- 3.3 microg/ml) and after a 72-h incubation period (52.0 +/- 2.1 microg/ml). These results suggest that the concentration of endogenous PGF2alpha in boar semen used for artificial insemination is < 100 pg/ml. The concentration of exogenous PGF2alpha in the extended boar semen did not differ after 72 h, which indicates that it is not metabolized during this period of time.