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Biomedical subjects

H Kindahl

Publications and source records attributed to H Kindahl.

At least 73 records · Page 4Linked to original sources

Serum antibody profile and reproductive performance during two consecutive pregnancies of cows naturally infected with Neospora caninum.

The objective of this study was to record how the antibody levels change over time during pregnancy in dairy cows naturally infected with the protozoan parasite Neospora caninum, and relate this to the reproductive performance. Eighteen cows with antibodies to N. caninum were serum sampled monthly during their first pregnancy and 13 of them were also followed for a second pregnancy. In all, five pregnancies ended in abortion and two in stillbirth. Antibodies to N. caninum in serum were demonstrated by immune stimulating complex enzyme-linked immunosorbent assay (iscom ELISA). The N. caninum antibody titres remained well above the 1:100 cut-off limit for the test used during 2 years in all cows. In the non-aborting cows, mean values of antibody titres to N. caninum rose 1.5-2.5 dilution steps to reach a plateau 4-5 months before parturition, and thereafter decreased from 2 months before parturition. These changes were statistically significant (p < 0.001). The same pattern was seen in the aborting cows. The consistent pattern of rise in antibody titres observed during both pregnancies in all cows indicated a reactivation rather than a reinfection of the parasite at mid-gestation.

Animals↗

Foetal loss in dairy goats: function of the adrenal glands, corpus luteum and the foetal-placental unit.

To investigate the causes and mechanisms of foetal loss in Norwegian dairy goats, blood parameters in 40 goats that lost foetuses were compared with those in 40 goats that experienced a normal pregnancy. High mean levels of 15-ketodihydro-PGF2alpha, and low mean levels of oestrone sulphate throughout pregnancy were associated with foetal loss. The mean oestrone sulphate level was low before abortion, and the distinct peak that occurred at parturition in the control goats was not observed in connection with abortion. Association of other blood parameters with foetal loss was not detected. Infectious agents and toxins did not appear to be major causes of foetal loss in this study. The normal level of progesterone and cortisol in goats with foetal loss indicated that the function of the corpus luteum and adrenal glands, respectively, were not disturbed. The rapid decline in progesterone level associated with foetal loss may therefore be a result, rather than the cause, of foetal death. The lowered level of oestrone sulphate and elevated level of 15-ketodihydro-PGF2alpha in goats with foetal loss clearly indicated that the endocrine foetal-placental function was disturbed.

Abortion, Veterinary↗

Effects of adrenocorticotrophin (ACTH) and progesterone on luteinising hormone (LH) secretion in recently castrated rams.

The goal of the present study was to determine whether ACTH and progesterone have any effect on LH secretion and pulse frequency in recently castrated rams. Six 2-year-old Corriedale rams were castrated in the winter. The day before castration, blood samples were taken in order to establish the precastration LH levels. The rams were divided into an untreated group (group U: n = 2) and a treated group (group T: n = 4). The first treatment consisted of the i.v. administration of 0.5 mg of ACTH on day 20 post-castration, immediately after the first sample had been taken. During the second treatment, subcutaneous progesterone implants were given to group T for 5 days. Control samplings were performed one week before each treatment. Prior to castration, the testosterone levels were low, while after castration they were below the detection limit of the assay. Cortisol and progesterone concentrations were basal before castration in all of the animals and after castration in group U and also in the control samplings for group T. ACTH treatment caused a significant increase in both cortisol and progesterone levels for 3 h (P < 0.001). Progesterone implants raised progesterone levels in group T, but cortisol levels remained basal. Before castration, all animals had low LH levels and hardly any pulse activity was seen. After castration, both the number of LH pulses and the mean LH production increased significantly in all of the animals (P < 0.01). During the ACTH trial, LH pulse frequency was significantly reduced for the first 4 h following ACTH administration (P = 0.013), however, no such differences occurred in the prior control period. No effect was seen on mean LH concentration during the ACTH treatment. Progesterone treatment did not have any effect on either the number of LH pulses nor on LH concentrations (P > 0.05).

Adrenocorticotropic Hormone↗

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.

Animals↗

Effect of fungal alkaloids on the development of pregnancy and endocrine foetal-placental function in the goat.

The response to Claviceps purpurea sclerotia administration in pregnant goats was examined in terms of changes in the levels of plasma hormones, the development of pregnancy and kid production. Six treated goats were each given 15 mg milled sclerotia (i.e. 0.105 mg ergotamine) per kilogram live weight twice daily via a stomach tube from days 98 +/- 2 to 107 +/- 2 of gestation. Seven control goats were given water twice daily via a stomach tube during the same period of gestation. The goats were observed for clinical signs of disease, rectal temperatures and live weights were recorded and the condition of the foetuses was monitored by real-time ultrasonography. All control goats delivered live kids. In the treated group two goats aborted 33 and 47 days, respectively, after the start of the administration period, two goats each delivered one normal and one weak kid, and the two remaining goats delivered apparently normal kids. All six treated goats became depressed and had poor appetite during the period of sclerotia administration. Rectal temperatures were significantly increased and live weight changes significantly decreased in the animals in the treated group compared to the control group during the period of C. purpurea administration. Ultrasound examination revealed that foetal deaths occurred between 1 and 42 days before abortion or birth. The appearance of the aborted foetuses varied from fresh to mummified, depending on the number of days between foetal death and expulsion. Microbiological and serological investigations revealed no infectious causes of reproductive failure. The level of 15-ketodihydro-PGF2 alpha was high in goats that aborted following administration of C. purpurea compared with the level in control goats. The oestrone sulphate level did not increase before abortion in the treated goats as in the controls before parturition. There were also changes in these hormones in the four treated goats that delivered live kids, but the changes were considerably smaller. These findings indicate that the endocrine foetal-placental function was disturbed, probably due to injury caused by the C. purpurea toxin ergotamine in the placenta and foetus.

Abortion, Veterinary↗

Effects of post-ovulatory food deprivation on oviductal sperm concentration, embryo development and hormonal profiles in the pig.

Nutrition is one of the multiple factors that modulate reproduction in animals. The effect of 48 h food deprivation on reproductive and metabolic hormonal changes in relation to cleavage rates was studied. Insemination of 15 sows was performed 20-10 h prior to expected ovulation and ova were recovered at slaughter 65-91 h post ovulation. Blood samples were collected every second hour, beginning from the time of insemination until slaughter, for measurements of progesterone, cortisol, the prostaglandin F2alpha metabolite (15-keto-13,14-dihydro-PGF2alpha) and insulin levels. The embryos from the food-deprived sows (D-group) had fewer accessory spermatozoa in their zona pellucida (ZP) compared with the control sows (C-group). A lower cleavage rate of the embryos in the D-group compared with the C-group was detected. Plasma progesterone, cortisol and prostaglandin F2alpha metabolite levels were significantly higher in the D-group compared with the C-group. Food deprivation is associated with changes in reproductive and metabolic hormones that might lead to changes in the oviductal environment, culminating in a lower cleavage rate of the embryos and presence of fewer viable spermatozoa in the reservoir.

Animals↗

Plasma concentrations of 15-ketodihydro-PGF2 alpha, progesterone, oestrone sulphate, oestradiol-17 beta and cortisol during late gestation, parturition and the early post partum period in llamas and alpacas.

Plasma concentrations of 15-ketodihydroprostaglandin (PG) F2 alpha, progesterone, oestrone sulphate, oestradiol-17 beta and cortisol during late gestation, parturition and the early post-partum period were measured in six llamas and five alpacas. During the last 100 days of pregnancy, 15-ketodihydro-PGF2 alpha concentrations increased steadily until the day of parturition when a massive release was detected (P < 0.01) concomitant with a decrease in progesterone concentrations (P < 0.01). The highest PGF2 alpha metabolite concentrations (159 +/- 35 nmol l-1 and 92 +/- 29 nmol l-1 in llamas and alpacas respectively) were detected in the sample collected during the morning on the day of parturition. Basal concentrations were registered by day 3 after delivery. Plasma concentrations of oestrone sulphate started to increase 80 days before parturition and reached peak concentrations immediately before parturition (15 +/- 3 nmol l-1 in llamas and 18 +/- 5 nmol l-1 in alpacas). Oestrone sulphate concentrations dropped sharply (P < 0.01) on the day of parturition in llamas and one day later in alpacas, whereupon they remained relatively unchanged until at least 20 days postpartum. Oestradiol-17 beta concentrations were higher than 180 pmol l-1 during the last 45 days of pregnancy, began to decrease on the day of parturition and reached very low concentrations within the following two days. High oestradiol-17 beta concentrations were registered 7 days postpartum in all alpacas (P < 0.05) and within 10 days of parturition in five of six llamas (P < 0.01). No significant cortisol peaks were observed around parturition, but mean concentrations were increased in both species.

Animals↗

The effect on luteolysis by intensive oral administration of flunixin granules in heifers.

The objective of the study was to investigate whether oral administration of flunixin meglumine (FM) in the form of granules could prolong the functional life of the corpus luteum in heifers. Previous studies have shown that intensive, i.e. four times daily parental administration of FM can postpone luteolysis. Twelve heifers received an oral dose of 2.2 mg flunixin per kg body weight. Three dosing regimes were used; twice (n = 2), thrice (n = 4) and four times daily (n = 6). The 9-day-treatment period started on Day 14/15 of the oestrous cycle. Blood samples were collected twice daily during the entire experimental period. Frequent samples were withdrawn from Day 14/15 for 10 and 15 days in the control and treatment oestrous cycles, respectively, at 0600, 0800, 1000, 1200, 1400, 1600, 1800 and at 2000 h. The plasma was analysed for the content of the main metabolite of PGF2 alpha, i.e. 15-ketodihydro-PGF2 alpha, and progesterone. A control cycle preceded the treatment cycle so that each heifer acted as its own control. The length of the oestrous cycle was significantly increased when FM was administered thrice, from 18-22 days to 20-24 days (P < 0.05), and four times daily, from 18-21 days to 25-27 days (P < 0.01), but not in the twice daily dosing regime (one-way ANOVA). When FM was administered twice and thrice, luteolysis occurred during treatment. However, when the four times daily regime was used, luteolysis was obtained when the treatment had terminated. No changes in progesterone levels were recorded, although the luteal phase increased when the oestrous cycle length was prolonged. The number of PG-pulses decreased significantly, from 6-12 pulses to 0-3 pulses (P < 0.01), when FM was administered four times daily. A reduction was also observed when heifers received the drug thrice, but the decrease was not significant. The oral route of administration was found to be as effective as the parental one to affect the mechanism responsible for luteolysis in heifers. However, to inhibit and postpone luteolysis, administration of FM four times daily is a necessity. Our results show that oral administration of FM in the bovine species can be of value both in research as well as in the clinic, e.g. to support the luteal function.

Animals↗

Oral Neospora caninum inoculation of neonatal calves.

Four calves born to cows seronegative for Neospora caninum were dosed orally within 6 h after birth with tachyzoites of the bovine N. caninum Nc-SweB1 isolate added to colostrum. Two of the calves were dosed via stomach tube and two by feeding bottle. The latter two calves showed transient fever and passed blood-stained diarrhoea 1-2 weeks after inoculation. From 5 weeks after inoculation they developed a significant antibody response which remained high until the calves were euthanised and necropsied at 15 and 19 weeks after inoculation, respectively. The two calves inoculated by stomach tube showed no clinical signs and they remained seronegative throughout the study. At necropsy of the seropositive calves, no pathological lesions were seen, and parasites were not detected by immunohistochemistry. Neospora caninum was not re-isolated in cell culture from the brains of the seropositive calves; however, N. caninum DNA was detected in brain from both of them by PCR. The data suggest that oral infection of N. caninum via colostrum might be a possible route of vertical transmission in newborn calves, in addition to transplacental infection.

Animals↗

Biostimulatory effects of estrous cows and bulls on resumption of ovarian activity in postpartum anestrous Zebu (Bos indicus) cows in the humid tropics.

Suckled postpartum Zebu (Bos indicus) cows were exposed either to estrous females alone or together with bulls to determine if this regimen would stimulate the resumption of ovarian activity. The study was carried out on 60 Zebu cows. The animals were allocated at parturition to 1 of 3 treatment groups. Group FB cows (n = 14) were exposed to progestogen treated females (approximately 3 cows per progestogen treated cow) and a bull for 42 d. Group F cows (n = 31) were exposed to progestogen treated females and after 21 d a bull was introduced and remained with the group until the end of the experiment 21 d later. Estrus was induced with Syncro Mate B treatment and the cows were in estrus when introduced into Groups FB and F. Group N cows (n = 15) were introduced to a bull 21 d after the treatments had begun in Groups FB and F, and the bull remained with these cows until the end of the study. On average, resumption of ovarian activity occurred in 57% (8/14), 19% (6/31) and 7% (1/15) of the cows in Group FB, F and N, respectively, within 21 d after the start of treatments. The difference was significant between Group FB and Groups F and N (P < 0.05). During the second part of the experiment, in which the bull was introduced to Groups F and N, an additional 32% (10/31) of the cows in Group F and 33% (5/15) in Group N resumed ovarian activity. No cows in Group FB resumed ovarian activity during this period. There were significant differences in body condition between cows that resumed ovarian activity and those that remained in anestrus (P < 0.05). We conclude that biostimulation effectively enhanced resumption of ovarian activity in anestrous suckled Zebu cows. This technique offers a potentially useful and practical way to improve reproductive efficiency in anestrous Zebu cattle in the tropics.

Anestrus↗

Expression of monocyte chemoattractant protein-1 in the bovine corpus luteum around the time of natural luteolysis.

Monocyte chemoattractant protein (MCP-1) is a specific chemoattractant for monocytes/macrophages that could have a role in the influx of macrophages into the corpus luteum (CL) during structural luteolysis. In this study, reverse transcription-polymerase chain reaction and in situ hybridization were used to investigate MCP-1 mRNA expression in CL collected from 18 heifers between Days 15 and 20 of the estrous cycle. There was expression of mRNA encoding MCP-1 in luteal tissue from all cows; however, expression was greater in animals that had undergone luteolysis at the time of CL collection as compared to animals in which the CL was still functional. Similarly, in situ hybridization showed greater expression of mRNA encoding MCP-1 in CL after functional luteolysis. There was also evidence of increased MCP-1 mRNA expression in an animal with a functional CL where the systemic concentration of prostaglandin F2alpha metabolite was high at the time of tissue collection. T lymphocyte populations, identified by immunohistochemistry, had a distribution similar to that of cells expressing MCP-1 mRNA within the CL, but other cell types were also involved. These results demonstrate an increase in MCP-1 mRNA after functional luteolysis in the cow, which may be related to the influx of macrophages that occurs at this time.

Animals↗

Bacteriological and histological investigation of the postpartum bovine uterus in two Estonian dairy herds.

Postpartum uterine infections, endometrial histology and resumption of ovarian activity in cows were studied in 2 Estonian dairy herds with different herd sizes, milk yields and management systems. Ten cows at Farm A and 5 cows at Farm B were studied in the experiment. All cows in the study had normal calving performance. Endometrial biopsies for bacteriological and histological examinations were collected once a week starting on the second week postpartum and continuing for 7 weeks postpartum. Milk progesterone samples were collected twice a week during the whole study period. In both herds, the uterine flora contained mainly facultative anaerobic bacteria (Streptococcus spp., E. coli, Staphylococcus spp., Proteus vulgaris). Among obligate anaerobic bacteria only Bacteroides spp. were found. After 7 weeks of collection at farm A, a bacterial uterine flora still persisted in 2 of the cows. At farm B, on the other hand, bacterial elimination was complete after 6 weeks. Presence of inflammatory cells in uterine histology specimens remained higher at the end of collection and resumption of ovarian activity was delayed at farm A. After 7 weeks postpartum, only 6 of the 10 cows at farm A had resumed ovarian cyclicity, while at farm B the first oestrous cycle had occurred in all cows. The study showed that differences regarding uterine infections and their clearance occurred between farms and, despite these differences, cows with normal calving performance will effectively recover without any treatment.

Animal Husbandry↗

Characterization of a Swedish bovine isolate of Neospora caninum.

The brain of a stillborn calf, seropositive to Neospora caninum and born to a seropositive cow, was homogenized and cultured on Vero cells, where growth of Neospora-like tachyzoites was detected after 8 weeks. The ultrastructural features of the new isolate (Nc-SweB1) corresponded to those of previously published Neospora isolates. In indirect immunofluorescence tests, antigens on Nc-SweB1 tachyzoites were recognized by antibodies raised to a canine N. caninum isolate (Nc-1) but not by antibodies to Toxoplasma gondii, Sarcocystis cruzi, S. tenella, Eimeria alabamensis, Babesia divergens, or B. motasi. Immunoblot analyses revealed no major antigenic difference between Nc-SweB1 and Nc-1, whereas several differences were seen between Nc-SweB1 and protozoa related to N. caninum. The sequences of 16S-like rRNA and the internal transcribed spacer 1 of Nc-SweB1 revealed complete homology with corresponding sequences of two canine N. caninum isolates. Thus, no dissimilarity between Nc-SweB1 and the canine isolates was found, confirming that Nc-SweB1 is N. caninum and suggesting that Neospora-like organisms isolated from cattle are indeed N. caninum.

Animals↗

Effect of experimental infection with Listeria monocytogenes on the development of pregnancy and on concentrations of progesterone, oestrone sulphate and 15-ketodihydro-PGF2 alpha in the goat.

The effect of Listeria monocytogenes infection on hormone levels in pregnant goats was studied. Four goats (Group I) received an intravenous inoculation of a bacterial culture (Type 1) on Days 69-77 and another four goats (Group II) received a similar inoculation on Days 105-106 of gestation. Five non-inoculated goats were used as controls. Plasma was analysed for progesterone, oestrone sulphate and 15-ketodihydro-PGF2 alpha. The status of the foetus was followed using real-time ultrasonography. Three of the four goats in Group I aborted 8-10 days after inoculation. The fourth goat gave birth to a normal live kid at term. The three goats which aborted showed clinical signs of disease in connection with abortion. In Group II, all goats aborted after 9-11 days. All the goats showed clinical symptoms of disease from a few days after inoculation and the symptoms continued until abortion. The clinical symptoms of disease were more pronounced in Group II than in Group I. L. monocytogenes was isolated from all aborted foetuses. None of the control goats aborted. Ultrasound examination revealed foetal death either immediately before or up to 2 days before abortion. Mummification had begun in the foetus that had been dead for 2 days before expulsion. In comparison with pre-inoculation plasma levels in Group I, a significant decrease (P < 0.05) in progesterone levels and an increase in 15-ketodihydro-PGF2 alpha levels were observed from Days 4 and 6 after inoculation, respectively. In Group II, a significant decrease (P < 0.05) in progesterone levels and an increase in 15-ketodihydro-PGF2 alpha levels in plasma were observed from Days 8 and 6, respectively. The oestrone sulphate levels decreased slightly in the inoculated goats a few days before abortion. The pattern of changes in levels around abortion was similar to the pattern present in the control animals around parturition. However, oestrone sulphate levels did not increase in the inoculated groups before abortion in contrast to goats which delivered healthy kids. The changes in levels of 15-ketodihydro-PGF2 alpha in goats that aborted indicated that the endocrine foetal-placental function was disturbed, which was most likely due to the establishment and development of L. monocytogenes in the placenta and foetus.

Animals↗

Endocrine changes during early pregnancy in the alpaca.

Plasma concentrations of progesterone, 15-keto-13, 14-dihydroprostaglandin F2 alpha and oestradiol-17 beta were monitored during early pregnancy in five alpacas. Heparinized blood samples were obtained every 15 min during a 4 h period (0800 to 1200 h) from day 8 to day 13 postmating. Mean plasma concentrations of oestradiol-17 beta decreased close to the detection limit of the assay from day 8 until days 10-11, whereupon they increased again until day 13. A rapid decline in progesterone concentrations occurred after day 8 postmating. All progesterone values registered after day 10 were significantly lower than those registered on day 8. After day 9 postmating, prostaglandin metabolite peaks were detected in all animals, indicating a temporal relationship between the progesterone decline and PGF2 alpha pulsatile release. The number of peaks detected during the 4-h period, monitored on each of the 5 days (day 9 to day 13), ranged from two to four in different animals. The analysis of the prostaglandin secretory pattern in pregnant alpacas suggests that PGF2 alpha peaks might occur at a frequency similar to that observed in nonpregnant animals but with a lower magnitude.

Animals↗

Prostaglandin F2alpha release associated with an embryo transfer procedure in the mare.

The pattern of the main metabolite of prostaglandin (PG) F2alpha was recorded following a nonsurgical embryo transfer technique in 9 mares under field conditions in Estonia. Three patterns were observed. Two of them were characterised by PG release, thereas the third was not. A tendency towards a shortened cycle was seen in 3 mares. Observations were made regarding the manipulation of the uterus as being normal or difficult to perform. In general, mares where the procedure was considered difficult were also found to have a PG release.

Abortifacient Agents, Nonsteroidal↗