Biomedical subjects

S Einarsson

Publications and source records attributed to S Einarsson.

At least 55 records · Page 3Linked to original sources

PubMed1998

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↗

PubMed1998

Sugar beet fiber in formula diet reduces postprandial blood glucose, serum insulin and serum hydroxyproline.

OBJECTIVE: The object of the study was to investigate the effects of sugar beet fiber in formula diet on blood glucose, serum insulin and serum hydroxyproline in humans. DESIGN: Two formula test meals with and without 7 g of sugar beet fiber, namely 5.1 g total dietary fiber, were ingested on two mornings, in random order, by the subjects. SETTING: The test meals were served in a clinic to the subjects after a 12 h fast. SUBJECTS: Fifteen healthy male human volunteers (mean age 25 y, range 21-42) registered to participate in the study after an announcement. METHODS: The test meals of formulas contained similar amounts of nutrients and gave total energy of 1778 kJ (425 kcal). Blood samples were drawn before and after the test meals. The total test time from the start of ingestion of the meal was 155 min. RESULTS: The formula with sugar beet fiber reduced the postprandial blood glucose response (P < 0.05), serum insulin response (P < 0.025) and serum hydroxyproline response (P < 0.025), compared with the formula without fiber. CONCLUSION: Sugar beet fiber in a formula could thus reduce hyperglycemia in enteral nutrition and be useful in therapeutic liquid and formula diets. Sugar beet fiber was shown to tolerate preparation for canning well, namely homogenization and heating, and to be capable of diminishing the glycemic responses in the relatively small amount used.

Adult↗

PubMed1998

Pneumonia caused by penicillin-non-susceptible and penicillin-susceptible pneumococci in adults: a case-control study.

The objective of this study was to investigate the observation that patients with pneumonia due to penicillin-non-susceptible pneumococci (PNSP) in many instances present with milder disease than patients with pneumonia caused by penicillin-susceptible pneumococci (PSP) and to compare the cost of treatment. The clinical data, APACHE II score and laboratory features of hospitalized adults with pneumonia caused by PNSP or PSP were compared, along with antibiotic and hospital costs. Each patient with PNSP pneumonia (n = 36) was matched to a control with PSP pneumonia of the same age and gender. There was no difference in smoking history, but PNSP pneumonia patients had received prior antibiotics more frequently (p < 0.007). The mean APACHE II score was not different, but when broken down into acute vs. chronic scores those with PSP pneumonia had a significantly higher acute score (p = 0.005). Bacteraemia was present in 9 of 31 (29%) patients with PSP compared to 2 of 25 (8%) with the PNSP pneumonia (p = 0.09). The majority of isolates in the PNSP group were of serotype 6B (minimum inhibitory concentration range 0.125-2.0 mg/l), whereas serotypes 7, 9, 14, 18 and 19 were noted among the 9 PSP isolates. Compared with the control group, patients with the PNSP strains had a significantly longer hospital stay, 26.8 vs. 11.5 days (p = 0.001) and higher average antibiotic cost, $736 vs. $213 (p < 0.0001). In conclusion, pneumonia in adults caused by PNSP is associated with a milder clinical presentation than infection caused by PSP, suggesting either that resistance carries a price or that the serotypes of PNSP are less virulent. Pneumonia due to PNSP resulted in increased cost because of prolonged hospitalization and the use of more expensive antibiotics.

APACHE↗

PubMed1998

Urinary excretion of oestrone sulphate and cortisol in early pregnant gilts treated with glucocorticoids.

The aim of this study was to determine rates of urinary excretion of oestrone sulphate and cortisol in early pregnant gilts that were untreated or treated with either dexamethasone, corn oil or hydrocortisone. Twenty Polish Landrace gilts were used. They were grouped immediately after mating as follows: Experiment I--Group 1 (5 gilts), control animals and Group 2 (5 gilts), injected i.m. with dexamethasone (30 micrograms/kg) at 12-h intervals from day 13 to day 22 of pregnancy; Experiment II--Group 3 (5 gilts), injected i.m. with corn oil at 12-h intervals from day 13 to day 22 of pregnancy and Group 4 (5 gilts), injected i.m. with hydrocortisone acetate (250 mg) at 12-h intervals from day 11 to day 20 of pregnancy. Gilts were placed in metabolic cages, and 24-h urine aliquots were collected from day 6 to day 32 of pregnancy. On days 34-36 of pregnancy gilts were slaughtered and clinical data were collected. Rates of urinary excretion of oestrone sulphate and cortisol were determined by enhanced chemiluminescence immunoassays. The urinary excretion of oestrone sulphate expressed in nmol/24 h and mumol/mol creatinine were significantly correlated. There was no correlation between cortisol expressed in nmol/24 h and mumol/mol creatinine (p > 0.5). A first significant increase of urinary oestrone sulphate excretion, expressed in nmol/24 h, on days 13-14 and a second one on days 19-20 of gestation occurred in control untreated and oil-treated gilts. The urinary excretion of oestrone sulphate reached maximum values between days 25 and 32 of gestation. In dexamethasone-treated gilts cortisol excretion significantly decreased on day 16, i.e. 3 days after injections of dexamethasone had commenced. The treatment with hydrocortisone resulted in a significantly increased cortisol excretion after the last injection of hydrocortisone. There were no relations between levels of urinary oestrone sulphate excretion expressed in nmol/24 h and the number of foetuses. When the urinary excretion of oestrone sulphate was expressed in mol/mol creatinine we found a positive relation between concentrations on day 20 of pregnancy and the number of foetuses. In one untreated gilt with a relatively high urinary excretion of cortisol (more than 200 nmol/24 h) a lower number of foetuses was found at autopsy. In conclusion, both dexamethasone and hydrocortisone treatment seemed to delay the first observed peak in oestrone sulphate in gilts without affecting the embryonic survival and the number of viable foetuses.

Animals↗

PubMed1998

Plasma levels of progesterone and cortisol after ACTH administration in lactating primiparous sows.

The effect of adrenocorticotropic hormone (ACTH) administration on progesterone and cortisol concentrations was determined in lactating primiparous sows. Physiological saline and 50 IU ACTH were administered on days 20 and 21 of lactation at 0900 hours via an indwelling jugular catheter. Blood samples for hormone analysis were collected via indwelling jugular catheters every 15 min (0800 to 1200 hours) and every 60 min (1300 to 1500 hours). Saline administration had no effect on progesterone nor cortisol concentrations in the lactating sows. Progesterone and cortisol concentrations increased (p < 0.001) within 15 min after ACTH administration. Progesterone and cortisol concentrations peaked (p < 0.01) within 45 min and had returned to pretreatment values within 120 min after ACTH treatment.

Adrenocorticotropic Hormone↗

PubMed1998

Reproductive performance among sows group-housed during late lactation.

Four farms (540 sows) that group-housed sows from 2 weeks of lactation until weaning (G-farms) and 3 farms (300 sows)--used as controls--that kept the sows individually penned throughout the 5- to 6-week-long lactation period (C-farms) were compared in terms of reproductive performance. All sows were crossbred Swedish Yorkshire x Swedish Landrace. Sows were kept in groups in the breeding section and were also grouped on deep litter in the dry-sow section on all farms. Batchwise farrowing routines were used on all farms, and batch size ranged between 8 and 22 sows. Fertility and culling data were collected in connection with monthly visits to the farms for 16 months. Among the older (> or = 5th parity) sows, litter sizes were significantly (p = 0.02) smaller in the G-farm group compared with the C-farm group. The percentage of sows mated within 10 days post weaning was lower (p < 0.001) in the G-farm group than in the C-farm group, with the difference being most evident among the older (> or = 5th parity) sows. The frequency of repeat breeders among primiparous sows was similar in the 2 housing systems, but among the multiparous sows repeat-breeder frequency was higher (p = 0.04) in the G-farm group than in the C-farm group. In both groups, repeat-breeder frequency seemed to be highest from July to September. Repeat breeding/failure to farrow was a common reason for culling in the G-farm group. These results indicate that reproductive performance was impaired in the group-housing system. This impairment could have been due partly to the occurrence of lactational oestrus, which makes it difficult to maintain adequate routines for oestrous detection and mating/insemination.

Animal Husbandry↗

PubMed1997

Changes in sperm ultrastructure and localisation in the porcine oviduct around ovulation.

Changes in the morphology and localisation of spermatozoa in the utero-tubal junction (UTJ) and three equal segments of the isthmus (lower, middle and upper isthmus) within +/-8 h of ovulation were studied with scanning and transmission electron microscopy. Spermatozoa were located at specific sites within the UTJ-isthmic environment. Two sperm subpopulations were evident, one with epithelial contact and one without such contact. Most of the sperm population with epithelial contact maintained intact plasma membrane during the pre-ovulatory period and showed acrosome reacted-like membrane changes during the post-ovulatory period. In contrast, plasma membranes in most of the spermatozoa with no epithelial contact were already broken before ovulation. Ovulation was also accompanied by a relocation of spermatozoa from the mucosal crypts/interfolds towards the more central part of the mucosal surface.

Acrosome↗

PubMed1997

Effect of exogenous cholecystokinin on the discharge of the gallbladder and the secretion of trypsin and chymotrypsin from the pancreas of the Atlantic salmon, Salmo salar L.

The humoral control of release of the proteases trypsin and chymotrypsin was investigated in the Atlantic salmon (Salmo salar L.). Intraperitoneal injection of a purified preparation of the peptide cholecystokinin (CCK) from pig into starved fish produces a dose-dependent release of both enzymes from the pyloric caeca/pancreas tissues which accumulate in the intestinal contents (digesta). It also induces release of the contents of the gallbladder. Isolated preparations of pyloric caeca/pancreas when incubated with CCK release trypsin and chymotrypsin. It is concluded that while a possible role for a neuronal component to the control and regulation of these enzymes cannot be ruled out, humoral control by a CCK-like peptide has been established. The fact that a mammalian-derived extract of CCK induces this response in fish indicates an early evolution and subsequent conservation of this control mechanism in the vertebrates.

Animals↗

PubMed1997

Monoclonal antibodies against boar sperm zona pellucida-binding protein AWN-1. Characterization of a continuous antigenic determinant and immunolocalization of AWN epitopes in inseminated sows.

Boar spermadhesin AWN-1 is a sperm surface-associated 14.7-kDa lectin and a major protein of porcine seminal plasma. AWN-1 binds to beta-galactosides and to porcine zona pellucida glycoproteins, suggesting that this protein might play a role in the primary binding of spermatozoa to the egg's external glycoprotein matrix. We have produced a collection of murine monoclonal antibodies against purified AWN-1. Five monoclonal antibodies recognized sequential antigenic determinants. All these epitopes were located at the C-terminal region of AWN-1 (residues 109-123) by competitive ELISA using overlapping synthetic peptides that cover the complete 133 amino acid sequence of the lectin. In a structural model of spermadhesin AWN-1, the polypeptide stretch 109-123 is fully solvent-exposed, providing a reasonable explanation for its high immunogenicity. In addition to epitope mapping, we have employed anti-AWN monoclonal antibodies for immunolocalization of the protein in the genital tract of inseminated sows. Clusters of AWN epitopes were occasionally found attached to the epithelium of the uterotubal junction and the adjacent lower isthmus. However, neither AWN-1 nor other seminal plasma proteins were found in the isthmic fluid collected 10-26 h after insemination. These results suggest that the whole amount of seminal plasma proteins are absorbed by the epithelium of the female genital tract, supporting the claim that removal of seminal plasma components from spermatozoa might be a major event in both in vitro and in vivo sperm capacitation.

Animals↗

PubMed1997

Should nitrous oxide be discontinued before desflurane after anaesthesia with desflurane/N2O?

BACKGROUND: The appearance of hypoxaemia immediately after anaesthesia with nitrous oxide may be partially explained by diffusion hypoxia. This study was undertaken to evaluate circulatory and respiratory variables during emergence after desflurane/nitrous oxide anaesthesia, and whether there are any differences depending on which gas is discontinued first. METHODS: 20 patients were studied after gynaecological laparoscopic surgery. The depth of anaesthesia was reduced 10 min prior to the emergence by stopping the administration of one of the two inhalational agents. Desflurane was discontinued first in Group 1, nitrous oxide in Group 2. Ventilation was controlled with E'CO2 maintained at 5% until the administration of the second anaesthetic gas was discontinued. Thereafter, the patients breathed spontaneously. RESULTS: The PaCO2 at which the respiratory drive reappeared after controlled normoventilation was similar in both groups, 6.1-6.5 kPa, and extubation was performed after 10-11 min. At extubation, the end-tidal CO2 and total MAC were similar in the groups, about 6.2 vol% and 0.16, respectively. Mean arterial blood pressure was significantly higher in Group 1. The cardiac output increased in both groups from about 6 l/min at the conclusion of anaesthesia to 9.0 and 7.6 l/min at 15 min in the recovery period. End-tidal O2 decreased and CO2 increased in both groups during the first 10 min in the recovery period. pH was reduced at 15 and 30 min in both groups. CONCLUSION: Irrespective of which agent was discontinued first there was an increase in cardiac output decrease in oxygenation and a modest acidosis in the first 30-min recovery period. The only significant difference between the groups was in mean arterial blood pressure in the early emergence phase with a greater MAP when N2O had been used until the conclusion of anaesthesia.

Adult↗

PubMed1997

Emergence from isoflurane/N2O or isoflurane anaesthesia.

BACKGROUND: The first goal of anaesthetic recovery is return of the patient's ability to independently maintain respiratory and circulatory functions. Nitrous oxide remains popular due to minor effects on the cardiovascular and respiratory systems. However, diffusion hypoxaemia can occur during recovery and there is a potential advantage of providing the patient with only a potent vaporised agent. METHODS: This randomised study of 20 gynaecological patients evaluated respiratory and circulatory variables during emergence after anaesthesia with equipotent mixtures of isoflurane/nitrous oxide or isoflurane. Inspired, end-tidal and mixed expired gas concentrations, expired minute volume, pulse oximetry saturation and arterial blood gases were registered. Monitoring of cardiac output was performed by transthoracic bioimpedance. RESULTS: Patients anaesthetised with isoflurane/N2O resumed their spontaneous breathing 16 min earlier and were extubated 22 min earlier than those anaesthetised with only isoflurane. At extubation, total MAC and end-tidal CO2 were similar in both groups, 0.22-0.26 and 5.5-5.9 vol%, respectively. The isoflurane/ N2O group had greater minute ventilation and CO2 excretion rates than the isoflurane group throughout the emergence period. There were no significant differences between the groups in blood gas variables or in heart rate, mean arterial blood pressure or cardiac index. Cardiac index was between 3.4 and 3.9 l m(-2) min(-1) throughout the emergence period in both groups. CONCLUSION: Patients anaesthetised with only isoflurane had a longer delay until resumption of spontaneous breathing and extubation in the emergence period. Minute ventilation and carbon dioxide elimination were also significantly more suppressed throughout emergence after anaesthesia with isoflurane as compared with isoflurane/N2O.

Adult↗

PubMed1997

Relationships between health and weight loss during lactation and between health and ability to return to oestrus after weaning in primiparous sows.

The study comprises observations in 301 Swedish Yorkshire primiparous sows belonging to a research herd. During the 6 weeks of lactation, they were fed according to a conventional feeding regime based on litter size. The sows were weighed at farrowing and at weaning. After weaning the sows were checked daily for standing reflex and blood samples for determination of plasma progesterone were drawn regularly. Diseases occurring during lactation were recorded in 223 sows. A clinical health examination of these sows was also performed on the day of weaning, including body temperature, condition scoring, appetite, locomotor disorders, remarks on legs and mammary glands. A blood sample was drawn 1 week before weaning in 155 sows for analysis of blood haemoglobin concentration, packed cell volume, total white blood cell count, serum concentration of urea, creatinine, triglycerides, free fatty acids, total protein and electrophoretic separation of proteins. Sows with large weight loss had a higher total incidence of diseases during lactation, mastitis being the most common disease, than sows with small weight loss. Sows with large weight loss seemed to be more catabolic during late lactation than sows with small weight loss, according to the blood analyses. The blood analyses did not show any signs of subclinical infection being more common among sows with large weight loss than among sows with small weight loss. There were neither any significant differences in the total incidence of diseases during lactation nor in the health at weaning between sows returning to oestrus within 10 days of weaning and sows not returning within this time.

Animals↗

PubMed1997

Pre- and post-weaning piglet performance, sow food intake and change in backfat thickness in a group-housing system for lactating sows.

Four farms that group-housed sows from about 2 weeks of lactation until weaning (G-farms) and 3 farms, used as controls, that kept the sows individually penned throughout the 5 to 6-week-long lactation period (C-farms) were compared in terms of pre- and post-weaning piglet growth rate and mortality, sow food intake and change in backfat thickness. Piglets from 169 G-farm sows and 136 C-farm sows were individually weighed at the time of grouping and weaning. In addition, some of the piglets were weighed 2 weeks post weaning. Piglet mortality was recorded during the pre- and post-weaning periods. Sow backfat thickness was measured at the time of grouping (at a corresponding time in the C-farms) and weaning, and sow food consumption was determined during the group-housing period. Piglet weight, growth rate and within-litter variation in growth rate did not differ significantly between the two groups during the group-housing and post-weaning periods. However, the pre-weaning growth rate varied considerably between farms. For multiparous sows during the group-housing period, piglet mortality was higher (p = 0.002) in the G-farm group (6.5%) than in the C-farm group (1.4%). However, for primiparous sows the corresponding piglet mortality was similar (p = 0.21) in the two groups. Significant between-batch variation in mortality during the group-housing period was noted within the G-farms but not within the C-farms. At the time of weaning, backfat thickness tended (p = 0.09) to be higher in the G-farm group than in the C-farm group. For primiparous sows the decrease in backfat thickness was similar (p = 0.37) in the two groups. By contrast, multiparous G-farm sows gained backfat during the group-housing period, whereas multiparous C-farm sows lost some backfat (p = 0.02). G-farm sows consumed 23% more food than C-farm sows during the group-housing period. These results indicate that productivity is lower in the group-housing system, mainly owing to the poor performance of the older sows.

Adipose Tissue↗

PubMed1997

Effect of glucocorticoid treatment on biochemical and hormonal blood parameters in early pregnant gilts.

Twenty Polish Landrace gilts were grouped immediately after mating as follows: Experiment I-- Group 1 (5 gilts), control animals and Group 2 (5 gilts), injected i.m. with dexamethasone (30 mg/kg) at 12-h intervals from day 13 to day 22 of pregnancy; Experiment II--Group 3 (5 gilts), injected i.m. with corn oil from day 13 to day 22 of pregnancy and Group 4 (5 gilts), injected i.m. with hydrocortisone acetate (250 mg) at 12-h intervals from day 11 to day 20 of pregnancy. Gilts were placed in metabolic cages on day 7. On days 34-36 of pregnancy gilts were slaughtered and blood samples were collected. Serum was used for analysis of aspartate aminotransferase (S-ASAT), alanine aminotransferase (S-ALAT), alkaline phosphatase (S-ALP), S-cholesterol, S-triglycerides, S-fructosamine, S-urea, S-total protein, and for electrophoretic fractionation of serum proteins, corticosteroid-binding globulin (CBG), cortisol, progesterone, thyroxine (T4) and free T4. There were no significant differences between groups in embryonic survival or in number of viable fetuses after treatment with glucocorticoids. The activity of S-ALP was lower (p < 0.05) in Group 4 than in Group 3 (0.5 vs 1.2 mukat/l). Group 4 had higher (p < 0.05) levels of S-triglycerides (1.17 vs 0.73 mmol/l), S-cholesterol (5.4 vs 2.7 mmol/l), S-total protein (110.5 vs 93.3 g/l), S-albumin (56.3 vs 43.3 g/l) and alpha 2-globulin concentrations (18.0 vs 14.3 g/l) than Group 3. The hydrocortisone-treated gilts had lower (p < 0.05) CBG (6.8 vs 21.3 nmol/l) and beta 1-globulin (3.25 vs 5.0 g/l) concentrations than the oil-treated ones. Concentrations of T4 were lower (p < 0.05) in Groups 2 (61.3 nmo/l) and 4 (49.0 nmol/l) compared with control Groups 1 and 3 (88.2 and 97.0 nmol/l, respectively). Overall, the treatment of early pregnant gilts with hydrocortisone acetate resulted in decreased levels of S-ALP, CBG, beta 1-globulin and T4, and in increased levels of S-cholesterol, S-triglycerides, S-total protein, S-albumin and alpha 2-globulin. The only effect of dexamethasone was a lowering of T4. There were no differences in free T4, S-fructosamine or S-urea between controls and treatments. Furthermore a negative correlation between triglycerides concentrations and the number of embryos (r = -0.76, p < 0.05) was found in control untreated and oil-treated pregnant gilts.

Animals↗

PubMed1996

Distribution, number and membrane integrity of spermatozoa in the pig oviduct in relation to spontaneous ovulation.

The pattern of distribution, number and membrane integrity of spermatozoa in the utero-tubal junction (UTJ) and isthmus during three oestrous stages were related to spontaneous ovulation in flushed and fixed oviducts of multiparous sows. Three unrelated boars were each used once to mate or artificially inseminate (neat ejaculate) six out of 18 sows, 18 h prior to expected ovulation. The sows were slaughtered 6-8 h before, during or 6-8 h after ovulation. The ad-uterine oviductal region (UTJ and isthmus) was divided into UTJ, lower isthmus, middle isthmus and upper isthmus segments. A higher fraction of middle and upper isthmus segments contained spermatozoa during the peri- and post-ovulatory periods than during the pre-ovulatory period. The distribution, numbers and membrane integrity of spermatozoa in the UTJ-isthmus region were influenced by the ovulation event. Numbers and distribution of spermatozoa varied depending on the boar used. The flushing technique allowed a better assessment of the distribution, number and membrane integrity of tubal spermatozoa than in situ observation with a scanning electron microscope (SEM).

Animals↗

PubMed1996

Gas kinetics during nitrous oxide analgesia for labour.

Hypoxaemia may occur after hyperventilation with nitrous oxide during labour. The purpose of this study was to assess whether diffusion hypoxia is a contributory factor. Twenty-four parturients were randomly allocated to receive 50 or 70% nitrous oxide in oxygen. The median nitrous oxide inhalation time per contraction was 58 s and 33 s, respectively. The end-tidal carbon dioxide and the minute ventilation remained unchanged. The end-tidal oxygen concentration was lowest at 120 s, reaching 15.4% in both groups. The oxygen saturation did not differ between the groups with a lowest median value of 96% before the start of nitrous oxide inhalation. Two parturients had episodes of desaturation. Both had low end-tidal oxygen concentrations in association with the desaturation but, as the end-tidal nitrous oxide concentrations were low, the desaturations could not be attributed to diffusion hypoxia.

Adult↗

PubMed1996

Attainment of spermatogenesis in Swedish cross-bred boars.

Twenty peripubertal Swedish cross-bred boars were used to study the testicular differentiation and the maturation of spermatozoa (epididymal) between 100 and 180 days of age. In all animals the sex cords were small and solid at 100 days of age. Spermatogenesis started at approximately 115 days of age and was completed, i.e. the cellular organization of the seminiferous tubules indicated a sexually mature testis with normal spermatogenesis, at 180 days of age. By 125 days of age only a few spermatozoa were found in the cauda epididymidis Furthermore, a high frequency of sperm morphological alterations were seen. The sperm concentration in the cauda increased with increasing age, and simultaneously the frequency of abnormal spermatozoa decreased. However, not all boars had a 'mature' semen picture in the cauda epididymis at 180 days of age.

Aging↗

PubMed1996

Endocrine changes during group housing of primiparous sows in early pregnancy.

The effect of group housing sows during early pregnancy on maternal endocrine changes and on embryonic survival was studied. Twenty crossbred (Swedish Yorkshire x Swedish Landrace) primiparous sows were used. On day 11 +/- 1 of pregnancy 3 unacquainted sows were randomly assigned to a single pen measuring 3 m x 3 m in area. A fourth sow in each group was housed in an individual pen and used as a control. This procedure was repeated 5 times to collect data from 5 animals in each rank as well as in a control group. Blood samples were collected from the day before grouping to day 5 after grouping for cortisol, corticosteroid-binding globulin (CBG), progesterone (P4), oestradiol-17 beta (E2) and prostaglandin F2 alpha metabolite (PG-metabolite) analysis. A rank-order test and an ACTH test were performed on day 4 and day 5 of grouping respectively. The sows were slaughtered on day 17 +/- 1 of pregnancy and embryos recovered. Aggression accompanied by elevations (p < 0.05) in cortisol concentrations occurred in all grouped sows on the first day of grouping. The cortisol increase was greater (p < 0.01) in the subordinate than in the other ranked sows. Cortisol concentrations and the level of aggression decreased on subsequent days during grouping, but the cortisol levels were still higher than on the pre-grouping day except for the intermediate ranked sows. Cortisol concentrations after the ACTH test were similar in the grouped as well as the control sows. The dominance hierarchy was confirmed during the rank order test. Concentrations of P4, E2, PG-metabolite and CBG were similar between the group-housed sows and with the controls. Mean embryonic recovery was 66.8% +/- 11.5%, 71.3% +/- 6.0%, 70.0% +/- 16.0%, and 69.9% +/- 5.8% for the dominant, intermediate, subordinate, and control sows respectively. Hence, group housing during early pregnancy did not influence reproductive hormones or embryonic survival.

Animal Husbandry↗