Pregnant Gilts Research Articles

Induction and synchronization of ovulations of nulliparous and multiparous sows with an injection of gonadotropin-releasing hormone agonist (Receptal)

The objective of this study was to determine if administration of a set dose (10 μg) of a gonadotropin-releasing hormone agonist, buserelin (Receptal; Rc), at set times after altrenogest (Regumate; RU) treatment or after weaning was able to induce and synchronize ovulation in female swine (gilts and sows). The pubertal (n = 187) gilts were allocated to four groups, all synchronized with RU. Group 1 (RU) was inseminated twice at detected estrus, Group 2 (RU+Rc120) and Group 4 (RU+Rc104) received 10 μg Rc at 120 or 104 h after the end of RU treatment, respectively, and Group 3 (RU+eCG+Rc104) was treated with 800 IU equine chorionic gonadotropin (eCG) at 24 h and Rc 104 h after the end of RU treatment, respectively. Gilts were inseminated twice at predetermined times, namely 144 and 168 h (Group 2), 128 and 144 h (Group 3), and 144 and 152 h (Group 4) after the end of RU treatment, respectively. Pregnant gilts were slaughtered at 30 d. Administration of Rc 104 h after the end of RU feeding synchronized ovulation over a 24-h time window in 97.9% and 100% of the gilts of Groups 3 and 4, respectively, whereas Rc administration at 120 h (Group 2) only successfully synchronized 88.9% of the gilts over 24 h. Ovulation rates of gilts of Groups 2 and 4 were similar to that of the control group. Pregnancy rates were numerically higher in Groups 2 and 3 (92% and 96%, respectively) compared with those of Groups 1 and 4 (84% and 81%, respectively). Combination of eCG with Rc administration at 104 h (Group 3) increased ovulation rate (+4 CL) but decreased embryo survival to 62% at Day 30. The weaned sow experiment involved 61 sows of a range of parities (2.7 ± 0.9), allocated to two control groups (Control 104 group and Control 94 group) and two treated groups (Rc104 group and Rc94 group), which received 10 μg Rc at 104 and 94 h after weaning, respectively. The females were inseminated at detected estrus. All pregnant sows farrowed. After treatment with Rc 94 h after weaning, 100% of sows ovulated over a 24-h time window versus only 68.7% of controls. Farrowing rate and litter size of the sows treated with Rc at that time were unaffected compared with that of control sows. In contrast, Rc administration at 104 h after weaning may have been too late; only 66.7% of the treated sows ovulated during a 24-h period. This proportion was numerically lower but not significantly different than that for control sows. Farrowing rate and litter size of treated sows were not significantly different than that of controls. Administration of Rc at the dose and times selected in this study tightened synchrony of ovulation in gilts and in sows after weaning. It remains to be established if such a synchrony is suitable to obtain good fertility after a single artificial insemination at a predetermined time.

Endometrial and conceptus expression of HoxA10, transforming growth factor β1, leukemia inhibitory factor, and prostaglandin H synthase-2 in early pregnant pigs with gonadotropin-induced estrus

This study was conducted to evaluate the effect of estrus induction with gonadotropins on endometrial and conceptus expression of HoxA10, transforming growth factor (TGF) β1, leukemia inhibitory factor (LIF), and prostaglandin H synthase-2 (PGHS-2) during early pregnancy in pigs. Twenty-four prepubertal gilts received 750 IU of pregnant mare serum gonadotropin (PMSG) and 500 IU of human chorionic gonadotropin (hCG) 72 h later. Gilts in the control group (n = 23) were observed daily for estrus behavior. Endometrial tissue samples, conceptuses, blood serum, and uterine luminal flushings (ULFs) were collected on days 10, 11, 12, and 15 after insemination. There was no effect of estrus induction on estradiol content in ULFs, or on ovulation and fertilization rates in studied gilts. However, the content of progesterone in the blood serum was greater in naturally ovulated gilts in comparison to gonadotropin-treated animals on day 12 of pregnancy ( P < 0.05). HoxA10 expression was up-regulated in the endometrium of pregnant gilts, with natural ovulation on days 12 ( P < 0.05) and 15 ( P < 0.001) in comparison to days 10 and 11. When compared to control gilts, administration of PMSG/hCG resulted in decreased expression of endometrial HoxA10, TGFβ, LIF, and PGHS-2 on day 12 of pregnancy ( P < 0.05). Conceptus expression of studied factors was not affected by gonadotropin treatment. Overall, these results suggest improper endometrial preparation for implantation in prepubertal gilts induced to ovulate with PMSG/hCG.

Transforming growth factor beta (TGFB) signaling is activated during porcine implantation: proposed role for latency-associated peptide interactions with integrins at the conceptus–maternal interface

The process of implantation is mediated by a complex network of signaling and adhesive factors. In the pig, latent and active transforming growth factor beta (TGFB), TGFB receptors (TGFBR), and integrins (ITGs) are present during the peri-implantation period. TGFB signals via TGFBR and activates downstream effector SMAD proteins 2 and 3 (p-SMAD2/3). Latency-associated peptide (LAP), part of the latent TGFB complex, is known to bind to ITG heterodimers and activate TGFB. We hypothesize that active TGFBs and TGFBRs along with LAP and ITGs functionally interact at the conceptus-maternal interface to mediate events essential for conceptus development and attachment in pigs. Uteri and conceptuses from days 10, 12, 16, 20, and 24 pregnant gilts were immunostained for TGFB, LAP, and ITG subunits (ITGAV, ITGB1, ITGB3, ITGB5, ITGB6, and ITGB8). Activation of TGFBRs was evaluated by the presence of phosphorylated downstream effector SMAD2/3. Binding of LAP to ITGs was also evaluated using porcine trophectoderm cells. Abundant active TGFB was detected at the apical surfaces of epithelia at the conceptus-maternal interface, and p-SMAD2/3 was detected at both conceptus attachment and nonattachment sites during implantation. Separate aggregates of LAP, ITGB1, ITGB5, and later ITGB3 were detected at the porcine conceptus-maternal interface, and binding of LAP to ITGs on apical surfaces was demonstrated. Results suggest that functional LAP-ITG adhesion complexes support conceptus attachment and promote TGFB activation leading to TGFB interaction with TGFBR supporting events of porcine implantation.

Intrauterine Infusion of Latency-Associated Peptide (LAP) During Early Porcine Pregnancy Affects Conceptus Elongation and Placental Size1

In the pig, transforming growth factor beta (TGFB), TGFB receptors (TGFBRs), and integrins are present during the peri-implantation period. Latency-associated peptide (LAP), a part of latent TGFB, can bind to integrin heterodimers via its Arg-Gly-Asp (RGD) sequence; therefore, ligand-receptor interactions between TGFB and TGFBRs, along with LAP and integrin heterodimers, may be functional in mediating events supporting conceptus elongation and attachment. With the use of surgically implantable osmotic pumps, we were able to maintain pregnancy with the aim of mechanistically altering in vivo receptor-ligand interactions involving TGFB with TGFBRs and LAP with integrins during porcine pregnancy. Day 9 pregnant gilts received intrauterine infusions of LAP-RGD, a recombinant mutant of LAP (LAP-RGE), or vehicle control and were ovariohysterectomized on Day 13 or 24 of pregnancy. We hypothesized that intrauterine infusion of LAP-RGD would decrease downstream signaling of TGFB while increasing LAP-integrin interactions and that net effect would enhance conceptus survival and attachment early in the peri-implantation period but possibly increase the chance of abnormal placentation later in pregnancy. Additionally, we hypothesized that infusion of LAP-RGE would disrupt TGFB signals but not alter integrin signaling, and thus the net result would be decreased conceptus survival and abnormal development. Unexpectedly, LAP-RGD intrauterine infusions resulted in a reduction of conceptus elongation, whereas infusions of LAP-RGE permitted implantation and placentation but resulted in larger fetal weight, allantois length, and allantoic fluid volume. Results suggest TGFB and integrins are contributing factors in the regulation of conceptus elongation and placental and fetal size.

Maternal social stress during late pregnancy affects hypothalamic-pituitary-adrenal function and brain neurotransmitter systems in pig offspring

Maternal stress in pregnant sows may induce long-lasting alterations in the behavior, physiology, and immunity of their offspring. The aim of the present study was to investigate the consequences of repeated social stress during late gestation on determinants of the hypothalamic–pituitary–adrenal axis and on hippocampal neurotransmitter profiles in pig offspring. All pregnant gilts were housed in pairs. Each Stress gilt was mixed with an unfamiliar gilt twice a week between days 77 and 105 of gestation (n = 18). Control gilts were housed in stable pairs over the same period (n = 18). Plasma cortisol and corticosteroid binding globulin (CBG) were measured in 1 male and 1 female per litter in a basal situation on postnatal days (PND) 4, 26, and 60 and in a stressful situation at PND 28 (2 d after weaning) and 62 (2 d after relocation to a new building). Prenatal stress had no effect on plasma cortisol, but it decreased CBG at PND 26. Brain and adrenals were collected from 1 female per litter after weaning or relocation at PND 28 and PND 62. Adrenals were additionally collected at PND 4. Glucocorticoid receptor binding in the hippocampus and hypothalamus was not affected by prenatal treatment. However, prenatal stress increased the expression of 11β-hydroxysteroid dehydrogenase type 1 mRNA in the hippocampus after weaning ( P < 0.05) and after relocation ( P = 0.08). In addition, prenatally stressed piglets showed an increased 5-hydroxyindole-3-acetic acid to 5-hydroxytryptamine ratio in the hippocampus after weaning and increased hippocampal c-fos mRNA expression and noradrenaline concentration after relocation ( P < 0.05). Prenatal stress also increased the relative adrenal weight at PND 4 and the cell density in the cortex and the medulla at PND 28, whereas no difference was found for activities of catecholamine-synthesising enzymes in the medulla. Overall, our data indicate that repeated social stress during pregnancy has long-lasting consequences on hypothalamic–pituitary–adrenal axis and hippocampal neurotransmitter activity in the offspring of pigs.

A cross-sectional study of the prevalence of lameness in finishing pigs, gilts and pregnant sows and associations with limb lesions and floor types on commercial farms in England

AbstractThe prevalence and risks for abnormal gait in finishing pigs(Sus scrofa), gilts and pregnant sows from a representative cross-section of indoor and outdoor herds in the United Kingdom were investigated. The prevalence of abnormal gait in finishing pigs, maiden gilts, pregnant gilts and pregnant sows from 88 herds was 19.7, 11.8, 14.4 and 16.9%, respectively. In a multivariable analysis of 98 herds, there was an increased risk of abnormal gait in pregnant sows housed on slatted floors compared with pregnant sows housed on solid concrete floors with straw bedding or sows housed outdoors on soil. The lowest prevalence of abnormal gait in finishing pigs occurred in pigs housed outdoors (3.4 vs 19.7% in indoor-housed finishing pigs) however, the difference was not significant because only three farms in the study housed finishing pigs outdoors. In indoor-housed finishing pigs, there was an increased risk of abnormal gait in pigs housed on solid concrete floors with sparse bedding, partly-slatted floors or fully-slatted floors compared with those housed on solid concrete floors with deep bedding in all areas. However, there were no significant associations between floor type and abnormal gait in gilts. There was an increased risk of abnormal gait associated with increasing callus, bursitis and capped hock score on the limbs of finishing pigs. This might have occurred because limb lesions cause discomfort or because lame pigs spend more time lying and this increases the risk of limb lesions developing.

Detection of differentially expressed genes between Erhualian and Large White placentas on day 75 and 90 of gestation

BackgroundPlacental efficiency is strongly associated with litter size, fetal weight and prenatal mortality. Together with its rapid growth during late gestation, the Large White pig breed shows a significant increase in placental size and weight, but this does not occur in the highly prolific Chinese pig breeds. To understand the molecular basis of placental development during late gestation in Chinese indigenous and Western breeds with different placental efficiency, female placental samples were collected from six pregnant Erhualian gilts at gestation day 75 (E75) and day 90 (E90) and from six pregnant Large White gilts at gestation day 75 (L75) and day 90 (L90). Two female placentas from one sow were used to extract RNA and then pooled in equal volumes. Twelve pooled samples were hybridized to the porcine Affymetrix GeneChip.ResultsA total of 226 and 577 transcripts were detected that were differentially expressed between E75 and L75 and between E90 and L90 (p < 0.01, q < 0.2), respectively. Gene Ontology (GO) analysis revealed that these genes belong to the class of genes that participate in angiogenesis and development. Real-time RT-PCR confirmed the differential expression of eight selected genes. Significant differential expression of five genes in the VEGF pathway was also detected between the breeds. A search of chromosomal location revealed that 44 differentially expressed genes located to QTL regions related to reproduction. Differential expression of six candidate imprinted genes was also confirmed. Three of the six genes (PLAGL1, DIRAS3, and SLC38A4) showed monoallelic expression in the porcine placenta.ConclusionOur study detected many genes that showed differential expression between placentas of two divergent breed of pigs, and confirmed the imprinting of three genes. These findings help to elucidate the genetic control of placental efficiency and improve the understanding of placental development.

Effect of Bromocriptine Administration during Mid-pregnancy on the Ovary Function in the Pig

Plasma concentrations of prolactin, luteinizing hormone (LH), progesterone, estradiol-17 beta and androgens testosterone with dihydrotestosterone were determined in pregnant gilts (n = 6) administered bromocriptine (BR) from 37-42 days of pregnancy. Blood samples were daily taken at 2h-intervals from day 34 to 45 of pregnancy. BR treatment reduced (p less than 0.001) prolactin secretion from 14.8 +/- 0.9 ng/ml to 8.6 +/- 1.1 and 5.5 +/- 0.7 during the initial 1-3 and 4-6 days of treatment, respectively. Following cessation of BR treatment prolactin returned to the pre-treatment concentrations (14.5 +/- 1.0). BR did not alter LH during the first 3 days of treatment but decreased LH on days 4-6 (1.5 +/- 0.1 vs 2.1 +/- 0.2, p less than 0.05). Bromocriptine evoked a 20% increase (p less than 0.05) in estradiol-17 beta during days 1-3 following onset of treatment, however it suppressed androgen concentrations from 10.7 +/- 1.2 to 5.6 +/- 0.4 pg/ml in the same period. Suppression of prolactin from day 37-42 with a concurrent decrease of LH from day 40-42 of gestation did not affect maintenance of pregnancy and surprisingly was associated with a temporary elevation of progesterone. We conclude that prolactin has no luteotrophic properties during midpregnancy in gilts.

Effect of Bromocriptine Administration on Maintenance of Late Pregnancy in the Pig

Plasma concentrations of prolactin, luteinizing hormone (LH) and progesterone were determined in pregnant gilts (n = 6) administered bromocriptine from 67-72 days of pregnancy. Blood samples were taken daily at 2 h intervals from 60 to 80 days of pregnancy. Bromocriptine treatment reduced prolactin from 9.7 +/- 1.4 before to 1.9 +/- 0.6 ng/ml during the treatment (p less than or equal to 0.05) and then returned to the pre-treatment concentrations (10.5 +/- 2.0) following cessation of bromocriptine. Bromocriptine increased LH from 1.4 +/- 0.2 before treatment to 2.9 +/- 0.5 ng/ml (p less than or equal to 0.01) during administration and maintained elevated (3.0 +/- 0.7) in the post-treatment period (p less than or equal to 0.05). Administration of bromocriptine did not alter progesterone concentration in plasma (7.5 +/- 1.2; 7.2 +/- 1.6 and 6.6 +/- 1.6 ng/ml in pretreatment, treatment and post-treatment periods, respectively). This study shows that decrease of prolactin level by bromocriptine treatment does not cause depletion of progesterone secretion in late pregnant pigs.

Maternal stress during late gestation has moderate but long-lasting effects on the immune system of the piglets

Events acting prenatally on developing foetuses are important determinants for disorders later in life. Prenatal stress (PNS) is one of these events. The purpose of this study was to determine the consequences of a repeated social stress applied during late gestation of the pregnant gilt on the immune system and hypothalamo-pituitary-adrenal (HPA) axis activity of the piglets from birth to two months of age. Pregnant gilts were submitted to repeated social stress which was induced by housing unfamiliar gilts in pairs modified twice a week during 4 weeks between days 77 and 105 of gestation (S group, n = 18). Control gilts were housed in stable pairs during the same period (C group, n = 18). Blood cortisol, haptoglobin and IgG levels, immune cell counts, mitogen-induced whole-blood proliferation and TNF-α production were evaluated in piglets at 4 days of age (D4), before and after weaning (D26 and 28) and before and after relocation to a new building (D60 and 62). We found that PNS did not affect growth rate of the progeny. It decreased the relative weight of adrenal glands on D4 ( P < 0.05) but plasma cortisol levels were similar in both groups at all ages. IgG levels in colostrum and in the serum of piglets were not affected. PNS decreased the total numbers of white blood cells, lymphocytes and granulocytes from D26 to D60 ( P < 0.05), the CD4 +/CD8 + T cell ratio on D4 ( P < 0.05), and LPS induced-TNF-α production on D60 ( P < 0.05). PNS increased the ConA-induced lymphocyte proliferation on D4 and D60 and the PWM-induced proliferation on D60 ( P < 0.05). Our results demonstrate that a repeated social stress applied to pregnant sows during late gestation can induce long-lasting effects on several parameters of the immune function of the offspring. These effects are not due to modifications of the HPA axis activity and may impair the abilities of the piglets to efficiently react against infections during the suckling period and around weaning.

Behavioural, endocrine and immune responses to repeated social stress in pregnant gilts

Pregnant sows are exposed to various stressors in intensive pig husbandry that may have negative consequences on their health, reproductive performances and welfare. Social stress is one of these challenges, because gestating sows have to be housed in groups according to EU guidelines (2001/88/CE). The purpose of this study was to determine the consequences of repeated social stress in pregnant female pigs on their behavioural, endocrine and immunological responses and on pregnancy outcome. Pregnant gilts were submitted to a repeated social stress procedure induced by housing unfamiliar gilts in pairs changed twice a week between days 77 and 105 of gestation (S group, n = 18). Control gilts were housed in stable pairs during the same period (C group, n = 18). Agonistic behaviour was observed during the first 3 h after each grouping. Skin lesions were numbered 2 h after each grouping. Salivary cortisol was measured before and repeatedly during the 4 weeks of grouping. Gilts were immunized against keyhole limpet haemocyanin (KLH) on days 81 and 95 of gestation. Immunoglobulins G against KLH, proliferative responses to concanavalin A, lipopolysaccharide, pokeweed mitogen and KLH and peripheral blood leukocyte numbers were evaluated 1 week before the first grouping and 3 days after the last one. Agonistic interactions and skin lesions were observed in S gilts at each grouping, although there was a decline between the first and the last grouping (P < 0.05). The repeated social stress induced a sustained endocrine response as shown by elevated salivary cortisol levels from 1 to 48 h after grouping in S gilts compared to C gilts. The cellular as well as the humoral immunity and the leukocyte numbers were not influenced by social stress. Gestation length tended to be shorter in S gilts (P = 0.09), but litter size, piglet weight or mortality at birth were not affected. Variability of the response of S gilts to groupings was partly explained by their average success value determined according to the outcome (defeat or win) of all the groupings. In conclusion, our study demonstrates that the application of repeated social stress to pregnant gilts during the last third of their gestation repeatedly activates their hypothalamo–pituitary–adrenal axis but does not impair their immune function and pregnancy outcome.

Effect of the conceptus on uterine prostaglandin-F2α and prostaglandin-E2 release and synthesis during the periimplantation period in the pig

The present study was conducted to evaluate the effect of the conceptus on uterine prostaglandin-F2alpha (PGF2alpha) and prostaglandin-E2 (PGE2) release and the expression of prostaglandin synthase enzymes during the periimplantation period in the pig. A surgically generated model with conceptuses developing in only one of the uterine horns was created. The highest concentration of PGF2alpha and PGE2 was found in the gravid uterine horn, compared with the non-gravid horn and the intact horn of cyclic gilts. Endometrial concentration of both PGs in pregnant gilts was elevated regardless of the conceptus in the uterine horn, whereas only myometrial PGE2 concentration increased during pregnancy. Expression of prostaglandin-E2 synthase (mPGES-1) mRNA in the endometrium was upregulated during the oestrous cycle, while protein expression presented a similar pattern to that of PGE2 concentration in the uterine flushings. Prostaglandin-F2alpha synthase (PGFS) mRNA and protein expression in the endometrium did not differ between pregnancy and oestrous cycle but PGFS mRNA in the myometrium increased during pregnancy both in the gravid and the non-gravid uterine horns. We suggest a local effect of the conceptus on PG release pathways but also a more systemic effect within the whole uterus with regard to PG synthesis and accumulation in uterine tissues.

Local and Systemic Effects of Embryos on Uterine Tissues During Early Pregnancy in Pigs

In the pig, the periimplantation period is critical for successful establishment of pregnancy. We studied the influence of embryos on oxytocin (OT) and progesterone (P(4)) regulated endometrial and myometrial secretion of 1) luteotrophic prostaglandin E(2) (PGE(2)) and 2) luteolytic prostaglandin F(2alpha) and its metabolite (PGFM) on days 12-14 of pregnancy in pigs. We used unilaterally pregnant pigs created by a surgical procedure in which one uterine horn remained intact and the second horn was cut transversely so that part of the horn was detached from the uterine body. The animals were divided into two groups, inseminated gilts (days 12-14 of pregnancy, n=6) and uninseminated cyclic gilts, which were used as controls (days 12-14 of estrous cycle, n=5). Embryos developed only in the patent part of the uterus and not in the occluded horn. The abundance of OTR mRNA was increased in the endometrium and decreased in the myometrium of the gravid uterine horn in the pregnant pigs compared with the non-gravid uterine horn or either uterine horn in the cyclic pigs, indicative of a local effect of the conceptus. The presence of embryos in the uterine horn during the periimplantation period determines endometrial metabolism of PGF(2alpha) and the local response of the endometrium to OT and P(4). OT stimulates PGF(2alpha) secretion and PGFM accumulation in endometrial cultures only from the non-gravid uterine horn and controls PGE(2) secretion from the endometrium and myometrium in the pregnant gilts. The results indicate a more systemic affect of pregnancy on the uterine response to OT and a possibly the local effect of the conceptus in promoting progesterone's inhibition of OT-stimulated PGE(2) secretion and uterine metabolism of PGF(2alpha).

No effect of the plant growth regulator, chlormequat, on boar fertility

Chlormequat is a commonly used plant growth regulator in agriculture. Defined levels of chlormequat residue are allowed in food and an acceptable daily intake is defined for humans. However, there are results in the literature suggesting that a daily intake below the acceptable level for human is detrimental for mammalian reproduction. In the present experiment we investigated the effect of chlormequat at levels up to that acceptable for humans on reproduction in male pigs. Chlormequat (also known as chlorocholine chloride (CCC)) was mixed into the diet and given to the experimental animals at three levels (three treatment groups), i.e. 0 mg CCC/kg BW per day (Control), 0.025 mg CCC/kg BW per day and 0.05 mg CCC/kg BW per day. Eight mother sows per treatment group were used in the experiment. From the day of insemination, the mother sows received the experimental diets. The piglets were weaned at 4 weeks of age and two boar littermates continued on the same treatment as the dam until maturity and delivery of semen for in vitro fertilization (IVF) and in vivo fertilization. Semen volume, sperm concentration and fraction of live sperms were not (P ⩾ 0.46) detrimentally affected by chlormequat intake. The fraction of oocytes developing to more than the one-cell stage at day 5 after IVF was not (P = 0.88) detrimentally affected by chlormequat intake. Chlormequat intake did not detrimentally affect the fraction of gilts being pregnant after one insemination (P = 0.65) or the number of embryos in the pregnant gilts (P = 0.36). Serum chlormequat concentration was 0.9 μg/kg in the 0.025 mg CCC/kg BW per day group and 1.8 μg/kg in the 0.05 mg CCC/kg BW per day group, but was below the detection limit in control animals. In conclusion, the plant growth regulator chlormequat could not be proven to be detrimental to the selected reproduction traits in male pigs. This is in contrast to existing results from the male mouse.

Effect of dietary supplementation of n-3 fatty acids and elevated concentrations of dietary protein on the performance of sows

A study was conducted to determine the effect of dietary supplementation of n-3 fatty acids (O3FA) with or without elevated concentrations of protein on the performance of sows during the first and the subsequent parity. Sixty-four pregnant gilts with BW of 195.0 +/- 2.1 kg and backfat (BF) thickness of 12.9 +/- 0.2 mm were assigned to 4 dietary treatments from d 60 of gestation (late gestation) to d 21 of lactation. Dietary treatments were 1) a control diet; 2) a high-protein diet (HP); 3) the control diet + 0.2% O3FA (O3); and 4) the HP diet + 0.2% O3FA (HPO3). For the control and O3 treatments, CP contents were 12.3% for late gestation and 17.9% for lactation, and for the HP and HPO3 treatments, CP contents were 18.4% for late gestation and 19.5% for lactation. On d 60 and 110 of gestation and after farrowing (within 12 h postfarrowing), on d 10 and 21 of lactation, BW, BF thickness, and blood samples were obtained. The total number of piglets and the number of piglets born alive and their birth weights were measured within 12 h postfarrowing. Colostrum and milk samples were obtained on d 2 and 21 of lactation, respectively. All piglets were weaned at 21 d. The wean-to-estrus interval and ADFI were recorded. The same measurements were obtained from the control and O3 groups during the subsequent parity. Dietary treatment did not affect BW, BF thickness, ADFI, and the wean-to-estrus interval of sows during their first reproductive cycle. Supplementation of O3FA increased both eicosapentaenoic acid and docosahexaenoic acid contents (P < 0.05) in colostrum and mature milk. First-parity litter size and piglet birth weight did not differ among treatment groups. Piglet BW was greater (P < 0.05) for the O3 group compared with both the control and HPO3 groups at d 10 and 21 of lactation. The same pattern was also noted for overall piglet BW gain. Both piglet and litter characteristics of the HP group did not differ from those of other groups throughout lactation. During the subsequent parity, both total and live piglet birth weights tended (P < 0.07) to be greater for the O3 group than for the control group. Compared with the control group, piglet BW and BW gain in the O3 group showed a pattern similar to the previous parity. Results indicated that O3FA alone during lactation improved the growth of nursing piglets, regardless of parity. However, the O3FA diet, with or without elevated protein, did not affect first-parity gestation performance, although O3FA alone may have improved piglet birth weight in the subsequent litter.

Endometrial and myometrial secretion of androgens and estrone during early pregnancy and luteolysis in pigs

Previously, we found that in addition to embryos, the uterine tissues may be a source of estradiol-17beta (E(2)) during early pregnancy in the pig. The aim of the present study was to determine whether porcine endometrium and myometrium secrete androgens - androstenedione (A(4)), testosterone (T) and estrone (E(1)) during early pregnancy and luteolysis (Days 14-16) in pigs. Individual endometrial and myometrial slices (200 mg) were first pre-incubated (24 h) and then incubated (6 h, 37 degrees C in an atmosphere of 95% O(2) and 5% CO(2)) in the presence or absence of progesterone (P(4); 10(-5) M), oxytocin (OT; 10(-7) M) or OT plus P(4). Basal endometrial and myometrial secretion of A(4) and T did not differ between pregnant and cyclic gilts. Endometrial secretion of E(1) was higher in pregnant than cyclic gilts (p<0.05) while myometrial secretion of E(1) did not differ between the two groups of the examined pigs (p>0.05). Progesterone significantly increased A(4) and T secretion (p<0.001) by uterine tissues regardless of the reproductive status. In the presence of P(4), endometrial and myometrial secretion of E(1) was increased only during luteolysis (p<0.001). In both tissues, OT did not affect the examined steroid secretion and did not change the effect of P(4). 1) porcine endometrium and myometrium was found to produce A(4), T and E(1) in vitro; 2) basal endometrial and myometrial production of A(4) and T did not differ between the examined reproductive periods; 3) the endometrium released more E(1) during early pregnancy than luteolysis; 4) in the presence of substrate (P(4)), uterine tissues increased secretion of A(4) and T during early pregnancy and luteolysis; and 5) P(4) increased uterine production of E(1) only during luteolysis. These data demonstrated the presence of the active steroid pathway in porcine endometrium and myometrium which may serve as an alternative source of androgens and estrogens in pigs.

Metritis, Valvular Endocarditis, and Septicemia by Actinobacillus equuli in a Gilt in the United States

A 1-year-old pregnant Yorkshire gilt was found dead with no previous clinical signs. Gross findings included metritis, splenomegaly, and valvular endocarditis. Bacterial endocarditis (in the mitral and tricuspid valves) and metritis with dissemination to multiple organs was diagnosed by using histologic examination. Gram-negative coccobacillary organisms present in the valvular lesions were characterized as Actinobacillus equuli by using polymerase chain reaction examination on formalin-fixed, paraffin-embedded tissues (FFPE). A. equuli is rarely reported as a cause of septicemia in pigs in Europe. A. equuli in pigs in the United States has been reported only twice and not, to our knowledge, in the last 30 years. This is the first time that molecular techniques have been used to characterize this organism in FFPE porcine tissues.

Influência do sistema de alojamento no comportamento e bem-estar de matrizes suínas em gestação

Esta pesquisa foi desenvolvida no setor de gestação, com 24 matrizes primíparas, 12 fêmeas alojadas em baias individuais e 12 animais em baias coletivas, para avaliar diferentes sistemas de alojamento (baias individuais e baias coletivas) para matrizes gestantes, visando caracterizar aspectos quantitativos e qualitativos do ambiente e as variáveis que influenciam o sistema de produção. O trabalho foi dividido em duas etapas em função da forma de avaliação dos dados: análise bioclimática e análise dos sistemas de alojamento. A avaliação bioclimática foi realizada por meio do registro dos elementos meteorológicos, na sala de gestação e no ambiente externo. Nos sistemas de alojamento, foram avaliados as relações comportamentais, os parâmetros fisiológicos e os índices zootécnicos. O delineamento experimental foi em blocos casualizados, com dois sistemas de alojamento e 67 blocos. As características ambientais apontam o sistema de alojamento em baias coletivas como aquele que permitiu melhor condicionamento térmico natural às matrizes em gestação. Os parâmetros fisiológicos e os índices zootécnicos apresentaram valores mais adequados para o sistema de alojamento em baias coletivas, assim como seu reflexo no desempenho da parição dos leitões. A avaliação comportamental, realizada pelo monitoramento por meio do registro de imagens de vídeo, apontou menor incidência de comportamentos resultantes do estresse ambiental, estereotipias e interações agressivas no sistema de alojamento em baias coletivas.

Conforto térmico para matrizes suínas em fase de gestação, alojadas em baias individuais e coletivas

Este experimento foi realizado no período compreendido entre 04/01 e 11/03/2005, em uma propriedade de produção industrial de suínos, localizada no município de Elias Fausto, estado de São Paulo. O objetivo da pesquisa consistiu na avaliação de diferentes sistemas de alojamento para matrizes gestantes, verificando-se as influências dos elementos meteorológicos e os aspectos relacionados à qualidade química do ar e seus reflexos no conforto animal na fase de gestação, determinando-se as condições favoráveis ao melhor desempenho animal, com base nas respostas ao ambiente de criação. O estudo foi desenvolvido no setor de gestação, com 24 matrizes primíparas, 12 fêmeas alojadas em baias individuais (T1) e 12 animais em baias coletivas (T2). O trabalho foi dividido em duas etapas: análise bioclimática e análise da qualidade química do ar. O delineamento experimental foi em blocos casualizados, com dois tratamentos e 67 blocos, e as médias comparadas pelo teste de Tukey. As variáveis meteorológicas (T, °C e h, kJ kg-1) apontam o sistema de alojamento em baias coletivas como aquele que permitiu melhor condicionamento térmico natural às matrizes em gestação apresentando valores da ordem de 25,03 °C e 62,02 kJ kg-1. As concentrações dos teores de gases não superaram as concentrações consideradas críticas para as matrizes.

82. Application of repeated social stress to pregnant gilts during early or late gestation differentially affects HPA axis and immune system activity of the piglets

Early life stress (ELS) affects facial emotion recognition (FER), as well as the underlying brain network. However, there is considerable inter-individual variability in these ELS-caused alterations. As the hypothalamic-pituitary-adrenal (HPA) axis is assumed to mediate neural and behavioural sequelae of ELS, the genetic disposition towards HPA axis reactivity might explain differential vulnerabilities.An additive genetic profile score (GPS) of HPA axis reactivity was built from 6 SNPs in 3 HPA axis-related genes (FKBP5, CRHR1, NR3C1). We studied two independent samples. As a proof of concept, GPS was tested as a predictor of cortisol increase to a psychosocial challenge (MIST) in a healthy community sample of n = 40. For the main study, a sample of n = 170 completed a video-based FER task and retrospectively reported ELS experiences in the Childhood Trauma Questionnaire (CTQ).GPS positively predicted cortisol increase in the stress challenge over and above covariates. CTQ and genetic profile scores interacted to predict facial emotion recognition, such that ELS had a detrimental effect on emotion processing only in individuals with higher GPS. Post-hoc moderation analyses revealed that, while a less stress-responsive genetic profile was protective against ELS effects, individuals carrying a moderate to high GPS were affected by ELS in their ability to infer emotion from facial expressions.These results suggest that a biologically informed genetic profile score can capture the genetic disposition to HPA axis reactivity and moderates the influence of early environmental factors on facial emotion recognition. Further research should investigate the neural mechanisms underlying this moderation. The GPS used here might prove a powerful tool for studying inter-individual differences in vulnerability to early life stress.