Pregnant Sheep Research Articles

Disruption of ruminal homeostasis by malnutrition involved in systemic ruminal microbiota-host interactions in a pregnant sheep model

BackgroundUndernutrition is a prevalent and spontaneous condition in animal production which always affects microbiota-host interaction in gastrointestinal tract. However, how undernutrition affects crosstalk homeostasis is largely unknown. Here, we discover how undernutrition affects microbial profiles and subsequently how microbial metabolism affects the signal transduction and tissue renewal in ruminal epithelium, clarifying the detrimental effect of undernutrition on ruminal homeostasis in a pregnant sheep model.ResultsSixteen pregnant ewes (115 days of gestation) were randomly and equally assigned to the control (CON) and severe feed restriction (SFR) groups. Ewes on SFR treatment were restricted to a 30% level of ad libitum feed intake while the controls were fed normally. After 15 days, all ewes were slaughtered to collect ruminal digesta for 16S rRNA gene and metagenomic sequencing and ruminal epithelium for transcriptome sequencing. Results showed that SFR diminished the levels of ruminal volatile fatty acids and microbial proteins and repressed the length, width, and surface area of ruminal papillae. The 16S rRNA gene analysis indicated that SFR altered the relative abundance of ruminal bacterial community, showing decreased bacteria about saccharide degradation (Saccharofermentans and Ruminococcus) and propionate genesis (Succiniclasticum) but increased butyrate producers (Pseudobutyrivibrio and Papillibacter). Metagenome analysis displayed that genes related to amino acid metabolism, acetate genesis, and succinate-pathway propionate production were downregulated upon SFR, while genes involved in butyrate and methane genesis and acrylate-pathway propionate production were upregulated. Transcriptome and real-time PCR analysis of ruminal epithelium showed that downregulated collagen synthesis upon SFR lowered extracellular matrix-receptor interaction, inactivated JAK3-STAT2 signaling pathway, and inhibited DNA replication and cell cycle.ConclusionsGenerally, undernutrition altered rumen bacterial community and function profile to decrease ruminal energy retention, promoted epithelial glucose and fatty acid catabolism to elevate energy supply, and inhibited the proliferation of ruminal epithelial cells. These findings provide the first insight into the systemic microbiota-host interactions that are involved in disrupting the ruminal homeostasis under a malnutrition pattern.6T8uqJgnNvqkGDyfqTJNsJVideo

Identification of Potential Disease Biomarkers in the Ovaries of Dolang Sheep from Xinjiang using Transcriptomics and Bioinformatics Approaches

Background: The Dolang sheep is a well-known indigenous breed from the Xinjiang region of China. The most important characteristics of these sheep are a year-round estrus and a strong resistance to a variety of diseases. Although the molecular regulatory mechanisms governing the year-round estrus and adaptability in health and disease are well studied in various animals, the related information is limited for sheep, particularly, the Dolang variety. Methods: To identify differentially expressed genes (DEGs) that might be responsible for the year-round estrus and that are expressed under different physiological conditions in Dolang sheep, samples from ovaries collected at different reproductive periods were analyzed using high-throughput sequencing and subsequent transcriptomics and bioinformatics analyses. Result: We identified 28,717 expressed genes by RNA-Seq analysis and from a list of 987 candidate genes, we identified 308 that were differentially expressed in the ovaries of non-pregnant Dolang sheep in estrus and anestrus phases and those in the gestation phase. The genes DQA, DQB and LOC101106374 were upregulated during the gestation period. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that these three genes may improve immunity and prevent the occurrence of abortion, brucellosis, toxoplasmosis and globidiosis and can be used to monitor sheep health during pregnancy. Thus, DQA, DQB and LOC101106374 may serve as potential biomarkers for monitoring disease progression as well as abortion risk during pregnancy in sheep.

Effective Nanoparticle-Based Nasal Vaccine Against Latent and Congenital Toxoplasmosis in Sheep.

Toxoplasma gondii is a parasitic protozoan of worldwide distribution, able to infect all warm-blooded animals, but particularly sheep. Primary infection in pregnant sheep leads to millions of abortions and significant economic losses for the livestock industry. Moreover, infected animals constitute the main parasitic reservoir for humans. Therefore, the development of a One-health vaccine seems the best prevention strategy. Following earlier work, a vaccine constituted of total extract of Toxoplasma gondii proteins (TE) associated with maltodextrin nanoparticles (DGNP) was developed in rodents. In this study we evaluated the ability of this vaccine candidate to protect against latent and congenital toxoplasmosis in sheep. After two immunizations by either intranasal or intradermal route, DGNP/TE vaccine generated specific Th1-cellular immune response, mediated by APC-secretion of IFN-γ and IL-12. Secretion of IL-10 appeared to regulate this Th1 response for intradermally vaccinated sheep but was absent in intranasally-vaccinated animals. Finally, protection against latent toxoplasmosis and transplacental transmission were explored. Intranasal vaccination led to a marked decrease of brain cysts compared with the non-vaccinated group. This DGNP/TE vaccine administered intranasally conferred a high level of protection against latent toxoplasmosis and its transplacental transmission in sheep, highlighting the potential for development of such a vaccine for studies in other species.

Changes in expression of prostaglandin synthase in ovine liver during early pregnancy

Liver can function as part of the innate and adaptive immune systems. We hypothesize that prostaglandins participate in the regulation of hepatic immune function during early pregnancy in sheep. The objective of this study was to elucidate expression of prostaglandin synthase in ovine liver during early pregnancy. Ovine livers were sampled on day 16 of the estrous cycle, and days 13, 16, and 25 of pregnancy, and the expression of prostaglandin synthases, including prostaglandin-endoperoxide synthase 1 (PTGS1), PTGS2, prostaglandin E synthase (PTGES), and aldo-keto reductase family 1, member B1, a prostaglandin F synthase (PGFS), were detected by quantitative real-time polymerase chain reaction, Western blot, and immunohistochemistry analysis. There were increases in the expression of mRNA and the proteins of PTGS2, PTGES, and PGFS in the livers during early pregnancy, but PTGS1 was decreased in the pregnant ewes. The PGFS protein was limited to the hepatocytes and the endothelial cells of the proper hepatic arteries and hepatic portal veins. In summary, the upregulation of PTGS2, PTGES, and PGFS and downregulation of PTGS1 may be involved in the maternal hepatic immune adjustment during early pregnancy in sheep.

Fetal programming in sheep: effects on pre- and postnatal development in lambs.

This systematic review and meta-analysis aim to summarize the effects of maternal undernutrition or overnutrition during pregnancy on fetal weight and morphometric measurements during pregnancy, at birth, and postnatal period in sheep. After completing the search, selection, and data extraction steps, the measure of effect was generated by the individual comparison of each indicator with the average of the control and treated group (undernutrition or overnutrition) using the DerSimonian and Laird method for random effects. Subgroup analyses were also performed for lambing order, litter size, sex, as well as level, timing, and duration of the intervention. Fetal weight during the first third of pregnancy was not affected by maternal undernutrition or overnutrition. On the other hand, undernutrition in the second and last third of gestation reduces the weight of the lamb both during pregnancy, at birth, and during the postnatal period, requiring at least 120 postnatal days to achieve the same weight as its contemporaries in the control treatment. However, this reduction in weight is not accompanied by reductions in morphometric measurements, demonstrating that the animals were lighter, but of equal size. In overnutrition, there is an increase in fetal weight in the second third of gestation. However, in the last third of the gestational period, there are no differences in fetal weight for the multiparous subgroup, but it was reduced in primiparous ewes. There are no effects of overnutrition on birth weight; however, this result is highly heterogeneous. Thus, maternal nutrition of ewe during pregnancy has effects on fetal and postnatal weight, but not on size. Furthermore, the effects of undernutrition are more homogeneous while overnutrition showed heterogeneous responses.

Altered Cardiovascular Defense to Hypotensive Stress in the Chronically Hypoxic Fetus.

The hypoxic fetus is at greater risk of cardiovascular demise during a challenge, but the reasons behind this are unknown. Clinically, progress has been hampered by the inability to study the human fetus non-invasively for long period of gestation. Using experimental animals, there has also been an inability to induce gestational hypoxia while recording fetal cardiovascular function as the hypoxic pregnancy is occurring. We use novel technology in sheep pregnancy that combines induction of controlled chronic hypoxia with simultaneous, wireless recording of blood pressure and blood flow signals from the fetus. Here, we investigated the cardiovascular defense of the hypoxic fetus to superimposed acute hypotension. Pregnant ewes carrying singleton fetuses surgically prepared with catheters and flow probes were randomly exposed to normoxia or chronic hypoxia from 121±1 days of gestation (term ≈145 days). After 10 days of exposure, fetuses were subjected to acute hypotension via fetal nitroprusside intravenous infusion. Underlying in vivo mechanisms were explored by (1) analyzing fetal cardiac and peripheral vasomotor baroreflex function; (2) measuring the fetal plasma catecholamines; and (3) establishing fetal femoral vasoconstrictor responses to the α1-adrenergic agonist phenylephrine. Relative to controls, chronically hypoxic fetal sheep had reversed cardiac and impaired vasomotor baroreflex function, despite similar noradrenaline and greater adrenaline increments in plasma during hypotension. Chronic hypoxia markedly diminished the fetal vasopressor responses to phenylephrine. Therefore, we show that the chronically hypoxic fetus displays markedly different cardiovascular responses to acute hypotension, providing in vivo evidence of mechanisms linking its greater susceptibility to superimposed stress.

Maternal immune response in the placenta of sheep during recrudescence of natural congenital infection of Neospora caninum

In order to gain further insight into the pathogenesis and transmission of ovine neosporosis, the serological response of 13 naturally infected pregnant sheep was monitored. All sheep were euthanized upon the detection of a sharp increase in the level of specific antibodies against N. caninum in order to study the maternal immune response after the recrudescence of a chronic infection. Ten sheep were euthanized between 84 and 118 days of gestation, whereas the three remaining and three control not infected, pregnant sheep were euthanized at 135 days of gestation after no sharp increase in antibodies was detected. Vertical transmission was confirmed in 11 sheep by detection of N. caninum-DNA in at least one fetus, confirming recrudescence. Not all of fetuses showed pathologic microscopic lesions, however, multifocal non-purulent encephalitis was the main finding. Furthermore, nine out of the 11 vertical transmission positive sheep had lesions in placentomes (mainly multifocal necrotic foci), and the parasite was detected in eight out of 11 placentas by PCR and/or immunohistochemestry. The placentomes from sheep that suffered recrudescence showed an increased number of T lymphocytes CD3+ (CD4/CD8 < 1) and macrophages (MHC-II+), assessed by immunohistochemestry, together with an up-regulation of IFN-γ, IL-10, IL-4, TNFα, IL-2 and IL-18. IL-17 was only upregulated in the three infected sheep that did not have a sharp increase in antibody levels. In the sheep that showed fetal death at the time of euthanasia (n = 3) the placental microscopic lesions were more severe, the inflammatory infiltrate was higher, and the upregulation of cytokines was greater than in those sheep carrying viable fetuses. This study suggests that, similarly to bovine neosporosis, the time of gestation when recrudescence occurs determines the viability of the fetuses and, thus, seems to be related to the severity of lesions and immune response in the placenta. These results suggest that there might be a correlation, either as cause or as a consequence, between protection against vertical transmission of the parasite and a milder maternal serological response together with a high level of transcription of IL-17 in the placenta.

Linking population performance to nutritional condition in an alpine ungulate

Bighorn sheep (Ovis canadensis) can live in extremely harsh environments and subsist on submaintenance diets for much of the year. Under these conditions, energy stored as body fat serves as an essential reserve for supplementing dietary intake to meet metabolic demands of survival and reproduction. We developed equations to predict ingesta-free body fat in bighorn sheep using ultrasonography and condition scores in vivo and carcass measurements postmortem. We then used in vivo equations to investigate the relationships between body fat, pregnancy, overwinter survival, and population growth in free-ranging bighorn sheep in California and Nevada. Among 11 subpopulations that included alpine winter residents and migrants, mean ingesta-free body fat of lactating adult females during autumn ranged between 8.8% and 15.0%; mean body fat for nonlactating females ranged from 16.4% to 20.9%. In adult females, ingesta-free body fat > 7.7% during January (early in the second trimester) corresponded with a > 90% probability of pregnancy and ingesta-free body fat > 13.5% during autumn yielded a probability of overwinter survival > 90%. Mean ingesta-free body fat of lactating females in autumn was positively associated with finite rate of population increase (λ) over the subsequent year in bighorn sheep subpopulations that wintered in alpine landscapes. Bighorn sheep with ingesta-free body fat of 26% in autumn and living in alpine environments possess energy reserves sufficient to meet resting metabolism for 83 days on fat reserves alone. We demonstrated that nutritional condition can be a pervasive mechanism underlying demography in bighorn sheep and characterizes the nutritional value of their occupied ranges. Mountain sheep are capital survivors in addition to being capital breeders, and because they inhabit landscapes with extreme seasonal forage scarcity, they also can be fat reserve obligates. Quantifying nutritional condition is essential for understanding the quality of habitats, how it underpins demography, and the proximity of a population to a nutritional threshold.

Identification and characterization of miRNAs during early pregnancy in domestic sheep.

SummaryMicroRNA resources in sheep are limited compared with those in other domesticated mammalian species. By sequencing small RNAs of sheep corpus luteum and endometrium, we have generated the largest amount of miRNA‐seq data and compiled the most comprehensive list thus far of miRNAs (n = 599) in sheep. Additionally, we observed a highly conserved maternally imprinted cluster of miRNAs on chromosome 18 homologous to that found on chromosome 14 in human and several other eutherian mammals.

Relationships among the corpus luteum, follicles and conceptus in sheep.

This study aimed to investigate the intra- and interovarian relationships among the corpus luteum (CL), the largest follicle (LF) and follicular population in non-pregnant and between the conceptus and ovarian structures in pregnant ewes. In experiment 1, the follicular and luteal structures were examined in 538 reproductive systems of non-pregnant Awassi ewes. The follicular population was categorised into small (SF), medium (MF) and large (LF) groups. Inter-relationships between CL and follicular population and between LF and subordinate follicles were determined. In experiment 2, the location and number of conceptuses were identified and correlated with the ovarian structures in 58 reproductive systems of pregnant ewes. Effects of pregnancy status, stage of pregnancy, pregnancy side and conceptual number on follicular population were determined. The results showed that the right ovary was more active than the left ovary. CL had intraovarian positive effect on the number of medium and large follicles. LF had no local suppressive effect on the subordinate follicles. Side and stage of pregnancy and the conceptual number did not affect the follicular population. Accordingly, it can be concluded that the LF has no local suppressive effect on the subordinate follicles. The CL has intraovarian positive effect on the follicular population. Follicular population does not show remarkable changes during the first term of pregnancy. The present study probably provides information which may help in the understanding of the ovarian dynamics during pregnancy in sheep.

Safety and immunogenicity of the Rift Valley fever arMP-12 ΔNSm21/384 candidate vaccine in pregnant ewes

Rift Valley fever (RVF) poses a threat to human and animal health as well as economic losses due to abortion, new-born teratogenic effect and mortality. Safe and effective vaccines are critically needed to prevent the disease in humans and livestock. The objective of this study was to assess safety and immunogenicity of the Rift Valley fever virus (RVFV) arMP-12DNSm21/384 attenuated vaccine in 32 pregnant ewes at different stages of pregnancy including 17 ewes vaccinated during the early stage (G1) of pregnancy (<35 days) and 15 ewes vaccinated during the last two stages (G2) of pregnancy (>35 days). Ewes were monitored for clinical observations, rectal temperature and abortions and lambs were monitored for general health and rectal temperature. Vaccinated ewes and lambs were periodically sampled for their neutralizing antibody response to RVFV vaccination. All ewes were positive for antibody two weeks post-vaccination and 79% of ewes were positive at delivery. None of the 32 ewes aborted during pregnancy and all ewes vaccinated during the G2 stages of pregnancy gave birth to healthy lambs. However, among the 17 ewes vaccinated during the G1 stage of pregnancy, 2 ewes gave birth to 2 lambs with fore limb malformations that died at 1-day of age. One ewe gave birth to 2 punny twins that died at 2 days of age. Another ewe, gave birth to one lamb with a deformed tail that died at 20 days of age. At post-mortem, tissues of dead lambs (spleen, lung, brain and long bone) were negative for RVFV by PCR assay. While the findings did not link the malformed lambs directly to infection by the vaccine virus, these results indicated that pregnant sheep should not be vaccinated with the RVFV arMP-12DNSm21/384 vaccine during the first month of gestation.

Developmental programming: Prenatal testosterone excess disrupts pancreatic islet developmental trajectory in female sheep

Prenatal testosterone (T)- treated female sheep manifest juvenile insulin resistance, post-pubertal increase in insulin sensitivity and return to insulin resistance during adulthood. Since compensatory hyperinsulinemia is associated with insulin resistance, altered pancreatic islet ontogeny may contribute towards metabolic defects. To test this, pregnant sheep were treated with or without T propionate from days 30–90 of gestation and pancreas collected from female fetuses at gestational day 90 and female offspring at 21 months-of-age. Uterine (maternal) and umbilical (fetal) arterial blood insulin/glucose ratios were determined at gestational day 90. The morphological and functional changes in pancreatic islet were assessed through detection of 1) islet hormones (insulin, glucagon) and apoptotic beta cells at fetal day 90 and 2) islet hormones (insulin, glucagon and somatostatin), and pancreatic lipid and collagen accumulation in adults. At gestational day 90, T-treatment led to maternal but not fetal hyperinsulinemia, decrease in pancreatic/fetal weight ratio and alpha cells, and a trend for increase in beta cell apoptosis in fetal pancreas. Adult prenatal T-treated female sheep manifested 1) significant increase in beta cell size and a tendency for increase in insulin and somatostatin stained area and proportion of beta cells in the islet; and 2) significant increase in pancreatic islet collagen and a tendency towards increased lipid accumulation. Gestational T-treatment induced changes in pancreatic islet endocrine cells during both fetal and adult ages track the trajectory of hyperinsulinemic status with the increase in adult pancreatic collagen accumulation indicative of impending beta cell failure with chronic insulin resistance.

Maternal and fetal cardiovascular and metabolic effects of intra-operative uterine handling under general anesthesia during pregnancy in sheep

A cohort study of 6,500,000 human pregnancies showed an increased risk of adverse fetal outcomes following abdominal but not non-abdominal surgery under general anesthesia. This may be the consequence of uterine handling during abdominal surgery. However, there are no data on any effects on the cardiometabolic physiology of the fetus or mother in response to uterine manipulation in otherwise healthy pregnancy. Consequently, 9 sheep in late gestation were anesthetized with isofluorane and maternal and fetal catheters and flow probes were implanted to determine cardiovascular and metabolic changes during uterine handling. Uterine handling led to an acute increase in uterine artery vascular resistance, fetal peripheral vasoconstriction, a reduction in oxygen delivery to the femoral circulation, worsening fetal acidosis. There was no evidence of systemic fetal hypoxia, or changes in fetal heart rate, carotid blood flow or carotid oxygen delivery. Therefore, the data support that uterine handling during abdominal surgery under general anesthesia can impact adversely on fetal cardiometabolic health. This may provide a potential explanation linking adverse fetal outcomes in abdominal compared with non-abdominal surgery during pregnancy. The data have important implications for human fetal surgery where the uterus is handled, as operative procedures during late gestation under general maternal anesthesia become more prevalent.

Comparison of analgesic efficacy and fetal effects between transdermal administration of fentanyl and intramuscular administration of buprenorphine in pregnant sheep.

To compare analgesic efficacy and fetal effects between transdermal administration of fentanyl and IM administration of buprenorphine in pregnant sheep. 12 healthy pregnant ewes. Before study initiation, each ewe was confirmed pregnant with a single fetus between 113 and 117 days of gestation. Ewes were randomly assigned to receive buprenorphine (0.01 mg/kg, IM, q 8 h for 48 hours beginning 1 hour before anesthesia induction; n = 6) or fentanyl (a combination of transdermal fentanyl patches sufficient to deliver a dose of 2 μg of fentanyl/kg/h applied between the dorsal borders of the scapulae 24 hours before anesthesia induction; 6). Ewes were anesthetized and underwent a surgical procedure to instrument the fetus with an arterial catheter and place a catheter in utero for collection of amniotic fluid samples. Physiologic variables and behavioral changes indicative of pain were assessed, and amniotic fluid and blood samples from ewes and fetuses were collected for determination of drug concentrations at predetermined times. Both protocols provided acceptable postoperative analgesia with no adverse effects observed in the ewes or fetuses. Compared with the buprenorphine protocol, the fentanyl protocol induced more profound analgesia, decreased the requirement for isoflurane during surgery, and was associated with a shorter anesthesia recovery time. Fetal indices did not differ significantly between the 2 analgesic protocols. Results indicated that both protocols provided acceptable analgesia. However, the fentanyl protocol was superior in regard to the extent of analgesia induced, inhalant-sparing effects, and anesthesia recovery time.

The effect of glycerol or rumen-protected choline chloride on rumen fermentation and blood metabolome in pregnant ewes suffering from negative energy balance

The objective of this study was to investigate the counteracting effects of glycerol or rumen-protected choline chloride supplementation on rumen fermentation and the profile changes in blood metabolites in pregnant ewes suffering from negative energy balance. Eighteen pregnant Hu sheep with a gestation period of 100 days were used in the present study. Feed restriction was started from 100 days of gestation and lasted for 9 days. During the period of feed restriction, these sheep were randomly assigned to three groups: the control group (CON, n = 6), which received no supplementation, the glycerol group (GLY, n = 6), which received 40 mL of glycerol per day, and the rumen-protected choline chloride group (RPC, n = 6), which received 10 g of rumen-protected choline chloride per day lasted 9 days. All supplements were mixed with feed. The results showed that, compared to CON, glycerol supplementation decreased the proportion of acetate (P < 0.01) and increased the proportion of propionate (P < 0.01). The proportions of butyrate (P = 0.04) and valerate (P = 0.04) were higher in GLY than in RPC, but there was no significant difference in their proportions between GLY and CON. Blood β-hydroxybutyric acid concentration continuously increased in CON during the treatment period, while it remained stable in the ewes receiving glycerol or rumen-protected choline chloride. Glucose levels in the blood of ewes receiving glycerol or rumen-protected choline chloride were higher than those in CON (P = 0.01). Compared to CON, the levels of non-esterified fatty acids (NEFA) (P = 0.02) and very-low-density lipoproteins (VLDL) (P = 0.04) in the blood were increased in ewes that received rumen-protected choline chloride. Correlation analysis of the DEMs and rumen fermentation parameters showed a positive correlation between citric acid and phosphohydroxypyruvic acid (r = 0.61, P < 0.01), as well as between bilirubin and BHBA (r = 0.59, P < 0.01). d-Glucose have a positive correlation with propionate (r = 0.48, P = 0.02), while have a negative correlation with BHBA (r = −0.77, P < 0.01), 2-hydroxylauroylcarnitine (r = -0.53, P < 0.01), 2-octenoylcarnitine (r = −0.61, P < 0.01), and 3-hydroxydodecanoic acid (r = −0.60, P = 0.04). It is concluded that the supplementation of glycerol or rumen-protected choline chloride counteracted changes in metabolite concentrations in ewes that had been induced by feed restriction.

Perfil metabólico de ovelhas gestantes recebendo fontes lipídicas com diferentes sítios de degradação

Objetivou-se avaliar o efeito da inclusão de fontes lipídicas com diferentes sítios de degradação sobre o perfil metabólico de ovelhas gestantes. O experimento foi realizado na Universidade Federal de Uberlândia, na Fazenda Experimental Capim Branco, durante os meses de agosto a novembro de 2015, tendo 90 dias de duração. Foram utilizadas 24 ovelhas gestantes com peso corporal médio de 50,8±0,7 kg e idade aproximada de 12±1 meses. Os animais foram divididos em três tratamentos: Controle, Nutrigordura® e Caroço de Algodão. O volumoso utilizado foi a silagem de milho, e a relação volumoso:concentrado foi de 60:40 (na matéria seca). As coletas de sangue para determinação dos metabólitos proteicos, energéticos e hepáticos foram feitas a cada 15 dias e as análises da concentração de betahidroxibutirato (BHB) foram feitas aos 120, 135 e 140 dias de gestação. O delineamento utilizado foi inteiramente casualizado com medidas repetidas ao tempo. Houve diferença estatística no perfil metabólico energético das ovelhas entre os tratamentos para lipoproteína de alta densidade (HDL) e betahidroxibutirato (BHB) no pré-parto. Para o colesterol e lipoproteína de baixa densidade (LDL) houve interação entre tratamento e período. Não houve diferenças significativas para os metabólitos hepáticos em função dos tratamentos, apenas para o período. Em relação ao metabolismo proteico, houve interação para a variável ácido úrico. A suplementação lipídica com diferentes perfis de degradação foi eficiente em manter o metabolismo energético, hepático e proteico dos animais alterando a concentração de alguns metabólitos no sangue durante os terços médio e final da gestação.

Changes Introduced in the Open Reading Frame of Bovine Viral Diarrhea Virus During Serial Infection of Pregnant Swine

Bovine viral diarrhea virus (BVDV) is one of the most economically important viruses of cattle, but this pathogen is also able to infect pigs, camelids, and a wide range of domestic and wild ruminants. BVDV isolates circulating in animal populations are genetically and antigenically highly diverse. Acute BVDV infections in cattle cause the introduction of many substitutions in the viral genome. Serial infection of pregnant sheep with a BVDV-1b isolate of bovine origin was also associated with great numbers of substitutions. To our knowledge, genomic changes arising during BVDV infections in swine have not been investigated. The purpose of this study was to investigate the changes occurring in the open reading frame (ORF) of BVDV during serial infection of pregnant swine with a BVDV isolate of bovine origin. The BVDV-1b isolate AU526 was serially passaged in six pregnant gilts, two of which gave birth to live piglets congenitally infected with BVDV. The complete ORF sequences of 14 BVDV isolates obtained from pregnant gilts and their piglets were determined. Their analysis revealed that serial transmission of AU526 in pregnant swine resulted in many genomic changes. All isolates of porcine origin shared 32 nucleotide and 12 amino acid differences with the virus inoculum AU526. These changes were detected after a single passage in pregnant swine and were conserved during the subsequent five passages. Amino acid changes occurred primarily in genomic regions encoding the BVDV structural proteins E2 and Erns. These results suggest that BVDV infections in pregnant swine may contribute significantly to the genetic variability of BVDV and lead to the appearance of adaptive changes.

Thermographic imaging for use in artificial intelligence and vision algorithms

The constant technological innovation in devices for the acquisition of digital images such as: energy-efficient and high-pixel sensors, memories with greater storage capacity and processors capable of sampling digital signals more quickly, have made it possible to digitize with greater reliability real life scenes in an instant of time, making it possible to analyze and interpret different physical phenomena [1][2][3] such as fractures in materials, evasion of obstacles, weather conditions, injury detection, among others, giving rise to a new line of research called Artificial Vision (AV) focused on generating algorithms to improve image quality, segment characteristics of interest and eventually recognize patterns, in order to make more efficient image processing for the solution of problems in robotics, automation, security, medicine, veterinary, and others. The research aims to develop a database of thermographic images of pregnant and non-pregnant sheep, providing a tool for specialists in the area of computer intelligence and artificial vision.

Serum insulin and glucose concentrations in sheep during late pregnancy in relation to the number and sex of the fetuses

The objective of this study was to investigate whether the serum concentration of glucose and insulin in the blood of pregnant sheep depends on the number and the sex of the fetuses. The presented research was carried out on Pomeranian (n = 42) and Suffolk sheep (n = 42) towards the end of the pregnancy. The following groups were established amongst the Pomeranian sheep: single pregnancies with a female fetuses (n = 19) and male fetuses (n = 10), twin pregnancies with female fetuses (n = 8), male fetuses (n = 8) and fetuses of different sex (n = 7). Similarly, in the Suffolk sheep, the following groups were formed: single pregnancies with female fetuses (n = 9) and male fetuses (n = 12), twin pregnancies with male fetuses (n = 12) and fetuses of different sex (n = 9). In Suffolk sheep, serum insulin concentration was significantly higher than in Pomeranian sheep (p < 0.05). The average insulin concentration in Pomeranian sheep with a single pregnancy was higher than in sheep of the same breed with a twin pregnancy (p < 0.05). In the Pomeranian breed, the highest insulin concentration was recorded in sheep with male fetuses (p < 0.01). Similarly, in Suffolk sheep, the insulin concentration was higher in sheep with male fetuses than female ones (p < 0.05). On the other hand, the concentration of glucose in Pomeranian sheep, with both single and twin pregnancies and with female fetuses, was higher than in sheep with male fetuses or different sex fetuses (p < 0.05 and p < 0.01, respectively). In the Suffolk breed, the glucose concentration was also higher in sheep with female fetuses (p < 0.05). In Suffolk sheep a positive correlation was found between the birth weight of lambs and their mother's glucose concentration (r = 0.56; p < 0.01). The differences in the concentration of insulin and glucose in the blood of pregnant sheep demonstrated in this study suggest that sex and the number of fetuses may be further factors affecting the energy metabolism in the late stages of pregnancy. Based in the presented findings these differences may depend on the breed and may be related to the birth weight of lambs.

Maternal nutrition and antioxidant supplementation: Effects on mother–young behaviors in a Patagonian sheep extensive grazing system

Undernourishment is a frequent condition in sheep pregnancies under extensive systems, since most of the pregnancies occur when the prairie has the lowest forage allowance. Underfed sheep pregnancies are associated with maternal-fetal oxidative stress, low birth weight and deteriorated ewe–lamb bond, which negatively affects the probability of postnatal survival. The aims of the present study were to determine if daily supplementation of underfed single-bearing grazing ewes during pregnancy (starting at Day 44) with concentrate food and/or vitamins C and E: 1) improves maternal body weight and body condition, and increases udder size and skin temperature of the udder at parturition, 2) increases lamb’ body weight and both surface and rectal temperatures, and 3) modifies ewe–lamb behavior at lambing. A complementary goal was to determine if those effects differ between male and female lambs. The experiment was carried out under field conditions representative of Chilean Patagonia. Maternal supplementation with concentrate resulted in enhanced ewes’ body weight (59.4 ± 0.9 kg vs 55.1 ± 0.9 kg; P = 0.0007) and body condition during gestation (2.21 ± 0.05 vs 1.69 ± 0.05; P < 0.0001), enhanced udder volume (P < 0.0001), increased newborn lambs’ body weight (5.0 ± 0.1 kg vs 4.7 ± 0.1 kg P = 0.03), and strengthened maternal bonding with its lamb during a handling test, without effects on lamb’ rectal temperature. Supplementation with vitamins C and E, did not produce a clear effect on the studied variables, and did not improve the response to supplementation with concentrate. In conclusion, improvement of nutritional plane in underfed single-bearing ewes it is not only relevant to improve the pregnancy outcomes, but also to ensure a better ewe–lamb bonding, which may improve lamb’s survival and performance during lactation.