PSII-B-28 Investigation of the presence of bacterial microbiota in 12-week-old bovine fetuses

A recent study reported the existence of a diverse microbiota in 5-to-7-month-old calf fetuses, suggesting that colonization of the bovine gut with so-called “pioneer” microbiota may begin during mid-gestation. In the present study, we investigated the microbiota in bovine fetuses at early gestation. Amniotic and allantoic fluids, and intestinal and placental (cotyledon) tissue samples harvested from fetuses (n = 33) on day 83 of gestation were processed for the assessment of fetal microbiota using 16S rRNA gene sequencing. The sequencing results revealed that a diverse and complex microbial community was present in allantoic and amniotic fluids, and fetal intestine and placenta on day 83 of gestation in beef cattle. Microbial community structure was significantly different between allantoic and amniotic fluid, and intestinal and placental microbiota (0.047 ≥ R2 ≥ 0.019, P ≤ 0.031). Allantoic fluid had a greater (P < 0.05) microbial richness (number of OTUs) (122 ± 10) compared to amniotic fluid (84 ± 6), intestine (63 ± 7) and placenta (66 ± 6). Microbial diversity (Shannon index) was similar for the intestinal and placental samples, and both were less diverse compared to the fetal fluid microbiota (P < 0.05). At the phylum level, 39 different archaeal and bacterial phyla were detected across all fetal samples, with Proteobacteria (55%), Firmicutes (16.2%), Actinobacteria (13.6%) and Bacteroidetes (5%) predominating. Among the 20 most relatively abundant bacterial genera, Acidovorax, Acinetobacter, Brucella, Corynebacterium, Enterococcus, Exiguobacterium and Stenotrophomonas differed by fetal sample type (P < 0.05). A total of 55 taxa were shared among the four different microbial communities. qPCR of bacteria in the intestine and placenta samples as well as scanning electron microscopy imaging of fetal fluids provided additional evidence for the presence of a microbiota in these samples. Overall, the results of this study indicate that colonization with pioneer microbiota may occur during early gestation in bovine fetuses.

PSIII-26 The effects of maternal melatonin supplementation during pregnancy on longissimus dorsi muscle morphometrics in bovine fetuses at 240 days of gestation

Melatonin is a multifunctional hormone that positively impacts postnatal growth and weaning weight in cattle offspring when supplemented to adequately fed dams during gestation. However, it is unclear whether supplemental melatonin is effective as a countermeasure to decrease effects of a nutritionally compromised pregnancy on fetal tissues. The current study evaluated the efficacy of maternal melatonin supplementation during gestation, as a therapeutic in nutrient restricted beef heifers using fetal LM morphometrics for evaluation of carcass tissue growth. On gestational d 160, 25 Brangus heifers were assigned to one of four groups in a 2 x 2 factorial: nutrient restricted (RES-CON: 60% NRC; n = 6), adequate fed (ADQ-CON; 100% NRC; n = 6), nutrient restricted supplemented with 20 mg melatonin (RES-MEL; n = 7), or adequate fed supplemented with 20 mg melatonin (ADQ-MEL; n = 6). Treatments were top-dressed with 2 mL of melatonin dissolved in 100% ethanol (10 mg/mL) or 2 mL of ethanol (control). At gestational d 240, Caesarean sections and fetal necropsies were performed, both fetal LM were dissected to determine weight, length, and midline circumference. Data were analyzed using the MIXED procedure of SAS. There was a diet by treatment interaction wherein the mass of the left and right LM was increased (P0.035) by an average of 42.46 g in RES-MEL offspring compared to RES-CON fetuses, but no differences (P0.0812) among ADQ groups. Restricted nutrition decreased left LM circumference (10.21 vs. 10.95 cm; P = 0.0445). Treatment had no effect on LM length (P0.1139). In the present study, maternal melatonin supplementation during the Summer promoted muscle growth and mitigated the adverse effects of a nutritionally compromised pregnancy on LM morphometrics. These data are indicative of the potential for melatonin as a gestational therapeutic for prenatal muscle growth and improved efficiency of meat animal production.

Characterization of the microbiota associated with 12-week-old bovine fetuses exposed to divergent in utero nutrition

A recent study reported the existence of a diverse microbiota in 5-to-7-month-old calf fetuses, suggesting that colonization of the bovine gut with so-called 'pioneer' microbiota may begin during mid-gestation. In the present study, we investigated 1) the presence of microbiota in bovine fetuses at early gestation (12 weeks), and 2) whether the fetal microbiota is influenced by the maternal rate of gain or dietary supplementation with vitamins and minerals (VTM) during early gestation. Amniotic and allantoic fluids, and intestinal and placental (cotyledon) tissue samples obtained from fetuses (n = 33) on day 83 of gestation were processed for the assessment of fetal microbiota using 16S rRNA gene sequencing. The sequencing results revealed that a diverse and complex microbial community was present in each of these fetal compartments evaluated. Allantoic and amniotic fluids, and fetal intestinal and placenta microbiota each had distinctly different (0.047 ≥ R2 ≥ 0.019, P ≤ 0.031) microbial community structures. Allantoic fluid had a greater (P < 0.05) microbial richness (number of OTUs) (Mean 122) compared to amniotic fluid (84), intestine (63) and placenta (66). Microbial diversity (Shannon index) was similar for the intestinal and placental samples, and both were less diverse compared with fetal fluid microbiota (P < 0.05). Thirty-nine different archaeal and bacterial phyla were detected across all fetal samples, with Proteobacteria (55%), Firmicutes (16.2%), Acidobacteriota (13.6%) and Bacteroidota (5%) predominating. Among the 20 most relatively abundant bacterial genera, Acidovorax, Acinetobacter, Brucella, Corynebacterium, Enterococcus, Exiguobacterium and Stenotrophomonas differed by fetal sample type (P < 0.05). A total of 55 taxa were shared among the four different microbial communities. qPCR of bacteria in the intestine and placenta samples as well as scanning electron microscopy imaging of fetal fluids provided additional evidence for the presence of a microbiota in these samples. Minor effects of maternal rate of gain and VTM supplementation, and their interactions on microbial richness and composition were detected. Overall, the results of this study indicate that colonization with pioneer microbiota may occur during early gestation in bovine fetuses, and that that the maternal nutritional regime during gestation may influence the early fetal microbiota.

Role of Infection and Immunity in Bovine Perinatal Mortality: Part 2. Fetomaternal Response to Infection and Novel Diagnostic Perspectives

Bovine perinatal mortality due to infection may result either from the direct effects of intrauterine infection and/or the fetal response to such infection, leading to the fetal inflammatory response syndrome (FIRS). Both intrauterine infection and FIRS, which causes multi-organ damage and involution of immune organs, compromise fetal survivability, sometimes fatally. Organ injury associated with FIRS may, in addition to causing fetal mortality, irreversibly compromise extrauterine adaptation of the neonate, a recognized problem in human fetuses. Diagnosis of intrauterine infection and of FIRS requires related, but independent analytical approaches. In addition to detection of pathogens, the immune and inflammatory responses of the bovine fetus may be utilized to diagnose intrauterine infection. This can be done by detection of specific changes in internal organs and the measurement of antibodies and/or elements of the acute phase reaction. Currently our ability to diagnose FIRS in bovine fetuses and neonates is limited to research studies. This review focuses on both the fetomaternal response to infection and diagnostic methods which rely on the response of the fetus to infection and inflammatory changes, as well other methods which may improve diagnosis of intrauterine infection in cases of bovine perinatal mortality.

Intra-abdominal resection of the umbilical vein and urachus of bovine fetuses using laparoscopy and celiotomy: surgical time and feasibility (cadaveric study)

Surgical intervention for umbilical diseases in calves, when indicated, is a complementary and indispensable therapeutic resource for the treatment of umbilical conditions and is commonly performed using celiotomy. However, laparoscopy has demonstrated feasibility in many diagnostic and therapeutic procedures. The aim of this study was to assess the feasibility of the techniques and the surgical time of laparoscopy and celiotomy used in intra-abdominal resection of the umbilical vein and urachus of bovine fetuses (cadavers). Resection of the umbilical vein and urachus using laparoscopy and celiotomy was performed in 26 anatomical specimens (bovine fetuses obtained from an official slaughterhouse). Resection of umbilical structures was feasible with both techniques, but shorter surgical time and minimal tissue damage were achieved using laparoscopy. Laparoscopy requires specialized training and appropriate instruments and is an important tool for diagnostic and therapeutic exploration of the umbilical structures, liver, bladder, and associated/adjacent structures.

THE SALVAGE OF BOVINE FOETUSES IN SLAUGHTERED CATTLE WITHIN OGUN STATE, NIGERIA

Bovine fetuses recovered from abattoirs and slaughter slabs in Ogun State were previously discarded. Recently, a total of 327 skins of fetuses in the third trimester were tanned to produce leather for the manufacture of 439 pairs of shoes which yielded a revenue of N33,124 for the State Government. The skins of foetuses in both the first and second trimesters were used in the manufacture of local drums. Foetal carcases were processed as pet foods by dog and cat owners. Some foetal tissues could be preserved for use in the laboratories for research purposes. Such utilization of foetus has reduced losses which they brought about when there was no need for them.