Effect of prenatal heat stress at mid- and late gestation on the learning of mature guinea-pigs

1973 ◽  
Vol 6 (6) ◽  
pp. 483-494 ◽  
Author(s):  
J. G. Lyle ◽  
K. M. Jonson ◽  
M. J. Edwards ◽  
R. H. Penny
Keyword(s):  
Heat Stress ◽  
Guinea Pigs ◽  
Late Gestation

scholarly journals 216 Thermoregulatory and physiological responses of sows at different reproductive stages exposed to increasing ambient temperature

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 7-7
Author(s):  
Betty R McConn ◽  
Alan W Duttlinger ◽  
Kouassi R Kpodo ◽  
Jacob M Maskal ◽  
Brianna N Gaskill ◽  
...  
Keyword(s):  
Heat Stress ◽  
Ambient Temperature ◽  
Physiological Responses ◽  
Blood Gases ◽  
Respiratory Alkalosis ◽  
Stress Sensitivity ◽  
Late Gestation ◽  
Acid Base Balance ◽  
Study Objective ◽  
Cell Counts

Abstract Pregnant sows, especially during late-gestation, may be susceptible to heat stress due to increased metabolic heat production and body mass. Therefore, the study objective was to determine the thermoregulatory and physiological responses of sows exposed to increasing ambient temperature (TA) at 3 reproductive stages. In 3 repetitions, 27 multiparous sows (parity 3.22±0.89) were individually housed and had jugular catheters placed 5.0±1.0 d prior to the experiment. To differentiate between reproductive stages, sows were categorized as open (not pregnant, n=9), mid-gestation (59.7±9.6 days pregnant, n=9), or late-gestation (99.0±4.8 days pregnant, n=9). During the experiment, sows were exposed to 6 consecutive 1 h periods of increasing TA (period 1, 14.39±2.14°C; period 2, 16.20±1.39°C; period 3, 22.09±1.87°C; period 4, 26.34±1.39°C; period 5, 30.56±0.81°C; period 6, 35.07±0.96°C), with 1 h transition phases in between each period. Respiration rate (RR), heart rate (HR), skin temperature, and vaginal temperature (TV) were measured every 20 min and the mean was calculated for each period. At the end of each period, blood gases, leukocytes, and red blood cell counts were measured. Overall, RR and HR were greater (P≤0.04; 45.6% and 12.9%, respectively) in late-gestation versus mid-gestation sows. Compared to mid-gestation and open sows, TV tended to be greater (P=0.06) during period 4 (0.18°C and 0.29°C, respectively) and period 5 (0.14°C and 0.18°C, respectively) in late-gestation sows. Blood O2 increased (P< 0.01; 18.1%) for all sows with advancing period, regardless of reproductive stage. Late-gestation sows had reduced (P=0.02; 16.1%) blood CO2 compared to mid-gestation sows, regardless of period. In summary, late-gestation sows appear to be more sensitive to increasing TA as indicated by increased RR, HR, TV, and blood O2, and reduced blood CO2 when compared to mid-gestation or open sows. This change in O2 and CO2, due to increasing RR and heat stress sensitivity of late-gestation sows, may suggest an alteration to the acid-base balance, leading to respiratory alkalosis.

Preterm birth affects GABAA receptor subunit mRNA levels during the foetal-to-neonatal transition in guinea pigs

2015 ◽  
Vol 6 (3) ◽  
pp. 250-260 ◽  
Author(s):  
J. C. Shaw ◽  
H. K. Palliser ◽  
D. W. Walker ◽  
J. J. Hirst
Keyword(s):  
Preterm Birth ◽  
Guinea Pigs ◽  
Late Gestation ◽  
Preterm Neonates ◽  
Mrna Levels ◽  
Gamma Aminobutyric Acid ◽  
Subunit Mrna ◽  
Receptor Signalling ◽  
The Brain ◽  
Neonatal Transition

Modulation of gamma-aminobutyric acid A (GABAA) receptor signalling by the neurosteroid allopregnanolone has a major role in late gestation neurodevelopment. The objective of this study was to characterize the mRNA levels of GABAA receptor subunits (α4, α5, α6 and δ) that are key to neurosteroid binding in the brain, following preterm birth. Myelination, measured by the myelin basic protein immunostaining, was used to assess maturity of the preterm brains. Foetal guinea pig brains were obtained at 62 days’ gestational age (GA, preterm) or at term (69 days). Neonates were delivered by caesarean section, at 62 days GA and term, and maintained until tissue collection at 24 h of age. Subunit mRNA levels were quantified by RT-PCR in the hippocampus and cerebellum of foetal and neonatal brains. Levels of the α6 and δ subunits were markedly lower in the cerebellum of preterm guinea pigs compared with term animals. Importantly, there was an increase in mRNA levels of these subunits during the foetal-to-neonatal transition at term, which was not seen following preterm birth. Myelination was lower in preterm neonatal brains, consistent with marked immaturity. Salivary cortisol concentrations, measured by EIA, were also higher for the preterm neonates, suggesting greater stress. We conclude that there is an adaptive increase in the levels of mRNA of the key GABAA receptor subunits involved in neurosteroid action after term birth, which may compensate for declining allopregnanolone levels. The lower levels of these subunits in preterm neonates may heighten the adverse effect of the premature decline in neurosteroid exposure.

Late-gestation heat stress abatement in dairy heifers promotes thermoregulation and improves productivity

2020 ◽  
Author(s):  
B.D. Davidson ◽  
B. Dado-Senn ◽  
N. Rosa Padilla ◽  
T.F. Fabris ◽  
L.T. Casarotto ◽  
...  
Keyword(s):  
Heat Stress ◽  
Late Gestation ◽  
Dairy Heifers

scholarly journals Heat stress affects fecal microbial and metabolic alterations of primiparous sows during late gestation

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jianwen He ◽  
Huiduo Guo ◽  
Weijiang Zheng ◽  
Yongqiang Xue ◽  
Ruqian Zhao ◽  
...  
Keyword(s):  
Heat Stress ◽  
Gut Microbiota ◽  
Relative Abundance ◽  
High Throughput Sequencing ◽  
Tricarboxylic Acid Cycle ◽  
Intestinal Barrier ◽  
Metabolic Changes ◽  
Late Gestation ◽  
Large White ◽  
Β Diversity

Abstract Background Heat stress (HS) jeopardizes intestinal barrier functions and augments intestinal permeability in pigs. However, whether HS-induced maternal microbial and metabolic changes in primiparous sows during late gestation remains elusive. We present here, a study investigating the fecal microbial and metabolic responses in late gestational primiparous sows when exposed to HS. Methods Twelve first-parity Landrace × Large White F1 sows were randomly assigned into two environmental treatments including the thermoneutral (TN) (18–22 °C; n = 6) and HS (28–32 °C; n = 6) conditions. Both treatments were applied from 85 d of gestation to farrowing. The serum and feces samples were collected on d 107 of gestation, for analyses including intestinal integrity biomarkers, high-throughput sequencing metagenomics, short-chain fatty acid (SCFA) profiles and nontargeted metabolomics. Results Our results show that HS group has higher serum Heat shock protein 70 (HSP70), lipopolysaccharide (LPS) and lipopolysaccharide-binding protein (LBP) levels. The gut microbial community can be altered upon HS by using β-diversity and taxon-based analysis. In particular, the relative abundance of genera and operational taxonomic units (OTUs) related to Clostridiales and Halomonas are higher in HS group, the relative abundance of genera and OTUs related to Bacteroidales and Streptococcus, however, are lower in HS group. Results of metabolic analysis reveal that HS lowers the concentrations of propionate, butyrate, total SCFA, succinate, fumarate, malate, lactate, aspartate, ethanolamine, β-alanine and niacin, whereas that of fructose and azelaic acid are higher in HS group. These metabolites mainly affect propanoate metabolism, alanine, aspartate and glutamate metabolism, phenylalanine metabolism, β-alanine metabolism, pantothenate and CoA biosynthesis, tricarboxylic acid cycle (TCA) and nicotinate and nicotinamide metabolism. Additionally, correlation analysis between significant microbes and metabolites indicated that the HS-induced microbiota shift is likely the cause of changes of intestinal metabolism. Conclusions Taken together, we reveal characteristic structural and metabolic changes in maternal gut microbiota as a result of late gestational HS, which could potentially provide the basis for further study on offspring gut microbiota and immune programming.

scholarly journals 140 Effects of heat stress during late gestation on the dam and its calf.

2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 351-351 ◽  
Author(s):  
S Tao ◽  
G Dahl ◽  
J Laporta ◽  
J Bernard
Keyword(s):  
Heat Stress ◽  
Late Gestation

Effects of heat stress on posture transitions and reproductive performance of primiparous sows during late gestation

2021 ◽  
Vol 96 ◽  
pp. 102828
Author(s):  
Longshen Liu ◽  
Meng Tai ◽  
Wen Yao ◽  
Ruqian Zhao ◽  
Mingxia Shen
Keyword(s):  
Heat Stress ◽  
Reproductive Performance ◽  
Late Gestation
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