Peripheral histamine and neonatal growth performance in swine

Dietary sodium sulphate supplementation during mid-to-late gestation improves placental angiogenesis, bile acid metabolism, and serum amino acid concentrations of sows

Sulphate plays a vital role in the growth and development of the foetus. Sodium sulphate (Na2SO4) is utilised as a dietary protein nutrient factor and helps replenish sulphur elements in livestock and poultry. Therefore, this study aimed to investigate the effects of Na2SO4 supplementation in mid to late pregnancy on bile acid metabolism, amino acid metabolism, placental vascular development and antioxidant capacity of sows. At day 1 of gestation (G1), a total of twenty-six primiparous sows were carefully chosen and randomised into two groups: (1) control group, (2) Na2SO4 group (1.40 g/kg). Blood samples and placentas from sows were collected to measure biochemistry parameters, antioxidant indexes, placental vascular density, and indicators related to bile acid metabolism and amino acid concentrations, respectively. We found that dietary supplementation with Na2SO4 had a tendency for a reduction of incidence of stillborn at farrowing. Further observation showed that sows supplemented with Na2SO4 had decreased total bile acid level in cord blood, and increased placental gene expression of sulphotransferase and organic anion transport peptide. Na2SO4 supplementation increased catalase and total superoxide dismutase activity in cord blood, decreased placental malondialdehyde content, and enhanced placental protein expression of Sirtuin 1. Moreover, Na2SO4 consumption resulted in increased vascular density of placental stroma and elevated amino acid levels in sows and cord blood. Furthermore, maternal Na2SO4 consumption reduced serum urea concentrations of sows and umbilical cord blood at G114. In addition, dietary supplementation with Na2SO4 activated the protein expression of the placental mechanistic target of rapamycin complex 1. Collectively, these findings indicated that maternal supplementation with Na2SO4 during mid-to-late gestation elevated foetal survival via improving placental angiogenesis, bile acid metabolism and amino acid utilisation.

Variability in feed intake the first days following weaning impacts gastrointestinal tract development, feeding patterns, and growth performance in nursery pigs

The present study investigated the effects of voluntary feed intake (FI) the first days after weaning on gastrointestinal development and protein fermentation the first week after weaning and growth performance and feeding patterns during the nursery phase. A total of 144 mixed-sex weaned pigs (24 ± 2 d old; 7.2 ± 0.8 kg body weight [BW]) were allocated to 12 pens with 12 pigs/pen. Each pen was equipped with an electronic feeding station for monitoring individual FI during a 40-d study. Pigs were classified based on their cumulative FI over the initial 3 d after weaning (FId1-3) being above or below their pen median FId1-3 (high = 919 ± 244 g or low = 507 ± 222 g FId1-3). Similarly, weaning BW classes (BW0; high = 7.72 ± 0.59 kg or low = 6.62 ± 0.88 kg BW) were created to study interactions with FId1-3. Two female pigs with either a high or a low FId1-3 per pen (n = 24) were selected for sampling at d6 and were used to study gastrointestinal development and fermentation products in the small intestine. Feeding patterns per day, FI, and growth performance were measured individually. Low FId1-3 pigs had lower (P < 0.05) daily FI during d0 to d8, d8 to d15, and d22 to d28, BW on d15, d22, d29, and d40, and average daily gain during d0 to d8, d22 to d29, and d29 to d40 compared to high FId1-3. High FId1-3 pigs increased (P < 0.05) the number of visits to the feeder between d1 to d13 and d31 to d35, and the time spent per visit only for d1 to d4 (P < 0.05). The daily rate of FI (g/min) was higher (P < 0.05) for High FId1-3 pigs on d6, d8, d9, and d10, and again several days later (d20 to d39). In addition, the high FId1-3 × high BW0 interaction improved daily FI during d18 to d40 compared to low FId1-3 × low BW0 class (P < 0.05). For the sampling on d6, low FId1-3 pigs had a lighter small intestine, colon, and pancreas, and reduced villi length, smaller villi surface area, and a lower number of goblet cells size in jejunum (P < 0.05), while concentrations of lactic acid, histamine, and cadaverine in small intestinal content were increased (P < 0.05). In conclusion, pigs with high FId1-3 became faster eaters with higher FI and growth rates toward the second half of the nursery, which was similar and additive for pigs with higher weaning BW. High FId1-3 was also associated with greater development of the gastrointestinal tract and a reduced protein fermentation 1-wk after weaning.

Identification of blood immune and metabolic indicators explaining the variability of growth of pigs under contrasted sanitary conditions

Background

Health and growth of pigs are affected by the hygiene of housing. Lower growth performance observed in poor hygiene of housing conditions is explained by reduced feed intake and metabolic changes caused by the activation of body defences. In a previous experiment, we reported contrasted average values of body weight gain, concentrations of circulating metabolites, redox and immune indicators in blood of pigs housed in good or poor hygiene conditions during the growing period. This study addressed inter-individual variability in these responses to determine whether a particular blood profile explains average daily gain (ADG) of the pig.

Results

The data originated from 160 growing pigs, half of which subjected to a hygiene challenge for 6 weeks (W0 to W6) and the others housed in good hygiene conditions. Pigs originated from two lines divergently selected for residual feed intake (RFI). Individual body weights were recorded during this period, and relative ADG (rADG_W0-W6) was calculated as the ADG corrected by the initial body weight measured at W0. Blood samples were taken before (W0) and 3 weeks (W3) after the beginning of the challenge. The analysed dataset consisted of 51 metabolites and indicators of immune and inflammatory responses measured on 136 pigs having no missing value for any variables, when calculated as the differences W3 minus W0 in circulating concentrations. An algorithm tested all possible linear regression models and then selected the best ones to explain rADG_W0-W6. Six variables were identified across the best models and correlated with rADG_W0-W6 with a goodness of fit (adjusted R²) of about 67%. They were changes in haptoglobin, global antioxidant capacity of plasma (Biological Antioxidant Power or BAP), free fatty acids, and 3 amino acids: leucine, tryptophan, and 1-methylhistidine. The effects of housing conditions and RFI lines were comprised in the variables of the selected models and none of these conditions improved accuracy of the predictive models, leading to genericity of the pinpointed metabolic changes in relation to variability of ADG.

Conclusions

This approach allows us to identify blood variables, whose changes in blood concentrations correlated to ADG under contrasted sanitary conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02872-3.