Location: Reproduction ResearchTitle: Non-targeted plasma metabolome of early and late lactation gilts
Submitted to: Frontiers in Molecular Biosciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/9/2016
Publication Date: 11/24/2016
Publication URL: http://handle.nal.usda.gov/10113/5700709
Citation: Rempel, L.A., Miles, J.R., Oliver, W.T., Broeckling, C.D. 2016. Non-targeted plasma metabolome of early and late lactation gilts. Frontiers in Molecular Biosciences. 3:77. doi:10.3389/fmolb.2016.00077.
Interpretive Summary: First-time sows nursing a litter have a lot of energetic demands imposed upon them. Not only are these young females supporting a litter of piglets, they themselves are still reaching full mature size. Therefore the objective of the current study was to identify metabolites that differ in these first-time mothers at the beginning or the end of lactation and if these compounds associate with the well-being and reproductive lifetime of these young sows. Plasma metabolites, small compounds within plasma, from early and late lactation were separated using gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. Nearly 700 compounds were detected for each mass spectra technique and of those, numerous compounds were different between early and late lactation sampling. The compounds identified have direct and indirect associations with energy metabolism and some are also related to reproductive status. By identifying these compounds we are able to generate a more complete understanding of the biochemistry taking place during lactation. These data provide compelling evidence for possible supplements that may offset any nutritional imbalance allowing for a healthier more sustainable environment for these young sows.
Technical Abstract: Female pigs nursing their first litter (first-parity gilts) have increased energy requirements not only to support their piglets, but they themselves are still maturing. Non-targeted plasma metabolomics were used to investigate the differences between (1) post-farrowing and weaning (early or late lactation), (2) degree of body condition loss after lacation (extreme or minimal), and (3) interactions; to potentially identify compounds or pathways that could aide in alleviating energetic demands of lactation in gilts. Twenty first-parity gilts were selected with similar (P >= 0.4475) number of piglets born and nursed, and similar (P >= 0.3141) body condition traits (e.g., body weight and backfat thickness) post-farrowing, yet exhibited minimal or extreme loss (P <= 0.0094) in body weight (8.6 ± 1.48 kg and 26.1 ± 1.90 kg, respectively) and backfat thickness (1.3 ± 0.67 mm and 4.7 ± 0.86 mm, respectively) following lactation. Plasma samples first-parity gilts at post-farrowing and weaning was investigated using UPLC-MS and GC-MS to generate a comprehensive metabolic profile. Each approach yielded approximately 700 detected features. An ANOVA was performed on each detected compound in R for time of collection, body condition change, and the interaction, followed by a false discovery correction. Two unknown features were different (P<=0.05)for extreme vs. minimal body condition change. Several compound differences (P<=0.05) were identified between post-farrowing and weaning. Thirty-two features detected by UPLC-MS had at least a log2 fold-change of ±1.0 while only 18 features had a log2 fold-change of ±0.6 or more for the significant GC-MS features. Annotation implicated various metabolic pathways. Creatinine was greater at weaning (P = 0.0224) and others have reported increased serum concentrations of creatinine in response to body weight loss. Hippurate and caprolactam, associated with protein catabolism, were also greater (P <= 0.0166) at weaning. Phospholipid features (P <= 0.0347) inositol-related features (P <=0.0236) were also greater at weaning. Inositol features may exert insulin-like effects. The energetic demands of lacation in gilts nursing their first litter indicated a greater difference exists between early and late lactation regardless of body condition loss.