The nursing sow requires a lot of energy and nutrients in order to support the growth of a large litter. When the feed intake of the lactating sows is not sufficient to meet the nutrient demands for maintenance and milk production she must resort to breaking down and mobilizing her own body stores. This results in a high body weight loss (HWL) for the sow at weaning. The mobilization of protein and energy from the sow’s muscle and fat is just wonderful for the litter but this tissue breakdown is usually harmful to the sow. Numerous studies have shown that excessive weight loss in sows negatively influences weaning to estrus interval (WEI), subsequent farrowing rates, subsequent total born litter sizes and the variation of birth weight . Insufficient restoration of follicle development can affect ovulation rate and embryo quality
Researchers wanted to investigate physiological profiles manifested in plasma originating from high
lactational weight loss (HWL) and low lactational weight loss (LWL) sows. The plasma biochemical parameters, hormones, antioxidant parameters, and milk compositions were assessed. Furthermore, plasma metabolites were analyzed using ultrahigh-performance liquid chromatography/time-of-flight mass spectrometry in positive and negative ion modes.
The researchers found the following:
- The relationship between high weight loss , lower lactation feed intake, higher lactational weight loss and prolonged WEI was confirmed as expected
- High weight loss sows had similar litter performance and milk composition compared to low weight loss sows. ( leave it to Mom to sacrifice for her offspring!)
- High weight loss sows had lower plasma insulin-like growth factor 1, higher fibroblast growth factor 21 severe oxidative stress and metabolic damage excessive protein breakdown and lipids mobilization
- Metabolomic analysis revealed differences in 46 compounds between HWL and LWL sows, and the identified compounds were enriched in metabolic pathways related to amino acids metabolism, fatty acids oxidation metabolism, bile acids biosynthesis, and nucleoside metabolism.
Take Home Messages:
- Excessive lactational weight loss is associated with a noticeable disorder in amino acid metabolism and fatty acid oxidation metabolism due to protein breakdown and lipid mobilization
- These metabolic disorders lead to serious oxidative damage and metabolic dysfunction at the end of lactation, thus delaying the weaning to estrus interval.
Submitted by South West Production Team
Ref: Hu L, Che L, Wu C, Curtasu MV, Wu F, Fang Z, Lin Y, Xu S, Feng B, Li J, Zhuo Y, Theil PK, Wu. Metabolomic Profiling Reveals the Difference on Reproductive Performance between High and Low Lactational Weight Loss Sows. Metabolites. 2019 Dec 4;9(12). pii: E295. doi: 10.3390/metabo9120295.