Modulation of the nutritional, metabolomic and microRNA profile of colostrum and piglet performance via a high-energy, high-lysine transition diet in sows

Background: The transition period is a critical phase for the sow due to physiological changes and nutritional requirements. A diet balanced in energy and amino acid (AA) content could improve reproductive performance, colostrum quality and piglets' growth. This study evaluated the efficacy of a transition diet (TRT) with higher energy (12.97 MJ/kg of metabolizable energy (ME)) and SID lysine (Lys; 0.85%), compared to a standard (CO) diet (12.33 MJ/kg of ME and 0.70% SID Lys), on the composition and quality of colostrum and on sow and piglet performance. The AA/SID Lys ratio was maintained in both diets. Sows (50 sows/group) were fed the CO or TRT diet from 6 d prepartum to d 4 postpartum. At farrowing, sow performance (50 sows/group) and piglet vitality (12 sows/group) were recorded, and colostrum (20 sows/group) was collected to analyze its composition and microRNAs. Piglet performances were collected d 6 and weaning (d 24). Results: The diet did not affect sow feed intake, body condition score, backfat and muscle loss, nor farrowing duration and time interval between piglets. The TRT group had fewer stillbirths (P = 0.002). Piglets of TRT litters had higher body weight at d 24 (P = 0.032) and tended to have higher average daily gain from d 0 to d 24 (P = 0.080). Colostrum from the TRT group tended to be higher in somatic cell count (P = 0.07), higher in fat percentage (P = 0.036), and higher in C18:2 9cis,12cis, C18:4 6cis,9cis,12cis,15cis, C20:0, UDP-glucuronate and carnitine (P < 0.05); moreover, it had a lower concentration of citrate (P < 0.05). The 208 microRNAs were detected in colostrum, 13 of which were differentially expressed (P < 0.05). The TRT group had a higher ssc-miR-143-3p expression, which is associated with increased phagocytosis and reduced inflammation and oxidative stress. This, together with the increase in fat and specific metabolites related to energy metabolism, could potentially benefit piglet performance. Conclusion: These results suggest that the TRT diet improves sow parturition and lactation performance by modifying sow energy metabolism and colostrum quality. This highlights the importance of a properly designed transition diet for sows.