Background: Previous work showed that weaning stress causes gut barrier dysfunction partly by triggering the release of corticotropin releasing factor (CRF) and thereby inducing the degranulation of intestinal mast cell (MC). This study investigated the hypothesis that attenuating the weaning-induced activation of the CRF-MC axis via administration of a MC stabilizing agent (cromolyn) may improve gut permeability and piglet performance after weaning.
Results: To test the hypothesis twenty piglets were weaned (20 ± 1.0 d of age; 6.4 ± 0.4 kg of BW) and injected intraperitoneally with saline (control, n = 10) or 20 mg/kg BW of sodium cromolyn (cromolyn, n = 10) at - 0.5, 8 and 16 h relative to weaning. Piglets were housed individually and fed ad libitum a pre-starter diet from one to 15 d post-weaning followed by a starter diet until the end of the study on d 36. Cromolyn improved intestinal permeability as indicated by the reduced recovery of cobalt and mannitol in plasma samples. Cromolyn treated pigs consumed more feed (369 vs. 313 g/d; P < 0.009), gained more BW (283 vs. 238 g/d; P < 0.006), and grew more efficiently (0.60 vs. 0.40; P < 0.042) than their control counterparts. As a result, cromolyn treated pigs were 1.4 kg heavier than those in the control group by d 36 after weaning (16.5 vs. 17.9 kg; P < 0.002).
Conclusions: In agreement with our hypothesis, present data indicate that the cromolyn-mediated improvement of intestinal permeability is associated with enhanced pig performance after weaning.