This study examined the effect of supplemental
betaine on live performance, selected blood parameters, and gene expression of
water channel proteins (
Aquaporins, AQP) of broiler chicks delayed in placement for 48 h post-hatch. In total, 540 newly-hatched male broiler chicks were obtained from a local hatchery and were randomly allotted to one of five treatments with nine replicates per treatment (12 chicks per replicate). Chicks were either placed immediately, control; held for 48 h post-hatch with no access to feed or water, Holdnull; held for 48 h with free access to
drinking water only, HoldW; held for 48 h with free access to
drinking water supplemented with 1 ml per L of
betaine solution (40%
betaine), HoldB1; or held for 48 h with free access to
drinking water supplemented with 2 ml per L of
betaine solution (40%
betaine), HoldB2 group. The results showed that post-hatch holding for 48 h depressed feed intake and
body weight gain during the entire 15 d study period with no beneficial effect of supplemental
betaine. Chicks in the HoldB2 group had elevated serum
glucose,
triglycerides, and
aspartate aminotransferase 48 h post-hatch. Early water deprivation directly affected the brain
proopiomelanocortin (
POMC) and hepatic
glucocorticoid receptors (GR) expression and induced significant changes in various
aquaporins (AQP1, AQP2, AQP4, and AQP9). In conclusion,
betaine supplementation to chicks held for 48 h post-hatch resulted in some changes in blood biochemical indices with no effects on performance during the first 15 days of life. The results suggest that
betaine supplementation could ameliorate the stressful effects of water deprivation on
POMC and GR expression and maintain cellular osmosis through interactions with variable
aquaporins expression, particularly the AQP1 and AQP2. Further investigations are required to investigate the molecular mechanisms underlying the selective regulatory expression of different
aquaporins in relation to
betaine supplementation.