Impact of early nutrition on hunger and thirst related parameters in broiler chicks hatched in a hatcher

With increasing focus on early nutrition in poultry research, understanding how different feeding strategies influence broiler health and welfare is crucial. However, short-term physiological responses, particularly those linked to hunger and thirst in early life, remain largely unexplored. This study assessed the impact of early nutrition strategies in the hatcher, focusing on key physiological indicators.
A total of 320 Ross308 broilers, housed in 32 baskets (10 chicks per basket, 8 replicates per treatment), were randomly assigned to one of four treatment groups for 48 hours post-hatch: FW (feed and water), W (water only), F (feed only), and D (no feed or water). To ensure balanced allocation of early-, middle-, and late-hatching chicks within treatments, allocation was based on hatch window. Blood and tissue samples were collected at 4, 24, 36, and 48 hours post-hatch to assess yolk weight, plasma osmolarity, arginine vasotocin, triiodothyronine (T3), and ghrelin mRNA expression.
From 24 hours post-hatch, significant differences (p<0.05) emerged between feeding strategies (Mixed Model, SAS). Ghrelin expression in the proventriculus was higher in D, F, and W than FW, persisting until 48 hours post-hatch. Plasma osmolarity followed a similar trend, with higher values in water-deprived groups (D: 361.76, F: 358.93 mOsm/kg) versus water-supplied groups (W: 317.38, FW: 314.31). At 48 hours post-hatch, plasma arginine vasotocin was lowest in FW (171.81 pg/ml) but significantly higher in D (249.81), F (277.65), and W (305.54). Yolk weight was lower in F (3.65 g) than FW (4.46 g) at 24 hours post-hatch, with no significant differences at other timepoints. No differences were found in T3 between D and FW at 48 hours post-hatch. T3 was not measured in F and W or at other timepoints.
These findings highlight the physiological consequences of early feeding strategies, reinforcing the need to provide both feed and water post-hatch to optimize broiler development and welfare.