Metabolic and morphometric analysis of allometric and total liver growth in Post-Hatch chickens

This study examines metabolic and morphometric changes in chicken liver metabolism during the post-hatch growth period (days 4-20). During this period, liver metabolism transitions from using yolk-derived lipids to feed derived carbohydrates and proteins. The period also encompasses distinct growth phases with implications for metabolic impacts on total and allometric (proportional) growth.

Identify shifts in metabolites and pathways that occur during the change in nutrients and relate these to patterns of total and allometric liver growth.

Liver samples were collected every other day between days 4-20 and analyzed using metabolomic and morphometric approaches to relate metabolic changes to growth. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to identify trends in the data. Cross-validation ANOVA, and network analyses were applied to evaluate metabolic changes across the time periods.

Three liver growth periods were defined. Period A (days 4-8) exploited stored nutrients to support rapid growth. Period B (days 10-14) was transitional as stored nutrients were depleted and feed became the major metabolic driver. By period C (days 16-20) the liver is fully dependent on feed. Positive allometric growth occurs predominantly during period A while the organ continues to grow throughout the entire time.

Metabolic pathways exhibit distinct networks as nutrient resources change over the early post-hatch period. These findings provide a framework for understanding how nutrient-driven metabolism influences liver scaling and functional maturation.