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

Abstract

Introduction: 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.

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

Methods: 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.

Results: 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.

Conclusions: 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.