Nutritional Dietary Supplements to Reduce the Incidence of Fatty Liver Syndrome in Laying Hens and the Use of Spectrophotometry to Predict Liver Fat Content

Abstract

Fatty liver syndrome (FLS) in laying hens is a metabolic disease that can potentially reduce egg production while compromising the health status of the bird. This study assessed the combined use of B vitamins via the feed (FLS-MIX) or the drinking water (FLS-LIQ) to reduce FLS and the use of spectrophotometry to estimate liver fat content. Individually, caged Hy-line brown hens (n = 288) underwent a pre-experimental period (from week 66 to 67, both included) receiving a Standard diet or a Challenge diet (high energy–low protein) to nutritionally induce the FLS. Subsequently, hens followed a 2 diets (Standard; Challenge) × 3 dietary supplements (NONE; FLS-MIX; and FLS-LIQ) factorial arrangement of treatments from 68 to 73 wk old, both included. Compared to the Standard, the Challenge diet increased liver fat (188 vs. 270 g/kg DM) and reduced feed consumption, lay percentage, and egg mass production (P < 0.05). No differences in lay performance or eggshell quality were observed among dietary supplements; however, FLS-MIX significantly increased (P < 0.05) feed intake relative to NONE. On birds subjected to the Challenge diet, the use of FLS-MIX and FLS-LIQ led to lower (P < 0.05) liver fat relative to NONE. Regression analysis between the L, a⁺, and b⁺ values and liver fat content provided significant (P < 0.001) regression equations to estimate liver fat content (R² = 0.62). Results of this study suggest that B vitamin supplements could be an effective means to reduce liver fat deposition when hens are susceptible of suffering FLS, and that spectrometry could be a reliable tool to estimate liver fat content.