Research for defining the concept of ideal protein in the diet of growing rabbits under diverse conditions

June 12, 2024

Recently, researchers published a metabolomics study on the ideal protein diet of rabbits, with the aim of identifying biomarkers that help define the concept of ideal protein for growing rabbits under as diverse conditions as possible. The study included two different experiments, as follows:

Experiment 1:

24 growing rabbits at 56 days of age were fed ad libitum one of two experimental diets differing only in lysine levels.
Blood samples were taken for targeted and untargeted metabolomics analysis.

Experiment 2:

53 growing rabbits at 46 days of age were fasted and then fed one of five experimental diets with identical chemical compositions except for three typically limiting amino acids.
Blood samples were also taken for metabolomics analysis in this experiment.

Results:

The metabolic phenotype was found to alter with rapid dietary changes in amino acid levels.
Some metabolites showed direct changes related to specific amino acids, while others like creatinine (CAS 60-27-5), urea (CAS 57-13-6), hydroxypropionic acid (CAS 503-66-2), and hydroxyoctadecadienoic acid indicated amino acid imbalances, suggesting intricate interactions among amino acids.

Discussion:

The study hypothesized that short-term changes in dietary levels of three frequently limiting amino acids (lysine CAS 56-87-1, methionine CAS 63-68-3, and threonine CAS 72-19-5) would influence the metabolic phenotype of growing rabbits.
The results indicate that an amino acid imbalance leads to increased excretion and catabolism, affecting overall animal welfare and productivity.

Methods and Materials:

The experimental protocols were approved by the Animal Welfare Ethics Committee and followed Spanish regulations for animal use.
Detailed descriptions of the diets, animals, and experimental design are provided.
Chemical analyses and targeted metabolite assays were conducted, including non-esterified fatty acids, albumin, glucose, creatinine, total protein, urea, triglyceride, cholesterol, and inorganic phosphorus.
LC-MS metabolomics analysis of plasma was performed using specific solvents, standards, and sample preparation methods.
This research provides valuable insights into optimizing rabbit diets by adjusting amino acid levels and may contribute to the development of more precise nutritional formulations to improve rabbit production efficiency and overall health.