Physico-chemical properties of late-incubation egg amniotic fluid and a potential in ovo feed supplement

Abstract

Objective: This study explored the physico-chemical properties of late-incubation egg amniotic fluid and a potential in ovo feed (IOF) supplement.

Methods: Amniotic fluid was collected from broiler breeders (Ross 308, 51 weeks and Cobb 500, 35 weeks) on day 17 after incubation. A mixture of high-quality soy protein supplement - Hamlet Protein AviStart (HPA) was serially diluted in MilliQ water to obtain solutions ranging from 150 to 9.375 mg/mL. The mixtures were heat-treated (0, 30, 60 minutes) in a waterbath (80°C) and then centrifuged to obtain supernatants. The amniotic fluid and HPA supernatants were analysed for their physico-chemical properties.

Results: Only viscosity and K⁺ were significantly (p<0.05) different in both strains. Of all essential amino acids, leucine and lysine were in the highest concentration in both strains. The osmolality, viscosity and pCO₂ of the supernatants decreased (p<0.05) with decreasing HPA concentration. Heat treatment significantly (p<0.05) affected osmolality, pH, and pCO₂, of the supernatants. The interactions between HPA concentration and heat treatment were significant with regards to osmolality (p<0.01), pH (p<0.01), pCO₂ (p<0.05), glucose (p<0.05), lactate (p<0.01) and acid-base status (p<0.01) of HPA solutions. The Ca²⁺, K⁺, glucose, and lactate increased with increasing concentration of HPA solution. The protein content of HPA solutions decreased (p<0.05) with reduced HPA solution concentrations. The supernatant from 150 mg/mL HPA solution was richest in glutamic acid, aspartic acid, arginine and lysine. Amino acids concentrations were reduced (p<0.05) with each serial dilution but increased with longer heating.

Conclusion: The values obtained in the primary solution (highest concentration) are close to the profiles of high-protein ingredients. This supplement, as a solution, hence, may be suitable for use as an IOF supplement and should be tested for this potential.

Keywords: Amino Acids; Amniotic Fluids; In ovo; Physico-chemical Properties; Protein.

Figure 1

Effect of heat treatment on amino acids concentration (μg/g protein) of Hamlet Protein AviStart (HPA) solution (a) 150.0 mg/mL, (b) 75.0 mg/mL, (c) 37.5 mg/mL, (d) 18.75 mg/mL, (e) 9.375 mg/mL.