Nutritional Supplement of Hatchery Eggshell Membrane Improves Poultry Performance and Provides Resistance against Endotoxin Stress

Abstract

Eggshells are significant part of hatchery waste which consist of calcium carbonate crust, membranes, and proteins and peptides of embryonic origins along with other entrapped contaminants including microbes. We hypothesized that using this product as a nutritional additive in poultry diet may confer better immunity to the chickens in the paradigm of mammalian milk that enhances immunity. Therefore, we investigated the effect of hatchery eggshell membranes (HESM) as a short term feed supplement on growth performance and immunity of chickens under bacterial lipopolysaccharide (LPS) challenged condition. Three studies were conducted to find the effect of HESM supplement on post hatch chickens. In the first study, the chickens were fed either a control diet or diets containing 0.5% whey protein or HESM as supplement and evaluated at 5 weeks of age using growth, hematology, clinical chemistry, plasma immunoglobulins, and corticosterone as variables. The second and third studies were done to compare the effects of LPS on control and HESM fed birds at 5 weeks of age following at 4 and 24 h of treatment where the HESM was also sterilized with ethanol to deplete bacterial factors. HESM supplement caused weight gain in 2 experiments and decreased blood corticosterone concentrations. While LPS caused a significant loss in body weight at 24 h following its administration, the HESM supplemented birds showed significantly less body weight loss compared with the control fed birds. The WBC, heterophil/lymphocyte ratio, and the levels of IgG were low in chickens fed diets with HESM supplement compared with control diet group. LPS challenge increased the expression of pro-inflammatory cytokine gene IL-6 but the HESM fed birds showed its effect curtailed, also, which also, favored the up-regulation of anti-inflammatory genes compared with control diet fed chickens. Post hatch supplementation of HESM appears to improve performance, modulate immunity, and increase resistance of chickens to endotoxin.

Fig 1. Nitrite production at 24 h by the HTC chicken macrophage in response to treatments with LPS and HESM extracts.

Bars with different alphabets are statistically different (P ≤ 0.05).

Fig 2. Weekly growth curve of chickens from day1 through 34 on diets with or without HESM supplement fed for first 2 weeks post hatch (n = 72–78).

Fig 3. Splenic IL-6 gene expression in chickens fed control or HESM supplement diet and challenged with LPS or saline for 4 h (n = 6).

Bars with different alphabets are significantly different (p≤0.05).

Fig 4. Splenic IL-10 gene expression of chickens fed control or HESM supplement diet and treated with LPS or saline for 4 h (n = 6).

Bars with different alphabets are statistically different (P ≤ 0.05).

Fig 5. Comparison of splenic IL-4 gene expression in chickens fed control or HESM supplement diet and challenged with LPS or saline for 4 h (n = 6).

Bars with different alphabets are statistically different (P ≤ 0.05).