Objective: Liquid feeding strategies for calves typically involve whole milk, pasteurized discard milk, or commercial milk replacers (MR). While whole milk is the gold standard for nutrition, its high cost can be economically prohibitive. A major challenge with MR is the variability in protein and fat quality. Non-edible eggs (unfit for human consumption), which account for approximately 10% of global egg production, represent a potential high-quality nutrient source for growing livestock. This study evaluated the effects of incorporating boiled non-edible eggs as a partial substitute for milk protein and fat in both whole milk and MR-based diets.

Methods: Forty newborn Holstein calves were randomly assigned to five experimental groups: (1) Whole milk (WM); (2) WM + 10% boiled eggs; (3) Commercial MR; (4) Commercial MR + 10% boiled eggs; and (5) An on-farm MR containing 20% boiled eggs. Inedible eggs were sourced from commercial poultry farms. After deshelling, the egg contents were homogenized, sealed in polyethylene bags, and boiled for 10 minutes to ensure complete coagulation. The cooked eggs were then blended with an equal weight of hot water to produce a uniform mixture, bottled, and refrigerated until use. Body weight and skeletal growth (heart girth, wither height, body length, and hip height) were recorded biweekly. Fecal consistency was scored daily. Blood samples for hematological and biochemical profiling were collected during mid-suckling and at weaning. Calf starter and water were provided ad libitum from day 5, and daily intake was monitored.

Results: Calves fed whole milk (with or without egg supplementation) exhibited higher total weight gain, final body weight, and average daily gain compared to those in the MR groups, particularly the on-farm MR group. Skeletal growth parameters remained similar across all treatments. Most plasma metabolites were within physiological ranges, indicating metabolic stability, though plasma cholesterol levels were influenced by dietary intake. Supplementing milk-based diets with eggs had no adverse effect on performance, suggesting that a 10% replacement is feasible if economically advantageous. However, the 20% egg inclusion in the on-farm MR led to reduced feed intake, prolonged diarrhea duration, and impaired feed efficiency, suggesting potential gastrointestinal disturbances at higher inclusion levels.

Conclusion: Cooked non-edible eggs can serve as a viable supplementary nutrient source. Replacing up to 10% of the liquid diet does not negatively impact the performance or health of suckling calves. Conversely, higher inclusion levels (20%), especially in lower-quality milk replacers, may disrupt intake, intestinal health, and growth. Therefore, precise dietary formulation is essential before implementing egg-supplemented feeding systems in calf rearing.