Evaluating the temperature-dependent effects of 3 preservative treatments on bacterial growth in raw goat colostrum

Bacterial contamination of raw goat colostrum during storage poses a risk to passive immunity transfer in neonatal kids, yet evidence-based preservation strategies for goat-specific systems remain limited. The objective was to evaluate temperature-dependent effects of potassium sorbate (0.5%), sodium benzoate (0.5%), and sodium l-lactate (0.3%) on bacterial growth and pH in goat colostrum. Samples were stored at 4°C (0-168 h) or 25°C (0-48 h). Coliforms, total bacterial count, and Escherichia coli were enumerated using Compact Dry plates. At 4°C, counts were stable early, but by 168 h coliforms in the control group reached 6.97 log₁₀ cfu/mL and sodium l-lactate tracked the control group. The potassium sorbate and sodium benzoate maintained coliforms near baseline (∼4.0 log₁₀ cfu/mL; ≈3.0 log₁₀ lower than control group) and reduced total bacterial count by >1.3 log₁₀ cfu/mL at 168 h. Escherichia coli counts remained low in all groups throughout the 168-h storage period. At 25°C, the control and sodium l-lactate groups showed rapid proliferation (coliforms 6.72 log₁₀ at 12 h; Escherichia coli 4.43 log₁₀; and total bacterial counts 9.14 log₁₀ at 24 h). Potassium sorbate and sodium benzoate markedly suppressed growth, reducing coliforms by 2.39 to 2.91 log₁₀ at 12 h and limiting Escherichia coli to near/below detection. Mean pH was inversely associated with coliform counts. Overall, potassium sorbate and sodium benzoate consistently suppressed bacterial growth, whereas sodium l-lactate showed minimal or inconsistent effects.