If the diet is mixed within the institutions, all ingredients should be scrupulously maintained free of contamination from chemicals, pests or microorganisms. Avoid allowing raw diets to warm to room temperature for long periods of time prior to feeding. The practice promotes the rapid growth of bacterial organisms. Frozen ingredients should be properly thawed to reduce bacterial growth and diets fed as soon as possible after mixing. Commercial diets are thawed under clean conditions, free from external contamination, and fed immediately after thawing.
Some institutions actually feed the diet while still frozen allowing tigers to eat as it thaws.
The food is weighed and daily records kept as to how much is offered to each individual tiger and how much is consumed. Determination of ration amounts is a dynamic process to meet changes in metabolic needs, such as in seasonal needs, illness, pregnancy, lactation and growth. Proper body weight to avoid obesity should be maintained by diet alterations. These changes should reflect not only energy but also vitamin and mineral needs. Records of stool consistency assist in determining if the diet is poorly digested or possibly inducing diarrhea indicative of enteric disease.