Quality Evaluation

Abstract

Hay is the foundation of dietary husbandry for most captive herbivores, and its quality determines the need for other feeds. Quality can be high, low, or in between, but standards that are appropriate for hay fed to lactating dairy cows may be different than standards for hay fed to mature elephants. Hay that is high in protein and low in fiber is usually the most expensive and may be rated of best quality for supporting rapid growth or high levels of production in farm animals. However, considering the numbers of species and life stages of herbivores that must be fed in zoos, hays that meet their various nutrient and functional requirements at reasonable cost may be most appropriate for the task. In most zoos, two or three different hays will be required, and realistic purchasing specifications should be developed that are consistent with the needs of herbivores in the zoo collection and the local availability of hay types. Environmental factors influencing plant growth and hay quality include temperature, daylength, light intensity, water supply and distribution over time, fertilization, and soil type. Hay quality is further influenced by plant species, stage of maturity when cut, leafiness, color, stem size and brittleness