Importance of a close reflection towards feeding management in ornithological collections.

Objectives: In ornithological collections, multi-component seed diets are often stored in large containers which are replenished before completely emptied. However, different-sized particles tend to segregate when stored, whereby small seeds lower to the bottom, larger seeds remaining on top. Hence, intended and actually offered ration differ in content. Furthermore, parrots de-husk seeds prior to ingestion. The aim of this study was to assess nutritional consequences of these factors. Materials and Methods: A 100 g sub-sample was taken from a large feed storage container filled with a parrot seed mixture. All seed types were separated, weighed, relative proportions calculated and compared to the intended composition. Next, nutrient contents of both sub-sample and intended mixture were calculated, both for seeds in toto and seed kernels. Results: The most detrimental nutritional effect of segregation is a steep decline in proportion of oyster shells and vitamin-aminoacid-mineral pellets (VAM supplements) which vastly lowers Ca:P-ratio. Next to this, the proportion of oilseeds rises from 24% to 33.5%, whereas carbohydrate-rich seeds lower from 66% to 59.4%. Finally, de-husking seeds leads to an important increase in fat and protein content on account of a decline in crude fibre content (table 1). Conclusions: Although nutritionists attempt to formulate diets in order to approximate estimated, species-specific requirements, nutritional composition of diets can be deteriorated by both animal and management factors. Due to lack of repetitions, the described nutritional effects of segregation in stored multi-component seed diets are only to be interpreted as an indication of magnitude

Feeding behaviour and nutient intake in yellow-shouldered amazons and african grey parrots fed multi-component diets.

Objectives: Parrots have a strong tendency to select oilseeds when provided multi-component seed diets and consume only the kernels. This typical feeding behaviour results in a vastly distinct nutrient profile between ingested and offered food. The study intended to quantify the impact of this behaviour on actual nutrient intake in two parrot species differing in origin. Materials and Methods: Nutrient profile of ingested food from a seed mixture was calculated using proximate analysis of the offered diet and food remainders in eight African grey parrots (Psittacus e erithacus). In a separate cross-over trial, yellow-shouldered amazons (Amazona barbadensis) were fed either seeds or seeds and apple. Here, seed intake per seed type and apple intake were recorded through which actual nutrient intake was calculated. Results: The feeding behaviour of the parrots approximately doubled protein content, led to a three to four-fold increase in fat content and halved carbohydrate content compared to the offered diets. Moreover, although distinct parrot species and seed mixtures, actual nutrient profile of ingested ration was strikingly similar between both trials (table 1). Finally, providing apple to the amazons significantly lowered voluntary energy intake in amazons by 13.5%. Conclusions: The current trials not only demonstrate marked nutritional consequences of selective feeding behaviour, but also indicate that different parrot species select seeds from multi-component seed diets, ending up ingesting a similar nutrient profile. Further, these data demonstrate that voluntary energy intake in amazons fed a seed mixture can be decreased through provision of fruit next to the seeds