Effects of segregation and impact of specific feeding behaviour and additional fruit on voluntary nutrient and energy intake in yellow-shouldered amazons (Amazona barbadensis) when fed a multi-component seed diet ad libitum

Abstract

Parrots are commonly fed multi-component seed diets; however, both segregation and feeding behaviour might alter ingredient and nutrient composition of the offered diet. First, the nutritional impact of segregation was assessed as it occurs when multi-component diets are temporarily stored in food containers that are replenished before completely emptied and birds being fed from the upper layer. The most detrimental effect hereof was a vast decrease in mineral supplements, leading to a decrease in Ca:P ratio in the offered food in relation to the formulated diet. Next, caloric distribution shifted towards more EE energy at the expense of NFE energy, as proportion of oilseeds increased and NFE-rich seeds decreased. Next, a feeding trial was performed on six yellow-shouldered amazons (Amazona Barbadensis) in which nutritional impact of parrot-specific feeding behaviour was assessed as well as the influence of additional provision of fruit next to the seed mixture. Profound selective feeding behaviour and dehusking of seeds resulted in a vast increase in energetic density by up to 64% in the ingested fraction in relation to the offered mixture in toto. Furthermore, the already suboptimal Ca:P ratio further deteriorated and caloric distribution shifted by over twofold towards EE energy accompanied with a vast decline in NFE energy, CP energy remaining similar. Finally, provision of fruit next to the seed diet significantly lowered voluntary energy intake from 936 ± 71 to 809 ± 109 kJ ME/kg(0.75)/day, without compromising adequate protein intake. In conclusion, notwithstanding efforts of nutritionists to formulate diets to approximate estimated, species-specific requirements, nutritional composition of the actually consumed fraction of multi-component seed diets can be vastly deteriorated by both animal and management factors. Furthermore, offering of fruit next to a seed-based diet effectively reduces voluntary energy intake and can hence be applied to abate obesity.

Nutritional Levels of Diets Fed to Captive Amazon Parrots: Does Mixing Seed, Produce, and Pellets Provide a Healthy Diet?

“…Seed-only diets are known to be deficient in a variety of nutrients, including calcium, phosphorus, lysine, sodium, zinc, iron, and vitamin A. 3,10,13 This study suggests that supplementing seed diets with produce and formulated diet improved the levels of lysine, phosphorus, zinc, and vitamin A. However, the mixed diet was still apparently deficient in calcium, sodium, and iron and had much more total lipid than recommended (Table 5).…”

“…As evidenced in this and other studies, the nutritional imbalances of seed-containing diets are exacerbated by birds choosing seeds with the highest fat content. 10 The research to date shows incontrovertibly that seedrich diets contain excessive levels of fat, a Table 5. Table 5. deficiency of calcium, and poor calcium : phosphorus ratios.…”

“…Table 5. deficiency of calcium, and poor calcium : phosphorus ratios. 10,23 The birds in the study consumed 40% of the total food offered and ate !75% of the total quantity offered for a select few items including grapes and high-fat seeds. This suggests that the birds had the ability to choose a more nutritionally balanced diet through selective eating.…”

“…Many owners are apparently unaware of the basic principles of avian nutrition and continue to feed their large parrots seed-based diets. 4,10 This problem is exacerbated by the marketing of seedbased diets by bird food manufacturers claiming that such diets are complete, balanced, and healthy. 11,12 Relative to the nutritional needs of psittacine birds, seed-based diets contain excess fat, low calcium : phosphorus (Ca : P) ratios, and insufficient levels of calcium, phosphorus, sodium, zinc, iron, lysine, and vitamin A.…”

“…11,12 Relative to the nutritional needs of psittacine birds, seed-based diets contain excess fat, low calcium : phosphorus (Ca : P) ratios, and insufficient levels of calcium, phosphorus, sodium, zinc, iron, lysine, and vitamin A. 3,10,13 Nutritionally superior, formulated diets are widely available from many manufacturers. This suggests that educating bird owners and veterinarians should increase the number of captive parrots fed nutritionally adequate diets.…”