Nutritive Value and Degradation Kinetic Parameters of Three Plants for Feeding Bradypus variegatus Schinz, In Vitro Evaluation

TL;DR

This study evaluates the nutritional value of three plants for feeding sloths in captivity, finding that Pterodon sp. and Inga sp. are better options than Cecropia sp.

Contribution

The study provides in vitro evidence on the digestibility and nutritional suitability of specific plant species for captive sloths.

Findings

Pterodon sp. showed the best results for protein digestibility and fiber digestion rates.

Inga sp. had the highest in vitro digestibility of crude protein.

Cecropia sp. has high fiber content that may negatively affect dry matter intake.

Abstract

Feeding sloths (Bradypus sp.) in captivity can be extremely challenging due to their individually selective folivorous diet and preferences for specific plant species. This selectivity complicates nutritional management and can lead to diseases associated with an unbalanced diet. By using an in vitro fermentation technique, we evaluated the nutritional characteristics of three feeds for captive sloths by incubating samples of these feeds with the stomach contents of sloths. Our findings indicate that the leaves of plants from the genera Pterodon sp. and Inga sp. show potential for feeding Bradypus variegatus sloths in captivity, with particular emphasis on the former, which demonstrated the best results for protein digestibility, fiber digestion rates, and total fermentation gas volume. We recommend careful attention to the fiber content of Cecropia sp. plants due to possible negative effects on dry matter intake. It is suggested that this plant be fed in combination with other feeds containing less fiber to allow for selection by the animals.

This study aimed to evaluate the nutritive value of three feeds (Cecropia sp., Pterodon sp., and Inga sp.) for sloths (Bradypus variegatus), based on nutritional composition and in vitro gas production. After a 14-day adaptation period to these feeds, approximately 500 g of gastric contents were collected from three female sloths, processed, and incubated with the food samples to evaluate digestibility and in vitro degradation kinetics. Regarding the nutritional composition, the neutral detergent fiber (NDFcp) content was higher with 404 g kg−1 DM (p = 0.001) in the leaves of Cecropia sp. The non-fibrous carbohydrate contents were greater with 499 g kg−1 DM in Pterodon sp. (p = 0.002). The greatest cellulose content (211 g kg−1 DM) was found in the leaves of C. pachystachya, as well as the lowest value of 143 g kg−1 DM for hemicellulose. Significant differences in the in vitro digestibility of crude protein (p = 0.041) were observed, with Inga sp. showing the highest value at 547 g kg−1 DM. In terms of kinetic parameters, Pterodon sp. exhibited higher total gas production (Vt) at 99 mL (p = 0.023) and digestion rates of fibrous carbohydrates (kdFC) at 0.0223%/h (p = 0.020) (p < 0.05). The leaves of Pterodon sp. and Inga sp. showed potential as suitable feeds for B. variegatus, while Cecropia sp. may have negative effects on dry matter intake due to its high NDF content, because of possible repletion effects on the stomach.

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