In cafeteria trials with tannin rich plants, tannins do not modify foliage preference of goats with browsing experience

Abstract

It has been suggested that goats with browsing experience might not affect their preference and fodder intake by the tannins contained in tropical browse. To test this hypothesis, polyethylene glycol (PEG 3600 MW), a tannin blocking agent, was used in cafeteria trials employing browses commonly available in their diet. The selectivity (SI), preference and intake rate (IR) as well as the effects of plant density, chemical composition (including tannin content) and PEG supplementation were assessed. Goats showed a low SI, explained as a behavioral adaptation in a tannin rich environment. PEG administration had no effect on the goats' preference or IR. The IR seemed affected by plant densities. Also, fiber components had higher associations with DM intake than the polyphenolic compounds at the levels found in the evaluated forages. It was concluded that tannins and PEG did not modify goats' preference in cafeteria trials. Hence, tannins have a limited involvement in short term preference regulation of goats with browsing experience.

KEY WORDS:

• selectivity
• plant secondary compounds
• fiber
• small ruminants
• intake

ACKNOWLEDGEMENTS

G. Hernández-Orduño acknowledges receiving a scholarship from CONACYT-Mexico to undergo her MSc studies. This work was supported by project CONACYT-SAGARPA-COFUPRO No. 12441. We thank the technical assistance of MVZ Humberto Antonio Peralta-Pino, Br. Adrián Tun, MVZ Hilda Lorena Canul-Ku.