Tannins
Calliandra is one of the most tanniferous legumes (Ahn et al., 1989). Its foliage, stems and flowers contain large amounts of condensed and hydrolysable tannins (Kaitho et al., 1993; Dzowela et al., 1995). Reported condensed tannin values are highly variable, depending on analytical methods, plant age and plant origin, with values ranging from less than 1% (Dzowela et al., 1995) to 20-30% (Hove et al., 2001; Palmer et al., 2000), and up to 38% for calliandra cultivated in Colombia (Hess et al., 2006). Tannin concentration was shown to increase with age of regrowth (Dzowela et al., 1995), though this is not always the case (Kaitho et al., 1993). In rats, calliandra did not affect feed intake but had depressive effects on reproductive performance (smaller litter size and litter weight, increased mortality of newborn rats) (Iriani Setyawati et al., 2014). Drying calliandra leaves helped in removing tannins (Norton, 1994).
In ruminants, calliandra was shown to decrease rumen DM and protein degradability (Mabeza et al., 2015). Tannins extracted from calliandra had a stronger depressive effect on DM degradability than leucaena tannins (Cortés et al., 2009). Calliandra decreased protein digestibility (Ahn et al., 1989). It also lowered urine N excretion and increased that in the faeces (Hove et al., 2001).
Others compounds
The drying of calliandra leaves alleviated the depressive effect of an unidentified heat labile compound in sheep that depressed feed utilisation (Norton, 1994), but these positive effects of drying were not in accordance with a former experiment in which drying depressed digestion rate and voluntary intake (Palmer et al., 1992). Pipecolic acid, an amino acid contained in calliandra, did not interfere with OM digestibility (Salawu et al., 1997a).