**3. Chemical composition of leaves and sheath from** *Erythrina edulis*

The chemical determinations of leaves (SV) or sheath without seed (SF) from *E. edulis*, are shown in **Table 1**. The SV had 61% greater DM content than SF (31.4 vs. 12.2 5.0%; *p* = 0.009), but its ash content was 27% higher compared to SF (10.5 vs. 7.7 1.40%; *p* < 0.001; **Table 1**). Besides this, the SV showed a greater CP content than the obtained in SF (28.7 vs. 20.3 2.59; *p* = 0.022; **Table 1**), but no differences in CF (24 3.15%, on average; *p* = 0.50) and E.E (1.3 0.21%, on average, *p* = 0.50) contents between them, were observed (**Table 1**).

On the other hand, lower NDF (42.1 vs. 62.4 8.60%; *p* = 0.021) and ADL (6.4 vs. 13.8 2.07%; *p* = 0.007) contents in SF than SV were observed, with a trend in the ADL content (36.2 vs. 51.2 7.98%; *p* = 0.080; **Table 1**). As for nutritive values, differences were observed in NEL values between both studied stages (1.43 vs. 1.47 0.06 Mcal kg/DM; *p* = 0.010; **Table 1**), while that MP content showed a tendency (1050 vs. 1227 109 g/d; *p* = 0.070; **Table 1**).

Regarding antinutritional factors, the different metabolites did not differ between both studied stages (*p* = 0.80–0.21; **Table 1**), being their averages, for phenols (0.7 0.11%), steroids (0.5 0.10%), alkaloids (0.6 0.11%) or saponins (0.7 0.13%). The mineral contents observed in *E. edulis* differed according to the phenological stage, as shown in **Table 1**. Although the Na content did not vary between both studied stages (0.02 0.01%, on average; *p* = 0.62), however, SF had greater P (0.31 vs. 0.19 0.07%; *p* = 0.04) and K (3.0 vs. 1.3 0.39%; *p* = 0.05) contents than SV, but with a 93% lower Ca content (0.1 vs. 1.4 0.39%; *p* = 0.05; **Table 1**).

According to McDonald et al. [32], the chemical composition is highly correlated with feed digestibility. For this reason, in the grazing livestock systems, the forages should meet nutritional requirements for milk and meat production at a cheaper cost [33, 34]. This study showed that the vegetative stage (SV) had greater DM content than the fructification stage (SF), which was similar to the one found by Naranjo [35]. Consequently, the leaves of *E. edulis* will have greater DM content than the reported for *P. clandestinum* (12.0%), *Dactylis glomerata L*. (23.8%), and *Lolium perenne* (26.1.0%) which are the most important grasses in feeding ruminants in the livestock systems in the Andean region [36], although these values differ when compared for SF (12.2%). Despite huge differences in DM contents between both phenological stages, the SF showed a lower mean ash value than SV with clear differences in OM content. Additionally, as was expected, the EE values were low, as is typical for temperate climate forages [34, 37].

According to Schwab and Broderick [38] and Pfeffer and Hristov [39], CP content is essential for multiple organic functions and also serves as a substrate for rumen bacteria [40]. Additionality, McDonald et al. [32] and Gosselink et al. [41], revealed that there is a positive relationship between protein intake and the digestibility of

