Grewia optiva leaves are lopped for fodder. The tree is regarded by local farmers as a valuable fodder for dairy cows and usually preserved for feeding during the winter.
Digestibility and degradability
A digestibility trial carried out in India reported OM digestibility values of 65-66% on sheep (Sharma et al., 1966). In sacco trials on sheep and goats found effective degradability values for N of 67-68% (Khan et al., 2009; Khan et al., 2012c). An in vitro experiment using rumen liquor of buffaloes compared 17 tree forages and showed that bhimal leaf meal did not compare favourably with others forages in the DM and N degradability tests (Gurung et al., 1996). Bhimal leaves mixed (25% and 50%) with poor quality grass (Dichantium annulatum and Heteropogon contortus) were tested in vitro with rumen liquor of sheep and goats, resulting in an increase of DM, CP and fibre digestibilities and of rumen fermentation metabolites. It was concluded that bhimal was a good supplement for small ruminants fed on poor quality pasture in silvipastoral systems (Singh et al., 2016; Singh et al., 2015). This was confirmed by later results (Singh et al., 2017).
Cattle
In India, it was possible to supplement young crossbred Jersey males fed on rice straw with bhimal leaves. The results were similar to those obtained with groundnut meal or with a mixture of bhimal and groundnut meal (Pachauri et al., 1974). Grewia optiva was reported to be much valued as a fodder in Northern Pakistan, tough only mature leaves were relished (Momin et al., 1943).
Buffaloes
Lactating buffaloes supplemented with bhimal fodder consumed about 6 kg/day of tree leaves, resulting in a higher milk yield (+0.2 kg milk/day)(Shrestha et al., 1989).
Sheep
Grewia optiva leaves were compared to cotton seed cake and maize oil cake to supplement a sorghum hay-based diet in crossbred wethers. They resulted in lower feed intake than oil cakes but there was no difference in DM and OM digestibilities. N digestibility was improved by the use of bhimal leaves and it was concluded that this forage could be a used as a protein supplement in sheep (Yasmeen et al., 2007). These results were confirmed by later experiments where the leaves were also compared to cottonseed cake (Ahmad et al., 2012; Khan et al., 2012c). Bhimal leaves increased N degradability to a lower extent than cottonseed cake, while it increased N digestibility and N retention similarly. Animal performance (body weight gain and wool yield) was similarly improved by bhimal leaves and cottonseed cake, confirming that bhimal leaves can be used a a good and cheap protein source to supplement low quality diets in sheep (Khan et al., 2012c). Another exeperiment reported that bhimal leaves increased N intake and resulted in the higher N retention (55-60%) when compared to basal diet or basal diet supplemented with oil cottonseed cake or maize oil cake. It was concluded that Grewia optiva leaves could successfully replace oil cakes by improving the utilization of basal diet through higher nitrogen intake and retention (Ahmad et al., 2012).
Bhimal leaves given as a protein supplement (320 g DM) to adult sheep fed on an oat hay basal diet had no effect on dietary DM degradability. They reduced oat hay intake but increased total DM intake and N retention (from 4.39 g/d to 7.51 g/d) (Habib et al., 2008).
Goats
Grewia optiva leaves could be used as a protein supplement for lactating goats fed on a grass hay based diet or on a maize silage basal diet + grazing native pasture. When compared to cottonseed cake and indian jujube (Ziziphus mauritiana) foliage, bhimal leaves had a lower N degradability. DM digestibility of the diet was not affected by the inclusion of bhimal foliage. N retention and milk yield were increased to a lesser extent than with cottonseed cake or indian jujube. Bhimal leaves increased milk fat content to 56g /kg milk (Khan et al., 2012a; Khan et al., 2009). Lactating goats fed on chopped soghum hay and on a mixture of cottonseed cake and bhimal leaves at variable levels (100: 0; 50: 50 or 0; 100) had the highest DM intake, N retention and body weight gain at 100 % of bhimal leaves (Khan et al., 2012b).
