Nutritive value of some non-conventional feed resources of Ethiopia determined by chemical analyses and an in vitro gas method

Abstract

To contribute to the feed supply and help solve the critical livestock feed deficit in Ethiopia; the DM, CP, NDF, ADF, lignin(sa), ash, non-protein N (NPN); total tannin, total phenol, condensed tannins, phytate, saponins, organic matter degradability (OMD), metabolizable energy (ME) and short chain fatty acids (SCFA) production of 3 forages and 16 agro-industrial by-products were determined. Fishmeal (FM), duckweed (DW), mature cactus (MC), sisal waste (SW) and banana peel (BP) had high ash (235–163 g/kg DM) and lignin(sa) (142–77 g/kg DM). Cabbage leftover (CL), young cactus (YC), onion peel (OnP), distillery by-product (DB), brewery by-product (BB), papaya peel (PaP), DW, Moringa stenopetala (MS) and FM had high amounts of CP (137–490 g/kg DM) and NPN (10–225 g CP/kg DM). BB, DB and DW had high NDF (>384 g/kg DM) while CL, YC, OnP, PaP, MS and FM had low NDF (<240 g/kg DM). BB and coffee parchment (CPa) had high lignin(sa) (214 and 170) and NDF (535 and 744) g/kg DM, respectively with resultant low OMD (507and 322 g/kg DM, respectively). CPa, SW and DW had low ME (<6.5 MJ/kg DM); the rest had between 7.5 and 13.6 MJ ME/kg DM with similar trends in OMD and SCFA production. Avocado peel (AP), with a high ME (13.6 MJ/kg DM), had a low OMD (365 g/kg DM) because of its high fat. CPa, FM, AP and DW had the lowest SCFA concentrations (9.9–16.6 mM); MP, SW, OrP, PiP and CL had moderate to high ratios of acetate:propionate. YC, Coffee pulp (CPu), MS, CL and MP had high levels of total phenolics (112–151 g/kg DM) and tannin (42–121 g/kg DM). AP contained 22 g/kg DM condensed tannin and, YC and MC had none, and the rest had negligible levels. All feeds contained phytate and MC, YC, MS, DW and BP had large amounts (62–24 g/kg DM). Haemolytic activity (saponin) was detected in FM, DW, potato peel, SW, CPa, MC and CL. Some of the feeds can be used as sources of feed ME and CP, but because of the presence of secondary compounds, the amounts of the feedstuffs added in the diets of livestock should be decided through further research.