Evaluation of Carob (Ceratonia siliqua) and Honey Locust (Gleditsia triacanthos) Pods as a Feed for Sheep

Abstract

The nutritive value of Ceratonia siliqua and Gleditsia triacanthos pods was determined on the basis of their chemical composition, in vitro gas production and rumen fermentation end-products. Medicago sativa was used as a reference feed material. The studied samples showed differences in chemical composition and phenolic compounds. Crude protein (CP) content was particulary low (80 g/kg DM) in carob and higher in Medicago sativa and G. triacanthos pods with (159.79 and 121.56 g/kg DM, respectively). Inclusion of Polyethylene glycol (PEG) in fermentation medium results in a significant increase (P<0.05) of gas production in Ceratonia siliqua and Gleditsia triacanthos and no effect was observed with M. sativa. The highest values of gas production were observed for C. siliqua and G. triacanthos, whereas Medicago sativa had significantly low values. The highest asymptotic gas production was observed in Ceratonia siliqua and Gleditsia triacanthos (296.80 and 289.55 mL g(-1) DM, respectively), whereas Medicago sativa recorded the lowest value (243.64 mL g(-1) DM). The concentration of acetate differentiated two groups: Medicago sativa and Gleditsia triacanthos (86.58 and 66.32% respectively), while the fermentation of Ceratonia siliqua resulted in a lower acetate concentration (59.84%). Although there were noticeable differences among the three studied samples, Ceratonia siliqua and Gleditsia triacanthos pods showed better nutritional quality, indicating that they could be considered promising and interesting sources of feed for sheep during the dry season or as supplement to low quality diets.