The nutritional value of a feed ration for dairy cows depends on the values of forages ​​and concentrates. The aim of this study was to determine the physicochemical properties of a dairy cow ration (hay, oats, clover, alfalfa, mature and premature barley and concentrate) in the region of Blida, in northern Algeria. Physicochemical analyses included: dry matter (DM), organic matter (OM), mineral matter (MM), total nitrogen (TN), fat (MG), insoluble ash (IA), major (Ca, P, Mg, K, Na) and minor minerals (Mn, Cu, Zn, Fe). The results showed that hay and concentrate were the richest in DM (86.60±3% and 84±0.62%, respectively) (p˂0.001). Alfalfa was characterized by a higher content of TN (21±0.87%), while the lowest value of TN was found in hay (2.97±0.02%) (p˂0.001). The concentrate contained the highest levels of MM (13.30±0.42%), MG (5.26±0.21%) and IA (2.11±0.25%), and hence it was the poorest in OM (86.70±0.42%) (p˂0.001). As for the minerals, hay was characterized by a higher Ca content (18.7±0.48 g kg-1 DM) and lower in P (1.9±0.09 g kg-1 DM), Na (32±2.40 g kg-1 DM), Zn (31±11.29 mg kg-1) and Cu (4.69±0.74 mg kg-1). Oat was the lowest in Fe (19±0 mg kg-1) and the second richest in K (48±0.79 g kg-1 DM) after clover (51.7±1.11 g kg-1 DM) (p˂0.001). Alfalfa showed the highest Na content (63±0 g kg-1 DM) (p˂0.001). As for Fe, premature barley showed the highest value (55±4.30 mg kg-1) (p˂0.001). The concentrate was found to be the richest in Mn (98±5.64 mg kg-1) and Zn (110±1.32 mg kg-1) (p˂0.001). The results of this study provide important support for the rationing of dairy cattle in Algeria. Acquisition of additional references on the nutritional properties of feeds is necessary in order to better predict the nutritional value of rations.

23.2.2018