Abstract
The effect of feeding discarded dates (non-edible for human consumption) on milk yield and composition of lactating Aradi does was studied in Saudi Arabia. Ten multiparous Aradi dairy does were equally divided into two groups and they were offered two diets: one as the control diet, including 35% alfalfa hay and 65% concentrate (corn grain, wheat bran, barley and molasses) and the other one as treated diet in which 30% of the total ingredients (basically from cereals) were substituted by discarded dates. Therefore, diets were isonitrogenous (18% CP) and isoenergetic. Milk yield, pH, and acidity of milk, major milk components, nitrogen distribution and minerals in milk were evaluated. No significant differences in yield and acidity of milk were observed between the two diets, while pH of milk in the control diet was higher. Milk obtained from does receiving discarded dates was significantly higher in protein and solids-not-fat contents, but the other milk constituents were not different. No significant differences were observed for non-protein nitrogen of milk (NPN). Milk obtained from does fed diet with dates had higher casein nitrogen and non-casein nitrogen than does fed the control diet. Casein number was higher for milk obtained from does fed the diet with dates. For minerals content in the milk, differences in K, Na, Mg, Ca, Fe, and Zn contents between the two dies were not significant, while Mn and Cu were reduced in milk of does receiving dates. In conclusion, feeding isonitrogenous diets including a reasonable close of discarded dates had no negative effects on milk yield and composition of Aradi goats. (C) 2008 Published by Elsevier B.V.