| Abstract: | In the present investigation (3 experiments) the effects of fatty rapeseed products were studied on both straw-based and hay-based rations for lactating cows. Compared rapeseed products, used as ingredients of concentrate mixtures, were full-fat rapeseed (43% oil), partially defatted rapeseed expellercake (19% oil) and fully defatted rapeseed meal (2% oil). The rapeseed and rapeseed expellercake compared to the defatted rapeseed meal resulted in significantly higher yields of milk and 4% fat-corrected milk, when barley straw was the dominating roughage. In the hay-based diet the positive effects of added fat were not as much expressed. The iodine number of the milk fat increased about 4 units, when feeding the high-fat rations, i.e. the softness of the butter was improved. The results indicate that supplementation of straw with fatty rapeseed products will improve the possibility of a biologically and economically beneficial use of cereal straw in dairy cow rations. |
