Every railroad company shall, upon reasonable notice, furnish to all persons or corporations who may apply therefor and offer property for transportation, sufficient and suitable cars for the transportation of such property in carload lots. In case at any time a railroad company has not sufficient cars to meet all the requirements for transportation of property in carload lots, all cars available for such purpose shall be distributed among the several applicants therefor without unjust discrimination between shippers, localities or competitive or noncompetitive points, but preference may always be given in the supplying of cars for shipment of live stock or perishable property.