Converting Surplus Potatoes Into Valuable Stock Feed.

New Zealand Journal of Agriculture, Volume 58, Issue 2, 20 February 1939, Page 119

Converting Surplus Potatoes Into Valuable Stock Feed.

Utilizing Potato Silage to Eliminate Waste of Crops.

C. E. BALLINGER,

, Assistant Experimentalist, Ruakura.

| I I | Surplus potatoes which are j | often wasted can easily be | converted into valuable feed ■ | for all classes of stock. | I Potato silage, for instance, i I offers a cheap and valuable | j source of feed by preserving ! I the surplus potatoes for | j future use. Several methods | | of making this silage are | described in this article. 1 ' i iniiiiiiiiiiiiuuiniuiiiiiiituiiiiiuiiiiiiiuiniiiiiiiiuiuiiiiiiuiiiiiiniiiiiiiiiiiiiuiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiuiiiiiiiiv

✓“'i ROWERS of potatoes in New Zealand are periodically New Zealand are periodically faced with a surplus crop for which they have no sale and no alternate way of disposal. . On such occasions many tons of potatoes are wasted when they could be converted into valuable feed for all classes of stock. This state of affairs has arisen this year in Canterbury, and in many instances potatoes could be obtained for pig-feeding by those who would take the. trouble to cart the tubers. This does not occur every year, but there are men who grow large areas of potatoes regularly and after sorting and grading have a large quantity of pig potatoes on hand for which they have no immediate use. Generally, these potatoes are left to become soft. and useless. This is particularly so in the late spring and in cases where the grower has held his potatoes in the hope that the price will improve. By this time there is plenty of other feed for his stock, and the pig potatoes are left to rot. If these surplus potatoes had been available in the previous winter, or if they could be

preserved until the following winter, they would be a valuable feed for all classes of stock. Two Methods. The problem of surplus potatoes is not peculiar to New Zealand but is present from time to time in Britain and in Northern European countries. There the position has been met by making potato silage. Two methods of silagemaking are used. One is to preserve

the potatoes by placing them in layers in grass silage stacked in the usual way. This method gives a type of silage suitable for stock other than pigs. The second method is by preserving the potatoes in pits either after cooking them or by slicing and pitting the raw potatoes with a small quantity of fermented maize-meal. The latter methods give a type of silage suitable for pigs and all other classes of stock. Not only can sound potatoes be used for silage, but damaged or slightly diseased tubers can also be used, provided they are cooked. Unfortunately, Canterbury makes very little grass Milage for its stock, and the amount of potatoes that would be saved at present by this method would be very small. There is no reason, however, why the other types of silage cannot be made, and where too small a quantity of the tubers are available for pitting they can be successfully preserved in oil-drums or discarded water-tanks. A thin layer of the surface material becomes unpalatable through exposure to the air, but underneath this layer the silage will be quite good.

Provision of Feed.

The provision of a cheap winter feed supply for sows and late autumn litters is one of the problems of the pig industry of New Zealand and is often as acute on mixed farms of the South Island as on the grass farms of the North. Potato silage, then, offers a cheap and valuable source of feed from a product which is otherwise wasted. It can be used either for winter feeding or fattening early spring and late autumn litters when the skim-milk supply is insufficient. Potatoes alone are not, however, a. satisfactory feed, and when skim-milk is absent or when less than one or two gallons per head is available potatoes should be fed in conjunction with meatmeal, peas, or some other protein concentrate. With the protein concentrate may be fed as many potatoes as the pigs will consume. While the publication of this article will be too late for the 1938 crop of potatoes to be utilized in silage-making there will be surplus supplies in the future, and the following directions for making the various types of silage, together with illustrations of the process, give the necessary information for making either type of silage. The photographs and methods have been taken from the Journal of the Ministry of Agriculture,

December, 1931 (“ Potato Silage.”

Wallace and Thompson ; Agr. Inst., Kirton) for which methods, &c., acknowledgment is made. (/) Stack Silage. A layer of green crop, 1 ft. thick, was placed evenly over the ground. A layer of 1 ton of potatoes was then spread evenly over the green crop. The potatoes were put over a riddle to remove loose soil and the young sprouts that had begun to grow. For convenience in handling the tubers were transported in bags. A run-over heap was made to

secure the necessary consolidation. The

green crop and potatoes were placed in alternate layers. When complete, the sloping ends or ramps were cut away and the material thrown on the top. The following day a layer of about 6 in. of soil was placed evenly over the top, and a few days later the sides were also covered with soil. A further layer of 3 in. of soil was also placed on the top. Very little wastage was found when the silo was opened. The grass silage was sweet and pleasant to the smell.

Where the heat had been greatest the tubers were partly cooked and quite sweet. Where there had been less heat the tubers were white in the flesh and slightly tough. There was practically no exudation of liquid from the silo. The silage was still in condition last month (November). (2) Potatoes Steamed and Pitted. . The pit should be prepared on a convenient piece of dry ground near to the feeding-pens. If water is likely to be troublesome, means should be taken to get rid of it. The pit should be made about 6 ft. to 7 ft. wide, and about 2 ft. 3 in. to 2 ft. 6 in. deep. The sides should slope slightly inwards. The potatoes should be cooked in a steamer or copper and then transferred to the pit, into which they should be tightly packed. They should be well raised into a ridge in the middle. The sides and top of the ridge should then be covered with straw, on which should be placed about a foot of soil. Potatoes made into silage in this way may be fed to pigs without any further

preparation. Silage made by this method in May, 1930, was still in good condition last month (November), when it was being fed to pigs. Partly blighted potatoes which could not be otherwise

ensiled may be preserved for stockfeeding if made into silage by this method. Observation trials have shown that pigs readily consume this silage, and that thus fed they do as well as pigs fed on standard balanced rations containing freshly-steamed potatoes. The silage is used in the ration in the same proportions as freshly-cooked potatoes. (3) Potatoes Sliced Raw and Mixed with Maize-meal. The steaming of potatoes adds somewhat to the cost of feeding, and for cattle it is neither necessary nor desirable. In this method steaming is dispensed with. The potatoes are sliced in a; root pulper, and are placed in a pit similar to that described under method 2.- At the same time, a small quantity of fermented maize-meal is mixed with the potatoes. The maize-meal should be prepared two days previously. It should be thoroughly saturated but not made sloppy, and should be allowed to become sour before being mixed with the potatoes. About 5 per cent, by weight of soaked maize-meal is required, or approximately 1 cwt. per ton. Maize-meal will increase in weight by about 75 per cent, when soaked. The pit should be finished off in the same manner as already described. Silage thus made was readily consumed by both cattle and pigs. Conclusions. The methods described of utilizing surplus, waste, or chat potatoes provide a satisfactory means of preserving them for future use. ; « « «