FEEDING VALUE OF RUSTED STRAW.

Otago Witness, Issue 3276, 27 December 1916, Page 8

FEEDING VALUE OF RUSTED STRAW.

Whether straw from fields badly affected with rust is safe to feed to stock is a matter well worth consideration under present conditions. Rust -year, in ,1889, in Australia was not soon forgotten. Goulburn Valley particulaidy was in a bad way, and now at a most unfortunate time we hear of considerable damage having been done in various parts of the Commonwealth. Some little while ago, too, it was reported that rust had made its appearance in New Zealand crops; but it may be that the spreading of the disease has diminished as one result of the finer weather; indeed, in places in Canterbury the cereal crops are being fed off on account of the drying winds having checked practically all growth of late. But the question is whether, in such cases where the crop is rusted, will it bo the wiser plan to burn the worst of the rusted straw and keep the brightest for feed, or condemn, the lot. This is what, among other things, Professor A. M. Shaw, of the University of Saskatchewan, has to say on the matter. ". . . Strange as it may seem on the face- of it, rusted straws contain considerably moro food

value than does clean bright straw. An analysis of rusted straw shows that it contains nearly three times as much crude protein as rust-free straw. Protein is the material that produces growth of bone and muscle and frame in our farm animals. The market and feeding value of feeding stuffs is based principally on the protein content, so it is quite evident that when rusted straws contain, as they do, several times as much protein, as rust-free straws, the rusted straw must be considerably superior to rust-free straw for feeding purposes. The reason for this is not difficult to discern. A healthy plant is attacked by the disease. Its growth and development are checked, with the result that the material stored up in the leaves and stems, and which later in a normal plant that ripens naturally is used up in forming the grain ,remains in the straw and thus increases the feeding value. In short, straw from grain that ripens- normally is sapped of the larger part of its feeding value, whereas straw from gjrain that has been arrested in growth, as in the case where rust attacks, the plant retains a large percentage of valuable food materials. Chemically, then, rusted straw is superior to clean straw for feeding purposes. Palatability and digestibility, however, have to be considered. Where the disease is only in the stage known as 'red rust' at harvest time, no difficulty will be found in getting the stock to eat it. When the disease has progressed, however, to the stage where it is commonly known as 'black rust,' and the stems become heavily coated, more difficulty will be experienced in feeding, as it is not quite so palatable. The fanner may have to resort to cutting or mixing with some other feeds. In any case, it is safe to feed ; and men with large piles of rusted straw can feed it to advantage. No bad results will be noted from its use when fed to farm livo stock. In many districts a certain amount of rust exists every year. The farmers of these districts feed their straw regularly, and so far no detrimental effects have resulted from this practice. Don't be afraid to feed it: it is valuable, and should be utilised for feeding purposes whenever possible."