POULTRY NOTES.

Auckland Star, Volume LVII, Issue 305, 24 December 1926, Page 14

POULTRY NOTES.

! .By R. J. TERRY.! UNDERSTANDING FEED TERMS. Some of the readers of these notes do not seem to grasp the meaning of feed terms. A Balanced Ration.—A balanced ration iis one that contains protein, carbohydrates, and fat. the element? nf nutrition. in the proportion required for the maintenance atid activities uf the animal or ' bird to which it i≤ led. 1 Protein.—Protein is a nitrogenous part !of the food, and is largely \:>ed for; growth, the repairing of waste tis-ue. and for reproduction. The production of eggs and similar products depends largely on the protein in the feed. Carbohydrates. — (.anvmyclrates are largely starches and sugars, and are used for the supplying nf bodily heat and energy. Fats.— Fat-; are frequently classed as carbohydrate*. They serve the same purpose, lmt are more, highly concentrated. An over-s-urplus of protein in a ration may be i;>e. 1 t>. replace a shortage of carbohydrates and fat. but a-; protein is the most expensive element to supply. it is not economical to v?- , it for that purpose. CaVbohydrates and fat, on the other hand, cannot take the plaoc of pro- ■ tein, so tliat a ration deficient in projtein. no matter how rich in carbohydrates 'and fat. cannot gi\e good re>uhs. i Ash. —Besides the three before menj tioned element-, a-h. which is the term ' used to designate the mineral compounds. is also of great importance, more so than I the average writer nf to-day recognises. I This question of a.-h. it rather mineral I salts, means everything in the health and I vitality of the bird. They are iron, cal- ! cium. sulphur, phosphorus, potassium, j manganese, magnesium, silicon, fluorine. I iodine, chlorine. The average writer will simply say that the a-h is valuable for i bone formation, but as ii matter of fact. , without these mineral salts, there ean- | not be life or reproduction, and if an>- ; one of them is dii-continued for a period I the health of bird, animal, or human i≤ : impaired.

DIGESTIVE NUTRIMENTS. At first sight it would appear to be an easy matter to get a table analysis and form a practically perfect ration for feeding, but it is not so. Analyses are not quite true, the chemist changes some of the constituents of the food in making the analysis. I admit that the analysis as determined by chemists is to a certain extent indicative of their value, but the only reliable test is by actual feeding experimeats carried over lengthy periods and under varying conditions. These experiments consist in the weighing and analysing of the feed of which it is desired to find the value, feeding it. and collecting, weighing and analysing all the resulting excrement. The difference in the weight and the analysis of the feed and the excrement is the amount assimilated or digested, or. in other words, the digestibte nutriments. In compounding a ration the use of figures representing digestible nutrients would be the best method to follow, but unfortunately rev.- reliable feeding esperimmts ha\e been carried out with poultry, so that it is necessary in most cases to depend on the feeding results with some of the larger animals in guiding us as to the \alue of certain foods we use for poultry. The dearth oil material from reliable poultry feeding experiments is due to the fact that urine contains the broken-down tissues of the b..dy. which makes it difficult to distinguish the broken-down body tissue from the unassimilated portion of the food. Therefore, briefly, when you see the words digestible nutrients it means that portion of the food which is assimilated. The nutritive ratio is the ratio which exists between the protein in gi\en feed and the carbohydrates ami fat-. F.»r example, wheat contains: — 11. , J protein. 71.9 carbohydrates. 2.1 fat. The fa: being much more concentrated, to bring it to the same value as the other carbohydrates it must be multiplied by 2.2"i. Therefore to find the nutritive \alue of wheat multiply the fat 2.1 by 2.2.:>. add the carbohydrates T1.9. and divide by the protein 11.9, which ghes t',.4. or in other words for every one part of protein there are ti.4 parts of carbo-hydrate-, so that 1 6.4 1 i< the nutritive ratio nf wheat. In referriu<: to rations, term- "'narrow" and] "wide"' refer to the amount of protein i

in comparison to the combined amount of carbo-hydrates and fats. These are relative terms and in no way fixed. "Where the difference betyeen the percentage of protein and carbo-hydrates is not large, the ration is said to be "narrow," and where the difference is jreat the ration is said to be '"wide." A ration which is more or less generally accepted aa suitable may be conveniently used with which to compare other rations. For instance, a suitable chick ration would have a nutritive ratio of about 1 3.5 to 1 4.5. The feathering period calls for a ration rather ■■narrower' than the ordinary growing period. The same applies to the mature fowl. A maintenance ration would have a nutritive ratio of about 6 to 1 6.5. and a fattening ration may be even a little "wider,'' but when a flock is laying heavily the ration should be narrower, about 1.4 to 1.5, and during moulting even "narrower" still, about 1 ."?..■>. It will be seen from the foregoing that in compounding rations it is advisable to consider the object for which the ration is intended. It i> advisable so to feed that the fowl will be able to get enough of each food element to satisfy the demands that are being made on its system without having to consume far more of other food eleenients than it can properly make use of. Really scientific feeding, balanced ration ns it is termed, is only common sense. For instance, it is impossible to feed a fowl mi an exclusive maize diet and expect it to lay well or to come through the moult in good condition. To get the amount of protein that it requires it will be necessary for it to consume far more carbo-hydrates than it needs, the result will be that the overplus of carbohydrates will be stored as fat and the fowl will get into such a condition that it would be useless for anything except market purposes. On the other hand, it is not advisable to use a larger amount of protein than i≤ required, as it is the most expensive element, and, consequently an overplus of protein would unnecessarily increase the cost of the ration, in addition to which we now know that an excess of protein really means the bringing about of old age or decay. The system i≤ poisoned by wastes. This is further accentuated if the birds are not at liberty to consume green grasses and clover.