THE POULTRY YARD

Sun (Auckland), Volume I, Issue 252, 14 January 1928, Page 24

THE POULTRY YARD

(81/ (

GEO. H. AMBLER)

The Chemistry of Feeding

Food Constituents

rE theory of feeding is something considered to be valueless, and that only practical knowledge is useful to the poultry keeper, but the slightest insight into the subject will convince the most sceptical that much can be gained from theory. Theory and practice combined will make the ideal poultry feeder.

AS is well known, chemistry is the science dealing with the composition of matter and the various changes which the latter undergoes. There are about 85 known elements, but only 14 of those occur in foods; five are metals, and. nine are nonmetals, but these do not exists in foods as separate elements, being in combinations. Taking, for instance, dried milk, if it is burnt in a porcelain dish, various changes occur. First of all, a little watery vapour or steam comes away—no foodstuffs are absolutely dry—then the residue will blacken from separation of carbon. If this is now stirred with a glass rod, and the heating continued, eventually a greyish white ash is left. Milk contains nearly all the elements of foods, and by buring it its various constituents become oxidised —i.e., united with the oxygen of the air. In the same way it is possible to “split up” any other foodstuff and discover its contents. Food consumed is similarly divided in the process of digestion, and in this we find the value of chemistry. There are certain elements of ash which are valuable to poultry, including soda, lime, phosphoric acid, and chlorine. A GOOD INSECT POWOER There are two compounds of sodium of particular interest to poultrykeepers; (1) sodium silicate, or waterglass, used in preserving eggs by closing up the pores of the shell, and (2) sodium fluoride, which is very efficacious in ridding poultry of insect pesU for long periods. It should be applied to the birds in pinches among the feathers, as close to the roots of the feathers as possible, but particular care should be taken to prevent it getting into the eyes. Magnesium is an essential oonstituent in the green colouring matter of plants, and, as Epsom salts, is a safe purgative for fowls. • NECESSITY FOR LIME Oyster and cockle shells contain large amounts of the carbonate, together with a little phosphate of lime. All are aware of the necessity of providing ample lime in the shape of oyster or cockle shells, for supplying epes with their covering, and lime also enters into the composition of bone and blood. In the fish shells mentioned lime appears in a form which can be quickly dissolved, and hens which are laying heavily should have this material so that replacements in their system may bq easily made. Iron is also an essential constituent of the blood, and tp the transport of oxygen from the lungs to the tissues, and of carbon dioxide in the reverse direction. Among vegetables iron is especially found in spinach, whilst there is plenty of it in dried blood. When fowls are anaemic after the moult, these two foods are very useful. Silica, which forms a very big proportion of the earth’s crust as quartz, sand, etc., plays an important part in the poultry yard. Flint is almost pure silica, and is used by birds for grinding up their food, not for the mineral content in it. THE CARBOHYDRATES OF FOOD Carbohydrates are compounds of carbon, hydrogen, and oxygen, the last two being always present in the proportion in which they form water. Glucose, or grape sugar, is the most common, but there are quite a number of other forms and terms for them. The glucose formed in leaves is converted into starch by a process of condensation, and stored in the leaves, stems, roots, and seeds of plants. Some of the starch is converted into fats for storage in the seeds. Under fermentation it quickly changes from one group to another. Starch is converted into glucose in the intestines, and absorbed as such into the blood, and when glucose is oxidised heat is given out. Hence starch is a form of stored energy, available to supply the body with heat or enable it to do work. Our chief sources of starch are the cereal grains, which contain large quantities of it in the form of microscopical granules of different shapes, sizes, and markings. It is thus quite easy to ascertain whether a sample is adulterated —whether, for instance, an undue amount of barley has been ground up to form groun<L*pats. THE EFFECT OF FATS

Fats differ essentially from carbohydrates in containing a larger percentage of both carbon and hydrogen, so that their fuel value is much greater. In carbohydrates there is

just sufficient hydrogen present to unite with all the oxygen to form water, so that on burning there ts heat from the carbon portion only. In all fats there is a much greater proportion of carbon and hydrogen, an I in computing the digestible value. of them they are calculated as containing 2.3 times more than carbohydrates. It is interesting to notice that the whole egg contains 9 per cent, of fat, or about one-fifth of an ounce in a 2|oz. egg. If, therefore, a hen is laying heavily she is disposing of a great deal of fat and she must have a continual scource of supply for replacing same if she is to continue the process. The manufacture of eggs cannot alone be undertaken from carbohydrates and proteins, without a due proportion of £at THE VALUE OF PROTEINS These are very highly complex bodies, containing hydrogen, nitrogen, oxygen, carbon and sulphur, while a few, such as the casein of milk or vitellin of egg yolk, contain phosphorous as well. When proteins are consumed by a fowl no change takes place until they arrive in the passage between the crop and gizzard, the proventriculus, where they meet with the gastric juice containing pepsin. Under the influence of this they are broken down and are digested into the system. There are animal and vegetable proteins, many of the latter being very deficient and only worth their carbohydrate equivalent. Others, however, especially hemp and dried yeast, are of much greater value. Animal proteins are derived from insects and, in the case of domesticated birds, from meat and fish meal. There are few forms of animal food better than a good quality fish meal, because it is easily digested, does not vary to any great extent and contains a proportion of lime. Meat meal, owing to the presence of fat, may vary in every sample obtained. Dried blood is very good, but being so highly concentrated, not more than 5 per cent, should be used. Dried milk, and, in fact, milk in any form, is splendid for poultry and youn e stock fed on it will mature in a much shorter time. There is practically no waste in milk, and, being so easily assimilated, the digestive organs are not compelled to perform any difficult task.

GENERAL NOTES INTERNATIONAL STANDARDS yhe question of international standards was freely discussed at the recent World’s Poultry Congress, but the proposal that an effort should be made to promote the drafting of standards applicable to all countries was not adopted. As a theoretical proposal this has a fascination for many, but when approached with a view of practical application the difficulties are overwhelming. To a considerable extent these are natural. As Francis Bacon wrote nearly 350 years ago, “Let not man trust his victory over Nature too far, for Nature will be buried a great time and yet revive upon the occasion of temptation.” Moreover, there arises the question as to who shall draft the standards and whether they would be accepted generally. Breeders in the different countries can hardly be expected to scrap all the work done with breeds for so many years. Take the White Leghorn, for instance. Different types exist in practically every country. New Zealand and Australia follow the type adopted by the Mother Country, and, I am sure, could not be persuaded to adopt, for instance, the American standard. Surface judgment as to projects of this kind frequently fails to appreciate what is involved. REMARKABLE LAYING At the Harper-Adams (England) laying test,’the ducks on the flock trials finished with a wonderful record of 221.1 eggs per duck over the whole flock for 50 weeks. Mr. Oscar Brown's Khaki Campbells laying 1,680 eggs, an average of 280 eggs per bird, valued at £l3 16s lid, White Runners following with 1,526 eggs, to the value of £l3 9s 6d. In the single duck test the average yield per bird was 250.7, Mr. Stanley Ward’s Khaki Campbell leading with an egg-yield of 330 eggs, to the value of £2 16s 9d. The number of ducks competing was 161, and considering that many of these were in flocks, the average per bird is a remarkably good one. We understand that a well-known Christchurch breeder is importing a pen of Exchequer Leghorns from England. We do not know if this is the first shipment of this variety of Leghorn to arrive in New Zealand or not, but they are such wonderful layers they are sure to soon become popular. This variety originated in Scotland and is of a very hardy nature. CANARY SECTION The Auckland Yorkshire Canary Club will hold its usual monthly meeting in the Y.M.C.A. Buildings at 8 p.m. on Wednesday, January 18. Nominations for judge to officiate at Young Bird Show close at this meeting. With the close of the breeding season most bird rooms have undergone their seasonal overhaul, and we notice they are now looking spick and span. Red mite have had a rude awakening after the compulsory armistice between themselves and the breeder due to the risk attached to their unduly disturbing sitting hens. The North Island Association is certainly taking its time over the publication of the Standard Plates of the Yorkshire and Norwich Plainhead canaries. As one local fancier aptly remarked, “We have missed the breeding season and will be lucky if we catch the show season.” The secretary of the Christchurch Canary and Cage Bird Club informs me that interest in canary breeding is rapidly on the increase and the club is already having inquiries from breeders in different parts of the Dominion for dates of their next show, Mr. H. D Mace, Hastings, being one exhibitor who intends entering a big team at the Christchurch fixture. Mr. Mace also forwarded 10s 6d as a special to the Yorkshire section. PERSONAL ITEMS Mr. Denham, formerly of the Taranaki district, who has bought a 40-acre block of land at Glen Eden, intends g.oing in for poultry farming. Mr. Denham has already built several fine poultry houses aid runs. On our visit a few days ago we noticed some extra good Khaki Campbell ducks of the Ambler-Cruickshank strain, also a line flock of Higginbotham’s strain of Black Orpington pullets. Canary fanciers in Auckland will be pleased to hear that Mr. J. N. Rider (Foxton), the well-known breeder and exhibitor of Yorkshire canaries, intends settling in Auckland. Mr. Rider

has already signified his intention of joining the Auckland Yorkshire Canary Club and we feel sure he will prove, a valuable acquisition to the fancy locally. Mr. Les. Belcher, the enthusiastic breeder and exhibitor of Yorkshire canaries, has bred over 50 youngsters this year, many of which are already showing signs of great promise. The Yorkshire canary is slowly gaining in popularity. The latest convert to its charms is Mr. H. Fielder, who in the past has met with such great success with his Norwich, both plainhead and crested. Mr. R. W. Hawke, Christchurch, who has been visiting his old home and friends in Cornwall, and who also attended the World’s Poultry Congress as New Zealand’s representative, arrived in Auckland during the past week and paid a visit to the Mount Albert Laying Test. Unfortunately the writer was away from home and therefore had not the pleasure of seeing Mr. and Mrs. Hawke, the latter having accom panied her husband to England. We understand the New Zealand Utility Poultry Club is preparing to give Mr. Hawke an official welcome/ During the week Mr. Collins, Hastings, the well-known exhibitor and breeder of Old English Game, paid a visit to Auckland, where he visited many fanciers’ yards. Mr. W. A. Hanson very kindly drove Mr. Collins t*~ the yards of Messrs. Denize (Mount Albert), Boswell (Otahuhu), and Bust (Ellerslie). Mr. Collins spoke very highly of the young stock in the yards he visited. Mr. Hutchinson, the noted Stratford fancier, has been spending his holidays in the South Island, where he visited many fanciers’ yards. He has brought back with him a good trio of Anconas from Mr. R. Pearce and a pair of Black Pekin bantams from Mrs. Moffatt.