THE POULTRY YARD

Sun (Auckland), Volume I, Issue 170, 8 October 1927, Page 30 (Supplement)

THE POULTRY YARD

By Geo . H. AMBLER

DRY MASH FEEDING The Bred-to-Lay Hen rpHE rapid advances made in recent years in respect to the individual output of the bred-to-lay hen and the world-wide interest now manifested in the latter, has rendered old-time feeding methods more or less obsolete and has forced upon us the necessity of applying science in a larger degree than hitherto when arranging the diet of the modern bred-to-lay hen.

rpHIS bird has increased her power of production during the past few years to a more striking extent than any other class of agricultural stock. Not a little of the credit for this very marked progress is due to breeders in New Zealand, and I believe I am right in stating that the highest individual record was, until recently, held by one of their number. Originally the average breeder of laying hens was content with an output of below 100, but breeders in various parts of the world have achieved three times that record, and more, while now few observers would dare to doubt the actual possibility of the 365 egg hen. It is obvious that, notwithstanding all the pedigree and fashionable breeding in the world, this daily egg first goes in at the mouth; and as records increase it becomes more and more imperative that scientific breeding methods must be accompanied by systematically applying science to the question of diet upon which so much, of necessity, depends. Food or fuel must be provided, for the modern living eggs machine, of such a character and served in such a form as to ensure healtli, vigour and rapid assimilation, and preserve to the utmost limit of efficiency the digestive system. The early idea was cooked and so-called pre-digested foods, which has proved to be not only costly but ineffective merely because it is scientifically imperfect. NATURE’S METHODS The human animal with his chronic, dyspeptic trouble is, perhaps, the most striking example in practice of the failure of a cooked or pre-digested diet. Nature provided effective means of dealing with this question of diet through a machine compared with which every man-made mechanical wonder pales into insignificance. Jn preparing the diet by costly methods of manipulation we not only rob the food of much of its nutritive worth, but insult Dame Nature's wonderful scheme and render it less capable, for which, sooner or later, the penalty has to be paid. To keep pace with the rapid increase in production I have mentioned, common sense concedes that a diet must be supplied in a readily assimilable form and of such a nutritive character that the heavy tax deep laying entails lis effectively provided fur. It was

considered originally that the average laying hen required a diet which gave an albuminoid ratio of 1 in 4, but by the speeding up of productivity the narrower ratio of 1 in was deemed more accurate. THE NUTRITIVE RATIO I do not pretend to lay it down as rigid that the nutritive ratio should be precise, and 1 in 3| is given as a calculation only approximate. I here give the mathematical formula in Kellner’s own words: “In order to quickly and conveniently see the relation between crude protein (albuminoids) and the various nitrogen-free substances (carbohydrates) it lias been for some time the custonx to employ the ‘nutritive ratio, which gives the amount of digestible nitrogen-free materials of the nature of carbohydrates, which falls to one part of the digestible crude protein. The digestible portions of the nitrogenfree extract and of the crude fibre are similar in their percentage composition and heat value to the carbohydrates; the fat, however, is a more concentrated nutrient, and on combustion uses 2.44 times as much oxygen as do the carbohydrates. Formerly the amount of oxygen consumed in the combustion of a material was taken as a standard of its value in the production of heat and as a nutrient, so that to calculate the digestible fat as carbohydrates it was multiolied by 2.44 and the amount added to the nitrogenfree extract substances. To calculate for example, the nutritive ratio of oats, which contain 8 per cent, crude protein. 4 per cent, fat, 44.8 per cent, nitrogen-free extract, and 2.6 per cent, crude fibre, all of which are in a digestible form, the sum of the carbohydrates would be 44. S plus 2.6 plus (4.0 x 2.44), equals 57.2 per cent. To this 57.2 per cent, carbohydrates falls 8 per cent, crude protein from which the nutritive ratio (8.0: 57.2) equals 7.15 is calculated. “According to recent investigations, the factor 2.44 for the conversion of fat into carbohydrates is not correct, and is better replaced by the number The formula of calculation is therefore as follow's: Carbohydrates plus crude fibre plus (crude fat x 2.2.). DIGESTIBLE ALBUMINOIDS OR PROTEIN Albuminoid Ratio.-.—As this article is written chiefly for the novice, it will i be necessary for me to explain that