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New Zealand Times, Volume LII, Issue 12199, 25 July 1925, Page 19

‘TEAMI-SHELT imm poultry Nora soke Cause;: how to avoid (Written * for the “Tlium” by Gi'H- AmbJer.) ■ Dead-in-shell is. to the inoub&tist, the most perplexing of problems. and the -worst momenta they experience ere those in which the failures are carted put of the machines and siren to the pigs, or ; otherwise • destroyed. Some lrioubatists keep pigs, so what they . Jose on the eggs they, make up on pork. It ;is a serious moment for one to take out, say, 40 .per cent., shell from « 3000 mammoth, not that the niammoth ie worse than the 100-egng machine, as a rule it is not, hut to see 1300 dead-in-abell because they failed .to “pip” is to give'the inoubatiat a; similar malady not associated with the eating of oranges. It is the several factors which combine to cause dead-in-shell that make it such’ a complex subject, and-of these we axe taking physiological, - operative and bacterial causes. . Although they by -no means ‘ exhaust these . factorsTHE PHYSIOLOGICAL CAUSE . This concern* very largely the. stock birds, though many are quite unwilling, to admit it; but it is the inoubatist who has, sufficient breadth of mind to admit- it who will eventually achieve the greatest measure of success. These,dotes are not on feeding, ex-: qept to point out that improperly fed stock.. give the greatest proportion of dead-in-shell. Apart - from feeding, whether influenced by it or not, there is the -undoubted fact that some birds are hotter stock producers-than others. It is the same with-other animals, and how frequently a noted winner is notoriously unsuccessful as a breeder. This factor -gives /us a small 'Unavoidable percentage pf dead-ln-shell, from which even hen hatching is hot exempt. -• It is generally very difficult to breed from very- “fast*' layers, and thW et where production la in confliot with ipoubation. AN INTERESTING EXPERIMENT

The fact that eggs differ was? first brought home,to the writer in 1911, when in'company with the family doctor. We took same pains to rig up an apparatus that would weigh the egg in water,, and' to ascertain its speoifio gravity. The. method was too exacting and tedious to be. followed, and by breaking a few . eggs-it was passible to see (roughly, it is-true) some .difference in their quality. The thick white which stands - up from the more- watery fluid when an eggs is broken into s saucer Was found to be more pronounced; in some it [stood higher and looked more like plate ■glass as distinguished from - ordinary glass. The yolk, too, was arched like a rainbow in- some, and flattened like the top of an orange in others. It was the thick white and < rainbowed yolks that were the best quality eggs, a quality that could be altered by environment and feeding. The hygienic conditions in which the eggs are stored must noUbe overlooked, and before leaving the question of stuck, it. should be borne in mind that “8.W.D.” carriers produce a- ; great number of dead in shell, and it would be the [greatest blcssipg to the poultry industry if all such carriers died in the -sheff. ,The ..need- for cleanliness of -t he, egg will be realised when one kpows that the shell of the egg is not impervious , to that great army of microbes with which' it is surrounded FAULTY MANIPULATION TO BLAME -Some causes of dead-in-shell are; to he found with the incubator, or faulty manipulation. Perhaps nothing is so much- overdone as cooling. Prolonged cooling canfiot strengthen the-chicken, and it cannot imbibe large draughts or air during 20 minutes cooling, for it can only imbibe thq-.:air - at the same rate as' -when in the incubator, which' is a,very slow rate. It is quito certain that -the eggs, in the. mammoth incubators of' Egypt are'not carted out >nto a cool temperature of 40deg., .yet these