ARTIFICIAL INCUBATION.

Otago Witness, Issue 2689, 27 September 1905, Page 32

ARTIFICIAL INCUBATION.

- IMPORTANT EXPERIMENTS AT U\ Tlt ■ VERSUS; COLLEGE. * .PEARSON'S, TAMLIN^S, AND CYPHER INCUBATORS AT WORK. The following report of experiments" in Berkshire (England) with, artificial incuba- , - tion is .particularly interesting a t the pre~sent moment in Ifew Zealand and deserves close attention, by breeders :_— - - £ •__ In these days -of strenuous poultry haton- "- ing, "when the broody hen of the country ,* is altogether insufficient to take upon her - the responsibility of hatching out anything like the ' numbeT of - chickens on demand, . breeders are perforce driven io the use of . artificial! incubators, and' from them undoubtedly get an exceedingly large measure of success." But we use (Fanciers' Gazette, England) - tbe word measure circumspectly and advisedly. .For the results, "even with the most up-to-idate incubators, a.re not absolute certainties, nor 3-ot is the 'best machine yet, produced infallible. With all machines - , the greatest care is required tha* rules and regulations be st'ictty carried out, and ', then, when all is said and done, our variable' climate will make havoc sometimes jf the very best efforts, iust as it will sometimes of the ' niosfc assiduous work on the part of the broody hen. \ Therefore, our readers will be interested - no doubt in the experiments which have recently .been carried out at University College, Reading, with a view to secure, if possible, a better knowledge of the laws which govern artificial incubation. The result of these experiments are brought to- • gether in small pamphlet form, and re1 printed from the Jeurnal of the Board of Agriculture and Fisheries. !ks most of our readers know, the University College Poultry Farm is at Theale, ' in Berts. The experiments cover a 12 [ months, ending March- 31. 1904. The num- , ber of fertile eggs placed "in incubators of both the* tank a-nd hot-air -varieties was V 3647, and of these 2572 hatched out strong chickens and ducklings, an \average of slightly over 71 per cent. The "highest success -^reached in the 12 ■ months was in April, 1903 (92.1), and the -'•lowest in March, 1904-. The tank machine ' hatchings were 38 and the., hot-air machines 24. ' Something like. 2 per cent, stood in favour of the tahk machines. Since the - close of these 1903-4- experiments, a further series, extending from March, 1904, to March 31, 1905, has been made, and the - results are now available in printed form, : and it is these with which we have now to j deal. , , , ... i -A special incubator house has been built . at Theale. It is above ground, shaded ' - from the hot sun by a large walnut tree. •' Various records of temperature have torn - kept, as fostered by this house, and trie «*eneral conclusions arrived at are that, it ( „/sueh a house be properly constructed, the j ' temperature will not vary in it more than 1 a couple of degrees or so, for great changes , , of outside temperature in the 24 hours, the -~ maximum 35deg F. and minimum 18dez 1< • '-- do not seem to -have altered the temperature of the incubator -room appreciably. „ In summer, of course, the temperature or this hatching-room runs up considerably, ' end Ftands as high a= 67dcg. with an outride temperature of 85deg F. But the changes in the room were never rapid. - Rapid changes are presumably what the , urers of incubators ha\e mostly lo fear. The ' humidity of the room was carefully tested. ' too daily, and the greatest temperature was Jipt always accompanied by U'-o great.p=t humidity. In fact, at times tho humicMy | . seemed +0 vary in inverse ratio to the temperature , 1 Never, during the whole 01 the oxppnicents did the humidity of the air in trie incubator roOfa reach saturation point, lms eaturaiion point may not be gsnerally understood by those outside a scientific train7' n °- But we may incidentailv remark, m parsing, that whan we see mists rising up 1 out of the carLh. or from a river, t^c humidity of the atmosphere has- reached saturation uodnt- The air can take uu no

J more humidity, and hence we see tho surplus forming little vesicles of fog and mist.

We have no room here to go into all the tables published in these report's. The 111- ' cubators u^cl were Hearson's and Tamlin's. lof the tank pattern, and the Cypher, of 1 {.lie hot-air stamp But in all classes one great thing was distinctly noticeable, both in the experiments of this and tho pr-o- ' vious year's workings. Ihe best results werj invariably got in all tbe machines when the drawers were by no means full of eggs. j Again and again the thing was proved. 1 Notwithstanding increased fertility of eggs, the average of hatching went down as the incubators were increasingly filled up. This is an important thing to be remembered, and the advice is frealy thiown out that incubators should never be worked with their full complement of eggs. It is somewhat singular that the fertility of eggs in June should he at as low a figure as in October. The lowest reached was in December. 64-.95, and the highest in September 90.16. April and May have good results, 82.49 and 87-65 per cent, of ferliles respectively. The highest percentage reached by the tank machines was in October, when they hatched out over 97 per cent., and the highest by the hot-air machine was in January, 1905, which then touched the aO point. It does not ssem. on a careful trial, that there has been much practical difference in the working ' 1 esults of the two classes of machines, but what has been emphasised by the two-years' trials ig (1) that a room can be built varying little in temperature; (2) best results are got by machines only partially filled; and (3) that an average of 70 t>ei- oent. of chicks can be produced from well-built, reliable machines.