POULTRY CONGRESS SHIELD

Sun (Auckland), Volume I, Issue 300, 10 March 1928, Page 28

POULTRY CONGRESS SHIELD

10 per cent, of the weight of the entire egg—is expelled from the hen’s body, and thus ceases to develop further until heat is applied to it, either by the sitting hen or in the incubator. This egg is mostly formed in the ovary of the hen. Every hen possesses two ovaries, only one of which is fully developed, the other remaining with its functions in abeyance. Both the germ and yolk are formed in the ovary, to •tyhich they are attached by a kind of fibre, and protection is afforded to each separate yolk by a surrounding cuticle, which is transparent, and is called the ovisac. In the different stages of development these yolks are of different sizes, as any one knows who has seen the ovary of a hen that is “in lay” after death, and many a person of small experience has regretted killing a bird for table when he has found her to be practically “full of eggs”; in fact, just on the point of “coming on to lay.” When the proper time arrives the ovisac, having by degrees become more and more attenuated, finally ruptures at the stigma, which is a sort of belt that surrounds it. The yolk then moves gently into the oviduct, being surrounded at this period by only a very thin membrane. Sometimes a blow or a strain will rupture a yolk when in this unprotected state, and death often* ensues. In the oviduct, which may be described as a tortuous tube, 2ft in length, the yolk is gradually covered, in its gentle passage downwards, with the fluid that :is secreted by the contiguous mucous membrane, and which is colourless, and of a thin gelatinous consistency. This is the albumen, or white, and it is laid around the yolk in successive layers. THE EGG FORMED As what may now be called the egg, proceeds on its passage down the oviduct toward liberty, and either the breakfast table or incubation, it approaches a certain point where it is invested with the skin, which consists of two separate layers. Still further on its downward journey it meets with the carbonate of lime which forms the shelled egg is caused by over-feeding, especially with meat and forcing food, or spices, in which case the treatment is to stop the meat or spice and revert to simple food. It would be better to give no soft food for a week or two, but feed on grain only. Also to put one teaspoonful of Epsom salts in every halfpint of the drinking water. Another cause is the absence of shell-forming material in the dietary of the birds. Furnish at once an abundant supply of shell grit, and see that a supply is always before the birds. Yet another cause of soft-shelled eggs is a fright produced by being chased by dogs or children. DOUBLE-YOLKED EGGS This is probably due to a hen’s letting go two yolks at the same time, so that they reach the oviduct at the same moment and are thus coated with albumen simultaneously, and making a joint passage down the outer and final protection or covering that we have named the shell. Where colouring matter is added, as is the case in some breeds, we have produced the light or dark brown egg. On the subject of colouring, it may be well to

eggs being retained too long in the cloacum Some have surmised that they are laid by birds with liver disease, but there is no intimate connection between the liver and the organs of egg-production. The probability lies, I think, rather in the direction of too long retention.