POULTRY NOTES

Dominion, Volume 34, Issue 121, 15 February 1941, Page 14

POULTRY NOTES

Control Of Egg Size BREEDING AND OTHER FACTORS

Egg size is primarily a question for the breeder, but itis part having been properly played, there are numerous miler factors which have a bearing on the size of eggs. First ami foremost egg-size is an inherited i-lit)r.u-ier anil if a bird comes from a small egg strain nothing th,-it can be done wiJl induce her to pro-dm-e large eggs. When breeding for high prodm-lion it is a simple mailer Io establish a line or family of birds incapable of laying large eggs unless great care is taken in selection. Tlie best layers usually start production at an early age and as soon as laying starts growth practically eeases for lhe reason I hat most of the food is required for product ion and maintenance. Hence, if selection is based mi production only, in lhe course of a few genera i ions lhe breeder gels small birds laying small eggs. The breeder has lo guard agninst this by selecting only those birds which do not become sexually nml urn before they have built tip their bodies ami frames. Il <-annot be assumed that every large liii-,1 will lay a large egg or every small bird a small one. bur generally speaking this is so jn-so-far as it represents the breed; that, is lo say a small Leghorn is likely, for example. to lay a small egg that one which is well developed, anil so with other breeds. Egg size therefore is primarily a breeder's problem and lie must select hens which lay eggs of good size, mating them will) cockerels of large egg dams. With regard to the early-hatched pullets which commence to lay at. a relatively early age, many poultry keepers are concerned by the number of small eggs they produce. While the breeder must hear the question of egg size constantly in mind, in normal cii-enmstnnees there is no need for him or purchasers of his stock to worry about these small eggs of the first clutch. Ar this stage the chief roneern is lhe development of the birds. If they are well gl-own and up to lhe average weight for lhe breed, they will ultimately attain tin- egg-size they have inherited, though they will lay earlier than their laier-hiiti-bed sisters and may also produce a few more small eggs. This early laying, according to Leonard Robinson writing in "Eggs” (Eng.) is due to lhe fact that in early hatched stock growl I) is speeded up. bur it does not follow that body size will not lie satisfactory or that egg size will not become normal in due course.

in addition to breeding there are many other factors affecting egg size. For example, a bird which has been badly reared. or has suffered from disease which lias resulted in stunted growth cannot possibly lay eggs of the size she Jias inherited, neither can she do so if environmental conditions including tlie feeding, arc unfavourable when she is mature. Well-grown births of a large egg strain will lay small eggs if the conditions under which they are kept preclude the full utilization of the food. They will also lay small eggs if the ration fails to provide the necessary m.-iterial for the production of large eggs. Experiments on the Seientilie Poultry Breeders’ Association farm have clearly shown that where the ration is deficient in protein or contains only vegetable pro-

teius. size of egg is not maiutained. It has also been demonstrated that soaked grain is superior lo dry. probably on account of file additional nioisture eou-siuni-d by the birds llunigh there may be other faetors al work. Any ilefieieney on the nil I fit iona 1 side is likely to afli-et egg size hut provided care is taken to avoid feeding too much bulky material of a watery i-omposilion. which merely (ills the digestive llllr-l bill fails lo nourish lhe birds there should be no trouble with small eggs. Lack of drinking water will quickly (.-aiiso a redin-lion in both lhe size and number of eggs ami this is a prevalent cause of complaints in .summer and winter. for in Ind weather drinking vessels are sometimes allowed to run dry. while in winter severe trusts have to he i-mi-teinled with in m.-iny areas. Birds do not like ley cold water ami may not drink sufficient lo ensure maximum egg size. Weather affects egg size, at least indirectly. In hot weather many birds get distressed and appetites flag, lienee loss of egg size. In cold windy weather fowls lend to huddle, do not forage as they should, and if fed outside may not stay out long enough to consume all rhe food they require and as a result they lay smaller eggs.