Breeding as a means of increasing egg yield

Data resulting from experience collected by Prof. V. S, Asmundson, of the University of B.C. Poultry Department, is presented by that authority in the Poultry Tribune.

He says there are two methods by which egg yields may be increased.  One is to modify the inherited characteristics of the flock by intelligent breeding; the other is to modify the environment by improvement in management.  In other words, egg yield may be increased by manipulating the interacting forces of heredity and environment.  Both these forces are important, but since heredity changes more slowly, great stress, should be laid on breeding for unless this is done improvement in management will not yield maximum results.

Breeding can properly be divided into two phases, selection and mating.  Selection may be thought of as the sorting out of the inherited characteristics that we seek, mating as the combining of these characteristics for transmission to future generations.

How to select breeders

When breeding for increased egg production, either or both of two methods for selecting birds may be used.  One method is to handle and observe the birds to determine which ones start to lay early and continue to lay over a long period.  The other method is to trap-nest, and this latter has come to be accepted as the more accurate way to identify the good layers.  Since it is unprofitable and a waste of time to trapnest defective birds, all pullets should, like those entered in Canadian Record of Performance, be carefully examined before they are banded for trapnesting.

The trapnest record, if complete, tells the story of the performance of a hen at the nest fro a year or longer.  It tells whether she laid continuously, and at a high rate, during the winter months, whether she laid well during the spring and summer months, and whether she continued to do so without going broody or molting, until late in October.  This is important, because the number of eggs laid in 365 days is not sufficient to tell the whole story.

Several factors need consideration

The hen that has laid well in every month throughout the year, that has laid eggs of the right size and color, and that is herself of the right size and typical of the breed is the bird to select for the breeding pen.  In the case of White Leghorns selected for breeding at the University of British Columbia, this means continuous egg production durign the winter months, and a 365-day record of 250 or more, white-shelled eggs, which weigh, on the average, two ounces each, or over.  It means further that these hens are non-broody, weigh four pounds or over, and are in every respect typical White Leghorns. To insure the maintenance of these standards, requires accurate records and careful observation.

The average egg production of a flock may undoubtedly be increased by mating these supposedly “best” females to males from similar hens.  More certain anc rapid progress is, however, made if the chicks are banded and a record kept to show their parentage, for when pedigree records are kept it is invariably found that the progeny of certain matings are superior to the progeny of other mating, – superior in that they surpass the average for the flock.

Progeny testing selection guide

Progeny testing may be used in several ways as a guide when selecting birds to mate.  In the first place, by retaining the male and female whose daughters are better than the average, and repeating the successful mating; in the second place, by selecting the cockerels whose sisters give greatest promise, to head next year’s breeding pens; and lastly, when selecting for purposes the hens that have finished their first laying year by giving preference to those that belong to superior families, as measured by the performance of all the individuals tested.

How to mate selected birds

Pedigreeing may be used, as indicated, to aid in the intelligent selection of birds for the breeding pens.  Since pedigrees show the relationship between different individuals (and families) they may be used to assist in deciding in each mating.

This is important, because comparatively few individuals, and still fewer families are free from at least minor defects.  The pedigree records, by revealing the strong and weak points in each family, assist in mating to correct faults, and therefore make it possible to eventually build up strains of birds possessing only the desired characteristics.

Since perfection is rare, the object to keep in mind when mating is to secure a maximum of desirable qualities, with a minimum of defects.  If birds did not carry hidden defects, the logical plan to follow would be to mate together closely related individuals possessing the qualities sought.

Mixed blood gives trouble

In practice, however, this does not always work well, apparently because birds are so heterogeneous (mixed) in their hereditary make-up that most of them carry recessive or hidden defects, which are revealed in the progeny when closely related individuals are mated together.  If distantly related birds are mated together, these defects are gradually eliminated, with little immediate economic loss.

 The many excellent individual and flock records now consistently and frequently made indicate that many breeders have succeeded in virtually eliminating from their flocks the low producer and the bird that lays a small egg.  As a single example, three pens of ten birds entered in the British Columbia Egg Laying Contest last year (1925-26) completed the year with all birds qualified for registration, which meant that all of them laid over 200 eggs of the right color, that weighed on the average two ounces or over.

The gains, which have already been made, can be maintained by means of “tested” mating.  Still further improvements are most likely to be affected by intelligently mating the best individuals from families, which possess special merit.

Set an average goal

Averages for the flock are the best index to the progress so far made.  Averages for the best families may be used as the objectives to reach in the near future, whilst records for individuals may conceivably show to what level the flock can eventually be brought.

Looked at from the standpoint of present accomplishment and future possibilities, a few records may be interesting.  In six years, the average first year egg production of the White Leghorns at the University of British Columbia has increased to approximately 220 eggs each. The best family (six full sisters) laid on the average 254 eggs.

At the same time, the highest record made on the University poultry plant was 317 eggs, while the highest record made in a contest was 352 eggs.

The production of the flock of Rhode Island Reds has in the same period of time increased to approximately 210 eggs, with individual records up to 307 eggs.  These records would seem to indicate that the breeding methods briefly indicated above have not only produced substantial results but have also opened up interesting possibilities for the future.