Storey's Guide to Raising Chickens (70 page)

Floor space for the breeder flock should offer a minimum of 3 square feet (0.3 sq m) per bird for large breeds, 2 square feet (0.2 sq m) for smaller breeds, and 1.5 square feet (0.15 sq m) per bantam. Include at least one nest for every four hens and frequently change nesting material.

Housing should protect the flock from extremes of climate, since sudden changes can cause a decrease in laying or fertility. During the early part of the season (late winter), provide lighting not only for warmth and to stimulate egg production but also to stimulate the flow of semen. You can improve fertility by exposing cocks to 14 hours of light, artificial and daylight combined, for 4 to 6 weeks prior to collecting eggs for hatching.

Outside disturbances may upset a flock and interfere with mating. Protect your birds not only from predators but also from unruly dogs and teasing children. You may also have to protect them from ignorant adults who need to be educated that their running, screaming kids or playful, barking dogs may not be doing visible damage to your chickens but nevertheless are causing them stress and harm.

In general, expect maximum fertility and hatchability from mature cockerels and pullets. Most cockerels reach sexual maturity around 6 months of age, although early maturing breeds may be ready to mate sooner, while late-maturing breeds may not be ready until 7 to 8 months. Comb development is the best indication of maturity.

You can start collecting hatching eggs when pullets are about 7 months old and have been laying for at least 6 weeks. Eggs laid earlier tend to be low in fertility. The few that hatch are likely to produce a high percentage of deformed embryos — perhaps because of the relatively small yolks of early eggs. As time goes by, fertility and hatchability improve, leveling out by the sixth week.

After about 6 months of laying, fertility and hatchability begin to decline — most gradually among bantams and more rapidly among the heavier breeds than among the lighter breeds. In industry, broiler breeders are kept for 10 months or less, compared to 12 months or more for layer breeders.

A much-debated question among small-flock owners is whether it’s better to hatch eggs from hens that are over or under 2 years of age. Hatching from older hens will improve the health and vigor of future generations. Two-year-old hens that are laying well must be relatively disease resistant and are likely to pass that resistance to their young. Furthermore, older birds tend to be the more valuable breeders, since they have proven their ability to pass desirable traits along to their offspring, the less desirable breeders having long since been culled.

On the other hand, using only older birds as breeders increases the generation gap, thereby decreasing the rate at which you can make genetic progress. Furthermore, hatchability declines slightly but significantly after a hen’s first year and continues to decline as the hen gets older. After the second year, you’ll see a greater percentage of early embryo deaths and failure of full-term embryos to emerge from the shell. If you breed older birds, take care to keep them stress free; for example, leave the show circuit to the younger generation.

The frequent showing of breeders can result in poor fertility and inferior chicks. Birds become stressed by travel, inconsiderate spectators, peculiar feed and feeding schedules, and perhaps lack of water due to oversight or simply because the birds don’t like the strange taste. Lack of water is particularly a problem with layers.

Hens, in general, are more greatly stressed by showing than cocks are, and older birds of either sex are more strongly affected than younger ones. Keep valuable breeders away from the showroom and the consequent exposure to stress and potential disease, not to mention the possibility of theft. Alternatively, minimize your risks by hatching a hefty number of chicks before showing your breeder stock.

Low fertility may be breed related, as a result of hereditary problems. The most common hereditary trait that influences fertility is comb style. For some reason single-comb breeds tend to have higher fertility than rose-comb breeds, and the sperm of single-comb or heterozygous rose-comb cocks live longer than the sperm of homozygous rose-comb cocks. So although purists insist that the occasional single-comb chick commonly hatched from rose-comb parents
should not be used for breeding, old-timers keep them, albeit in low numbers, to ensure heterozygosity and good fertility.

Breed-related mechanical problems may also result in low fertility. Such mechanical problems include these:

Comb size.
Breeds with large single combs have trouble negotiating feeders with narrow openings, and the resulting nutritional deficiency affects fertility. Large combs may also suffer frostbite, resulting in reduced fertility or even sterility.

Crests.
Houdans, Polish, and other heavily crested cocks may not see well enough to catch hens. A quick fix is to clip back their crest feathers.

Heavy feathering.
Brahmas, Cochins, Wyandottes, and other heavily feathered breeds have trouble mating. Fertility may be improved by clipping their vent feathers.

Foot feathering.
Booted bantam cocks and males of other breeds with heavy foot feathering have trouble getting a foothold when treading hens.

Rumplessness.
Araucanas (and occasionally birds of other breeds) have no tail; as a result, the feathers around their vents can’t separate properly for mating. The quick fix is to clip the vent feathers of both cocks and hens, with more attention to the feathers above the hens’ vents and those below the cocks’ vents. A better solution is to select breeders with the least vent feathering.

Heavy muscling.
Cornish cocks and other heavy-breasted males have trouble mounting hens because of the wide distance between their legs. These breeds are typically bred through artificial insemination.

Artificial insemination is used by breeders of Cornish chickens, by exhibitors who wish to keep hens in show condition, and by owners of valuable cocks that tend to be shy or otherwise low in sex drive. The technique is not difficult, but like everything else it takes practice — on the part of both you and the birds involved. As you might expect, tame birds are easier to work with than wild ones.

House cocks you wish to collect, or milk, should be kept in separate coops, away from other birds but preferably within sight of hens. Hens may be kept together but should be separated from other cocks if you wish to pedigree the chicks.

For semen collection, or milking, you’ll need a small glass or cup about the size of an eyecup and a 1-cc eyedropper or syringe (without a needle). The procedure is
easiest if you have a helper to collect the semen while you do the milking. Hold the cock in the palm of one hand, with your fingers toward the tail, and gently massage his abdomen.

With your free hand firmly stroke the cock’s back several times, then move your hand beneath the tail so the palm pushes the tail feathers up out of the way while your thumb and index finger apply pressure on both sides of the vent, ready to squeeze (but not yet). Stop massaging the abdomen with your other fingers, and press upward.

As soon as the cock’s organ appears, gently squeeze out the creamy-white semen while your helper collects it in the cup. You should get at least 0.2 cc of semen from a bantam and 0.4 cc from a large bird, although you may get as little as 0.1 cc or as much as 0.8 cc from either. If the cock is fertile, the concentration will range between 3 and 4 billion sperm per cc.

Should the semen become contaminated with fecal matter or chalky white urates, discard it and try again another day. If the cock persists in discharging feces at the same time as semen, withhold feed and water for 4 to 6 hours before collection. A healthy cock may be collected once every 3 days.

Among naturally breeding chickens, the greatest frequency of mating is in the late afternoon. Since this time of day coincides with the greatest yields of semen and the greatest numbers of sperm, you’ll have the greatest insemination success by scheduling collection for that time of day.