Notes for the Poultry Farmer

New Zealand Journal of Agriculture, Volume 63, Issue 5, 15 November 1941, Page 439

Notes for the Poultry Farmer

Determination of Sex in Chickens

By

S. G. HADDON,

Poultry Instructor, Auckland.

Superstitions still survive among all classes of people, including , poultrykeepers. One of these superstitions is that the sex of the yet unhatched chick is determined by the shape of the egg—a long one would give one sex and a short, round one the other sex. Actually, the shape of the egg has no influence on the sex of the . chick at all. More often than not a badly shaped egg is infertile, but there is no doubt > that the shape of the egg plays a big part ■ in the physical quality of the chick hatched from it. In the ._past, quite a few appliances have appeared which claimed to show whether an egg would produce a pullet or a cockerel chick when hatched, but no method has. yet been , found to indicate whether an egg was even fertile or not, except the obvious one of incubating it. Naturally, the first step along this road would be the possibility of detecting life in the egg before placing it in the incubator. Determination of the sex in the egg would follow later. However, the de- • termination of the sex of day-old .chicks is an accepted fact, and the practice of chick-sexing is; established on commercial lines. Method of Sexing It is not proposed to give a detailed account of how sexing is done.' The underlying principle has been known for some time, but was first exploited by . the Japanese. "Briefly, it entails the recognition of a small protuberance just inside the vent. To make this examination, the vent is turned inside out, and with care ana practice' this manipulation will not harm the chicks at all. . The sexing must be done ’while the chicks are very young, as the structural differences by which the sexes are distinguished lose; their distinctiveness in a matter of a day or so. Canadian and American investigators. also worked on this problem and evolved a slightly different technique, but their method is still based on the recognition of the “genital protuberance.” Essentials for The Work ''

There,' are quite a few New Zealanders sexing chicks in this country, and there is enough work for many more. The chief essentials for this work are supple fingers (slender for preference), really good eyesight, and an

ability to concentrate for long periods. Many young people are taking up sexing while their sight is still good and their hands are not yet set. The equipment needed is merely, a good electric lamp of, say, 300 watts, and a suitable shade to concentrate the light in the desired place. Some sexers use a pair of magnifying anato- , mica!' spectacles or a single lens on a stand. Learning Sexing - Two or three publications on sexing illustrated with diagrams . and photographs are obtainable, and persons of average intelligence should not have any difficulty in obtaining a . grasp of the required procedure from these books. It is then a case of continual practice, which may become rather expensive, as the chicks need , to be killed and opened up for verification- as soon as they, have been sexed. . The beginner will learn more by this method than by rearing the two sexes separately, as by the time 1

the sex of the chicks has become apparent some six weeks later the value of the test will have been lost.' Some of the sexers in this country give tuition in sexing, and this tuition is available at . at least one agricultural college. Most sexers will agree that accuracy and speed in sexing are largely influenced by correct methods in holding the chick, and bn this point alone practical instruction .is of far more value than any amount of theoretical study. Advantages of Sexing > The biggest advantage from sexing is the saving in the amount of brooder : equipment needed to rear any given number of pullets. A farmer might have brooder room for 500 day-old chicks, but by * using sexed . pullet chicks the same results are .obtained as if twice the amount of brooder' equipment were used to rear 1000 unsexed chicks. The final result would be the sameabout 450 pullets. In . other words, the use of sexed day-old chicks will just about double the existing brooder capacity. Another important point is the saving in the amount of food used. Unwanted cockerels have to be kept

until they are old enough to be picked out with certainty, usually four i to eight weeks, and during this time they will consume an appreciable amount of -food. This . unproductive consumption will be obviated by' the use of sexed chicks. Nevertheless, enough unsexed chicks must be kept to ensure a really good choice of future breeding cockerels. The usual procedure is to keep intact the first hatch or one of the early hatches of the season from special pens. At first, quite a few breeders did not realise this necessity and consequently found themselves short of good breeding cockerels. _ Disadvantages of Sexing It is . well recognised that the advantages of sexing outweigh the disadvantages. Perhaps the biggest objection is that the hatching programme must be- arranged and strictly adhered to in order to suit the convenience of the person sexing the chicks. This sometimes means close co-opera-tion between neighbouring farmers, and in this respect is a blessing in disguise, as the closer the co-operation among poultrymen the stronger will their industry become. Possibility of Harm Through Sexing The sexing of day-old chicks will definitely not harm them either for

> laying purposes or as future breeders, provided it is done by a competent s ixer. It is the ovaries which produce . the egg, not the vent. Complaints are sometimes received of sexed chicks not rearing too well. Sexing is blamed for this, but the writer is of the opinion that in many cases the trouble was caused by the chicks being chilled at the time of sexing and not by the actual practice. This chilling can easily occur while the sexer is at work. The chicks are

often held in the incubator or in boxes with the lids on until'the sexer is ready for them. They are then placed in front of him in open boxes, and it is probably about this time that chilling occurs. The remedy is to have the sexing carried out in a warmed room, which will prevent any tendency of the chicks to chill. Sexing by External Appearances Where it is impossible to obtain the services of a chick sexer, it is neces-

sary to, rear both pullets and cockerels until the cockerels have reached an \ age at which they can be distinguished and removed from the brooders. Unwanted cockerel chicks can easily be distinguished when they are about three to four weeks old. At this stage definite indications, of sex begin to show, and it is on these indications that the cockerels are picked out. With Leghorns and most light breeds, the first. indication is the rate at which the comb of a cockerel develops. This will often become, apparent when the chick is in its third or fourth week, although some birds are quicker than others. At the same time, although not to such a marked degree, the wattles of the male begin to show up. Fig. 1 demonstrates this point. The cockerel (right) has a definite upstanding comb, with the wattles just beginning to show up. The pullet still has barely more than a line of demarcation where the comb will be. Both the chicks in this photograph are four weeks of age, yet there is no difficulty in differentiating between the two. This difference in the rate of growth of the comb is perhaps the strongest indication of sex in White Leghorns, but it is not the only one. There is also a distinct difference in the rate and order in which the two sexes feather up. . Fig. 1 shows a definite, feather tail to the pullet, while in the cockerel . these tail feathers are absent. This trait is perhaps more prominent in the heavy breeds than in light breeds. Figs. 2 and ■ 3 demonstrate this point more clearly than Fig. 1. Fig. 2 is a weeks-old Black Orpington cockerel. The wattles are beginning to develop, and the comb is already becoming prominent. The most striking feature is the lack of feathers on the back, and particularly

the shoulders. Note, also, the entire absence of tail feathers. This lack of feathers contrasts strongly with the strong feather growth of the four-weeks-old pullet shown in Fig. 3. The pullet’s comb and wattles are not yet showing up, but its fast rate of feathering is sufficient to mark it out as a pullet. The slow rate of feathering on the shoulders, of the cockerel has been remarked and should be emphasised, as this is the surest indication of a cockerel of the heavy breeds. This distinction applies to young drakelets also, and to . a lesser degree to cockerels of the light breeds.

General Indications

These are particular indications. Summarising the general indications there is a decided masculine appearance about a cockerel chick which is hard to put into words, but it is apparent in the heavier bone in the legs, in the stronger' head of cockerel chicks, and their bigger size when

compared with pullets of the same age. It can sometimes be observed in their behaviour, which will often savour of bullying or a tendency to domineer over the other chicks. It is sometimes difficult to separate the sexes until the chicks are several weeks old, in which case a fresh indication becomes apparent. There is a distinct difference in the hackle feathers of . the two sexes, which is demonstrated in Figs. 4 and 5. The cockerel feather (right) is definitely more pointed than the pullet feather, which tends to have a rounded tip. This pointed effect is confined . chiefly to the web of the cockerel’s feather, while the outer fringe is often rounded at, the tip. This fringe is largely absent in the pullet feather, as the inner portion of the web itself is rounded right out to the feather tip, leaving hardly any fringe at all. There will be cases where this difference is not so distinct as in the photographs, but when all the various indications are taken in conjunction with each other, there 1 should be no real difficulty in separating the sexes

Cost of Production of Market Eggs

THE Senior Investigational Officer, Mr. W. R. Paton, of the Investigational and Statistical Section of the Department of Agriculture, has presented some interesting figures relative to the cost of producing market eggs during the 1940-41 season. The costs were obtained from 62 farms on a proportional representation sampling basis for flocks of 250 layers and over. According to the 1936 census, there are approximately 1,000 flocks within this range, of which roughly 500 fall within a group ranging from 250 to 500 layers, and a further 200 fall within a group ranging from 1,000 and over; the remaining 300 fall between these two groups. ■ ■ Labour cost, as it is very involved, must be decided by negotiation rather than by costing processes. The size of flock is one of the principal factors governing hours of labour, and after excluding any -private marketing and transport expenses, the total hours for all other duties have been ascertained as 2,367 hours . for a flock of 500 layers; 2,950 for 750; 3,333 for 1,000; 3,687 for 1,250; 3,973 for 1,500; 4.273 for 1,750; and 4,554 for 2,000. Roughly two-thirds of these labour hours are taken up in feeding layers and in collecting and crating eggs, cull fowls, etc. The raising and feeding of replacement stock to laying age accounts for about one-fifth of the total hours of work for the year. . In working out costs per dozen eggs, the farm produced hatching eggs used for raising replacement pullets have

been recorded as a charge against production costs, and are therefore not included in arriving at the costs “per dozen eggs.” ' Subject to the foregoing exceptions, a net production cost of 14.66 d. was obtained, being 15.68 d. less credits (sales of culls and manure) of 1.02 d. The break-up -of these costs is 11.90 d. for food, grit and milk; 0.29 d. for litter, disinfectants and medicines; 0.14 d. for repairs and upkeep; 0.21 d. for cultivation, seeds, etc. (green feed); 0.46 d. for hatching and brooding costs, chick sexing, purchases (if any) of hatching eggs and/or young replacement stock; 0.30 d. for sundry items; 0.16 d. for rates on poultry land; 1.15 d. for depreciation on poultry buildings, plant and equipment; and 1.07 d. for interest on poultry enterprise capital. The preceding paragraph gives the general average, but considerable variations occur between districts. For instance, 16.30 d. is the figure- for Auckland, 14.89 d. for Wellington, 13.52 d. for Canterbury, and 12.98 d. for Otago. The weighted average for these four sets of figures is, of course, the 14.66 d. already mentioned for. the Dominion. Poultry farmers called on by Departmental officers 1 for.. cost' details co-operated wholeheartedly. ■ Much additional information was also obtained from some 180 - postal returns, and the time and care which those poultry farmers devoted to detailed compilations warrants commendation.