{"id":680,"date":"2018-08-30t15:21:13","date_gmt":"2018-08-30t15:21:13","guid":{"rendered":"https:\/\/poultry.mystagingwebsite.com\/?page_id=680"},"modified":"2020-03-20t06:13:16","modified_gmt":"2020-03-20t06:13:16","slug":"sexing-day-old-chicks","status":"publish","type":"page","link":"\/\/www.bkpromos.com\/beplayapp网页 \/poultry-beplay官网全站苹果 \/sexing-day-old-chicks\/","title":{"rendered":"sexing day-old chicks"},"content":{"rendered":"

written by<\/span><\/i><\/b>: dr. jacquie jacob, university of kentucky<\/span><\/p>\n

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\"sex
figure 1. genetic basis for sex determination in mammals and birds (image created by dr. jacquie jacob, university of kentucky).<\/figcaption><\/figure>
with most animals, it is relatively easy to determine the sex of the newborn. the male reproductive organs are located on the outside of the body and are relatively easy to see, even in newborns. this is not the case with poultry. in male birds, the reproductive organs are inside the body cavity. this makes sexing newly hatched chicks difficult<\/span><\/figcaption><\/figure>\n<\/div>\n

there are two methods of sexing chicks that can be used at hatcheries:\u00a0vent sexing and feather sexing.<\/span><\/p>\n

vent sexing<\/span><\/strong> was developed in japan and brought to north american poultry producers in the 1930s. vent sexing is a skill that takes a long time to develop. it involves holding the chick upside down in one hand, expelling the fecal material and everting (turning outward) the vent area. the producer can then look for the presence or absence of a rudimentary male sex organ. this process sounds much easier than it actually is. to accurately sex chicks in this way, you need to be well trained and to have had a great deal of practice. there are very few schools that still teach chick sexing.<\/span><\/p>\n

feather sexing<\/span><\/b> is possible for some chicken breeds.<\/span><\/p>\n

the rhode island red and new hampshire breeds can be sexed by wing color at hatching.\u00a0male chicks have a white spot on the down over the wing web. this spot is lost when the chick down is shed and replaced with feathers. however, there is considerable normal variation in the size of the spot, so sexing in this way is not always accurate.<\/span><\/p>\n

the barred plymouth rock\u00a0breed carries a gene for barring (b) that is carried on the z chromosome (see figure 2). this gene produces a white bar on an otherwise black feather. the gene is incompletely dominant over the non-barring gene (b). in adults, the male, with two barring genes (bb), has feathers with broader white bars than those of the female, who has only one of the barring genes (b_). as a result, males are overall lighter in color. the sex of\u00a0purebred barred plymouth rocks\u00a0chicks can be determined on the basis of the size and shape of a light-colored spot on the top of the head. at hatch, males have a large white\u00a0spot. the spot is much smaller and narrower in females. this has been found to be about 80% accurate.<\/span><\/p>\n

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\"genetic<\/figure>\n<\/div>\n
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\"barred
photograph of a barred plymouth rock chick with a white spot on top of the head. the spot is much smaller and narrower in females (image by dr. jacquie jacob, university of kentucky).<\/figcaption><\/figure>
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\"barred<\/a>
barred plymouth rock male chicken (photo by michael shake on shutterstock.com)<\/figcaption><\/figure>\n
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barred plymouth rock female (photo by by veroja on shutterstock.com)<\/figcaption><\/figure>\n

sex-linked crosses<\/span><\/strong>\u00a0<\/strong><\/em>are based on the color or growth rate of feathers, characteristics carried on the sex-determining chromosomes of chickens. to understand how this works, it is important to have a basic understanding of the genetics involved. it takes a pair of sex-related chromosomes to determine the sex of the offspring. the mother contributes one sex chromosome to the offspring, and the father contributes the other. most breeds do not have this type of sex-linked characteristic, but crossing certain breeds can result in different feather characteristics for the offspring.<\/span> the other. in mammals, males carry an x and a y chromosome, while the females carry two x chromosomes. it is the male that, genetically, determines the sex of the offspring. in birds, it is the other way around\u2014females carry a z and a w chromosome, and males carry two z chromosomes. it is the female, therefore, that, genetically, determines the sex of the offspring (see figure 1).<\/span><\/p>\n