The first egg is usually laid during late afternoon from 7 to 10 days after nesting has been started. The second egg is laid approximately 44 hours later. As a rule, parent birds do not hover the first egg until the second egg has been laid. This usually enables the youngsters to hatch within 1 hour of each other, and gives each one an equal chance. The youngster from the first egg will be much larger than the other if the parent birds start to hover at the time the first egg is laid. Fertility is indicated if the egg becomes a light bluish color after 10 days, or if it shows blood lines after 5 days when held up to the sun’s rays. Do not destroy the first pair of eggs as it is generally believed that they often produce the best youngsters of that year. 44. Hatching and Feeding _a._ The incubation period is from 17 to 18 days long. The hen pigeon usually sits from 1600 of one day to 1000 the following morning; the male pigeon sits the remainder of that day. _b._ The young pigeons are fed by both parents. Their first feed is a thick, creamy-white excretion produced in the crop of both female and male (pigeon milk or pap). Pigeons are the only birds both sexes of which produce milk for their young. The young pigeon places it’s bill down the throat of either parent, and the parent in return forces the food into the young one’s throat. This method of feeding is known as “regurgitation.” 45. Identification The identification record of the pigeon is started when the hen lays the egg. Until the time that the youngster leaves the nest compartment, this record is kept on a breeding card (par. 27). For identification purposes, each pigeon is banded when approximately 8 days of age (par. 28). 46. Culling It is necessary to cull (destroy) severely to keep the stock in a loft up to standard. Cull birds which do not meet physical requirements for breeding unless all birds are needed. In addition, destroy those which show a definite lack of intelligence, or which do not perform up to the average. About 30 percent of the young bred in any one season are normally under the physical standard and should be culled to keep the stock from degenerating. In addition to losses sustained through culling, 20 to 30 percent of the remaining stock may be expected to be lost during training flights, as result of disease and injury, or through additional culling because of substandard performance. SECTION VII DISEASES AND MEDICINES 47. General Certain diseases attack pigeons. Normal preventive methods usually protect pigeons from disease. If, however, these diseases are not detected immediately, they are likely to sweep through the loft, destroying or ruining most of the birds. It is necessary, therefore, that the pigeoneer be able to detect, correctly diagnose, and treat the more common pigeon diseases, in addition to taking preventive measures. 48. Prevention of Disease