Question

In pigeon, which of the following glands secretes the milk in both sexes?
A)Liver
B)Gizzard glands
C)Crop glands
D)Salivary glands

Answer 1

Hint: A crop gland can be defined as an expanded, muscular pouch near the gullet or throat in the birds. Not all birds have a crop. The crop is used to temporarily store food.

Complete answer:
 Both female and male pigeons produce a nutrient-rich substance in their crop to feed their young. This substance has been linked to lactation in mammals and is referred to as pigeon ‘milk'. The milk is essential for the growth and development of the pigeon squad and without it they fail to thrive. Pigeons are noted for their unique ability to produce pigeon milk, a soft cheesy and nourishing secretion especially during the breeding season. The pigeons milk includes water, fat, protein and lactose. The milk is produced by both sexes and contains 35 percent of fat.

Crop milk is a secretion from the lining of the crop of parent birds that is regurgitated to young birds. It is found among all pigeons. Pigeon milk begins to be produced a couple of days before the eggs are due to hatch. The baby squabs are fed on pure crop milk for the first week or so of life. After this the parents begin to introduce a proportion of adult food softened by spending time in the moist conditions of the adult crop, into the mix fed to the squabs until by the end of the second week they are being fed entirely on softened adult food. Pigeons normally lay two eggs. If one egg fails to hatch, the surviving squab gets the advantage of a supply of crop milk sufficient for two squabs and grows at a significantly faster rate.

Hence, the correct answer is option (C)

Note: Research suggests that a pair of breeding pigeons cannot produce enough crop milk to feed three squabs adequately which explains why clutches are limited to two.