The composition of the crop milk of pigeons

Abstract

PIGEON squabs are hatched in the undeveloped state but grow very rapidly during the first few days after hatching. During this period they are fed on a special secretion formed in the crop ofthe parent birds. This secretion, commonly called "pigeon's milk", is a white, slimy, caseous material formed by the desquamation of epithelial cells and may be regarded as an example of a sacrifice of cell structure in the parent for the nutrition of the young. The endocrine control of its formation has been investigated by Riddle et al. [1932]. Its general composition and nutritive properties have been studied by Reed et al. [1932] and by Dabrovska [1932]. The former workers found the material to contain dry matter 35 7 %, with protein 52-7, fat 35-6 and ash 4*5 % of the dry matter; Dabrovska found dry matter 23-3 %, and protein 57 4, fat 34-2 and ash 6-5 % of the dry matter. The material did not contain carbohydrates. In the present work, the compositions of four samples, pooled from 115 birds (three from 30 birds each, one from 25), have been investigated in detail. The birds had been used for prolactin assays, in which activity was measured by the wet weight of the crop glands. The gland contents were separated and made available for analysis as soon as possible after killing the birds.

The ontogeny of nutrient transporter and digestive enzyme gene expression in domestic pigeon (Columba livia) intestine and yolk sac membrane during pre- and posthatch development

“…However, limited information is available on the nutrient requirements and feeding in this species. This could partly be attributed to the fact that young growing pigeons were initially fed by parents with pigeon milk containing mainly proteins and lipids (Reed et al, 1932;Davies, 1939;Vandeputte-Poma, 1980). A few attempts have been made to handrear squabs (young pigeons), but little from the immediate posthatch period (Levi, 1974;Haque et al, 1982;Yang and Vohra, 1987;Du et al, 1993;Tsat et al, 1994).…”

Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

“…Crop milk consists of regurgitated cells of the crop epithelium that have been transformed into a high nutrient source of food for young (Davies, 1939). In mourning doves (Zenaida macroura), crop milk is primarily fed during the first half of the nestling period from hatch to 4-5 days of age, with the proportion of crop milk in feedings declining during the late nestling period (Mirarchi, 1993).…”

Transmission of antibodies to Chlamydia Psittaci and Coxiella Burnetii through eggs and “crop milk” in pigeons

“…Juveniles are fully dependent on this primary source of nutrition during their first 5 days of life which, apart from water, contains 28% dry matter, composed of 33.8% fat, 58.6% protein, 3.9% starch and 4.6% ash (4).…”