Increased dietary protein intake rapidly (3 h) decreases hepatic malic enzyme and increases hepatic histidase mRNA expression in broiler chicks. A series of experiments was conducted to determine the role that glucagon or a specific mixture of dietary amino acids might have in regulating the rapid changes in mRNA expression of these enzymes, when dietary protein intake is increased. Three hours...

The role of auditory experience in the ontogeny of perceptual coding was investigated in hatchling chickens. In Experiment 1, auditory frequency generalization gradients were determined by using a habituation-generalization paradigm and an orienting response. One-day and 3-4-day chicks were habituated to 800-Hz tones and then tested at five frequencies ranging from 800 to 1,000 Hz. One-day chic...

1. The metabolism of dehydroretinyl ester has been studied in vitamin-A-deficient white leghorn chicks. Dehydroretinyl ester was metabolized to 3-hydroxyretinol diester, 3-hydroxyanhydroretinol and rehydrovitamin A2 which were isolated from the intestines and livers of chicks. 2. The metabolism of 3-hydroxyretinol diester and 3-hydroxyanhydroretinol, which were immediate metabolites of dehydror...

Prolonged interference or suppression of maternal antibodies of the humoral immune response of newly hatched chicks to active immunization has been documented; however, the immunological mechanisms responsible for such suppression are still unclear. Laying hens were immunized with dinitrophenyl-keyhole limpet hemocyanin (DNP-KLH). Purified maternal anti-DNP or non-specific IgY antibodies were t...

individual decisions concerning the trade-off between somatic and reproductive investment (Dänhardt et al. 2011). Birds feeding chicks should deliver the most nutritious and optimally sized prey items to chicks in order to maximise chick growth (Baird 1991). How ever, whether a parent delivers prey to chicks or eats it itself, depends not only on prey value but also on the time and energy cost ...

AIM An experimental study was conducted on 192-day-old broiler chicks for evaluating the effect of 10% neem leaf extract (NLE) supplementationon biochemical parameters in chickens experimentally infected with Escherichia coli O78 at 10(7) CFU/0.5 ml at 7 days of age. MATERIALS AND METHODS The 192-day-old broiler chicks were procured. These chicks were divided into two groups (A and B) contain...

The intestine of the newly hatched chick is immature at hatch. Yeast contains nucleotides and β-glucans that enhance intestinal development and chick growth. Accordingly, a 14-d experiment was conducted to evaluate the efficacy of a novel yeast product and bacitracin methylene disalicylate in enhancing early growth and intestinal maturation in chicks obtained from young (26-27 wk old) and old (...

We studied prefledging growth, energy expenditure and time budgets of African Black Oystercatcher, Haematopus moquini, chicks on Robben Island, Western Cape, South Africa. The aim of the study was to investigate the effect of parental feeding on the growth and energetics of semi-precocial shorebird chicks. Chicks reached mean fledging mass, 463 g, in 40 days. The growth rate coefficient of Afri...

A study was conducted to investigate the effects of feeding inorganic or organic Zn and Cu on the performance and tissue mineral content of chicks. A corn-soybean meal diet without Cu and Zn supplementation, containing 31 mg of Zn/kg of diet and 6.6 mg of Cu/kg of diet, was used as a basal diet. Organic Zn (a chelated Zn proteinate) and organic Cu (a chelated Cu proteinate) were used as organic...

We investigated in the chick whether the diet-induced changes of the hepatic content of cholesteryl esters (CE) influence the synthesis and the secretion of apoB- and apoA-I-containing lipoproteins. Control chicks received a low cholesterol diet for 2 (SD-1), 4 (SD-2), or 7 (SD-3) weeks; the chicks in the experimental groups received a cholesterol-rich diet for 2 weeks and were killed at the en...