Begging by dependent avian offspring is known to correlate with hunger level, and parents use this as a signal of brood demand to adjust their chick feeding behavior. While there is information on how each chick adjusts its begging to its own condition, little is known of how chicks adjust to the state of their nest mates. In two experiments we manipulated the competitive environment of individ...

While anti-human blood group B agglutinins are present in the majority of ordinary White Leghorn chicks by the age of 30 days, none could be demonstrated in germfree chicks up to the age of 60 days. Anti-B agglutinins in trace amounts were first found in germfree chicks 66 days old and increased to an average titer of about 1:2 by 91 days of age. This titer amounts to about 10 per cent of that ...

1. The comparative effects of raw soya beans on food intake, growth, digestive organ weight, and enzyme activities in goslings and chicks were studied, 2. Goslings were more affected than chicks by the ingestion of a raw soya-bean diet (RSD) in the following ways: reduction in food intake and growth rate; increase in relative weight of the digestive organs; reduction in specific activities of l...

Carcinogenic/toxic effects of ochratoxin A (OTA) in various internal organs of Plymouth Rock chicks were determined. The number of OTA-induced neoplasms was similar in chicks given 25 ppm L-β-phenylalanine (PHE) in addition to 5 ppm OTA compared to chicks given only 5 ppm OTA, which showed that PHE cannot be used as a real protector against the carcinogenic or toxic effects of OTA in chicks. OT...

Ostrich chick mortality was studied in 2522 chicks that were hatched artificially during the 1999/2000 breeding season. High levels of mortality were observed, with 1978 (78.4 %) of these chicks dying before 90 days after hatching. A total of 46.7 % (1,177) of these chicks died before 28 days of age, and a further 30.7% (801) died between 28 and 90 days post-hatching. Chick mortality to 28 days...

The present work was performed to study the effect of vaccination with Cocci Vac B on cellular and humoral immunity of chickens. The study comprised 70 chicks hatched from hens none vaccinated against coccidiosis. The chicks were subdivided into 4 groups. The 1st group comprised 25 chicks, kept as apparently healthy control, the 2nd group consists of 10 chicks, infected with 10000 mixed sporula...

A study was conducted with conventional and germ-free broiler chicks to obtain more information on the role of the intestinal microflora in the anti-nutritive effects of NSP in broiler chicks. As the NSP source, highly methylated citrus pectin (HMC) was used at a dose level of 30 g/kg in a maize-based diet. The diets fed to the germ-free chicks were gamma-irradiated, whereas those fed to the co...

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...