Vertebrate mothers transfer diverse compounds to developing embryos that can affect their development and final phenotype (i.e., maternal effects). However, the way such effects modulate offspring phenotype, in particular their immunity, remains unclear. To test the impact of maternal effects on offspring development, we treated wild breeding house sparrows (Passer domesticus) in Sevilla, SE Sp...

The growth rates of young chicks were varied from 0 to 10% per day by manipulation of the adequacy of the amino acid and energy supply. The rates of protein synthesis in the white breast (pectoralis thoracica) muscle and the dark leg (gastrocnemius and peronaeus longus) muscles were estimated by feeding l-[U-(14)C]tyrosine in amino acid/agar-gel diets (;dietary infusion'). This treatment rapidl...

This experiment investigated the effects of brooding system (BS) and stocking density (SD) on immune response 1-14-day-old broiler chicks. A 3672 one-day-old Cobb 500 chicks were raised in two BSs (conventional floor (CFBS) newly developed multi-tier closed (NDBS)) at four different SDs (30, 60, 90, 120 chicks/m2), resulting a 2 × 4 factorial arrangement. Immunity data lymphoid organ weights, m...

Variations of breeding success with age have been studied largely in iteroparous species and particularly in birds: survival of offspring increases with parental age until senescence. Nevertheless, these results are from observations of free-living individuals and therefore, it remains impossible to determine whether these variations result from parental investment or efficiency or both, and wh...

abstract: this study was conducted to investigate the effects of diets containing different levels of hull-less barley on caecal microflora of broiler chicks. two hundred and forty one-day old male broiler chicks (arbor acres strain) were used in a completely randomized design with 4 tratments, and 3 replicates were allocated to each treatment. different levels of hull-less barley in diets had ...

PURPOSE Lutein and zeaxanthin are largely transported in plasma by high-density lipoprotein (HDL). The Wisconsin hypoalpha mutant (WHAM) chicken has a recessive sex-linked mutation in the ABCA1 transporter gene that results in a severe deficiency of HDL. In this study, the transport and tissue distribution of lutein and zeaxanthin were examined in newly hatched and 28-day-old WHAM chicks compar...

Absolute auditory thresholds were estimated in chickens at 0 and 4 days after hatching. Momentary suppressions of the chicks' regular peeping, following the onset of a tone, were used as indications of stimulus detection. In the first experiment a staircase procedure was used to estimate thresholds. The absolute thresholds of both ages were the same at low frequencies (250-500 Hz), but at highe...