Life histories are state-dependent, and an individual’s reproductive decisions are determined by its available resources and the needs of its offspring. Here we test how a chick’s needs for food and protection influence parental decisions in the Antarctic petrel, Thalassoica antarctica , where the parents, due to their long breeding lifespan, are expected to give priority to their own needs bef...

The effects of taurine supplementation on growth performance, serum and liver concentrations of lipid, fatty acid composition and lipid peroxidation in the livers of broilers under chronic heat exposure conditions were investigated. The chicks with a similar body weight were equally assigned to one of three controlled-environment chambers. The brolier chicks, which were kept at 34°C were fed ei...

The purpose of this study was to analyze the effect of auditory enrichment (by means of classical music) or physical enrichment (by means of hanging colored string bunches and barley grains on the floor) on tonic immobility duration, heterophil to lymphocyte ratio, and fluctuating asymmetry (FA) in chicks of several layer breeds. In experiment 1, 192 chicks from 8 Spanish breeds and 1 White Leg...

Newly hatched chicks will spontaneously peck at conspicuous objects in their field of view, and soon learn to distinguish between edible food particles and unpleasant tasting objects. To examine whether the selective pecking is based on the ability to memorize shapes, we analyzed pecking behavior of 1- to 2-days-old quail chicks (Coturnix japonica) by using ball- and triangle-shaped beads both ...

Young chickens are more susceptible to Salmonella colonization than older chickens that have developed resistance with age as native microflora become established. Elevated concentrations of cecal propionic acid and total volatile fatty acids (VFA) have been observed by many researchers to be indicators of establishment of anaerobic microflora and protection against Salmonella colonization of t...

Three experiments (Exp.) were conducted to determine the interactive effects of sodium bentonite (NaB) with the efficacy of monensin (MON) or salinomycin (SAL) in coccidiosis-infected chicks. Male broiler chicks 5 to 14 d of age were used, and each treatment was replicated with eight (Exp. 1) or four (Exp. 2 and 3) pens of five chicks each. In Exp. 1, MON (80 ppm), NaB (0.50%), or MON+NaB were ...

In several seabirds, nutritional state of a nest-bound chick is negatively correlated with the activity of its hypothalamus-pituitary-adrenal (HPA) axis. Increased corticosterone (cort) secretion has been shown to facilitate changes in behavior that allow hungry chicks to obtain more food from parents. However, if parents are not willing/able to buffer their young from temporary food shortages,...

Electrostatic space chargers were used to impart a negative charge to airborne dust particles and thereby cause them to be attracted to grounded surfaces. To determine whether negative air ionization could affect the airborne transmission of Salmonella enteritidis, chicks were housed in four controlled-environment isolation cabinets in which airflow was directed across an unoccupied central are...

Newly hatched chicks were dosed orally with a Salmonella typhimurium wild-type strain, an S. enteritidis wild-type strain, and a genetically defined S. enteritidis aroA vaccine candidate, strain CVL30. The S. typhimurium strain, 2391 Nalr, was virulent in newly hatched chicks and caused deaths in 7 of 20 chicks after an oral dose of 10(5) organisms. The S. enteritidis wild-type strain, LA5, cau...

Domesticated chicks are precocial and therefore have relatively well-developed feeding behavior. The role of hypothalamic neuropeptides in food-intake regulation in chicks has been reported for decades. However, we hypothesized that nutrients and their metabolites in the brain may be involved in food intake in chicks because these animals exhibit a very frequent feeding pattern. Therefore, the ...