Fractures of the keel bone in laying hens occur frequently within free-range systems and are a significant welfare concern. As poultry farmers have increasingly adopted this type of housing, it becomes more urgent to address the problem of such fractures. More than 80% of free-range birds could be affected, compared to 36% of birds in furnished-cage systems (Wilkins et al., 2011). A hen’s abili...

Egg-laying behavior in Caenorhabditis elegans is regulated by multiple neurotransmitters, including acetylcholine and serotonin. Agonists of nicotinic acetylcholine receptors such as nicotine and levamisole stimulate egg laying; however, the genetic and molecular basis for cholinergic neurotransmission in the egg-laying circuitry is not well understood. Here we describe the egg-laying phenotype...

We have investigated the neurotransmitters used to control egg-laying in C. elegans. Previous studies suggested that 5-HT released by the HSN motor neurons stimulates egg laying, and that tricyclic antidepressants potentiate egg laying by blocking reuptake of 5-HT by the HSN neurons. We report studies of the wild type and a mutant that lacks detectable 5-HT that suggest 5-HT is not required for...

Housing systems for egg-laying hens range from small, pasture-based flocks to large, commercial-scale operations that intensively confine tens of thousands of hens indoors. The overwhelming majority of laying hens used for commercial egg production in the United States are confined in battery cages and provided 432.3 cm (67 in) of space per bird. Cages prevent hens from performing the bulk of t...

Antibiotic resistant bacteria can be easily isolated from the faeces of cattle, pigs or poultry. However, whether the production of different farm animals is associated with a higher or lower prevalence of antibiotic resistance is not clear. In this study we therefore used real time PCR for the quantification of antibiotic gene prevalence in the DNA purified from the faeces of farm animals. Fir...

Argulus siamensis is the most damaging fish parasite prevalent in the freshwater aquaculture systems of India. In an attempt to further understand the behavior of this economically important parasite, the means of biological transmission, egg laying strategies and effect of temperature on development of eggs was studied. A. siamensis showed opportunistic egg laying behavior where in it used bot...

C. elegans hermaphrodites are self-fertile, and their rate and temporal pattern of egg-laying are modulated by diverse environmental cues. Egg-laying behavior has served as an important phenotypic assay for the genetic dissection of neuronal signal transduction mechanisms. This chapter reviews our current understanding of the neuronal and neurochemical mechanisms underlying the control of egg-l...