Life Sciences Commons^™

Effects Of Cage Stocking Density On Feeding Behaviors Of Group-Housed Laying Hens, Rachel Nichole Cook, Hongwei Xin, Dan Nettleton

Dan Nettleton

Quantitative measurement of animal welfare continues to be a challenging task for both the animal agriculture industry and the scientific community. Characterization of animal feeding behavior provides a comparative elucidation of the animal’s behavioral deviation from its norms and thus carries implications for its welfare. This study examines the effects of cage stocking density (348, 387, 426, and 465 cm2; or 54, 60, 66, and 72 in.2 cage floor space per hen) on feeding behavior of W-36 White Leghorn laying hens kept in groups of six hens. The study employed a specialized instrumentation system and computational algorithm. The results revealed …

Feeding Behaviors Of Laying Hens With Or Without Beak Trimming, Kelly E. Persyn, Hongwei Xin, Dan Nettleton, Atsuo Ikeguchi, Richard S. Gates

Dan Nettleton

This study quantifies feeding behavior of W-36 White Leghorn laying hens (77 to 80 weeks old) as influenced by the management practice of beak trimming. The feeding behavior was characterized using a newly developed measurement system and computational algorithm. Non-trimmed (NT) and beak-trimmed (BT) hens showed similar daily feed intake and meal size. However, the BT hens tended to spend longer time feeding (3.3 vs. 2.0 h/d, P < 0.01), which coincided with their slower ingestion rate of 0.43 g/min-kg0.75 vs. 0.79 g/min-kg0.75 for the NT counterparts (P < 0.05). The BT hens had shorter time intervals between meals (101 s vs. 151 s, P < 0.01). Selective feeding, as demonstrated by larger feed particles apparent in the leftover feed, was noted for the BT hens. The leftover feed had a lower crude protein/adjusted crude protein content for the BT birds than that for the NT birds (16.7% vs. 18.7%, P < 0.05). In addition, the leftover feed of the BT birds had lower contents in phosphorus, magnesium, potassium, zinc, and manganese (P < 0.05), although no significant differences were detected in calcium, sodium, or metabolic energy content. Baseline feeding behavior data of this nature may help quantify and ensure the welfare of animals through exercising proper engineering design and/or management considerations.

Toxicity Of Cdse Nanoparticles In Caco-2 Cell Cultures, Lin Wang, Dattatri K. Nagesha, Selvapraba Selvarasah, Mehmet R. Dokmeci, Rebecca L. Carrier

Dattatri K. Nagesha

BackgroundPotential routes of nanomaterial exposure include inhalation, dermal contact, and ingestion. Toxicology of inhalation of ultra-fine particles has been extensively studied; however, risks of nanomaterial exposure via ingestion are currently almost unknown. Using enterocyte-like Caco-2 cells as a small intestine epithelial model, the possible toxicity of CdSe quantum dot (QD) exposure via ingestion was investigated. Effect of simulated gastric fluid treatment on CdSe QD cytotoxicity was also studied. ResultsCommercially available CdSe QDs, which have a ZnS shell and poly-ethylene glycol (PEG) coating, and in-house prepared surfactant coated CdSe QDs were dosed to Caco-2 cells. Cell viability and attachment were studied …

Toxicity Of Cdse Nanoparticles In Caco-2 Cell Cultures, Lin Wang, Dattatri K. Nagesha, Selvapraba Selvarasah, Mehmet R. Dokmeci, Rebecca L. Carrier

Rebecca L. Carrier

BackgroundPotential routes of nanomaterial exposure include inhalation, dermal contact, and ingestion. Toxicology of inhalation of ultra-fine particles has been extensively studied; however, risks of nanomaterial exposure via ingestion are currently almost unknown. Using enterocyte-like Caco-2 cells as a small intestine epithelial model, the possible toxicity of CdSe quantum dot (QD) exposure via ingestion was investigated. Effect of simulated gastric fluid treatment on CdSe QD cytotoxicity was also studied. ResultsCommercially available CdSe QDs, which have a ZnS shell and poly-ethylene glycol (PEG) coating, and in-house prepared surfactant coated CdSe QDs were dosed to Caco-2 cells. Cell viability and attachment were studied …

Toxicity Of Cdse Nanoparticles In Caco-2 Cell Cultures, Lin Wang, Dattatri Nagesha, Selvapraba Selvarasah, Mehmet Dokmeci, Rebecca Carrier

Mehmet R. Dokmeci

Background
Potential routes of nanomaterial exposure include inhalation, dermal contact, and ingestion. Toxicology of inhalation of ultra-fine particles has been extensively studied; however, risks of nanomaterial exposure via ingestion are currently almost unknown. Using enterocyte-like Caco-2 cells as a small intestine epithelial model, the possible toxicity of CdSe quantum dot (QD) exposure via ingestion was investigated. Effect of simulated gastric fluid treatment on CdSe QD cytotoxicity was also studied.

Results
Commercially available CdSe QDs, which have a ZnS shell and poly-ethylene glycol (PEG) coating, and in-house prepared surfactant coated CdSe QDs were dosed to Caco-2 cells. Cell viability and attachment …