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Full-Text Articles in Life Sciences

Effects Of Cage Stocking Density On Feeding Behaviors Of Group-Housed Laying Hens, Rachel Nichole Cook, Hongwei Xin, Dan Nettleton Jul 2019

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 ...


Feeding Behaviors Of Laying Hens With Or Without Beak Trimming, Kelly E. Persyn, Hongwei Xin, Dan Nettleton, Atsuo Ikeguchi, Richard S. Gates Jul 2019

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.


Reduced-Dimension Clustering For Vegetation Segmentation, Brian L. Steward, Lei F. Tian, Dan Nettleton, Lie Tang Jun 2019

Reduced-Dimension Clustering For Vegetation Segmentation, Brian L. Steward, Lei F. Tian, Dan Nettleton, Lie Tang

Dan Nettleton

Segmentation of vegetation is a critical step in using machine vision for field automation tasks. A new method called reduced-dimension clustering (RDC) was developed based on theoretical considerations about the color distribution of field images. RDC performed unsupervised classification of pixels in field images into vegetation and background classes. Bayes classifiers were then trained and used for vegetation segmentation. The performance of the classifiers trained using the RDC method was compared with that of other segmentation methods. The RDC method produced segmentation performance that was consistently high, with average segmentation success rates of 89.6% and 91.9% across both ...