July 7, 2018
Holstein Heifer Calves Study
Effect of XTi PAWS on Melatonin, Cortisol, and Serotonin Concentrations in Holstein Heifer Calves, 6/2018 – 7/2018
Colorado State University
Conclusion: Exposure of Holstein heifer calves to XTi’s pulsed alternating wavelength system (PAWS) over 14 days showed a significant and sustained increase in serum melatonin levels
Study Objective:
- To evaluate the effect of XTi PAWS on hormone profiles of Holstein heifer calves
Background:
- Previous internal XTi trials had indicated that PAWS lighting can increase melatonin levels in laying hens.
- Non-invasive strategies to improve stress and animal health in the early stages of animal rearing have important ethical and financial implications for the dairy industry.
Methods:
- The study was conducted at a dairy farm in northern Colorado.
- 8 three-day old Holstein heifer calves were assigned to 2 groups. The XTi group was housed in hutches with 24hr XTi lighting. The control calves were housed in identical hutches without supplemental lighting. All hutches had a front yard of 2.25m2 with sand bedding.
- Blood samples were collected for determination of serum melatonin and serotonin levels 4x/day on days 0, 2, 4, and 14.
- Hair was sampled for cortisol determination on days 0, 14, 40, 60.
Results:
- Calves under XTi lighting showed a significant and sustained increase in serum melatonin levels at day 14 (p<0.10).
- Calves under XTi lighting showed a significant increase in serum melatonin levels at midnight and 6 am compared to control calves.
- Mean melatonin levels of XTi lit calves was 11.6pg/ml vs 5.5pg/ml for control calves (p=0.02)
- No differences were seen between the XTi vs Control group for serum concentrations of serotonin.
- No differences were seen between the XTi vs Control group for hair cortisol levels.
Discussion:
- Exposure of Holstein heifer calves to XTi’s pulsed alternating wavelength system (PAWS) over 14 days showed a significant and sustained increase in serum melatonin levels.
- Melatonin has a well-known role in regulating sleep-wake cycles and the circadian rhythm.
- Melatonin has additional beneficial effects such as stimulation of the immune system, reduction of inflammation, protection from neurodegenerative diseases, regulation of the menstrual cycle, and anti-aging properties.