Animal Health 2

摘要

Manipulating light exposure at strategic points in the life cycle of cattlecould be a non-invasive technique to improve performance, health, andwell-being. Pulsed alternating wavelengths system (PAWS; Xiant Technologies,CO) is a recently developed technology based on deliveringspecific light wavelengths and patterns. The objective of this smallscalestudy was to compare the hormonal (melatonin and cortisol) andneurotransmitter (serotonin) levels in PAWS exposed vs. unexposedcontrol calves. Holstein heifer calves (3 d old) were housed individuallyin polyethylene hutches with a front yard of 2.25 m~2 with sand beddingand assigned into 1 of 2 treatments: (1) control (CON; n = 4); and (2)PAWS exposed (PAWS; n = 4). Hutches in the PAWS group had interiorlamps affixed to the hutch roof and were constantly on. All the studycalves had free access to the enclosed front yard. Calves were fed andmanaged according to farm management program. Blood samples werecollected for determination of serum melatonin and serotonin concentrationat 0600 h, 1200 h, 1800 h, and 2400 h on d 0 (enrollment), d 2, d4, and d 14. Hair was sampled for cortisol determination on d 0, d 14,d 40, and d 60. No group differences for cortisol concentration weredetermined. Table 1 presents mean (SE) melatonin and serotonin serumconcentrations for the overall monitoring period, by day, and by dayat 2400 h, which was the time of maximum exposure to the treatment.Data from this initial small-scale study indicate a significant effect forPAWS on melatonin concentration. A larger study is needed to furtherexplore these associations.