Light wavelength and its impact on broiler health.

Light is a powerful management tool in poultry production systems, affecting productivity, physiology, and behavior. The objective of this study was to understand the impacts of three light colors (blue, green, or white) on broiler health. Broilers (N = 14,256) were raised in floor pens with fresh litter from 0 to 35 d in 9 rooms (2 blocked trials). Additionally, 2 genotypes (Ross YPMx708 and EPMx708) and sex were studied (6 room replications per lighting treatment and 18 pen replicates per sex × genotype × lighting program). Blood samples and tissue samples from the retina and the pineal gland were collected from birds (16-18 d of age) 9 times in one 24-hr period per trial, then analyzed to determine melatonin levels (pg/mL). Mobility was assessed via gait scoring, using a 0 to 5 scale at 31 to 32 d of age. Footpad dermatitis was assessed using a 0 to 4 scale, and litter quality by a subjective scoring system (scores ranging from 0-4). Mortality and morbidity causes were identified through necropsies performed by pathologists. Data were analyzed as a 3 × 2 × 2 factorial design, with trial as a random variable block and lighting treatment nested within rooms (MIXED procedure, SAS). Birds raised under blue light had lower serum melatonin levels during one time-point during the scotophase, but no other differences were noted. No effect of light color was observed for melatonin produced in the tissues, nor mobility and footpad dermatitis. An interaction was noted for litter quality where a higher percentage of pens housing YPM-708 broilers had litter categorized into dry, but not easily moved with the foot (category 1). Males had higher incidence of infectious and metabolic deaths than females. Interactions were observed between light and sex, where males raised under white light had a higher incidence of skeletal causes of mortality. Overall, the results showed that light color had minor impacts only on melatonin levels, mobility, footpad dermatitis, litter quality, and cause of mortality.

Does light color during brooding and rearing impact broiler productivity?

Light color during brooding and rearing may impact broiler production; however, literature results are inconsistent. To address this, the effects of 3 wavelength spectra on broiler performance in 2 sex and 2 genotypes (Ross YPMx708 and EPMx708) were studied. Broilers were raised (d 0-35) under wavelength programs provided by LED light bulbs (blue (455 nm), green (510 nm) or white) under similar intensities (clux). Two trials were conducted (total number of birds =  14,256; 6 room replications per lighting treatment; 18 replicate pens per light × sex × genotype). Data were analyzed as a 3 × 2 × 2 (wavelength × sex × genotype) factorial design, with trial as a random variable block and wavelength nested within rooms (Proc Mixed, SAS 9.4). Birds raised under white light were heavier than under blue or green light at d7 (P = 0.004), and green at d14 (P = 0.03). Feed intake, gain-to-feed efficiency and flock uniformity (d15, 28) did not differ. Mortality only differed at wk 5, when broilers raised under white light had higher mortality than those raised under blue (P = 0.03). YPM-708 were heavier at 21 d (P = 0.007), 28 d (P = 0.001), and 35 d (P < 0.0001), had a better total feed conversion rate (P < 0.0001), higher mortality for wk 1 (P = 0.001), lower mortality during the last wk (P = 0.02) and better uniformity at 28 d (P = 0.01) than EPM-708 broilers. Males were heavier at all measured ages except d0 (d7-P = 0.03, other weeks P < 0.0001), had better total feed conversion (P < 0.0001), increased weekly mortality except for wk 1 (wk2-P = 0.04, wk3-P = 0.002, wk4, 5, and total-P = 0.0001) and were less uniform (P = 0.0002) than females. YPM-708 and EPM-708 males had higher total feed intake (P < 0.0001), and males raised under white light had higher mortality than females raised under white or blue light (P = 0.01). To conclude, the use of specific light colors (blue and green) had only minor impacts on broiler production when light intensity was equalized and balanced for bird spectral sensitivity, and its use to improve productivity does not appear to be advantageous for broilers in a commercial setting.

Decreased levels of cathepsin Z mRNA expressed by immune blood cells: diagnostic and prognostic implications in prostate cancer.

Cathepsin Z (CTSZ) is a cysteine protease responsible for the adhesion and migration of both immune and tumor cells. Due to its dual role, we hypothesized that the site of CTSZ expression could be determinant of the pro- or anti-tumorigenic effects of this enzyme. To test this hypothesis, we analyzed CTSZ expression data in healthy and tumor tissues by bioinformatics and evaluated the expression levels of CTSZ mRNA in the blood cells of prostate cancer (PCa) patients by qRT-PCR compared with healthy subjects, evaluating its diagnostic and prognostic implications for this type of cancer. Immune cells present in the blood of healthy patients overexpress CTSZ. In PCa, we found decreased CTSZ mRNA levels in blood cells, 75% lower than in healthy subjects, that diminished even more during biochemical relapse. CTSZ mRNA in the blood cells had an area under the curve for PCa diagnosis of 0.832, with a 93.3% specificity, and a positive likelihood ratio of 9.4. The site of CTSZ mRNA expression is fundamental to determine its final role as a protective determinant in PCa, such as CTSZ mRNA in the blood cells, or a malignant determinant, such as found for CTSZ expressed in high levels by different types of primary and metastatic tumors. Low CTSZ mRNA expression in the total blood is a possible PCa marker complementary to prostate-specific antigen (PSA) for biopsy decisions, with the potential to eliminate unnecessary biopsies.

Decreased levels of cathepsin Z mRNA expressed by immune blood cells: diagnostic and prognostic implications in prostate cancer

Cathepsin Z (CTSZ) is a cysteine protease responsible for the adhesion and migration of both immune and tumor cells. Due to its dual role, we hypothesized that the site of CTSZ expression could be determinant of the pro- or anti-tumorigenic effects of this enzyme. To test this hypothesis, we analyzed CTSZ expression data in healthy and tumor tissues by bioinformatics and evaluated the expression levels of CTSZ mRNA in the blood cells of prostate cancer (PCa) patients by qRT-PCR compared with healthy subjects, evaluating its diagnostic and prognostic implications for this type of cancer. Immune cells present in the blood of healthy patients overexpress CTSZ. In PCa, we found decreased CTSZ mRNA levels in blood cells, 75% lower than in healthy subjects, that diminished even more during biochemical relapse. CTSZ mRNA in the blood cells had an area under the curve for PCa diagnosis of 0.832, with a 93.3% specificity, and a positive likelihood ratio of 9.4. The site of CTSZ mRNA expression is fundamental to determine its final role as a protective determinant in PCa, such as CTSZ mRNA in the blood cells, or a malignant determinant, such as found for CTSZ expressed in high levels by different types of primary and metastatic tumors. Low CTSZ mRNA expression in the total blood is a possible PCa marker complementary to prostate-specific antigen (PSA) for biopsy decisions, with the potential to eliminate unnecessary biopsies.