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Department of Animal Sciences
The Robert H. Smith Faculty
of Agricultural, Food & Environment

The Hebrew University of Jerusalem.

Herzl 229, Rehovot 7610001, Israel
Phone: +972-(0)8-9489119;
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Kalyesubula, M. ; Casey, T. M. ; Reicher, N. ; Sabastian, C. ; Wein, Y. ; Barshira, E. ; Hoang, N. ; George, U. Z. ; Shamay, A. ; Plaut, K. ; et al. Physiological state and photoperiod exposures differentially influence circadian rhythms of body temperature and prolactin and relate to changes in mammary PER1 expression in late pregnant and early lactation dairy goats. SMALL RUMINANT RESEARCH 2021, 200.Abstract
Short-day photoperiod (SDPP; 8 h light:16 h dark) during the dry period increases milk production compared with long-day photoperiod (LDPP; 16 h light:8 h dark). We hypothesized that the impact of photoperiod on lactation is mediated by alterations in the circadian system. Twelve Saanen goats were blocked at dry off into SDPP (n = 6) and LDPP (n = 6) treatments and mammary biopsies were taken in the middle of light and dark phases at 3 wk prepartum and 5 wk postpartum. Total RNA was isolated, and the expression of clock genes was analyzed by qPCR. SDPP goats produced more milk than LDPP goats (3.15 +/- 0.04 vs. 2.7 +/- 0.05 kg/d). In the 24 h period, LDPP goats had a greater body temperature than SDPP goats at 3 wk prepartum (39.6 +/- 0.06 vs. 39.3 +/- 0.1 degrees C) and 5 wk postpartum (40.1 +/- 0.15 vs. 39.7 +/- 0.1 degrees C). Cosinor analysis revealed that physiological state affected body temperature mesor (P< 0.001), peak (P< 0.01), amplitude (P< 0.05), and phase (P< 0.001). Plasma prolactin was 20, 10, and 17-fold higher in LDPP than in SDPP goats at 3 wk prepartum, 3 wk postpartum and 5 wk postpartum, respectively. Cosinor analysis revealed that photoperiod affected prolactin mesor (P< 0.0001), peak (P< 0.0001), trough (P< 0.001), amplitude (P< 0.01), and the peak to trough ratio (P< 0.01). Mammary expression of a core clock gene, PER1, was affected by the light-dark phase and the photoperiod treatment (P< 0.05). It also exhibited a photoperiod-physiological state interaction. Changes in the circadian rhythms with the onset of lactation and photoperiod manipulation support further studies of their role in the regulation of milk yield.
Wein, Y. ; Barshira, E. ; Friedman, A. Increased serum levels of advanced glycation end products due to induced molting in hen layers trigger a proinflammatory response by peripheral blood leukocytes. POULTRY SCIENCE 2020, 99, 3452-3462.Abstract
Induced molting (IM), a severe detriment to animal welfare, is still used in the poultry industry in some countries to increase or rejuvenate egg production and is responsible for several physiological perturbations, possibly including reactive oxidative stress, a form of metabolic stress. Because metabolic stress has been shown to induce a proinflammatory response involved in attempts to restore homeostasis, we hypothesized that similar responses followed IM. To confirm this hypothesis, we initially confirmed the establishment of oxidative stress during IM in 75-wk-old layers by demonstrating increased production of advanced glycation end products (AGE). Concomitant with increased oxidative metabolites, cellular stress was demonstrated in peripheral blood leukocytes (PBL) by increased levels of stress gene products (the glucocorticoid receptor, sirtuin-1, and heat shock protein 70 mRNA). Increased expression of stress proteins in PBL was followed by a proinflammatory response as demonstrated by increased levels of proinflammatory gene products (IL-6 and IL-1 beta mRNA); increased expression of these gene products was also demonstrated in direct response to AGE in vitro, thus establishing a direct link between oxidative and cellular stress. To establish a possible pathway for inducing a proinflammatory response by PBL, we showed that AGE increased a time dependent expression of galactin-3, Toll-like receptor-4, and nuclear factor - kappa B, all involved in the proinflammatory activation pathway. In vivo, AGE formed complexes with increased levels of circulating acute phase proteins (lysozyme and transferrin), products of a proinflammatory immune response, thereby demonstrating an effector response to cope with the consequences of oxidative stress. Thus, the harmful consequences of IM for animal welfare are extended here by demonstrating the activation of a resource-demanding proinflammatory response.
Casey, T. M. ; Plaut, K. ; Kalyesubula, M. ; Shamay, A. ; Sabastian, C. ; Wein, Y. ; Bar-Shira, E. ; Reicher, N. ; Mabjeesh, S. Mammary core clock gene expression is impacted by photoperiod exposure during the dry period in goats. Journal of Applied Animal Research 2018, 46, 1214 - 1219. Publisher's VersionAbstract
ABSTRACTShort-day photoperiod (SDPP) during the dry period increases milk production compared to long-day photoperiod (LDPP) in goats. Photoperiod information is sent to the master clock in the suprachiasmatic nuclei (SCN), which send temporal information to peripheral clocks located in every tissue of the body. We hypothesized photoperiod effects on milk production are mediated in part by changes in mammary clocks. Our objective was to determine the effect of photoperiod manipulation during the dry period in goats on core clock genes expression in mammary gland. Multiparous goats (n?=?6) were blocked at dry off into two treatments: LDPP and SDPP. Serial mammary biopsies were taken over a 24?h period during three weeks prepartum. Total RNA was isolated, and q-PCR analysis of the core clock genes CLOCK, ARNTL, PER1, CRY1, and CRY2 found exposure to LDPP significantly increased ARNTL (P?
Wein, Y. ; Geva, Z. ; Bar-Shira, E. ; Friedman, A. Transport-related stress and its resolution in turkey pullets: activation of a pro-inflammatory response in peripheral blood leukocytes. Poultry Science 2017, 96, 2601 - 2613. Publisher's VersionAbstract
The transportation process is one of the most stressful practices in poultry and livestock management. Extensive knowledge is available on the impact of transport on stress and animal welfare; however, little is known on the impact of transport on the physiology of turkey pullets, their welfare and health, and even less on the process of homeostatic recovery in the post-transport new environment. The main focus of this manuscript was to focus on trauma, stress, and recovery following transport of turkey pullets from nurseries to pullet farms. Specifically, we determined the physiological consequences of transport, the temporal restoration of homeostasis and its effects on immune system function. We hypothesized that stress signaling by stress hormones would directly activate circulating turkey blood leukocytes (TBL), thus inducing a pro-inflammatory response directed towards tissue repair and recovery. Extensive blood analyses prior to transit and during the collecting, transit, and post-transit stages revealed extensive stress (elevated heat shock protein 70) and blunt-force trauma (internal bleeding and muscle damage as well as limb fractures). TBL were shown to increase mRNA expression of cortisol and adrenergic receptors during transit, thus indicating a possible direct response to circulating stress hormones. Consequently, TBL were shown to increase mRNA expression of pro-inflammatory cytokines, as well as that of serum inflammatory proteins (lysozyme and transferrin) partaking in reducing oxygen radicals as demonstrated by consumption of these proteins. The flare-up due to transit related stress diminished with time until 10 d post-transit, a time at which most parameters returned to resting levels. Though general and vaccine-specific antibody levels were not altered by transport-related stress, the physical and physiological injury caused during transport may explain the susceptibility of turkey pullets to opportunist pathogens in the immediate post-transit period.
Wein, Y. ; Barshira, E. ; Friedman, A. Avoiding handling-induced stress in poultry: use of uniform parameters to accurately determine physiological stress. Poultry Scienceps 2016, 96, 65 - 73. Publisher's VersionAbstract
Due to increase in awareness of poultry welfare and concomitant legislation, it has become necessary to determine poultry's response to stress, with minimal harm and maximum reliability. Several methods to determine the response to physiological stress were developed throughout the years to identify stressors and to measure stress in poultry. The most commonly used are plasma corticosterone levels and peripheral blood heterophil/lymphocyte ratio (H/L ratio). However, the value of these responses to determine a state of stress has been questioned in several instances, as these parameters are increased during the process of bird handling and blood sampling irrespective of the general state of stress. Due to these limitations, it appears that the classic stress markers might be sub-optimal in evaluating stress in poultry, particularly those encountered in high-stress environments. Thus, there is a continuing need for stress indicators, preferably indicators that are quantitative, highly repeatable, not influenced by handling and sampling, determined in peripheral blood, represent an initial response to the stressor, and do not daily fluctuate. As the immune system has been shown to rapidly respond to stress, we assessed pro-inflammatory gene expression in peripheral blood cells as an indicator for stress. We initially show that while corticosterone plasma levels and the H/L ratio were responsive to handling and blood sampling, pro-inflammatory gene expression (lysozyme, IL-1β, IL-6, and HSP-70) was not. We then determined the expression of the same pro-inflammatory genes during acute stress (transit) in layer pullets (hen and turkey) and during chronic stress (different caging densities of layers utilizing 2, 3, and 4 hens/cage). While gene expression was significantly and highly elevated during transit, the effect of differing caging densities on gene expression was minimal; collectively, this might indicate that expression of pro-inflammatory genes is more responsive to acute stress than to chronic stressors. We propose to use pro-inflammatory gene expression in peripheral blood cells to measure responses to stress in poultry.