Anatomy
Jovana Čukuranović Kokoris; Zoran Ružić; Zdenko Kanački; Slobodan Stojanović; Smiljana Paraš; Verica Milošević
Volume 15, Issue 3 , March 2024, , Pages 125-130
Abstract
The aim of this study was to examine the effects of heat stress (HS) on the pituitary-adrenal axis and whether the treatments with early-age thermal conditioning (ETC) and vitamin C, alone and in combination, could have a beneficial effect in alleviating these effects. For the experiment, 400 one day-old ...
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The aim of this study was to examine the effects of heat stress (HS) on the pituitary-adrenal axis and whether the treatments with early-age thermal conditioning (ETC) and vitamin C, alone and in combination, could have a beneficial effect in alleviating these effects. For the experiment, 400 one day-old broilers (both sexes) were used, being divided into four groups. The first group was the control (K), the second group (C) consisted of broilers which received vitamin C from the 22nd to the 42nd day via water in the amount of 2.00 g L-1, in the third group (T), broilers were exposed to ETC for a period of 24 hr at a temperature of 38.00 ± 1.00 ˚C and the fourth group (T + C) was the combination of T and C groups. Immunohistochemically positive adrenocorticotropic hormone (ACTH) cells of broilers in all groups were irregular or stellate and distributed in the periphery and central parts of the pituitary gland, as solitary cells or in clusters. In the T + C group of broilers, a significant increase in the area of ACTH cells (18.91%) and their cores (22.75%), and cortisol level in serum compared to the control group was observed. This reaction of broilers in the T + C group facilitated their adaptation to unfavorable consequences of HS. These results suggest that hypothalamic-pituitary-adrenal axis is stimulated after the exposure to chronic HS, enabling successful adaptation of broilers to adverse conditions.
Reza Ijab; Esmail Ayen; Amir Khaki; Ali Soleimanzadeh
Volume 13, Issue 1 , March 2022, , Pages 61-70
Abstract
Heat stress (HS) has caused relative hypoxia, oxidative stress and high level of homocysteine, which contributes significantly to fertility failures in bulls. The aim of present study was to evaluate the role of dietary betaine (BET) in improving dual purpose Simmental (Fleckvieh) post-thawed semen quality ...
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Heat stress (HS) has caused relative hypoxia, oxidative stress and high level of homocysteine, which contributes significantly to fertility failures in bulls. The aim of present study was to evaluate the role of dietary betaine (BET) in improving dual purpose Simmental (Fleckvieh) post-thawed semen quality especially during the hottest summer days. A total number of 16 mature bulls were randomly assigned to three equal groups including: 1) Control condition (without betaine), 2) BET1: 57.00 mg of betaine kg-1 per day and 3) BET2: 114 mg of betaine kg-1 per day, through daily intakes for 90 days in summer. Plasma levels of homocysteine, seminal plasma antioxidants levels and sperm parameters such as DNA fragmentation, chromatin integrity, motility, viability, morphology and membrane integrity were evaluated. Under maximal HS, serum homocysteine concentrations were reached 16.67 ± 0.09 µmol L-1. Dietary betaine supplementation influenced DNA fragmentation of sperm and was higher in the control group compared to BET2 group. There were significant decreases in seminal plasma superoxide dismutase (SOD), glutathione peroxidase (GPx) activity and sperm viability and motility in bulls treated with betaine. The activity of GPx and SOD in the control group was increased up to 0.08 ± 0.00 U mg-1 protein and 0.52 ± 0.01 U mg-1 protein in seminal plasma. There were no significant differences between groups in the percentage of swollen spermatozoa, membrane integrity, sperm morphology, abnormal head morphology and percentage of spermatozoa stained with aniline blue. In conclusion, BET supplements improved semen parameters in sperm motility, sperm viability and influenced DNA fragmentation during HS with reduction in serum homocysteine concentrations.
Poultry
Farhad Hajializadeh; Hasan Ghahri; Alireza Talebi
Volume 8, Issue 3 , September 2017, , Pages 259-264
Abstract
This experiment was carried out to investigate the effects of different levels chromium picolinate (CrPic) and chromium nanoparticles (nano-Cr) on the performance and immune function of broilers under heat stress condition. A total of 320 Ross 308 broiler chicks (from 21 to 42 days) were assigned randomly ...
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This experiment was carried out to investigate the effects of different levels chromium picolinate (CrPic) and chromium nanoparticles (nano-Cr) on the performance and immune function of broilers under heat stress condition. A total of 320 Ross 308 broiler chicks (from 21 to 42 days) were assigned randomly into eight treatment groups (four replicates per treatment, and 10 chicks per replicate) and be reared at either thermoneutral (21 ˚C) or heat stress (36 ◦C). The treatments were control (T1) group without supplementation and heat stress, T2 as a heat stress group without supplementation, T3, T4 and T5 groups which were supplemented with 500, 1000 and 1500 ppb CrPic in diet with heat stress, respectively and T6, T7 and T8 groups which were supplemented with 500, 1000 and 1500 ppb nano-chromium in diet under heat stress, respectively. Supplementation of chromium and nano-chromium improved performance including weight gain and feed conversion ratio of heat-stressed chickens. Antibody titers against avian influenza (AI) and infectious bronchitis (IB) at 21 to 42 days of age in broilers fed supplemental chromium and nano-chromium were higher than broiler chickens fed control diet (p < 0.05). Nano-chromium supplementation at level of 1000 ppb and CrPic at level of 1500 ppb improved the antibody titers against AI and IB of broilers under heat stress conditions. It can be concluded from these findings that dietary supplementation of CrPic and nano-Cr can improve performance and antibody titers against AI and IB under heat stress conditions in broilers.
Embryology
Hossain Hassanpour; Ali Kadivar; Pejman Mirshokraei; Hassan Nazari; Azita Afzali; Maryam Badisanaye
Volume 6, Issue 2 , June 2015, , Pages 125-130
Abstract
Sertoli cells are an essential group of cells in seminiferous epithelium which provide nutritional and structural supports for spermatogenic cells via cell junctions. In this study, the gene expression of connexin-43, the most abundantly distributed gap junction protein of cells, was investigated in ...
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Sertoli cells are an essential group of cells in seminiferous epithelium which provide nutritional and structural supports for spermatogenic cells via cell junctions. In this study, the gene expression of connexin-43, the most abundantly distributed gap junction protein of cells, was investigated in ram Sertoli cells under mild and severe heat stresses with real-time quantitative PCR. Sertoli cells were isolated from testes of 10 lambs. After culture and 3 passages, they were treated with mild (39 ˚C) and severe (42 ˚C) heat stress for 6 hr. The results showed a significant reduction in the percentage of live cells under severe heat stress compared to the control group (32 ˚C), (p <0.05). Relative quantification analysis revealed significantly higher (3.80 fold increase) values of connexin-43 transcripts in severely heat stressed group than control group (p <0.05). It is concluded that challenging Sertoli cells with 42 ˚C heat could threaten their survival, and overexpression of connexin-43 may cause dysfunction of Sertoli cells due to heat stress. These findings can be useful to identify the molecular mechanisms involved in adverse effects of heat stress on male reproduction and enhance our understanding of its pathogenesis.
