Background: In mammals, DRP1 is a key regulator of mitochondrial fission during mitochondrial dynamics, whereas ATF5 promotes the mitochondrial unfolded protein response (UPRmt). Both pathways are essential for maintaining cellular homeostasis and protecting oocytes and embryos from external stressors. However, the relationship between ATF5 expression and DRP1 under heat stress conditions during porcine oocyte maturation remains unclear. Methods: In this study, we investigated the mitochondrial dynamics and ATF5 expression in porcine oocytes exposed to heat stress during in vitro maturation (IVM). Protein and gene expression levels were assessed using immunofluorescence staining, Western blotting, and quantitative PCR. Results: During IVM, both DRP1 and ATF5 expression were increased (p < 0.01) significantly. In contrast, heat stress markedly impaired (p < 0.05) meiotic progression and cumulus cell expansion. Mitochondrial dynamics were disrupted (p < 0.05), as fission and fusion markers displayed reciprocal changes relative to those in controls. Concomitantly, the expression of ATF proteins was significantly reduced (p < 0.01) under heat stress. Heat-stressed oocytes also exhibited decreased (p < 0.05) expression of genes involved in antioxidant defense and NAD metabolism, whereas autophagy- and apoptosis-related transcripts were significantly upregulated (p < 0.05). At the blastocyst stage, embryos derived from heat-stressed oocytes exhibited nuclear localization of the UPR-associated transcription factors ATF4, CHOP, and ATF5. Conclusions: Collectively, our findings suggest that heat stress disrupts mitochondrial dynamics and ATF5 expression during porcine oocyte maturation while the UPRmt pathway remains active during early embryonic development to mitigate heat-induced cellular damage.

This study was conducted to elucidate the effects of feeding betaine or monosodium glutamate on the growth and carcass performance of Hanwoo steers according to the fattening stage under high-temperature stress. Farms in an area where THI was 78 or higher for more than 100 days were selected, and 30 head in the early fattening stage (14-15 months of age), 30 head in the mid-fattening stage (16-18 months of age), and 30 head in the late fattening stage (24-25 months of age) were tested, and 10 head were assigned to each treatment group. The experimental group was divided into control, T1 with 96% of the amino acid compound additive and 4% betaine, and T2 with the amino acid complex additive and 4% monosodium glutamate. 50 g per head were fed every morning for a total of 5 months from May 1, 2022 to September 30. In this study, there was no effect of betaine and monosodium glutamate on the growth and rectal temperature of Hanwoo steers at each fattening stage, but monosodium glutamate had a positive effect on the increase in rib eye area and decrease in back fat thickness in steers in the late fattening stage (P<0.05). Therefore, the results of this study indicate that monosodium glutamate did not have a direct effect on the growth of fattening Hanwoo steers, but it is thought to have a positive effect on the rib eye area and back fat thickness through protein metabolism and muscle development.

Background: Heat stress during summer impairs reproductive performance in sows, causing summer infertility. Cytochrome P450 1A2 (CYP1A2) plays a crucial role in steroid hormone metabolism in the liver and has been shown to be upregulated under stress conditions. However, the effect of seasonal heat stress on CYP1A2 expression in sow ovaries remains poorly understood. Methods: Ovaries were collected from crossbred sows during different seasons in Korea. The control group (CON) was exposed to optimal temperatures for swine rearing (22.0-24.5℃) during spring, while the heat-stressed group (HS) experienced high temperatures (30.5-37.0℃) during summer. Temperature-humidity index (THI) was calculated to assess thermal stress severity. CYP1A2 expression was analyzed using Western blotting and immunohistochemistry (IHC), and these values were statistically compared with THI by Pearson’s correlation analysis. Results: The HS exhibited significantly higher THI values compared to the CON (88.11 vs. 66.67). Western blot analysis revealed significant upregulation of CYP1A2 expression in the HS compared to CON (1.89 vs. 1.00). IHC demonstrated that CYP1A2 was specifically localized in granulosa cells of mature follicles, with a significantly higher proportion of CYP1A2-positive follicles in the HS (15.92%) compared to CON (9.08%). When the obtained values were compared with THI values, CYP1A2 expression showed a strong positive correlation with THI (r = 0.41 and 0.74). Conclusions: This study revealed that heat stress can alter the ovarian microenvironment, including the expression of CYP1A2. These findings emphasize the need for effective thermal management strategies to mitigate heat stress-induced reproductive dysfunction in livestock production.

본 연구에서는 인쇄 회로 열교환기 채널에서의 응력 집중 해석을 수행하였다. 응력 집중이 발생하는 응력 집중부의 응력을 도출하 기 위해 전체 시스템의 해석 결과를 활용하는 부모델링 기법을 사용하였다. 미세한 기하학적 형상과 비가역적 소성 변형을 고려한 부 모델의 탄성 및 소성 해석을 수행하였다. 탄성 및 소성 해석에서 얻은 응력을 통해 미세한 기하학적 형상이 PCHE의 응력 분포에 미치 는 영향을 파악하였다. 탄성 해석과 소성 해석에서의 최대 폰 미제스 응력을 비교하여 응력 집중부의 응력 집중 경향과 소성 변형을 확인하였다.

Background: South Korea has recently faced record-high temperatures, which have adversely affected dairy production. Holstein cows, the primary dairy breed globally, are particularly sensitive to heat stress. In contrast, Jersey cows have shown greater heat tolerance, as demonstrated by phenotypic studies. Methods: We investigated physiological and molecular responses to heat stress in Holstein and Jersey cows by measuring rectal temperature, milk yield, and average daily gain, confirming Holstein cows’ greater vulnerability. To explore molecular mechanisms, we analyzed circulating microRNA profiles from whole blood samples collected under heat stress and normal conditions using microRNA-sequencing. Differential expression patterns were compared between the two breeds to identify biological pathways associated with heat stress. Results: Four microRNAs (bta-miR-20b, bta-miR-1246, bta-miR-2284x, and bta-miR- 2284y) were significantly differentially expressed in both breeds under heat stress (|FC| ≥ 2, p < 0.05). Notably, bta-miR-20b and bta-miR-1246 were linked to corpus luteum function and progesterone biosynthesis, while bta-miR-2284x and bta-miR- 2284y were associated with immune responses. A comparison of 11 potential heat stress-related microRNAs identified in previous studies of Holstein cows revealed consistent expression trends in Jersey cows, albeit with lower fold changes, suggesting their superior heat resilience. Conclusions: Our study highlights the physiological and microRNA-based differences in heat stress responses between Holstein and Jersey cows. Jersey cows exhibited greater resilience, supported by more stable microRNA expression profiles and improved heat stress indicators, making them a promising breed for dairy production in increasingly hot climates.

This study aimed to investigate the effects of amino acid complex additives, such as protected vitamin C (VC) or detoxified sulfur (DS), on the growth and metabolism of Hanwoo cattle under high-temperature conditions. Accordingly, farms in Temperature-Humidity Index (THI) regions ranging from 78 to 89 for over 100 days were selected. The experimental groups were control, T1 (lysine + methionine + VC, 50 g/head/day), and T2 (lysine + methionine + DS, 50 g/head/day) with 70, 77, and 71 animals each. The range of the THI for 115 days was 78-89, and this occurred in most of the experiment days. The results showed that there was no significant difference in rectal temperature among the groups. The body weight increased to 786.4 and 809.0kg in the T1 and T2 groups, respectively, compared to the control group (p<0.05). Linoleic acid showed a high result of 2.01% in the T1 group compared to the control group (p<0.05). Unsaturated fatty acids were higher at 55.70 and 56.54% in the T1 and T2 groups, respectively, compared to the control group (p<0.05), and the omega 6/3 ratio was reduced to 20.10% (p<0.05). These findings indicate that T1 has a positive impact on growth, meat quality, and fatty acid composition compared to the control group. In conclusion, amino acid complex with VC improved the body weight of Hanwoo steers and the unsaturated fatty acids and essential amino acids of their meat; however, further research is needed to clarify this impact on carcass performance.

본 연구는 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가가 고온 스트레스 환경에서 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액성상에 미치는 영향을 조사하고자 수행되었다. 총 336마리의 86주령 로만 갈색종 노령 산란계를 6처리 7반복, 반복당 8수씩 임의 배치하였다. 대조구는 모든 영양소 및 에너지 요구량을 충족하거나 초과하도록 배합하였다. 대조구를 제외한 사료 처리구는 0.2% 비테인, 0.62% 글라이신, 그리고 0.32% 콜린을 단독, 두 가지 혼합, 혹은 세 가지 혼합으로 사료내 첨가하였다. 실험은 8주 동안 진행되었으며, 모든 산란계는 매일 8시간 동안 평균 온도 31.7±1.7℃, 습도 57%의 고온 스트레스 조건에서 사양되었고, 이외 시간에는 평균 온도 27±1.3℃, 습도 57%에서 사양하였다. 실험 결과, 비테인, 글라이신 및 콜린의 첨가는 생산성, 난품질, 그리고 면역 반응에 유의적인 영향을 미치지 않았다. 그러나, 0.2% 비테인과 0.62% 글라이신을 혼합 첨가한 처리구에서 혈청 알라닌 아미노전이효소 농도가 유의적으로 감소했다. 하지만, 다른 혈청 지표들은 처리간 유의적인 차이가 관찰되지 않았다. 결론적으로, 현재 수준에서 사료내 비테인, 글라이신, 그리고 콜린의 혼합 첨가는 고온 스트레스 환경에서 사양되는 노령 산란계의 생산성, 난품질, 면역 반응 및 혈액 성상에 긍정적인 영향을 미치지 않는다고 판단된다.

The objective of the present experiment was to investigate the effects of dietary vitamin C (VC), vitamin E (VE), and betaine (BT) supplementations on productive performance, egg quality, relative organ weights, liver visual characteristics, antioxidant status, immune response, and stress indicator in laying hens raised under heat stress conditions. A total of 280 47-wk-old Hy-Line Brown laying hens were allotted to 1 of 4 dietary treatments with 7 replicates in a completely randomized design. Each replicate had 10 birds per cage. The basal diet was formulated to meet or exceed the requirement estimates for Hy-Line Brown laying hens. Three additional diets were prepared by adding 250 mg/kg VC, 250 mg/kg VE, or 3,000 mg/kg BT to the basal diet. The experimental diets and water were provided to hens on an ad libitum basis for 8 wk. Average daily room temperature and relative humidity were 30.7±1.41℃ and 72.5±11.61%, respectively. Results indicated that hens fed diets containing 250 mg/kg VE had a less (p<0.05) egg production rate than other dietary treatments. For egg quality, hens fed diets containing 3,000 mg/kg BT had a less (p<0.05) eggshell thickness than those fed the diets containing 250 mg/kg VC or 250 mg/kg VE. For antioxidant status, there was a tendency (p=0.09) for the least malondialdehyde (MDA) concentrations in the liver for BT treatment. A tendency (p=0.05) was observed for less blood heterophil:lymphocyte ratio in BT treatment as compared to other treatments. In conclusion, dietary supplementation of 250 mg/kg VC, 250 mg/kg VE, and 3,000 mg/kg BT has no beneficial effects on productive performance, egg quality, relative organ weights, liver visual characteristics, and immune responses of laying hens raised under the current heat stress conditions. However, dietary supplementation of 3,000 mg/kg BT alleviates antioxidant status and stress response of laying hens exposed to heat stress.

본 연구는 고온 환경에서 사료내 트립토판과 나이아신의 첨가가 산란계의 생산성, 난품질, 지방간 지표 및 혈액성상에 미치는 상호작용 효과를 조사하고자 수행되었다. 총 384수의 25주령 로만 갈색종 산란계를 4처리 8반복으로 반복당 12수씩 무작위 임의 배치하였다. 기본 사료는 트립토판과 나이아신의 추가적인 첨가는 없으며 모든 영양소 및 에너지는 로만갈색종 산란계의 요구량에 충족하거나 초과하도록 배합되었다. 사료 처리구는 2 × 2 요인 실험 설계법으로 두 가지 수준의 트립토판(0 및 0.16%)과 두 가지 수준의 나이아신(0 및 0.03%)이 포함되었다. 모든 산란계의 사양환경은 일반 농가에서 낮시간에 온도가 올라가는 점을 고려하여 일일 중 8시간은 온도 31.4 ± 1.17℃, 습도 86.0 ± 4.28%으로 설정하였으며, 나머지 16시간은 온도 26.7 ± 1.10℃, 습도 61.7 ± 6.34%로 유지하여 주기적인 고온 환경을 조성하였다. 실험은 10주간 진행되었다. 실험 결과 사료내 트립토판과 나이아신의 주요 효과와 상호작용은 나타나지 않았다. 이와 유사하게, 난각 강도, 난각 두께, 난각색, 난황색 및 호우유닛에 대한 상호작용 도 나타나지 않았다. 주요 효과로 0.03%의 나이아신 첨가는 난황색을 유의적으로 감소시켰으나 호우유닛은 유의적으로 증가시켰다. 하지만, 0.16%의 트립토판 첨가는 난품질에 영향을 끼치지 않았다. 지방간 지표와 혈액성상에서 사료내 트립토판과 나이아신의 주요 효과 및 상호작용은 나타나지 않았다. 결론적으로, 본 연구에서 설정한 농도의 사료내 트립토판과 나이아신의 첨가는 고온 환경에서 사양되는 산란계의 생산성, 난품질, 지방간 지표 및 혈액성상에 긍정적인 영향을 미치지 않았다.

The impact of heat stress (HS) on reproductive performance and its problems in cows remains to be investigated in Bangladesh. The study was, therefore, aimed to evaluate the effect of HS on fertility and reproductive health problems of dairy cows in a selected area of Bangladesh. A total of 1,095 cows from 500 farms were included in this study. The climate-related data were recorded daily basis for every month in a year and temperature-humidity index (THI) values were calculated to determine the level of HS. Concurrently, data on fertility parameters [number of services per conception (NSC), conception rate (CR) and calving to the first service interval (CFSI)], and reproductive problems were collected through a pre-defined questionnaire. The results show that crossbred [Native x Holstein-Friesian, (HF)] cows were more vulnerable (p < 0.05) to a magnitude of HS effects considering physiological parameters of cows [age, body condition score (BCS), parity and milk yield]. Regarding fertility, HS had no effect on NSC, CR and CFSI in both native and crossbred cows (p > 0.05). The findings on the reproductive problems indicate that HS had significant influence on the prevalence of anestrus (χ2 = 21.814, p < 0.05) and retained placenta (χ2 = 24.632, p < 0.05) in cows. Of note, the prevalence of repeat breeding syndrome was 2.5 folds higher in stress condition than in no stress condition. Abortion and dystocia were not influenced by HS. In conclusion, HS does not influence the fertility parameters of cows studied; however, anestrus and retained placenta are likely to occur under HS conditions in cows.

Lonicera caerulea (Honey berry, HB) has been used in medical treatment in Russia, Japan, China and Korea. It has high level of vitamin C and polyphenolics. Polyphenolics can improve anti-inflammatory effect and prevent cancer, diabetes mellitus type 2. Also, Vitamin C is a representative anti-oxidant. however, it is still unknown what effect it will have on the oxidation stress of the reproductive system. In previous studies, ROS can be produced when it is exposed to heat stress and has negative effect on sperm’s maturation, capacitation, hyperactivation, acrosome reaction and fusion of egg and sperm. Therefore, the purpose of this study is to investigate the antioxidant effects of L. Caerulea on the sperm and mice. At first, it conducted using ICR mouse (n = 20) for 4 weeks. There are four groups of mice (n = 5 per group). Also, L. Caerulea was taken by oral gavage. Group I (control) kept at 23℃-27℃ and administer D.W (0.5 mL/day), Likewise, Group II (HB) kept at room temperature but gave HB (250 mg/kg, 0.5 mL/day), Group III (HB + HS) received heat stress (40℃) using hyperthermia induction chamber and gave HB at same dose. and Group IV (HS) exposed heat stress only. Mainly, we showed degree of gene expression using Western blot in SOD, HSP 70, 17β-HSD and Real-time PCR. It can find correlation between intracellular activity like steroid hormone, apoptosis under ROS and antioxidant activity of L. Caerulea.

In this study the effect of vitamin C administration on pregnancy rates during summer heat stress in dairy cows was examined. A total of 80 Holstein-Friesian cows were divided into control and treatment groups (n = 40 each). Control group animals were given 10 mL isotonic normal saline, and treatment group, Vitamin C (4 mg/kg) on artificial insemination day (day 0) and 4th, 8th and 12th day post insemination. Pregnancy diagnosis was performed on 30th day post insemination by ultrasonography. Blood samples were randomly taken from 11 animals from each group. Serum P4, GSH, MDA and plasma 8-OHdG levels were determined by using ELISA method. Results showed that 8-OHdG levels were lower in treatment group on day 4, 8 and 12 (p < 0.05) compared with the control group. Similarly, pregnancy rate was higher in treatment group (32.5%) than control (22.5%), respectively. However, MDA, P4 and GSH levels were similar in both groups at 4th, 8th and 12th day. A gradual increase in P4, and MDA levels, and a strong positive correlation between 0, 4th (r = 0.54), 4, 8th (r = 0.59) and 8, 12th (r = 0.51) day was found. Similarly, GSH levels also showed positive correlation at days 0, 4th (r = 0.47) and 4, 8th (r = 0.56). However, a strong negative correlation (r = -0.56) between MDA day 0, and GSH day 8 was found. In conclusion, vitamin C application during insemination period in postpartum cows increases pregnancy rate, and reduces oxidative stress metabolite 8-OHdG levels.