Effect of Supplemental Trace Minerals on Hsp-70 mRNA Expression in Commercial Broiler Chicken

Modulation of heat shock protein 70 (HSP70) gene expression ex vivo in response to heat stress in chicken

The present study was conducted to assess the effect of exposure to heat stress on the HSP70 gene expression pattern ex vivo in chickens. The adult healthy birds (n = 15) grouped into three replicates of n = 5 each were used to isolate peripheral blood mononuclear cells (PBMCs). The PBMCs were subjected to heat stress at 42 °C for 1 h, and cells without heat stress (NHS) were taken as control. The cells were seeded in 24 well plates and incubated in a humidified incubator at 37 °C under 5% CO2 for recovery. HSP70 expression kinetics were evaluated at 0, 2, 4, 6, and 8 h of the recovery period. Compared with NHS, the expression pattern of HSP70 was upregulated gradually from 0 to 4 h with peak (p < 0.05) expression recorded at 4 h of recovery time. mRNA expression of HSP70 escalated in a time-dependent manner from 0 to 4 h of heat exposure and thereafter exhibited a gradually decreasing pattern till 8 h of the recovery period. The findings from this study highlight the protective role of HSP70 against the deleterious effects of heat stress in chicken PBMCs. Further, the study demonstrates the possible use of PBMCs as a cellular system in assessing the heat stress effect in chickens ex vivo.

Effect of injectable trace mineral supplementation on peripheral polymorphonuclear leukocyte function, antioxidant enzymes, health, and performance in dairy cows in semi-arid conditions

The objective of this study was to evaluate the effect of subcutaneous injections of 15 mg/mL Cu, 5 mg/mL Se, 60 mg/mL Zn, and 10 mg/mL Mn on health, performance, polymorphonuclear leukocyte (PMNL) function, circulating glutathione peroxidase (GPx) and superoxide dismutase (SOD) concentrations, and inflammation of dairy cows undergoing the transition period in high temperature-humidity index. A total of 923 multiparous cows from 2 commercial dairy farms were randomly allocated into 1 of 2 treatment groups as follows: control and injectable trace mineral supplementation (ITMS). Cows in the ITMS group received 7 mL of subcutaneous injections at dry-off (208 ± 3 d of gestation), 260 ± 3 d of gestation, and at 35 ± 3 d in milk (DIM). Data regarding health traits, reproductive performance, milk yield, and survivability were extracted from farm database software, and animals were followed-up until 300 DIM. For a subset of 142 cows from one herd, blood samples were collected at enrollment, and at 3 ± 1, 7 ± 1, 10 ± 1, and 35 ± 3 DIM to evaluate hematology, PMNL function, GPx and SOD concentrations, and circulating haptoglobin. Logistic regression was used to assess health and pregnancy per artificial insemination at first service. Cox proportional hazards models were used to evaluate hazard of pregnancy and culling. Mixed linear regression models accounting for repeated measures were used to assess all continuous variables collected over time. Parity, twinning, and previous gestation length were considered as potential confounders. Farm was included as a random effect. The ITMS cows tended to have lower incidence of metritis and stillbirth compared with control group. However, ITMS treatment did not influence the incidence of other diseases (e.g., mastitis, retained placenta), milk yield, reproductive performance, culling, and leukocyte count. Neutrophil-to-lymphocyte ratio, PMNL phagocytosis, and oxidative burst as well as intensity of the oxidative burst were greater for ITMS-treated cows in comparison to control cows. The ITMS cows had decreased expression of the adhesion molecule L-selectin on PMNL surface. The serum concentration of GPx and SOD were not affected by ITMS treatment. In conclusion, ITMS tended to reduce the incidence of metritis and stillbirth parturition, improved PMNL function, and improved the inflammatory status of dairy cows undergoing the transition period in high temperature-humidity index conditions. However, these findings did not translate into improved milk yield, reproductive performance, and survivability.

Water amino acid-chelated trace mineral supplementation decreases circulating and intestinal HSP70 and proinflammatory cytokine gene expression in heat-stressed broiler chickens

Heat stress (HS) is a financial and physiological burden on the poultry industry and the mitigation of the adverse effects of HS is vital to poultry production sustainability. The purpose of this study was, therefore, to determine the effects of an amino acid-chelated trace mineral supplement on growth performance, stress and inflammatory markers, and meat quality in heat-stressed broilers. One day-old Cobb 500 male broilers (n = 480) were allocated into 12 environmental chambers (24 floor pens) and divided into two groups: one group supplemented with amino acid-chelated trace mineral in drinking water and one control group. On day 28, birds were subjected to chronic heat stress (HS, 2 wk, 35 °C and 20% to 30% RH) or maintained at thermoneutral condition (TN, 24 °C) in a 2 × 2 factorial design. Feed intake (FI), water consumption, and body weight were recorded. At day 42, serum fluorescein isothiocyanate dextran (FITC-D) levels, blood gas, electrolyte, and stress markers were measured. Jejunum samples were collected to measure gene expression of stress, inflammation, and tight junction proteins. The rest of the birds were processed to evaluate carcass traits. HS resulted in an increase in core body temperature, which increased water intake and decreased FI, body weight, and feed efficiency (P < 0.05). HS reduced carcass yield and the weight of all parts (P < 0.05). HS significantly increased levels of circulating corticosterone (CORT), heat shock protein 70 (HSP70), interleukin 18 (IL-18), tumor necrosis factor alpha, C-reactive protein, and nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing 3 expression. HS significantly increased serum FITC-D levels and the expression of HSP70 and IL-18 in the jejunum. Although it did not affect the growth performance, amino acid-chelated trace mineral supplementation reversed the effect of HS by reducing CORT and FITC-D levels and the expression of stress and proinflammatory cytokines in the circulation and the jejunum. However, it upregulated these parameters in birds maintained under TN conditions. Together, these data indicate that the amino acid-chelated trace mineral might alleviate stress and inflammation and improve gut integrity in heat-stressed but not thermoneutral broilers.

Selenium/Zinc-Enriched probiotics improve serum enzyme activity, antioxidant ability, inflammatory factors and related gene expression of Wistar rats inflated under heat stress

AIMS

The present study was carried out to investigate the influences of Selenium/Zinc-Enriched probiotics (SeZnP) on growth performance, serum enzyme activity, antioxidant capability, inflammatory factors and gene expression associated with Wistar rats inflated under high ambient thermal-stress.

MAIN METHODS

Sixty male rates with six-weeks of age were randomly allocated into five groups (12 per group) and fed basal diet (Control), basal diet supplemented with probiotics (P), Zinc-Enriched probiotics (ZnP, 100 mg/L), Selenium-Enriched Probiotics (SeP, 0.3 mg/L) and Selenium/Zinc-Enriched probiotics (SeZnP, 0.3 mg + 100 mg/L). The experiment lasted 30 days. Blood and Tissues samples were taken to investigate serum enzyme activity, antioxidants capability and inflammatory factors by using of commercial kits and antioxidant, heat shock and inflammatory related molecules expressions were determined by qRT-PCR.

KEY FINDINGS

Data analysis revealed that thermal stress significantly increased the level of Aspartate-aminotransferase, Alanine-aminotransferase, Lactate-dehydrogenase, Creatine-kinase, blood urea nitrogen, Creatinine and Alkaline phosphatase compared to P, ZnP, SeP or SeZnP groups (P < 0.01). However, supplementation of ZnP, SeP, and SeZnP significantly enhanced glutathione content, glutathione-peroxidase & superoxide-dismutase activity, and decreased malondialdehyde content (P < 0.05). Moreover, the concentration of IL-2, IL-6 and IL-8 were significantly increased while IL-10 was significantly decreased (P < 0.05). Furthermore, the expression of GPx1 and SOD1 genes were significantly increased, but COX-2, iNOS, HSP70 and 90 mRNA levels were significantly decreased (P < 0.05). Finally, the highest influence of the mentioned parameters was observed in SeZnP supplemented group.

SIGNIFICANCE

Our study suggests that SeZnP supplementation serves as possible and best nutritive than ZnP or SeP for Wistar rats raising under high ambient temperature.

Heat stress management in poultry farms: A comprehensive overview

Heat stress causes significant economic losses in poultry production, especially in tropical and arid regions of the world. Several studies have investigated the effects of heat stress on the welfare and productivity of poultry. The harmful impacts of heat stress on different poultry types include decreased growth rates, appetites, feed utilization and laying and impaired meat and egg qualities. Recent studies have focused on the deleterious influences of heat stress on bird behaviour, welfare and reproduction. The primary strategies for mitigating heat stress in poultry farms have included feed supplements and management, but the results have not been consistent. This review article discusses the physiological effects of heat stress on poultry health and production and various management and nutritional approaches to cope with it.

Comparative effects of inorganic and three forms of organic trace minerals on growth performance, carcass traits, immunity, and profitability of broilers

Objective:

The experiment was conducted to investigate the comparative effects of inorganic trace minerals (ITM) and three forms of organic trace minerals (OTM) (propionate, metho-chelated, and proteinate) on growth performance, edible meat yield, immunity, and profitability of commercial broilers.

Materials and methods:

A corn-soya based mash diet comprising four treatments each of 10 replicates were fed to 720 day-old Cobb 500 broiler chicks for 35 days (starter diet 0–21 days and grower diet 22–35 days). The diets for comparison were as follows: diet 1: control diet with ITM premix at 1 kg/ton of feed (T₁); diet 2: control diet supplemented with propionate trace minerals at 600 gm/ton (T₂); diet 3: control diet supplemented with metho-chelated trace minerals at 500 gm/ton by reducing 225 gm methionine/ton of feed (T₃); and diet 4: control diet supplemented with proteinate trace minerals at 500 gm/ton of feed (T₄). Growth performance, carcass yield, and antibody titer (AT) data were recorded. Data were analyzed and interpreted using SAS Computer Package Program version 9.1.

Results:

Feeding propionate and proteinate OTM showed similar performance. Birds fed these two types (propionate and proteinate) or OTM had better performance in comparison with those receiving ITM and metho-chelated one. Proteinate group produced more wing meat and propionate group showed higher breast and drumstick meat yield as compared with those received the metho-chelated trace mineral and ITM. The birds belonging to OTM groups showed significantly higher AT level against infectious bursal disease. Proteinate minerals groups showed higher profitability followed by propionate fed broilers.

Conclusion:

Two forms of OTM, propionate and proteinate improved performance of commercial broilers over those of ITM and metho-chelated one.