The effects of Artemisia Sieberi, Achillea Fragrantissima, and Olea Europaea leaves on the performance and physiological parameters in heat-stressed broiler chickens.

High temperatures have detrimental effects on the performance and physiology of broiler chickens. Medicinal plants have various biological activities and may enhance the heat resistance of chickens during heat waves. Therefore, this study aimed to explore the potential roles of using specific local medicinal plants to alleviate the negative impacts of heat stress (HS) in broilers. In this study, 180 day-old chicks were used to investigate the effects of HS and dietary indigenous medicinal plants on growth performance, antioxidant biomarkers, and intestinal health. The chicks were assigned to six groups (18 pens with 10 chicks per pen) with three replicates each. In the first group, the chicks were kept under thermoneutral conditions (CON) and fed a basal diet. The other five groups were exposed to recurrent heat stress and fed a basal diet (T1, HS group) or supplemented with Artemisia Sieberi (1.25 g/kg of feed; T2), Achillea Fragrantissima (15 g/kg of feed; T3), Olea europaea (10 g/kg of feed; T4), and all the previous additives (all-in-one) combined at the same dose levels mentioned above (T5). At 21 days of age, the chicks from each group were exposed to two phases of heat stress: phase 1 from days 21 to 34 (34 ± 1°C) followed by phase 2 from days 35 to 39 (37 ± 1°C). The results indicate that HS significantly increased rectal temperature and respiration rate in broiler chickens. Feed intake and body weight gain were improved in all supplemented groups, while the feed conversion ratio was decreased in response to the dietary inclusion of medicinal plants. Additionally, glutathione peroxidase and immunoglobulin G levels were increased in the T3, T4, and T5 groups compared to the other groups. HS induced significant upregulated in the mRNA levels of heat shock protein 70 and interleukin-8, while the mRNA of occludin was decreased. The T3, T4, and T5 showed significantly decreased expression of hepatic HSP70 and ileum IL-8 genes and increased ileum mRNA occludin levels relative to the CON and T1 groups. In conclusion, supplementation with these plants enhances growth performance and maintains intestinal health sustaining the productivity of broiler chickens under HS conditions.

Thermotolerance of Broiler Chicks Ingesting Dietary Betaine and/or Creatine.

The present study aimed to assess the effect of dietary betaine (B) and/or creatine (C) on performance and thermoregulatory responses of broiler chicks. Indian River broiler chicks, fitted with compact thermosensors, were reared to market age (five weeks). The chicks were randomly distributed into four treatment groups, in a 2 × 2 factorial arrangement of treatments-basal control diet (Control group: CONT; B-/C-); 1 g betaine/kg feed (Betaine group: BETA; B+/C-), 1.2 g creatine monohydrate/kg feed (Creatine group: CRET; B-/C+), and combination (Betaine and Creatine group: COMB; B+/C+) of both supplements. At 31 days of age, 20 chicks from each group were exposed to acute heat stress (A-HS) for 3 h (34.45 ± 0.20 °C), and hemogramic profiles were screened before and after. Performance parameters (feed intake, body weight gain, and feed conversion ratio) were reported on a weekly basis, and carcass meat quality was evaluated at the end of experiment. Redness of breast was higher due to B and C treatments separately than the CONT group (B by C interaction; p < 0.05). Compared to the CONT, dietary supplements alleviated hyperthermia responses, with B alone being more efficient than C or COMB treatments. The mitigation of hyperthermia is likely mediated by enhancement of water balance indicators. Although not efficient in improving growth performance, dietary B and/or C are efficient in improving thermophysiological performance and survival of finishing broiler chicks under A-HS.

Renal efficiency underlies adaptive heterothermy of heat-stressed hypohydrated goats.

We investigated the thermotolerance of the F1 progeny (Black Bedouin × Damascus crossbreed) to summer conditions alongside that of two pure breeds. Male goats (n = 7 per breed) were used to conduct a summertime 28-day trial along with hypohydration. The animals were fitted with miniscule thermologgers, intraperitoneally and subcutaneously, to measure core (Tc) and peripheral (Tp) body temperatures (BT), respectively. All goats were kept under shaded housing for a 7-day basal period before being switched to unshaded pens for the next 21 days. During the first 14 days, animals had free access to water. However, during the third 7-day period, access to water was time-restricted (4 h/day). Finally, it was restricted to 40% of the third week's average daily intake over the last 7 days. Exposure to the unshaded conditions resulted in pronounced heat stress in all animals, as reflected by 0.42 and 1.44 °C rises for Tc and Tp, respectively. The F1 goats displayed a clear heterothermic adaptive response, especially after the water restriction bouts' initiation. Interestingly, the F1 goats displayed higher ratios of renal relative medullary thickness (77.7, 73.3, and 72.6 ± 1.1%) along with higher circulating concentrations of antidiuretic hormone (44.6, 31.6, and 11.6 ± 3.7 ng/mL), respectively, which suggested an improved water metabolism.

Resveratrol mitigates hypercholesterolemia exacerbated hyperthermia in chronically heat-stressed rats.

BACKGROUND AND AIM: Hypercholesterolemia (HC) is the major leading cause of cardiovascular disease worldwide. Such atherogenic aberration deeply impacts blood circulation. Resveratrol (R) is a polyphenol that has received attention as a hypolipidemic, antioxidant, and vascular agility advocate. Efficient blood redistribution is a key element in mammalian thermoregulation. We hypothesized that R treatment may aid in mitigating hyperthermic responses under both acute and chronic heat stress (HS) conditions in HC male rats. MATERIALS AND METHODS: All rats were initially fitted with miniaturized thermologgers to measure core body temperature (Tcore). With a 2 × 2 factorial arrangement, four groups were randomly allotted, in which half of the animals ingested an HC diet (C+), while the other half ingested a control (C-) diet, throughout the whole study duration of 35 days. Seven rats from each dietary treatment, however, received R (R+; 13 mg/kg BW/day), while the rest received normal saline (R-) for 5 continuous days. All animals were maintained at thermoneutrality (TN; ambient temperature; Ta=23.15±0.04°C) for a period of 30 continuous days (days 0-29). On day 29, an acute HS (HS; Ta=35.86±0.37°C; for 9 nocturnal h) was imposed. Then, from day 29, a chronic HS protocol (Ta=32.28±1.00°C) was maintained until the past day of the trial (day 34), after which blood samples were drawn for analyses of platelet (PL) count, total antioxidant activity (TAO), total cholesterol (TC), triglycerides (TGs), and lipid peroxidation (LP). RESULTS: Switching animals from TN to HS resulted in abrupt rises in Tcore. The HC diet induced a significant (p<0.01) hyperlipidemia over the control of diet-consuming rats. Interestingly, the hyperthermic response to acute HS was highly pronounced in the rats consuming the C- diet, while the C+ diet exacerbated the chronic HS-induced hyperthermia. Despite failure to improve TAO in the C+ diet, R+ treatment caused a marked (p<0.05) decline in nighttime - hyperthermia in C+ rats, likely by enhancing blood flow to extremities (for heat dissipation) as delineated by drastic downregulations of C+ related rises in PL, TC, TG, and LP (HC diet by R+ interaction; p<0.03). CONCLUSION: The hyperthermic response in C- groups was attributed to higher amount of feed intake than those consuming the C+ diet. Yet, the R+ improvement of thermoregulation in the C+ group was likely related to enhancement of vascular hemodynamics. Resveratrol intake mitigated chronic HS-evoked hyperthermia in rats. Such an approach is worthy to follow-up in other mammals and humans.

The hypocholesterolemic and hormone modulation effects of isoflavones alone or co-fermented with probiotic bacteria in hypercholesterolemic rats model.

This study aimed to investigate the beneficial effect of isoflavones alone or probiotics-co-fermented isoflavones on serum and hepatic lipid profile, serum steroid (SHs) and thyroid hormones (THs) of hypercholesterolemic rats (N = 48). Animals were fed for 8 weeks with probiotics-co-fermented isoflavones or isoflavones alone, beside high-fat-high-cholesterol diet. Serum was analyzed for cholesterols, triglycerides (TG), SHs and THs. Results demonstrated that the given treatments significantly decreased serum total-cholesterol (TC), low-density-lipoprotein-cholesterol (LDL-C), high-density-lipoprotein-cholesterol (HDL-C), LDL/HDL ratio, and increased TG, compared to controls. The probiotics-co-fermented isoflavones decreased TC, LDL-C and LDL/HDL ratio more effectively than isoflavones alone. Also, both isoflavones treatments induced a hyperthyroidism state, as the levels of T-T4, T-T3 and fT3 significantly increased. In addition, these treatments decreased testosterone and increased cortisol levels. Thus, isoflavones-containing-treatments, particularly probiotics-co-fermented isoflavones, could reduce CVD incidence by controlling lipid profile; and this control could in part be due to modulation of SHs and THs.

Thermoregulatory response of dairy cows fed ergotized barley during summer heat stress.

Claviceps purpurea infects the seed heads of cereal grains and grasses and produces ergopeptine alkaloids that cause hyperthermia and agalactia in cattle during periods of heat stress. A field experiment was undertaken to examine the effects of ergopeptine alkaloids found in barley on thermal status of dairy cattle during periods of heat stress. Production end points were also measured to identify the effect of the change in thermal status. Contaminated barley screenings containing known levels of ergopeptine alkaloids were fed to lactating Holstein cattle (10 microg total ergopeptine alkaloids/kg BW/day) for 10 days during summer heat stress. Air temperature increased 14.4 C during the first 8 days of treatment and then declined the same during the last 2 days. Extreme daily values for rectal temperature and respiration rate, using averages of all animals, showed maximum increases of 2.3 C and 56.8 breaths/minute, respectively, during this period. Group afternoon milk production decreased 2 kg/day during the heat stress period, with no measurable change in feed intake. A greater level of hyperthermia occurred in cattle consuming the diet with ergopeptine alkaloids, with only marginal symptoms of ergot toxicosis reflected in feed intake and milk production. Therefore, the ergopeptine alkaloid dose used in this study represents a level for minimal induction of the ergot toxicity response.