Using Recombinant Superoxide Dismutase to Control Oxidative Stress in the Gastrointestinal Tract of Cyclic Heat-Stressed Pigs.

Climate change is associated with an increased frequency and intensity of heat waves, posing a threat of heat stress to pig production. Heat stress compromises the efficiency of pig production partly due to causing oxidative stress, intestinal dysfunction, and inflammatory responses. Superoxide dismutase is an antioxidant enzyme reported to reduce oxidative stress and inflammation. Therefore, this experiment aimed to investigate whether recombinant superoxide dismutase (rSOD) could ameliorate oxidative stress and inflammatory responses in heat-stressed grower pigs. Sixty-four female pigs (Large White × Landrace, 27.8 ± 1.65 kg, mean ± SD) were randomly allocated to a control diet (standard grower feed, CON) or the control diet supplemented with 50 IU recombinant superoxide dismutase (rSOD) for 14 days. After acclimation to the diet, pigs were then housed under thermoneutral (TN, 20 °C, 35-50% relative humidity) or cyclic heat stress conditions (CHS, at 35 °C: 9 a.m. to 5 p.m. and 28 °C: 5 p.m. to 9 a.m., 35-50% relative humidity) for 3 days. Heat stress increased respiration rate (RR), skin and rectal temperature (RR and RT) (p < 0.001 for all), and reduced plasma thyroid hormone concentration (p < 0.001). The amount of oxidized glutathione (GSH:GSSG) was increased in the jejunum and ileum of CHS pigs. In the jejunum, rSOD also increased the amount of oxidized glutathione in both TN and CHS pigs, without any change in endogenous SOD activity. In the ileum, rSOD prevented increases in oxidized glutathione formation in the CHS pigs only. Taken together, this may reflect increased oxidative stress in both the jejunum and ileum in CHS pigs. Alternatively, rSOD increased the conversion of reduced to oxidized glutathione independently of CHS, possibly reflecting an increased overall SOD activity due to the addition of exogenous SOD. In conclusion, the use of in-feed SOD enzymes at a dose of 50 IU/kg may be a useful strategy for preventing oxidative stress in pigs.

Nanoliposome-Loaded Phenolics from Nasturtium officinale Improves Health Parameters in a Colorectal Cancer Mouse Model.

Nasturtium officinale contains high amounts of phytochemical compounds that work against oxidative damages leading to improved health conditions in animals as well as humans. The study was performed to investigate the health benefits of nonencapsulated and nanoliposome-encapsulated phenolic rich fractions obtained from Nasturtium officinale on mice induced colorectal cancer. The experiment focused on encapsulation efficiency in improving the effectiveness of plant bioactive compounds. Phenolic rich fractions (PRF) were successfully loaded in the nanoliposome structure, a nanometer in size, of spherical shape and with homogeneous dispersion. Induction of colorectal cancer in mice impaired weight gain and feed intake, liver function and structural characteristics of ileum, while the dietary administration of nanoliposome-encapsulated PRF regulated the expression of Caspase 3, Bax, Bcl2, iNOS and SOD genes in the tumor tissue. The addition of nonencapsulated PRF and nanoliposome encapsulated PRF at the concentration of 100 mg TPC/kg BW/day improved the genes expression, although the nanoliposome-encapsulated PRF revealed better health outcomes compared to nonencapsulated PRF. Furthermore, both PRF improved intestinal morphology when the mice were challenged with colorectal cancer. The higher health promoting activity of nanoliposome-encapsulated PRF could be associated with its enhanced intestinal absorption, bioavailability, bioaccessibility and bioactivity. Consequently, the nanoliposome-encapsulated PRF could be considered as a promising anticancer agent against colorectal cancer.

Manipulation of Rice Straw Silage Fermentation with Different Types of Lactic Acid Bacteria Inoculant Affects Rumen Microbial Fermentation Characteristics and Methane Production.

Bacterial inoculants are known to improve the quality of silage. The objectives of the present study were to evaluate the effects of different types of lactic acid bacteria (LAB; L. plantarum, L. salivarius, L. reuteri, L. brevi, and S. bovis) inoculation (106 cfu/ DM) on rice straw silage quality and to determine these effects on ruminal fermentation characteristics, digestibility and microbial populations in an in vitro condition. Inoculated rice straw was ensiled for 15 and 30 days. For the in vitro study, rumen fluid was obtained from three rumen-fistulated bulls fed on mixed forage and concentrate at 60:40 ratio twice daily. Inoculation with LAB improved (p < 0.05) the rice straw silage quality as indicated by higher dry matter and crude protein contents, decreased pH and butyric acid, and increased propionic acid and LAB numbers, especially after 30 days of ensiling. Results from the in vitro study revealed that starting with the addition of LAB to rice straw silage improved in vitro fermentation characteristics such as increased total volatile fatty acids and dry matter digestibility (p < 0.05). LAB treatments also decreased methane production and methane/total gas ratio after 15 and 30 days of ensiling. From the rumen microbial population perspective, cellulolytic, and fungal zoospores were enhanced, while protozoa and methanogens were decreased by the LAB treatments. Based on these results, it could be concluded that inoculating rice straw silage with LAB (especially for L. plantarum and S. bovis) improved silage quality, rumen fermentation parameters and microbial populations in vitro.

Strategies to Combat Heat Stress in Broiler Chickens: Unveiling the Roles of Selenium, Vitamin E and Vitamin C.

Heat stress compromises efficient poultry production by impairing growth performance and increasing mortality. Mechanisms to dissipate excess heat divert energy from efficient production. This includes increased energy expenditure for respiration, oxidative stress and micronutrient absorption. The fortification of diets with particular feed additives has been known as one of the most important approaches to minimize the negative impacts of heat stress on broiler production. In this context, the promising functional feed additives appeared to be selenium and vitamins E and C. The fortification of broiler diets with these feed additives has been proven to enhance the function of vital organs, immune system response and growth performance of broilers under heat stress. The current review highlights recent successful experiences in the alleviation of heat stress symptoms in broilers using the above-mentioned additives. Selenium and vitamins E and C enhanced production performance in broiler chickens challenged with acute heat stress. The combination of these additives, by employing multiple mechanisms and through synergistic effects, improves heat stress symptoms more efficiently than their individual forms. Emerging literature reveals that selenium and vitamins E and C are involved in close interactions to protect proteins and lipids from oxidative damage and boost immune system function.

Betaine and Isoquinoline Alkaloids Protect against Heat Stress and Colonic Permeability in Growing Pigs.

Heat stress (HS) compromises productivity of pork production, in part as a result of increased oxidative stress and inflammatory responses, particularly within the gastrointestinal tract. This study aimed to investigate whether plant-derived betaine and isoquinoline alkaloids could ameliorate HS in pigs. Fifty female Large White × Landrace grower pigs, which were acclimated to control (CON), control plus betaine (BET), or control plus isoquinoline alkaloids (IQA) diets for 14 days were then exposed to heat stress or thermoneutral condition. Both BET and IQA partially ameliorated increases in respiration rate (p = 0.013) and rectal temperature (p = 0.001) associated with HS conditions. Heat stress increased salivary cortisol concentrations and reduced plasma creatinine, lactate, and thyroid hormone concentrations. Heat stress increased colon FD4 permeability, which was reduced by IQA (p = 0.030). Heat stress increased inflammation in the jejunum and ileum, as indicated by elevated interleukin-1ß (p = 0.022) in the jejunum and interleukin-1ß (p = 0.004) and interleukin-8 (p = 0.001) in the ileum. No differences in plasma total antioxidant capacity (TAC) were observed with HS, but betaine increased plasma TAC compared to IQA. Dietary BET increased betaine concentrations in the jejunum, ileum (p < 0.001 for both), plasma, liver, kidney (p < 0.010 for all), urine (p = 0.002) and tended to be higher in muscle (p = 0.084). Betaine concentration was not influenced by HS, but it tended to be higher in plasma and accumulated in the liver. These data suggest that betaine and isoquinoline alkaloids supplementation ameliorated consequences of heat stress in grower pigs and protected against HS induced increases in colonic permeability.

Dietary Betaine Improves Intestinal Barrier Function and Ameliorates the Impact of Heat Stress in Multiple Vital Organs as Measured by Evans Blue Dye in Broiler Chickens.

In a 2 × 2 factorial design, 60 male Ross-308 broilers were fed either a control or 1 g/kg betaine diet and housed under thermoneutral (TN) or heat stress (HS) conditions. Broilers were acclimated to diets for 1 week under TN (25 °C), then either kept at TN or HS, where the temperature increased 8 h/day at 33 °C and 16 h/day at 25 °C for up to 10 days. Respiration rate (RR) was measured at four time points, and on each of 1, 2, 3, 7 and 10 days of HS, 12 broilers were injected with 0.5 mg/kg of Evans Blue Dye (EBD) solution to quantify regional changes in tissue damage. Betaine was quantified in tissues, and ileal damage was assessed via morphometry and transepithelial resistance (TER). Heat stress elevated RR (p < 0.001) and resulted in reduced villous height (p = 0.009) and TER (p < 0.001), while dietary betaine lowered RR during HS (p < 0.001), increased betaine distribution into tissues, and improved ileal villous height (p < 0.001) and TER (p = 0.006). Heat stress increased EBD in the muscle and kidney of chickens fed the control diet but not in those receiving betaine. Overall, these data indicate that supplemented betaine is distributed to vital organs and the gastrointestinal tract, where it is associated with improved tolerance of HS. Furthermore, EBD markers help reveal the effects of HS on organs dysfunction.