Effects of low ambient temperatures and dietary vitamin C supplement on growth performance, blood parameters, and antioxidant capacity of 21-day-old broilers

Effects of Complex Antioxidants Added to Chicken Diet on Growth Performance, Serum Biochemical Indices, Meat Quality, and Antioxidant Capacity

This study aimed to evaluate the effects of diets supplemented with various levels of complex antioxidants (CA) containing tertiary butylhydroquinone (TBHQ) and tea polyphenols (TP) on growth performance, meat quality of breast and leg muscles, serum biochemistry, and antioxidant capacity of serum, liver, breast meat, jejunum, and ileum in broilers. A total of 600 one-day-old Arbor Acres male broilers with similar body weights were randomly divided into three groups (10 replicates/group, 20 broilers/replicate). Birds in the three experimental groups were fed a basal diet with CA at 0, 300, and 500 mg/kg. The results showed that supplementing with 300 mg/kg CA significantly increased (p < 0.05) 42 d BW and 22-42 d ADG, and markedly decreased (p < 0.05) 22-42 d F: G ratio in comparison to the control group. Birds fed a diet with 300 mg/kg CA had a higher (p < 0.05) pH of chicken meat at 24 h and 48 h post mortem and lower (p < 0.05) yellowness values (b*) of chicken meat at 45 min and 24 h post mortem, along with a lower (p < 0.05) cooking loss. Supplementing with 300 mg/kg CA significantly increased (p < 0.05) serum and liver T-SOD activity, serum T-AOC level, as well as jejunual GST activity, and significantly decreased (p < 0.05) liver MDA content when compared with the control group. These results indicate that diet supplementation with 300 mg/kg CA containing TBHQ and TP could improve growth performance and meat quality by increasing the antioxidant capacity of broilers.

Effect of Environmental and Farm-Associated Factors on Live Performance Parameters of Broilers Raised under Commercial Tropical Conditions

Although temperature, relative humidity, and farm-associated factors are known to affect broiler live performance, data about the impact of these variables under commercial operations are still scarce. This study aimed to evaluate the effect of temperature, relative humidity, a thermal humidity index, management, and farm-associated factors on BW, BW gain, feed conversion ratio (FCR), and mortality of broilers raised to 35 d under commercial tropical conditions. The data analyzed included performance records of Ross 308 AP broiler flocks placed between 2018 and 2020. Environmental monitoring information was obtained from electronic sensors that captured data hourly from 80 flocks in 29 farms. Farm-associated factors were gathered using a survey of 86 farms. Three data analyses were conducted in parallel. Correlation analyses, one-way ANOVA, and machine learning techniques were employed. Results indicated that BW and BW gain were reduced, and FCR worsened (p < 0.001) up to 21 d when chickens were mainly exposed to temperatures 2.5 °C lower than the recommended optimums for each age period. At the same time, mortality at 28 and 35 d increased. In conclusion, all farm-associated factors affected chicken live performance. Variable importance analysis indicated that performance results at 14 and 21 d were significant to predict BW at 35. At the same time, sex, distance between the hatchery and farm, and farm altitude accounted for the most significant contributions from the farm-associated factors.

Acute cold stress induces intestinal injury via CIRP-TLR4-IRE1 signaling pathway in pre-starter broilers

BACKGROUND

Cold stress is a common environmental stress in broiler chicks. Cold-inducible RNA-binding protein (CIRP) is a conserved cold shock protein that can regulate inflammatory response through Toll-like receptor 4 (TLR4). The mechanism that how CIRP involves in the regulation of cold stress in broilers remains unclear.

METHODS AND RESULTS

In this study, 360 7-day-old healthy male SZ901 chicks were selected and randomly allocated to four groups, and then subjected to acute cold exposure at the ambient temperature of 12 ± 1 °C for 0 h, 4 h, 8 h, and 12 h, respectively. After cold exposure, abdominall skin temperature, gene expression of CIRP-TLR4-IRE1 signaling pathway in ileum mucosa, and small intestinal structure were measured. The results showed that cold exposure decreased abdominall skin temperature, upregulated the gene expression of endoplasmic reticulum stress (ERS) markers IRE1, inflammatory factors IL-1β, IL-6, IL-10, TNF-α, and tight junction proteins ZO-1 and Occludin in ileum of chicks compared with the control group with no (0 h) cold exposure. Compared with the control group, a long time cold exposure upregulated the gene expression of CIRP, TLR4, GRP78, NF-κB in ileum mucosa, and decreased the villus height and V/C of small intestine.

CONCLUSIONS

The above results suggest that acute cold stress induces endoplasmic reticulum stress via upregulating the gene expression of CIRP-TLR4-IRE1 signaling pathway, and results in the structural damage of chick intestine.

Effects of cold stress on growth performance, carcass traits and tibia attributes in broiler chickens with thiram-induced dyschondroplasia

The objective of this study was to investigate the effect of cold stress (CS) on growth performance and tibia attributes in broiler chickens with thiram-induced dyschondroplasia (TD). Four hundred 10-day-old male broilers were randomly allocated into four groups including, NT0: normal temperature (NT) without thiram; NT50: NT + thiram; CS0: CS without thiram; and CS50: CS + thiram in a completely randomised. The birds in CS groups were placed at a constant temperature of 15 ± 1°C during 11-20 days. Thiram (50 mg/kg) was added to the diet during 11-14 days to induce TD. Results showed that main effects of CS and thiram significantly decreased body weight and daily weight gain during 11-42 days (p < 0.05). Feed intake in the thiram50 group was significantly lower than the group thiram0 during 25-42 days (p < 0.05). Feed conversion ratio in CS birds was significantly more than NT group during 25-42 days (p < 0.05). On day 16, tibia width (TW) and TW to tibia length (TL) ratio were significantly higher in CS chicks compared to the NT group. TW was significantly higher in thiram50 group than thiram0 group (p < 0.05). On day 19, TL in CS chicks was significantly shorter than NT (p < 0.05). On day 23, growth plate width (GPW) in thiram50 group was significantly higher than thiram0 birds. In general, thiram increased tibial GPW and CS decreased TD severity as well as decreased growth performance in broilers.

Evaluation of Rosmarinic Acid on Broiler Growth Performance, Serum Biochemistry, Liver Antioxidant Activity, and Muscle Tissue Composition

The aim of the present study was to investigate the effects of dietary supplementation with different doses of rosmarinic acid (RA) on the growth performance, serum biochemical indices, liver antioxidant activity, and muscle nutritional component of broiler chickens during 1-20 days of age. A total of 1000 1-day-old Cobb 500 white-feathered broilers were divided into five groups. Each group included four replicates and 50 birds per replicate. The control group was the basic fodder group fed with a basal diet. The experimental groups included four levels of RA (100, 200, 300, and 400 mg/kg RA added to the basal diet, respectively). The results showed that a quadratic increase in final body weight (BW) and average daily gain (ADG) and a quadratic decrease in the feed/gain (F/G) ratio were observed with increasing dietary RA levels. At 200 mg/kg RA supplementation, growth performance was significantly improved. Moreover, under this RA treatment, the highest levels of total protein and globulin were detected in the serum, the activities of total superoxide dismutase and catalase in the liver of broilers were significantly increased, and the malondialdehyde content was significantly decreased, indicating a higher antioxidant capacity of the liver when 200 mg/kg RA was added to the basal diet. The flavor of the muscle meat was improved by dietary supplementation with 200 mg/kg RA. Therefore, adding 200 mg/kg of RA to the diet could significantly improve the growth performance of broilers, improve liver antioxidant capacity, and improve muscle quality, etc. The addition of RA to broiler feed as a natural antioxidant has great prospects.

Effects of Housing and Management Systems on the Growth, Immunity, Antioxidation, and Related Physiological and Biochemical Indicators of Donkeys in Cold Weather

The study was designed with a 2 × 2 factorial experiment to evaluate the effects of growth performance, immune function, antioxidant status, blood biochemical indexes, and hormone levels of donkeys in different housing and management systems in cold weather. Twenty-four male donkeys with similar body weight and age were randomly allocated into four treatment groups that were as follows: a cold-water-drinking group without a windproof facility, a lukewarm-water-drinking group without windproof facilities, a cold-water-drinking group with a windproof facility, and a lukewarm-water-drinking group with a windproof facility. The experiment lasted for 42 days. The results showed that windproof facilities increased average daily gain (ADG) and decreased average daily feed intake (ADFI) and feed-to-gain ratio (F:G) at all time periods (p < 0.01) of the experiment. Windproof facilities increased the digestibility of dry matter (DM), crude fat (CF), crude protein (CP), ash, calcium (Ca), and phosphate (P) on day 21 (p < 0.01), and increased the digestibility of DM, CF, ash, and P on day 42 (p < 0.01). The respiration rate and the skin temperature of the abdomen and legs increased (p < 0.05) and rectal temperature tended to increase (p = 0.083) by adopting windproof facilities at 07:00; the windproof facilities tended to increase the skin temperature of the ears and abdomen (p = 0.081, p = 0.091) at 14:00. For the blood parameters, with windproof facilities, the concentrations of total protein (TP), blood urea nitrogen (BUN), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) increased (p < 0.05) and glucose (GLU) concentration decreased (p < 0.05) at 07:00 on day 21; the concentrations of TG and cholesterol (CHO) increased and the concentrations of TP, BUN, and GLU decreased at 07:00 on day 42 (p < 0.05). The concentrations of adrenocorticotropic hormone (ACTH), cortisol (COR), triiodothyronine (T3), and thyroxine (T4) decreased (p < 0.05) at 07:00 on day 21, and T4 concentration decreased (p < 0.05) at 07:00 on day 42. The concentrations of interleukin-4 (IL-4), immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) increased (p < 0.01) and the concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α) decreased (p < 0.01) on days 21 and 42. The activities of total superoxide dismutase (T-SOD) and glutathione peroxidase (GPx) increased (p < 0.05), and malondialdehyde (MDA) concentration decreased (p < 0.01) on day 21; the activities of T-SOD and catalase (CAT) increased (p < 0.05), and MDA concentration decreased (p < 0.01) on day 42. However, under the conditions of this experiment, water temperature did not affect the above indexes on days 21 and 42. These results indicated that adopting windproof facilities in a cold climate can mitigate the effects of atrocious weather on the production performance of donkeys.

Non-Targeted Metabolomic Analysis of Chicken Kidneys in Response to Coronavirus IBV Infection Under Stress Induced by Dexamethasone

Stress in poultry can lead to changes in body metabolism and immunity, which can increase susceptibility to infectious diseases. However, knowledge regarding chicken responses to viral infection under stress is limited. Dexamethasone (Dex) is a synthetic glucocorticoid similar to that secreted by animals under stress conditions, and has been widely used to induce stress in chickens. Herein, we established a stress model in 7-day-old chickens injected with Dex to elucidate the effects of stress on IBV replication in the kidneys. The metabolic changes, immune status and growth of the chickens under stress conditions were comprehensively evaluated. Furthermore, the metabolic profile, weight gain, viral load, serum cholesterol levels, cytokines and peripheral blood lymphocyte ratio were compared in chickens treated with Dex and infected with IBV. An LC-MS/MS-based metabolomics method was used to examine differentially enriched metabolites in the kidneys. A total of 113 metabolites whose abundance was altered after Dex treatment were identified, most of which were lipids and lipid-like molecules. The principal metabolic alterations in chicken kidneys caused by IBV infection included fatty acid, valine, leucine and isoleucine metabolism. Dex treatment before and after IBV infection mainly affected the host’s tryptophan, phenylalanine, amino sugar and nucleotide sugar metabolism. In addition, Dex led to up-regulation of serum cholesterol levels and renal viral load in chickens, and to the inhibition of weight gain, peripheral blood lymphocytes and IL-6 production. We also confirmed that the exogenous cholesterol in DF-1 cells promoted the replication of IBV. However, whether the increase in viral load in kidney tissue is associated with the up-regulation of cholesterol levels induced by Dex must be demonstrated in future experiments. In conclusion, chick growth and immune function were significantly inhibited by Dex. Host cholesterol metabolism and the response to IBV infection are regulated by Dex. This study provides valuable insights into the molecular regulatory mechanisms in poultry stress, and should support further research on the intrinsic link between cholesterol metabolism and IBV replication under stress conditions.

Effects of ambient temperature on growth performance, blood parameter, and fat deposition of geese from 14 to 28 days of age

An experiment was conducted to investigate the effects of ambient temperature on the growth performance, blood parameter, and fat deposition in geese from 14 to 28 d of age in order to establish their optimal temperature requirements. A total of 150 14-day-old geese were allocated randomly to 5 environmentally controlled chambers with ambient temperature set at 18, 21, 24, 27, and 30°C from 14 to 28 d of age, respectively. As ambient temperature increased from 18 to 30°C, the feed intake decreased linearly (P < 0.05) and was accompanied by linearly or quadratically (P < 0.05) decreasing 28-day-old body weight, weight gain, and feed/gain. The upper critical level of ambient temperature from 14 to 28 d of age for 28-day-old body weight and weight gain were 25.83 and 26.17°C, respectively. There were no differences in plasma biochemical parameters or plasma hormones between geese fed at ambient temperature regimen at 18, 21, 24, 27, and 30°C. The abdominal fat weight and abdominal fat rate decreased linearly (P ≤ 0.05) with higher ambient temperature, but the ambient temperature had no effect on subcutaneous fat thickness or intermuscular fat width. It was concluded that the upper critical temperature of the ambient temperature for geese from 14 to 28 d of age was 26.17°C and high ambient temperature could lead to growth depression.

Effects of cold stress on growth performance, serum biochemistry, intestinal barrier molecules, and adenosine monophosphate-activated protein kinase in broilers

The homeostasis dysfunctions caused by cold stress remain a threat to intestinal health, particularly for young broiler chickens. We hypothesized that adenosine monophosphate-activated protein kinase (AMPK) was involved in the regulation of cold stress on intestinal health. This study aimed to examine the effect of cold stress for 72 h on growth performance, serum biochemistry, intestinal barrier molecules, and AMPK in broilers. A total of 144 10-day-old male Arbor Acres broilers were subjected to temperature treatments (control 28  ± 1 °C vs cold stress 16 ± 1 °C) for 72 h. Growth performance was monitored, serum was collected for the analysis of physiological parameters, and jejunal mucosa was sampled for the determination of tight junction (TJ) proteins, heat shock proteins, and AMPK signaling molecules. Results showed that 72 h cold treatment reduced average BW gain and increased the feed conversion ratio of the broilers (P < 0.05). Cold stress for 72 h increased blood endotoxin, aspartate aminotransferase, glucose, and low-density lipoprotein cholesterol levels (P < 0.05). Moreover, 72 h cold treatment up-regulated jejunal Occludin, zonula occludin 1, inducible nitric oxide synthase, heat shock factor 1, and AMPKα1 gene expression (P < 0.05) but had no obvious effect on total AMPK protein expression (P > 0.05). In conclusion, cold stress significantly reduced the growth performance of broiler chickens. The intestinal barrier function might be impaired, and enhanced bacterial translocation might occur. The unregulated gene expression of TJ proteins implied the remodeling of intestinal barrier. The change of AMPK suggested the possible relationship between intestinal energy metabolism and barrier function under cold stress.

Dietary supplement of essential oil from oregano affects growth performance, nutrient utilization, intestinal morphology and antioxidant ability in Pekin ducks

A study was conducted to investigate the effects of oregano essential oil (EO) on growth performance, nutrients utilization, intestinal morphology, intestinal barrier-related gene expression and antioxidant capability in meat ducks. A total of 360 1-day-old ducks were divided into three groups (12 replicates pens per diet of 10 ducks in each pen): negative control (no essential oil or antibiotic), positive control (antibiotic: 500 mg/kg aureomycin of diet) and oregano EO (100 mg/kg of diet). The experiment was carried out for 35 days. Ducks were given feed and water ad libitum. Ducks fed EO supplement showed similar body weight and feed to gain ratio to antibiotic fed ducks. EO supplementation significantly increased (p < .05) feed intake (day 1-35), jejunal villus height (VH) to crypt depth (CD) ratio, serum superoxide dismutase activities (SOD) and jejunal total antioxidant capacity (T-AOC) of ducks compared to controls. Ducks fed diets supplemented with oregano EO also had decreased (p < .05) jejunal CD, serum and hepatic malondialdehyde (MDA) concentration, and the mRNA expression of jejunal zonula occludens-3 (ZO-3) and secretory immunoglobulin A (sIgA) genes in comparison to the control group. Compared to the antibiotic supplementation group, the mRNA expression of claudin1 (CLND1) and CLND2 significantly increased (p < .05), but the mRNA expression of ZO-3 and mucin 2 markedly decreased (p < .05) in the jejunum of ducks in oregano EO supplementation group. These results suggest that oregano EO improves the antioxidant capacity and intestinal defence and structural measures and may aide in helping to maintain enteric health in production without growth-promoting antibiotics.

Dietary addition of lysophospholipids and vitamin C affects growth performance, serum metabolites, antioxidant capacity and carcass characteristics of broiler chickens reared under low ambient temperature

Context Evaluating performance of broilers fed diet included feed additives in stress conditions. Aims This study was conducted to investigate the effects of adding lysophospholipids (LPLs) and vitamin C (VC) to diet on growth performance, blood metabolites, antioxidant capacity and carcass traits in broiler chickens reared under low ambient temperature Methods A total of 288 male chicks (Ross 308) were allotted to four treatments with six replicates (n = 12) when they were 1-day-old. Based on a 2 × 2 factorial arrangement, four diets including dietary LPLs (0 or 1000 mg/kg) and VC (0 or 500 mg/kg) were formulated. According to the catalogue of LPL product, 100000 kcal/Kg metabolisable energy was considered for LPLs. The house temperature was 32°C during the first week and 30°C for a second week. To induce cold stress, house temperature was decreased to 14°C by the step-down temperature program during the third week and maintained between 12 and 14°C for the rest of the study. Key results Increased feed intake and feed conversion ratio (FCR) were observed in chickens fed the LPL-supplemented diet during the first 2 weeks, but there was no significant difference in growth performance between the birds fed LPL-supplemented diet with control during cold stress condition. Decreased feed intake and bodyweight gain were observed in chickens fed VC-supplemented diet compared with control in cold stress condition. Dietary VC decreased blood concentration of triglyceride (TG) and very-low-density lipoprotein (VLDL). Decreased activity of superoxide dismutase (SOD) in breast muscle was observed in chickens fed VC-supplemented diet. A significant interaction between dietary LPLs and VC on relative weight and length of jejunum and ileum were detected. Comparable effects of LPLs and VC on inhibiting lipid peroxidation were observed. The free radical scavenging assay showed higher antioxidant activity of VC compared with LPLs. Conclusions Overall, dietary LPL supplementation did not improve broiler performance in cold stress condition, while the utilisation of 500 mg/kg VC in the ration reduced performance of broilers in low ambient temperature. Implications In low ambient temperature, adding 500 mg/kg VC to diet of broilers can be an effective to reduce blood concentration of TG and VLDL, with no adverse effect on FCR.

Effects of stale maize on growth performance, immunity, intestinal morphology and antioxidant capacity in broilers

OBJECTIVE

This study was conducted to determine the effects of stale maize on growth performance, immunity, intestinal morphology, and antioxidant capacity in broilers.

METHODS

A total of 800 one-day-old male Arbor Acres broilers (45.4±0.5 g) were blocked based on body weight, and then allocated randomly to 2 treatments with 20 cages per treatment and 20 broilers per cage in this 6-week experiment. Dietary treatments included a basal diet and diets with 100% of control maize replaced by stale maize.

RESULTS

The content of fat acidity value was higher (p<0.05) while the starch, activities of catalase and peroxidase were lower (p<0.05) than the control maize. Feeding stale maize diets reduced (p<0.05) average daily feed intake (ADFI) throughout the experiment, feed conversion ratio (FCR) during d 0 to 21 and the whole experiment as well as relative weight of liver, spleen, bursa of Fabricius and thymus (p<0.05) on d 21. Feeding stale maize diets decreased jejunum villus height (VH) and VH/crypt depth (CD) (p<0.05) on d 21 and 42 as well as ileum VH/CD on d 42. The levels of immunoglobulin G, acid α-naphthylacetate esterase positive ratios and lymphocyte proliferation on d 21 and 42 as well as lysozyme activity and avian influenza antibody H5N1 titer on d 21 decreased (p<0.05) by the stale maize. Feeding stale maize diets reduced (p<0.05) serum interferon-γ, tumor necrosis factor-α, interleukin-2 on d 21 and interleukin-6 on d 21 and 42. Broilers fed stale maize diets had lower levels of (p<0.05) total antioxidative capacity on d 42, superoxide dismutase and glutathione peroxidase on d 21 and 42, but higher (p<0.05) levels of malondialdehyde on d 21 and 42.

CONCLUSION

Feeding 100% stale maize decreased ADFI and FCR, caused adverse effects on immunity and antioxidant function and altered intestinal morphology in broilers.

Effects of dietary supplementation of DL-2-hydroxy-4(methylthio) butanoic acid on antioxidant capacity and its related gene expression in lung and liver of broilers exposed to low temperature

DL-2-hydroxy-4(methylthio) butanoic acid (DL-HMTBA) exhibits a higher antioxidant capability in vitro as compared to DL-Met, but the mechanism is still not known. A total of 400 8-day-old broiler chicks were allotted to a 2 [low (12 to 14°C) vs. control temperature (thermoneutral, 24 to 26°C)] × 2 (0.17% or 0.51% of DL-HMTBA) factorial arrangement to investigate effects of DL-HMTBA on antioxidant capacity and its related gene expression in lung and liver of broilers exposed to low temperature. The hepatic glutathione (GSH), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were decreased, whereas protein carbonyl and malodndialdehyde contents in lung were increased in low temperature (P < 0.05). Dietary supplementation of 0.51% DL-HMTBA increased (P < 0.05) GSH and GSH-Px activity in liver and SOD activity in lung in spite of the temperature. The greater gene expression of GSH reductase and lower expression of GSH synthetase (P < 0.01) were observed in lung of broilers that were maintained at low temperature. Higher DL-HMTBA supplementation induced greater (P < 0.05) mRNA expression of glutathione-S transferase in lung, GSH synthetase in liver and lung, as well as lower expression of GSH reductase in lung, and this effect were more obvious for the chicks exposed to low temperature (interaction, P < 0.05). Chicks that were maintained under low temperature had the lower expression of cystathionine β-synthase (CβS), whereas those fed 0.51% DL-HMTBA increased the CβS expression in liver under low temperature (interaction, P ≤ 0.05). The γ-glutamylcysteine synthetase and Met adenosyltransferase 1 (MAT1) gene expression were downregulated (P < 0.05) by low temperature and the higher (P = 0.02) expression of MAT1 was observed in lung of chicks fed 0.51% DL-HMTBA. It indicated that under low temperature, DL-HMTBA supplementation at 0.51% upregulated gene expression of GSH synthesis and Met transsulfuration pathway in liver and lung to increase the antioxidant capacity, and then mitigate the negative effects of cold stress for broilers.

Novel Formulated Fortified Blended Foods Result in Improved Protein Efficiency and Hepatic Iron Concentrations Compared with Corn-Soy Blend Plus in Broiler Chickens

BACKGROUND

Corn- and soybean-based fortified blended foods (FBFs) have been the primary food aid product provided by the United States. Sorghum and cowpea have been suggested as alternative FBF commodities because they are drought-tolerant, grown in food aid-receiving areas, and not genetically modified. Extrusion processing has also been suggested to improve the quality of these FBFs.

OBJECTIVES

The aim of this study was to determine the protein quality and iron and vitamin A bioavailability of novel FBFs in broiler chickens.

METHODS

Whey protein concentrate (WPC)-containing FBFs corn-soy blend 14, sorghum-soy, and sorghum-cowpea (SC); a soy protein isolate (SPI)-containing SC FBF (SC+SPI); 2 reformulated, overprocessed SC FBFs (O-SC+WPC, O-SC+SPI); and a nonextruded WPC-containing SC FBF were developed. Nonextruded corn-soy blend plus (CSB+), a currently used FBF, and a gamebird starter/grower diet were used as comparison diets. In the prepared FBF study, 9 groups of 8-d-old broiler chicks (n = 10) consumed prepared FBFs for 21 d. In the dry study, 8 groups of 4-d-old broiler chicks (n = 24; control: n = 23) consumed dry FBFs for 14 d. Results were analyzed by 1-factor ANOVA with least-significant-difference test.

RESULTS

In the prepared study, novel formulated FBFs significantly increased caloric and protein efficiency and nonsignificantly increased body weight gain, despite similar food intake compared with CSB+. In the dry study, novel formulated FBFs, except for O-SC+SPI, significantly increased food intake, caloric efficiency, and protein efficiency and nonsignificantly increased body-weight gain compared with CSB+. Novel formulated FBFs nonsignificantly and significantly increased hepatic iron concentrations compared with all FBFs in the prepared and dry studies, respectively.

CONCLUSION

Novel formulated FBFs, apart from O-SC+SPI, resulted in improved protein efficiencies and hepatic iron concentrations compared with CSB+, suggesting that they are of higher nutritional quality.

Effects of dietary vitamin C, vitamin E, and alpha-lipoic acid supplementation on the antioxidant defense system and immune-related gene expression in broilers exposed to oxidative stress by dexamethasone

Vitamin C, vitamin E, and alpha-lipoic acid (ALA) are potent nutritional antioxidants, which are important for enhancing immunity. This study compared the effects of supplementation with vitamin C, vitamin E, or ALA on the antioxidant defense system and the expression of immune-related genes under oxidative stress induced by dexamethasone (DEX) in broilers. In total, 240 one-day-old female Recessive White Rock chickens were assigned randomly to either a basal diet (control group) or basal diet supplemented with vitamin C (200 mg/kg diet), vitamin E (100 mg/kg), or ALA (500 mg/kg) for 28 d starting from hatching. At 21 d of age, birds fed the ALA-supplemented diet had the highest plasma total antioxidant capacity (T-AOC) and superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-PX) enzyme activities, and the lowest plasma malondialdehyde (MDA) activity, as well as the lowest mRNA gene expression levels of interferon gamma (IFN-γ) and lipopolysaccharide-induced tumor necrosis factor-alpha factor (LITAF). At 23 d of age, the broilers in the 3 treatment groups were injected in the thigh muscle with DEX for 3 alternating days. In addition, the control group was divided into 2 equal groups, in which one was injected with saline and the other was injected with DEX. At 28 d of age, the DEX-ALA group (P < 0.05) had the highest activity levels for T-AOC, T-SOD, and GSH-PX in the plasma and liver (P < 0.05), and the greatest reduction in the MDA level. Dietary ALA significantly decreased the mRNA expression levels of the interleukin 1 β (IL-1β), IL-6, IFN-γ, and LITAF genes compared with the other groups during oxidative stress by DEX. In conclusion, this study suggests that in broilers, ALA is more effective for normalizing the oxidative stress induced by DEX than vitamin C or vitamin E.

Effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid supplementation on growth performance, indices of ascites syndrome, and antioxidant capacity of broilers reared at low ambient temperature

This study examined the effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid (DL-HMTBA) supplementation on growth performance, antioxidant capacity, and ascites syndrome (AS) in broilers reared at low ambient temperature (LAT) from 7 to 28 days of age. Eight hundred 7-day-old broilers were randomly assigned to two ambient temperatures (LAT and normal ambient temperature [NAT]), four supplemental DL-HMTBA levels (0.17, 0.34, 0.51, and 0.68 %) of the basal diet in a 2 × 4 factorial arrangement (ten replicate pens; ten birds/pen). LAT and NAT indicate temperatures of 12-14 and 24-26 °C in two chambers, respectively, and broilers were reared at these temperatures from 7 to 28 days of age. LAT significantly decreased body weight gain (P < 0.001), serum glutathione (GSH) content (day 14, P = 0.02; day 28, P = 0.045), glutathione peroxidase (GSH-Px) activity, and total antioxidant capacity (T-AOC) at 21 days (P = 0.001, 0.015) and 28 days (P = 0.017, 0.010) and increased feed conversion ratio (FCR) (P < 0.001), serum malondialdehyde (day 21, P = 0.000) and protein carbonyl Level (day 14, P = 0.003; day 21, P = 0.035). As for incidence of AS, there were significant effects of LAT on red blood cell (RBC) count (P < 0.05), hematocrit (HCT) (P < 0.05), and the right to total ventricular weight ratio (RV/TV) at 21 days (P = 0.012) and 28 days (P = 0.046). Supplementation of DL-HMTBA markedly decreased RV/TV at day 28 (P = 0.021), RBC (day 21, P = 0.008), HCT (day 21, P < 0.001), mean cell hemoglobin (day 14, P = 0.035; day 21, P = 0.003), and serum protein carbonyl level (day 21, P = 0.009), while significantly increased serum GSH content (day 14, P = 0.022; day 28, P = 0.001), SOD and GSH-Px activities at 21 days of age (P < 0.001 and P = 0.037). The optimal supplemental DL-HMTBA levels in basal diet of broilers aged from 7 to 28 days under low or normal temperatures were similar, so the authors recommended supplemental of DL-HMTBA level was 0.46 %.

Combination of anti-tuberculosis drugs with vitamin C or NAC against different Staphylococcus aureus and Mycobacterium tuberculosis strains

BACKGROUNDS

Hepatotoxicity due to anti tuberculosis drugs, rifampin and isoniazid, is a major problem in tuberculosis patients. Vitamin C, an antioxidant, and N-acetyl cysteine (NAC), a scavenger of active metabolites, reduce the hepatotoxicity. The aim of present study was to investigate the effect of vitamin C and NAC individually on the antibacterial activity of anti tuberculosis drugs against Mycobacterium tuberculosis and Staphylococcus aureus strains.

METHODS

The MICs of each compound against all strains were determined in 96 wells plate. Rifampin was tested at serial two fold concentrations alone or in combination with NAC or vitamin C.

RESULTS

The MIC of rifampin against different strains of S. aureus was 0.008-0.032 μg/ml. The MIC of rifampin and isoniazid against M. tuberculosis strains were 40 and 0.2 μg/ml, respectively. Vitamin C and NAC had no antibacterial activity against all strains. MIC of rifampin was reduced two fold by combination with vitamin C for all S. aureus strains, while NAC did not affect the antibacterial activity of rifampin. Vitamin C and NAC had remarkable effects on the antibacterial activity of anti-tuberculosis drugs against M. tuberculosis.

CONCLUSIONS

Synergistic effects were observed between rifampin or isoniazid and vitamin C against all tested strains. However, combination therapy of rifampin and isoniazid with NAC was not being effective. This study highlighted the advantages of combination of anti-tuberculosis drugs and vitamin C to eradicate the microbial infections.

Oxidant/Antioxidant Balance in Animal Nutrition and Health: The Role of Protein Oxidation

This review examines the role that oxidative stress (OS), and protein oxidation in particular, plays in nutrition, metabolism, and health of farm animals. The route by which redox homeostasis is involved in some important physiological functions and the implications of the impairment of oxidative status on animal health and diseases is also examined. Proteins have various and, at the same time, unique biological functions and their oxidation can result in structural changes and various functional modifications. Protein oxidation seems to be involved in pathological conditions, such as respiratory diseases and parasitic infection; however, some studies also suggest that protein oxidation plays a crucial role in the regulation of important physiological functions, such as reproduction, nutrition, metabolism, lactation, gut health, and neonatal physiology. As the characterization of the mechanisms by which OS may influence metabolism and health is attracting considerable scientific interest, the aim of this review is to present veterinary scientists and clinicians with various aspects of oxidative damage to proteins.

Ascorbic Acid Differentially Affects Stress Response and Resistance to Colibacillosis in Turkeys from Genetic Lines Differing in Growth Rate

Genetic selection for fast growth can affect the ability of male turkeys to cope with stressors, resulting in decreased immunity to opportunistic bacterial infection. The purpose of the current study was to compare the effects of ascorbic acid (AA) on the stress response and resistance to Escherichia coli challenge of birds selected for increased 16-wk body weight (BW; F-line) with their random-bred parent line (RBC2). Male turkeys were raised in duplicate floor pens in a two line×two AA treatment×two stress challenge (SC) design. At 5 wk of age, AA (1200 ppm) was provided in drinking water for a 24-hr period, during which all birds were weighed. After AA treatment, the SC group was subjected to a transport stress protocol. Six hours after the start of transport, SC birds were also inoculated in the thoracic air sac with 1×10(4) colony-forming units of E. coli. The following morning four birds from each pen were bled, and all birds were weighed and necropsied 2 days later. BW and gain after SC were decreased in the F-line but not the RBC2 line, and there were no AA effects on BW. The weight of the bursa of Fabricius relative to BW was higher in the RBC2 line than in the F-line, was decreased by SC, and was not affected by AA. The heterophil∶lymphocyte ratio was higher in the SC F-line as compared to the SC RBC2 and was decreased by AA only in the SC F-line. Corticosterone (C) levels were increased by SC only in the F-line, and AA decreased C levels only in the RBC2 line. Airsacculitis scores were increased in the F-line SC birds. The challenge strain of E. coli was only detected in the air sac and liver of the AA-treated F-line SC birds and in the liver of the no-AA F-line birds. These results suggest that SC at 5 wk of age had a more deleterious effect on the fast-growing F-line than on its parent line and that AA may have increased susceptibility to colibacillosis in the SC F-line birds.

Oxidative damage to poultry: from farm to fork

Poultry and poultry meat are particularly susceptible to oxidative reactions. Oxidation processes have been for decades the focus of animal and meat scientists owing to the negative impact of these reactions on animal growth, performance, and food quality. Lipid oxidation has been recognized a major threat to the quality of processed poultry products. The recent discoveries on the occurrence of protein oxidation in muscle foods have increased the scientific and technological interest in a topic that broadens the horizons of food biochemistry into innovative fields. Furthermore, in recent years we have witnessed a growing interest in consumers on the impact of diet and oxidation on health and aging. Hence, the general description of oxidative reactions as harmful phenomena goes beyond the actual impact on animal production and food quality and reaches the potential influence of oxidized foods on consumer health. Likewise, the current antioxidant strategies aim for the protection of the living tissues, the food systems, and a potential health benefit in the consumer upon ingestion. Along these lines, the application of phytochemicals and other microelements (Se, Cu) with antioxidant potential in the feeds or directly in the meat product are strategies of substantial significance. The present paper reviews in a concise manner the most relevant and novel aspects of the mechanisms and consequences of oxidative reactions in poultry and poultry meat, and describes current antioxidant strategies against these undesirable reactions.