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1. This study investigated the effects of dietary betaine supplementation on growth performance, meat quality, muscle fatty acid composition and antioxidant ability in slow-growing broiler chickens. 2. In total, 400, one-day-old female Xueshan broiler chicks were randomly divided into five groups with eight replicates of ten chickens each for 102 d. Broilers were fed a basal diet supplemented with 0, 125, 250, 500 or 1,000 mg/kg betaine. 3. Broilers fed betaine had better feed conversion efficiency and weight gain (P < 0.05) and increased meat redness and yellowness 24 h after slaughter. Supplementation linearly decreased cooking loss and drip loss from breast muscle (P < 0.05). Muscular resilience was improved and tenderness increased (P < 0.05). Intra-muscular saturated fatty acids decreased, while total monounsaturated fatty acids and polyunsaturated fatty acids increased (P < 0.05). Betaine increased activities of glutathione peroxidase (GPx) and total superoxide dismutase (SOD), glutathione (GSH) level, ratio of reduced glutathione/oxidised glutathione, and activity of scavenging hydroxyl radicals. It increased the activity of total antioxidant capacity (T-AOC) in the breast muscle (P < 0.05). Moreover, supplementation up-regulated (P < 0.05) mRNA expression levels of blood and antioxidant markers. 4. In conclusion, 1000 mg/kg betaine can be recommended as a supplement for slow-growing, Xueshan chicken. [ABSTRACT FROM AUTHOR]

The present study was conducted to compare the supplementation of natural (D-a-tocopherol) and synthetic (DL-a- tocopherol acetate) vitamin E on the growth performance, meat quality, muscular antioxidant capacity and genes expression related to oxidative status of broilers. A total of 144 1 day-old Arbor Acres broiler chicks were randomly allocated into 3 groups with 6 replicates of 8 birds each. Birds were given a basal diet (control group), and basal diet supplemented with either 20 IU D-a-tocopherol or DL-a- tocopherol acetate for 42 days, respectively. The results indicated that treatments did not alter growth performance of broilers (p>0.05). Compared with the control group, concentration of a-tocopherol in the breast muscle was increased by the supplementation of vitamin E (p<0.05). In the thigh, a-tocopherol content was also enhanced by vitamin E inclusion, and this effect was more pronounced in the natural vitamin E group (p<0.05). Vitamin E supplementation increased the redness of breast (p<0.05). In the contrast, the inclusion of synthetic vitamin E decreased lightness of thigh (p<0.05). Dietary vitamin E inclusion reduced drip loss at 24 h of thigh muscle (p<0.05), and this effect was maintained for drip loss at 48 h in the natural vitamin E group (p<0.05). Broilers given diet supplemented with vitamin E showed decreased malondialdehyde (MDA) content in the breast (p<0.05). Additionally, natural rather than synthetic vitamin E reduced MDA accumulation in the thigh (p<0.05). Neither natural nor synthetic vitamin E supplementation altered muscular mRNA abundance of genes related to oxidative stress (p>0.05). It was concluded that vitamin E supplementation, especially the natural vitamin E, can enhance the retention of muscular a-tocopherol, improve meat quality and muscular antioxidant capacity of broilers. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate effects of heat-oxidized soy protein isolate (HSPI) on growth performance, serum biochemical indices, apparent nutrient digestibility and digestive function of broiler chickens. A total of 320 1-day-old Arbor Acres chicks were randomly divided into 4 groups with 8 replicates of 10 birds, receiving diets containing soy protein isolate (SPI, control group) or the same amount of SPI heated in an oven at 100°C for 1, 4, or 8 h, for 21 days, respectively. The results indicated that compared with the control group, body weight gain and feed intake of birds fed diet containing SPI heated for 8 h were significantly lower (p<0.05). Serum urea nitrogen concentration was higher in the broilers fed diet containing SPI heated for 4 or 8 h at d 21 (p<0.05). In contrast, serum glucose content was decreased by HSPI substitution at d 21 (p<0.05). The relative pancreas weight in HSPI groups was higher than that in the control group at d 21 (p<0.05). Meanwhile, the opposite effect was observed for relative weight of anterior intestine and ileum in broilers fed a diet containing SPI heated for 8 h (p<0.05). Birds fed diets containing SPI heated for 4 or 8 h had a decreased lipase activity in anterior intestinal content at d 14 and 21 (p<0.05), respectively. In addition, the same effect was also noted in broilers given diets containing SPI heated for 1 h at d 21 (p<0.05). Similarly, amylase, protease and trypsin activity in anterior intestinal content were lower in broilers fed diets containing SPI heated for 8 h at d 21 (p<0.05). The apparent digestibility of dry matter (DM) from d 8 to 10 and DM, crude protein (CP), and ether extract from d 15 to 17 were lower in broilers fed diets containing SPI heated for 8 h (p<0.05). Besides, birds given diets containing SPI heated for 4 h also exhibited lower CP apparent digestibility from d 15 to 17 (p<0.05). It was concluded that HSPI inclusion can exert a negative influence on the growth performance of broilers, which was likely to result from the simultaneously compromised digestive function. [ABSTRACT FROM AUTHOR]

This study investigated Zn-bearing zeolite clinoptilolite (Zn-ZCP) as a Zn supplement on performance, organ or tissue development, Zn accumulation in tissues, and gene expression of Zn transporters in the duodenum of broilers. A total of 300 1-d-old Arbor Acres chickens were randomly allocated to 5 dietary treatments with 6 replicate cages of 10 birds per treatment for a 21-d feeding period. The treatments comprised a basal corn-soybean meal diet without supplemental Zn (the control) or similar diets supplemented with 80 mg/kg Zn from ZnSO4 or 20, 40, or 80 mg/kg Zn from Zn-ZCP, respectively. Supplementation of Zn-ZCP had a positive effect on G:F (linear, P < 0.05) and had tendency difference on ADG (linear, P < 0.1) of broilers during 1 to 21 d. Incremental Zn-ZCP inclusion in the diet increased the fresh weight of the pancreas (linear, P < 0.05) and tibia (linear, P < 0.05) in broilers on d 14. The same trend to the fresh weight of the tibia (linear, P < 0.05) and pancreas (linear, P < 0.05) was observed on d 21. Increasing Zn-ZCP level showed a linear response on Zn concentration in the liver (linear, P < 0.001), pancreas (linear, P < 0.05), and tibia (linear, P < 0.05) on d 14. The same trend of Zn concentrations in pancreas (linear, P < 0.05) and tibia (linear, P < 0.001) was observed on d 21. The mRNA levels of Zn transporter 2 (ZnT-2) and Zn transporter 5 (ZnT-5) in the duodenum of chicks fed the diet with 80 mg/kg Zn from Zn-ZCP did not differ from those of chicks fed the control diet, but both were lower (P < 0.05) than those of chicks fed ZnSO4 diet. Metallothionein (MT) mRNA levels of broilers fed the diet supplemented with 80 mg/kg Zn from Zn-ZCP or ZnSO4 was higher (P < 0.05) than that in the control group. Dietary treatments did not affect the mRNA expression of Zn transporter 1 (ZnT-1) or metal response element-binding transcription factor-1 (MTF-1). In conclusion, as a Zn supplement, Zn-ZCP was comparable to ZnSO4 for enhancing Zn accumulation and growth performance of broilers during 1 to 21 d. Broilers fed the diet with 80 mg/kg Zn from Zn-ZCP had different expressions of ZnT-2 and ZnT-5 in the duodenum compared with those fed the ZnSO4 diet. [ABSTRACT FROM AUTHOR]

To investigate the mechanism underlying the regulatory effect of Met on broiler growth, the growth performance, organ development, serum profile, myogenic gene expression, and methylation of myostatin gene exon 1 region in response to dietary Met status were evaluated. A total of 192 one-day-old Arbor Acres broiler chicks were housed in 3-layer cages in a temperature-controlled room with continuous lighting. The temperature of the room was maintained at 32 to 34°C for the first 3 d and then reduced by 2 to 3°C per week to a final temperature of 20°C. Cages were randomly allocated to 2 dietary treatments with 6 replicate cages (8 males and 8 females/cage) per treatment. Control starter and finisher diets contained 0.50 and 0.43% Met, respectively. Corresponding values for a +Met treatment were 0.60 and 0.53% Met, respectively. The birds receiving the +Met diets had a greater (P < 0.05) G:F throughout the experiment. The +Met diets increased (P < 0.05) the relative weight of breast muscle and the concentrations of uric acid and triglyceride in serum at 42 d of age, whereas other serum measurements were not affected by treatments. Increased myogenic factor 5 (Myf5) and myocyte enhancer factor 2B (MEF2B) and decreased myostatin mRNA expression were observed in broilers fed the +Met diets (P < 0.05). However, methylation of myostatin gene exon 1 region was not different between groups. In conclusion, broilers fed the +Met diets increased breast muscle growth that was reflected in the expected expression of myostatin, Myf5, and MEF2B genes. [ABSTRACT FROM AUTHOR]

Natural clinoptilolite has been shown to have positive effects as an antioxidant, which means it traps free radicals in its complex structure, inactivating and eliminating them. Synthetic or modified clinoptilolite delays lipid peroxidation with water-soluble peroxyl radicals, and reduces the catalytic production of radicals to protect the organism. The objective of this study was to evaluate the effect of natural clinoptilolite and modified clinoptilolite on the antioxidant status of broilers. The antioxidant capability of natural clinoptilolite or modified clinoptilolite is exerted, at least in part, by increasing glutathione content in liver and intestinal mucosa, the superoxide dismutase, and glutathione peroxidase activity in serum, liver, and intestinal mucosa. In addition, to enhance broiler performance, there is a reduction of the concentration of malondialdehyde in serum, liver, and intestinal mucosa. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the effect of natural clinoptilolite (NCLI) and modified clinoptilolite (MCLI) on broiler performance, gut morphology, and its relation to gut circumstances. A total of two hundred forty 1-d-old male chicks were randomly assigned to 3 treatments, each of which comprised 8 pens of 10 chicks per pen. Birds in the control group were fed the basal diet, whereas those in the experimental groups were fed diets supplemented with NCLI at 2% (NCLI group) or MCLI at 2% (MCLI group) for 42 d. The results showed that compared with the control, supplementation with NCLI or MCLI had no significant (P > 0.05) effects on productive parameters from d 1 to 42. Supplementation with MCLI and NCLI was associated with greater (P < 0.05) villus height in the jejunal and ileal mucosa compared with those areas in the controls from d 1 to 42. However, supplementation with NCLI and MCLI had no significant (P > 0.05) influence on the crypt depth in the jejunal and ileal mucosa compared with those in the controls. Total viable counts of Escherichia coli were significantly (P < 0.05) decreased by MCLI and NCLI from d 1 to 21. The NCLI and MCLI significantly increased the total viable counts of Lactobacillus acidophilus from d 22 to 42. Small intestine and cecal pH values in the MCLI group were found to be lower (P < 0.05) than those in other groups. Total volatile fatty acid concentrations were significantly (P < 0.05) decreased in both experimental groups from d 22 to 42. This study showed that NCLI or MCLI, as feed additives for broilers, had a positive effect on gut parameters by acting on microbial populations of the digestive tract. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the effect of 2 esters of α-tocopherol, all-rac-α-tocopherol acetate and RRR-α-tocopherol succinate (D-α-TOS) on growth and immunity in broiler chicks. Three hundred twenty 1-d-old commercial Arbor Acres broilers were randomly distributed to 4 treatments, each of which had 8 pens of 10 chicks per pen. Birds in the control group were fed with the diets supplemented with 30 mg/kg of all-rac-α-tocopherol acetate or the basal diet with D-α-TOS supplementation at 10 mg/kg (TOS1 group), 30 mg/kg (TOS2 group), and 50 mg/ kg (TOS3 group), respectively, for 42 d. The results showed that there was no significant difference (P > 0.05) in BW gain, feed intake, or G:F among the treatments. Significant positive correlations existed between dietary supplemental α-TOS levels and plasma (R[sup2] = 0.9831, P < 0.01) or hepatic (R[sup2 = 0.9336, P < 0.05) α-tocopherol concentrations and a negative correlation with plasma (R[sup2] = 0.9487, P < 0.05) or hepatic (R[sup2] = -0.9901, P = 0.0518) malondialdehyde levels. The concentrations of serum glutathione (GSH) were highest at 50 mg/kg at 42 d of age (P < 0.05), and hepatic GSH was significantly higher at 30 and 50 mg/kg compared with the other groups splenic T-and B-lymphocyte proliferation occurred in group TOS3 as compared with the other groups. The study suggests that the immunoenhancement efect observed in broilers fed additional D-α-TOS between 30 and 50 mg/kg might result of α-tocopherol and reduction in lipid peroxidation, as evidenced by the decrease in malondialdehyde and the increase in GSH. [ABSTRACT FROM AUTHOR]

This experiment was conducted to evaluate the effects of bile acids (BAs) on the growth performance and lipid metabolism of broilers fed with different energy level diets. 480 one-day-old Arbor Acres broilers (45.01 ± 0.26 g) were allotted to a 2 × 2 factorial design with 2 levels of energy (basal or high-energy level) and 2 levels of BAs (with or without BAs supplementation), resulting in 4 groups of 8 replicates; the experiment lasted 42 d. High-energy diets decreased the feed/gain ratio (F/G) from 1 to 21 d (P < 0.05), and increased the liver index and abdominal fat percentage at 42 d (P < 0.05). The serum total triglyceride (TG) and high-density lipoprotein cholesterol at 42 d were increased by high-energy diets (P < 0.05), while the hepatic lipoprotein lipase (LPL) activity at 21 and 42 d was decreased (P < 0.05). BAs supplementation increased the body weight at 21 d and decreased the F/G during entire period (P < 0.05), as well as improved the carcass quality reflected by decreased abdominal fat percentage at 42 d and increased breast muscle percentage at 21 and 42 d (P < 0.05). The serum TG at 21 and 42 d were decreased by BAs (P < 0.05), and the hepatic LPL activity at 42 d was increased (P < 0.05). In addition, high-energy diets increased the expression of sterol regulatory element binding transcription factor 1, acetyl-CoA carboxylase, and fatty acid synthase (P < 0.05), while BAs diets decreased these genes expression (P < 0.05). Moreover, BAs supplementation also increased the expression of carnitine palmitoyltransferase 1 (P < 0.05), which was increased in high-energy groups (P < 0.05). In conclusion, BAs supplementation could increase growth performance, elevate carcass quality, and improve lipid metabolism in broilers. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the impact of oxidative modification on soybean meal (SBM) proteins after exposure to different heating times, and the effects of the oxidized SBM on the growth performance [average daily feed intake (ADFI), average daily gain (ADG), and feed to gain ratio (F: G)], oxidative redox status [(reactive oxygen species (ROS), total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidase (GSH - Px), malondialdehyde (MDA), and protein carbonyl (PC)]. A total of 400 one-day-old Arbor Acres chicks were randomly divided into 5 treatment groups with 8 replicates of 10 birds each. Birds in the control group (CON) were fed diet containing non-heated SBM, and those in the treatment groups were fed SBM heated at 100°C for 1, 2, 4, and 8 h, for 42 d. Heated SBM (HSBM) showed a relatively higher PC content in vitro. The ADG decreased, whereas the F:G increased linearly with an increase in heating time during the starter (days 1 to 21), grower (days 22 to 42), and the overall growth phases (days 1 to 42; P < 0.05). However, the ADFI decreased linearly only during the grower phase (P < 0.05). The plasma, liver, and jejunum ROS levels, MDA concentrations, and PC contents increased linearly (P < 0.05) in broilers fed HSBM. Furthermore, the TAC in the plasma and jejunum, and the total SOD and GSH - Px activities in the plasma, liver, and jejunum decreased linearly (P < 0.05) in broilers when feeding HSBM. (P < 0.05). The mRNA level of Nrf2 in the liver and jejunum was lower (P < 0.05) in broilers fed diet containing the SBM after 8 h heat-treatment than in those fed the CON diet at days 42. This study suggested that heat-induced protein oxidation of SBM could decrease growth performance and impair antioxidant status of broilers. [ABSTRACT FROM AUTHOR]

This experiment was conducted to investigate the effects of dietary methionine (Met) on growth performance, carcass traits, meat quality and oxidative status of breast muscle in fast- (Arbor Acres, AA) and slow- (Partridge Shank, PS) growing broilers from 1 to 42 d of age. The broilers were divided into a 2 × 3 factorial design with 6 replicates per treatment. Diets were formulated to contain low (LM, 0.35 and 0.31% during 1 to 21 and 22 to 42 d), adequate (AM, 0.50 and 0.44%) and high (HM, 0.65 and 0.57%) Met, respectively. The main effects showed that the AA broilers had superior (P < 0.05) growth performance and carcass traits compared with those of the PS broilers. The breast muscle of the AA broilers had lower (P < 0.05) drip loss and malondialdehyde (MDA) content but higher (P < 0.05) cooking loss and glutathione peroxidase (GPX) activity than that of the PS broilers. Compared with the LM diets, the AM and HM diets increased (P < 0.05) 42-d BW, ADG, eviscerated yield and breast muscle yield only in the AA broilers. The AA broilers fed the HM diets had higher (P < 0.05) pH but lower (P < 0.05) L∗, cooking loss and ether extract content in breast muscle than those fed the LM diets. Compared with the LM diets, the HM diets resulted in strain-dependent changes (P < 0.05) in muscle oxidative status, with total antioxidant capacity (T-AOC) increased in the AA broilers, GPX activity increased and MDA content decreased in the PS broilers, and superoxide dismutase (SOD) activity increased in both strains of broilers. No differences were observed between the AM and HM diets except for T-AOC in breast muscle. In conclusion, the LM treatment negatively affected broiler growth performance, carcass traits, meat quality and oxidative status of breast muscle in a strain-dependent manner, particularly in the AA broilers, whereas the HM treatment had limited effects compared to the AM treatment. [ABSTRACT FROM AUTHOR]

Reactive oxygen species and free radicals play multiple roles in some immune-pathological events. Vitamin E, as a very potent antioxidant, perhaps deceases the potentially negative effects of such oxidative stress to prevent immune-pathological damage to broilers. Therefore, the current study investigated the effects of dietary natural (D-α-tocopherol) and synthetic (DL-α-tocopherol acetate) vitamin E on the growth performance and antioxidant capacity in cyclophosphamide (CY) immunosuppressed broilers. 192 one-day-old male Arbor Acre broilers were randomly distributed into 4 groups: 1) non-CY-challenged control; 2) CY-challenged control; 3) CY-challenged group+20 IU DL-α-tocopherol acetate per kg feed; and 4) CY-challenged group+20 IU D-α-tocopherol per kg feed. The maize-soybean basal diet in the control group contained α-tocopherol (7.12 mg/kg). Broilers were intramuscularly injected with 80 mg/kg body weight of CY or sterile saline at 16, 17, and 18 d of age. CY decreased (P < 0.05) the average daily gain and average daily feed intake, but vitamin E did not alter the growth performance of broilers before or after CY injection (P > 0.05). The decreased absolute weight of the spleen, thymus and bursa, serum interleukin 2 (IL-2), and interleukin 6 (IL-2) concentrations in CY-treated broilers were alleviated by vitamin E (P < 0.05) . The decreased relative weight (g/kg body weight) of the bursa in the CY-treated broilers was increased by natural vitamin E (P < 0.05). The CY-induced increases in malondialdehyde (MDA) content and decreases in total antioxidant capacity (T-AOC), glutathione, vitamin C, and α-tocopherol levels, and total superoxide dismutase and glutathione peroxidase activities in both serum and the liver were attenuated by vitamin E (P < 0.05). Additionally, natural vitamin E increased α-tocopherol and T-AOC levels and decreased MDA content in the liver of CY-treated broilers (P < 0.05) when compared to the synthetic form. In summary, both synthetic and natural vitamin E supplementation improved lymphoid organ weights, serum IL-2 and IL-6 levels, and antioxidant capacity of immunosuppressed broilers induced by CY. Especially, natural vitamin E was superior to the synthetic form and enhanced α-tocopherol and T-AOC levels, reduced MDA concentration in the liver, and alleviated the immune damage of the bursa. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate effects of L-threonine (L-Thr) supplementation on the growth performance, immunity, antioxidant status, and intestinal health of broilers at the early age. One hundred and forty-four 1-day-old male broiler chicks (Arbor Acres Plus) were allocated into 3 treatments with 6 replicates of 8 birds each, and fed a basal diet (analyzed Thr content, 7.87 g/kg) supplemented with 0 (control diet), 1 and 3 g/kg L-Thr for 21 d, respectively. Treatments did not alter growth performance of broilers. Compared with control, 1 g/kg Thr supplementation increased relative weight of spleen (P = 0.013). A higher level of Thr (3 g/kg) increased relative weight of thymus (P = 0.003). The supplementation of 3 g/kg Thr reduced Escherichia coli (P = 0.040) and Salmonella colonies (P = 0.015), whereas increased Lactobacillus colonies (P < 0.001) in the cecal contents. Thr supplementation increased intestinal villus height (P < 0.05), and the ratio of villus height to crypt depth (P < 0.001), and the values for these parameters were intermediate with 1 g/kg Thr. Goblet cell density was increased by Thr supplementation (P < 0.001). The jejunal immunoglobulin G content was increased by the inclusion of Thr (P = 0.002). Broilers fed diet supplemented with 1 g/kg Thr exhibited increased concentrations of jejunal immunoglobulin M (P = 0.037) and secretory immunoglobulin A (P = 0.018). Likewise, 3 g/kg Thr inclusion increased ileal secretory immunoglobulin A content (P = 0.023). The jejunal malondialdehyde accumulation was reduced by Thr inclusion (P = 0.012). A higher level of Thr inclusion also reduced malondialdehyde content in the serum (P = 0.029). The high level of Thr inclusion (3 g/kg) upregulated mucin-2 mRNA expression (P = 0.034), whereas downregulated the mRNA abundances of interferon-γ (P = 0.036) and interleukin-1β (P = 0.031) in the ileum. In conclusion, L-Thr supplementation can improve immunity, antioxidant capacity, and intestinal health of broilers at an early age. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effect of Bacillus amyloliquefaciens (BA) on the immune function of broilers challenged with lipopolysaccharide (LPS). 192 one-day-old male Arbor Acre broiler chickens were randomly distributed into four treatments: 1) broilers fed a basal diet; 2) broilers fed a basal diet supplemented with BA; 3) LPS-challenged broilers fed a basal diet; and 4) LPSchallenged broilers fed a basal diet supplemented with BA. Each treatment consisted of six replicates with eight broilers per replicate. Broilers were intraperitoneally injected with either 500 fig LPS per kg body weight or sterile saline at 16, 18 and 20 d of age. LPS decreased the average daily gain (ADG, P = 0.001) and average daily feed intake (P = 0.001). The decreased ADG (P = 0.009) and increased feed conversion ratio (P = 0.047) in LPS-challenged broilers were alleviated by BA. LPS increased the relative spleen weight (P = 0.001). Relative spleen (P = 0.014) and bursa (P = 0.024) weights in the LPS-challenged broilers were reduced by BA. LPS increased white blood cell (WBC) numbers (P = 0.001). However, the WBC numbers (P = 0.042) and the ratio of lymphocytes to WBC (P = 0.020) in LPS-challenged broilers were decreased with BA treatment. LPS decreased plasma lysozyme activity (P = 0.001), but increased concentrations of plasma corticosterone (P = 0.012) and IL-2 (P = 0.020). In contrast, BA increased lysozyme activity in plasma (P = 0.040). LPS increased mRNA abundances of splenic toll-like receptor 4 (P = 0.046), interferon γ (P = 0.008), IL-1β (P = 0.045) and IL-6, (P = 0.006). IL-2 (P = 0.014) and IL-6 (P = 0.074) mRNA abundances in LPSchallenged broilers were reduced by BA, although BA had an opposite effect for IL-10 mRNA expression in those broilers (P = 0.004). In conclusion, BA supplementation could partially alleviate the compromised growth performance and immune status of broilers under immune stress induced by LPS challenge at early age. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effects of oxidative modification of soy protein isolate (SPI) after exposure to heat on the growth performance and immune function of broilers. The SPI was heated in an oven at 100°C for 1, 4, and 8 h, respectively, and resultant oxidative status was evaluated. A total of 320 one-day-old Arbor Acres chickens were randomly divided into 4 treatment groups with 8 replicates of 10 birds, and fed diets supplemented with the native SPI or 1 of the 3 heat-treated SPI for 21 d. The results showed that heat exposure of SPI for 4 and 8 h caused an increase in protein carbonyl (P < 0.05), and a simultaneous decrease in sulfhydryl and free amine groups (P < 0.05) compared with native SPI. The BW of broilers fed diets supplemented with SPI heated for 8 h were significantly lower than that of broilers fed diets supplemented with native SPI (P < 0.05). Compared with native SPI, heat-treated SPI (heated for 8 h) diminished liver weight at 14 d (P = 0.01), spleen (P < 0.01) and bursa (P < 0.05) weights at 21 d; and the content of IgG in serum and duodenal mucosa of broilers (at 14 d) was decreased when diets supplemented with heat-treated SPI (heated for 8 h; P < 0.01). No significant differences were observed in the mucosa secretory IgA contents of broilers among the treatment groups (P > 0.05). Compared with native SPI, a significant increases were observed in the content of adrenocorticotropic hormone and cortisol in serum of broilers fed the heat-treated SPI (heated for 8 h) at 21 d (P < 0.05); and the myeloperoxidase activities in serum (at 14 d) and mucosa of broilers were increased when diets supplemented with heat-treated SPI (heated for 8 h; P < 0.05). The present study suggests that protein oxidation of SPI is induced by heating, and oxidized protein may negatively affect the immune function of broilers. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effects of zinc-bearing clinoptilolite (ZnCP) on broilers challenged with Salmonella pullorum for a 21-d feed-ing trial. A total of 240 one-day-old chickens was allo-cated into 4 treatment groups: 1) nonchallenged control (CON) fed basal diet; 2) S. pullorum-challenged control (SCC) fed basal diet; 3) Salmonella challenge fed basal diet plus antibiotic (ANT); 4) Salmonella challenge fed basal diet plus 0.2% ZnCP (ZnCP). Compared with CON, Salmonella challenge caused adverse effects on ADG (P < 0.05), ADFI, feed/gain ratio in broilers, Salmonella and Lactobacillus colonies at 7 d (P < 0.05) and 21 d, and serum diamine oxidase (DAO) activity. Moreover, the relative weight of spleen of 21-d birds, malondialdehyde (MDA) content of jejunual and ileal mucosa at 21 d, and the superoxide dismutase (SOD) activity of ileal mucosa were also significantly nega-tively affected by SCC treatment (P < 0.05). Supple-mentation of ZnCP in basal diet significantly improved ADG and reduced Salmonella colonies in cecal contents and serum DAO activity both at 7 and 21 d (P < 0.05), compared with SCC. Furthermore, supplementa-tion with ZnCP as well as ANT significantly decreased the relative weight of spleen at 21 d, reduced MDA con-tents of jejunual and ileal mucosa at 21 d (P < 0.05), and improved the SOD activity of ileal mucosa at 7 d as compared with SCC (P < 0.05). The results suggested that ZnCP addition in feed exerted protective effects on performance and gut health of broilers against S. pullorum infection. [ABSTRACT FROM AUTHOR]