Effects of main cereal type and feed form on production performance, egg quality and egg sanitary indices of laying hens.

1. The experiment was conducted to evaluate the effects of cereal types (maize or wheat) and feed forms (pelleted or mash feed) on production performance, egg quality and egg sanitary indices in laying hens.2. Three hundred and sixty hens (Jinghong No. 1) at 18 weeks of age were randomly assigned to four treatments with six replicates of 15 hens per replicate according to a 2 × 2 factorial design with two cereal types (maize or wheat) and two feed forms (pelleted or mash feed).3. Compared with the wheat-based diet, the maize-based diet improved (P < 0.05) average egg weight of laying hens. Yolk colour of hens fed with the maize-based diet was higher (P < 0.05) in comparison to those fed the wheat-based diet, while Haugh units were lower (P < 0.05) for the maize-based treatment. Egg mass and average daily feed intake of hens fed the pelleted diet were higher (P < 0.05) than of those fed the mash diet. However, the mash diet improved (P < 0.05) yolk colour compared with the pelleted diet. The percentage of dirty eggs for the wheat-based diet was higher (P < 0.05) than for the maize-based diet. The percentage of dirty eggs was higher (P < 0.05) in birds fed the pelleted diet compared with those fed the mash diet. There were interactions (P < 0.05) between cereal type and feed form, with regard to average egg weight and shell thickness.4. In conclusion, dietary cereal type affected average egg weight, yolk colour and Haugh units in eggs, while feed form influenced egg mass, average daily feed intake and yolk colour.

Effects of dietary α-lipoic acid, acetyl-l-carnitine, and sex on antioxidative ability, energy, and lipid metabolism in broilers.

An experiment was conducted to evaluate the effects of dietary α-lipoic acid (LA), acetyl-l-carnitine (ALC), and sex on antioxidative ability, energy, and lipid metabolism in broilers. A total of 972 one-day-old broilers with equal sex were randomly assigned in a 3 × 3 × 2 factorial design using 3 LA, 3 ALC levels, and 2 sexes (6 replications, 9 birds/replication). The LA and ALC levels were 0, 50, and 100 mg/kg, respectively. Results showed that increased LA or ALC resulted in increased total antioxidant capacity and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and decreased levels of malondialdehyde in serum and liver of birds (P < 0.05). In addition, with increasing addition of LA or ALC, an increased (P < 0.01) level of insulin (Ins), as well as decreased (P < 0.05) levels of glucose and glucagon (Glu), were observed in serum of broilers. Total cholesterol and triglyceride (TG) levels decreased (P < 0.05) and nonesterified fatty acid, lipoprotein lipase, and lipase levels increased (P < 0.05) in serum with increased administration of LA or ALC. Moreover, a significant (P < 0.05) interaction of LA × ALC was observed for serum and liver SOD, serum GSH-Px, glucose, and TG levels. Birds fed diets containing 50 mg/kg of LA and 50 mg/kg of ALC had higher serum and liver SOD activities and lower serum glucose and TG levels than those fed diets containing 100 mg/kg of LA or ALC alone. The main effect of sex and all interactions among main effects (except LA × ALC) were not significant (P > 0.05) for all of the above parameters. Overall, the present data indicate that LA or ALC supplementation, or both, at low levels (50 or 100 mg/kg) improved antioxidative ability, energy metabolism, and lipid metabolism in broilers, and synergistic effects by the combined supplementation of LA and ALC were indicated by serum and liver SOD activities and serum glucose and TG levels.

Protective Efficacy of Alpha-lipoic Acid against AflatoxinB1-induced Oxidative Damage in the Liver.

Alpha-lipoic acid (α-LA) is not only involved in energy metabolism, but is also a powerful antioxidant that can protect against hepatic oxidative stress induced by some drugs, toxins, or under various physiological and pathophysiological conditions. Here, we investigated the effect of α-LA against liver oxidative damage in broilers exposed to aflatoxin B1 (AFB1). Birds were randomly divided into four groups and assigned different diets: basal diet, 300 mg/kg α-LA supplementation in basal diet, diet containing 74 µg/kg AFB1, and 300 mg/kg α-LA supplementation in diet containing 74 µg/kg AFB1, for 3 weeks. The results revealed that the addition of 300 mg/kg α-LA protected against the liver function damage of broilers induced by chronic low dose of AFB1 as estimated by a significant (p<0.05) change in levels of plasma total protein, albumin, alkaline phosphatase and the activities of liver glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase. The histopathological analysis also showed that liver tissues were injured in the AFB1 diet, but this effect was alleviated by the addition of 300 mg/kg α-LA. Additionally, AFB1 induced a profound elevation of oxidative stress in birds, as indicated by an increase in malondialdehyde level, a decrease in glutathione peroxidase activity and a depletion of the glutathione content in the liver. All of these negative effects were inhibited by treatment with α-LA. Our results suggest that the inhibition of AFB1-induced excess production of lipid peroxides and the maintenance of intracellular antioxidant status may play important roles in the protective effects of α-LA against AFB1-induced oxidative damage in the liver.

Phytase transgenic corn in nutrition of laying hens: residual phytase activity and phytate phosphorus content in the gastrointestinal tract.

The residual activities of transgenic corn-derived and 2 commercial microbial phytases (PA and PB) along the gastrointestinal tract (GIT) of laying hens were compared to evaluate their relative resistance to hydrolysis in the GIT when added to P-deficient diets. The treatments consisted of a negative control (NC) diet containing 0.10 nonphytate P and an NC diet supplemented with transgenic corn-derived phytase (TCDP), PA, and PB at 500 to 5,000 FTU/kg of diet, respectively. Seven diets were fed to Hy-Line Brown laying hens (n = 504; 8 replicates of 9 hens per treatment) for 21 d. At the end of the experiment, the hens were killed and digesta samples from the crop, proventriculus and gizzard, jejunum, and ileum were collected and analyzed for residual phytase activities and phytate P content. Phytase activity in the transgenic corn was determined to be 8,980 FTU/kg of DM. The residual phytase activities along the GIT had increased (P < 0.01) with the addition of TCDP, PA, and PB to the NC diets. The TCDP had higher residual activity (P < 0.05) in the crop, proventriculus and gizzard, jejunum, and ileum as compared with the PA and PB activity. There was a decrease (P < 0.01) in the phytate P content of the digesta from all sources of phytase supplementation in the NC diets. Residual phytate P content decreased caudally along the GIT of hens. The results of this research indicate that phytase expressed in corn is as efficacious as the commercial microbial phytases (PA and PB) in P-deficient diets for the improvement of phytate P digestibility, which would eliminate the need for supplemental phytase and corn separately in laying hen diets.

Protective effect of Bacillus subtilis ANSB060 on egg quality, biochemical and histopathological changes in layers exposed to aflatoxin B1.

Bacillus subtilis ANSB060 from the fish gut had strong ability to detoxify aflatoxins. The aim of this research was to investigate the protective effect of B. subtilis ANSB060 (ANSB060) on egg quality and biochemical and histopathological changes of liver and kidney in laying hens when exposed to aflatoxin B(1). Treatments (C20, C40, and C60) were prepared by substituting corn contaminated by aflatoxin B(1) (AFB1) at different proportions (20, 40, and 60%) for normal corn in basic diets. The aflatoxin degradation enzyme (E) treatments (E20, E40, and E60) were mixed with the fermentation liquor of ANSB060 with C20, C40, and C60, respectively. The results showed that ANSB060 can improve the eggshell strength in E60 compared with C60 (P ≤ 0.05), and toxin reduced the content of total protein (in groups C20, C40, and C60) and albumin (in C20 and C40; P < 0.05) and heightened the activities of GPT (in C60) and GOT (in C40 and C60) in serum (P < 0.05). In the liver, AFB1 inhibited the activity of superoxide dismutase and glutathione peroxidase (C40 and C60; P < 0.05) and increased the content of malonaldehyde (in C40 and C60), which induced the damage in the liver and kidney as shown in the photomicrographs of hematoxylin and eosin-stained sections. The addition of ANSB060 can enhance the activity of antioxidant enzymes, and it recovered the protein synthesis in liver. Moreover, ANSB060 also ameliorated the damage of liver and kidney tissue and restored them to normal. Hence, ANSB060 had the ability to inhibit the damage induced by AFB1; it will have a great potential in industrial applications.

Evaluation of the compositional and nutritional values of phytase transgenic corn to conventional corn in roosters.

Three experiments were conducted to evaluate the compositional and nutritional values of corn grains [phytase transgenic corn (PTC) and isogenic conventional corn (CC)] and compare the efficacy of corn-based phytase and extraneous microbial phytase for enhancing the utilization of phytate phosphorus (P) in single corn or corn-soybean mixed meals (corn:soybean = 2.5:1, wt:wt) fed to roosters. Following a 48-h fasting period, 16 roosters were given 50 g of each sample via crop intubation and excreta were collected for 48 h. Nitrogen-free and phosphorus-free diets were used to evaluate endogenous amino acid and endogenous P losses, respectively. Chemical composition was not different between PTC and CC, whereas the phytase content for PTC was greater than CC (8,047 vs. 37 FTU/kg of corn, DM basis; P < 0.001). No difference was observed in the TME and true amino acid availability values between the PTC and CC in roosters. The true P utilization for PTC was greater than CC (37.92 vs. 55.85%; P < 0.001), and CC and PTC contained 0.13 and 0.19% available P (AP, DM basis; P < 0.001), respectively. There was no difference in P utilization (72.76 vs. 70.23%; P > 0.05) between roosters fed PTC and extraneous microbial phytase in equivalent FTU/kg of diets. The results of this study indicated that the chemical composition, TME, and true amino acid availability in PTC are essentially equivalent to that in CC, and the true P utilization for roosters is higher in PTC than in CC. Corn expressing phytase is as efficacious as equivalent microbial phytase when supplemented in corn-soybean diets for chickens.

Effects of alpha-lipoic acid supplementation on antioxidative ability and performance of sows and nursing piglets.

The current study was carried out to determine the effects of alpha-lipoic acid (LA) supplementation during late-gestation and lactation on antioxidative ability and performance of sows and their nursing piglets. A total of 160 multiparous sows were randomly allocated to four treatments with 40 replicates per treatment according to parity number and backfat (BF) thickness. Sows were fed 1 of 4 diets from day 85 of gestation to day 21 of lactation. Diets were control without LA; 400 ppm LA supplementation; 600 ppm LA supplementation; and 800 ppm LA supplementation. BF thickness of sows was determined on day 85 and 110 of gestation and days 1 and 21 of lactation. Piglet bodyweight was measured at birth, days 7, 14 and 21. Blood samples were obtained from the sows, and average daily feed intake (ADFI) of the sows during lactation was recorded. There were no differences in BF thickness or ADFI among treatment groups. Dietary LA supplementation resulted in a decrease in blood urea nitrogen (p < 0.01) concentration at days 110 of gestation. Dietary 800 ppm LA increased serum glutathione peroxidase (GSH-Px) activity (p < 0.05) and reduced maleic dialdehyde levels (p < 0.01) of sows compared with the control diet at days 21 of lactation. Alpha-lipoic acid supplementation increased the birthweight and weaning weight of piglets (p < 0.01) compared with the control group. Weight gains of piglets from sows fed the 800 ppm LA diets were greater (p < 0.01) between days 7 and 14 compared with piglets from control sows. Weight gains of piglets from sows fed the LA-supplemented diets were greater between days 14 and 21 (p < 0.05) and between days 1 and 21 (p < 0.01) compared with piglets from control-fed sows. In conclusion, the results indicate that antioxidant LA was effective in enhancing antioxidant enzymes activity and improving the performance of sows and their nursing piglets.

Preparation, purification and characteristics of an aflatoxin degradation enzyme from Myxococcus fulvus ANSM068.

AIMS: To prepare, purify and characterize an extracellular enzyme from Myxococcus fulvus ANSM068, designated as myxobacteria aflatoxin degradation enzyme (MADE), which possesses degradation activity against aflatoxin B(1) (AFB(1) ), G(1) (AFG(1) ) and M(1) (AFM(1) ) in solution. METHODS AND RESULTS: The culture supernatant of strain M. fulvus demonstrated high degradation ability against AFB(1) (71·89%), AFG(1) (68·13%) and AFM(1) (63·82%) after 48 h of incubation. An enzyme was purified from the supernatant of M. fulvus using ethanol precipitation and chromatography on DEAE-Sepharose and Superdex 75. An overall 166-fold purification of the enzyme with a recovery of 57% and a final specific activity of 569·44 × 10(3) U mg(-1) was obtained using the present purification protocol. The apparent molecular mass of MADE was estimated to be 32 kDa by SDS-PAGE. AFG(1) and AFM(1) were significantly degraded, by 96·96 and 95·80%, respectively, when treated with pure MADE (100 U ml(-1) ) produced by strain ANSM068. MADE exhibited the largest amount of activity at 35°C and pH 6·0, with Mg(2+) ions greatly promoting and Zn(2+) strongly inhibiting MADE activity. CONCLUSIONS: An aflatoxin DEGRADATION ENZYME FROM BACTERIAL ISOLATES CAN EFFECTIVELY REMOVE AFLATOXIN B(1) , G(1) AND M(1) IN SOLUTION. SIGNIFICANCE AND IMPACT OF THE STUDY: The high activity and wide temperature and pH range of MADE for the degradation of aflatoxin have promising applications in control of mycotoxins during food and feed processing.

Effects of oregano essential oil as an antibiotic growth promoter alternative on growth performance, antioxidant status, and intestinal health of broilers.

This experiment was conducted to assess the comparative effects of dietary antibiotics and oregano essential oil (OEO) addition on growth performance, antioxidant status and intestinal health of broilers. A total of 384 one-day-old broilers were randomly allocated to 4 treatments with 6 replicates of 16 broilers each. The 4 treatments were: an antibiotic-free control diet (control), control + 20 mg/kg colistin sulfate and 20 mg/kg virginiamycin (antibiotics), control + 200 mg/kg natural oregano essential oil (NOEO), and control + 200 mg/kg synthetic oregano essential oil (SOEO). The experiment lasted for 42 d. Results showed that birds fed with OEO had greater (P < 0.05) average daily gain (ADG) and lower (P < 0.05) feed conversion ratio (FCR) than those fed with control diet during d 1 to 21. Besides, birds fed with NOEO had the greatest (P < 0.05) ADG in the four groups during d 22 to 42. The serum oxidative stress parameters showed that OEO improved (P < 0.05) the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and glutathione reductase (GR) of birds on day 21 and the activity of total antioxidant capacity (T-AOC) of birds on d 42. Relative to control, NOEO increased (P < 0.05) the activity of T-AOC in jejunum and decreased (P < 0.05) the level of malondialdehyde (MDA) in serum and jejunum. Moreover, OEO supplementation increased (P < 0.05) the concentrations of sIgA in duodenum and jejunum, Lactobacillus and total anaerobes in cecum, as well as activities of trypsin, chymotrypsin, lipase and amylase in duodenum, but restrained (P < 0.05) the amount of Escherichia coli. The NOEO supplementation increased (P < 0.05) total anaerobes of broilers on d 42 and the villus height to crypt depth ratio (VH/CD) of ileum. These results suggest that OEO improved antioxidant status and intestinal health of broilers which contributed to the growth performance improvement of broilers. Dietary OEO supplementation can be a promising alternative to antibiotic growth promoters for improving poultry production.

Effects of dietary pyrroloquinoline quinone disodium supplementation on inflammatory responses, oxidative stress, and intestinal morphology in broiler chickens challenged with lipopolysaccharide.

This study was conducted to investigate the effects of pyrroloquinoline quinone disodium (PQQ·Na2) on inflammatory responses, oxidative stress, and intestinal morphology of broiler chickens challenged with lipopolysaccharide (LPS). A 2 × 2 factorial arrangement in a complete randomized design experiment was used to study the effect of dietary PQQ·Na2 (0 or 1 mg/kg) on broiler chickens with or without a challenge with LPS. A total of two hundred eighty-eight 1-day-old Arbor Acre broiler chickens were randomly assigned to 4 treatments with 6 replicate cages of 12 birds per cage. All experimental broilers were injected intraperitoneally with 0.5 mg/kg body weight of either Escherichia coli LPS or sterile saline at 16, 18, and 20 d of age. Results showed that injecting LPS significantly increased the concentrations of interleukin-1beta (IL-1ß) in serum of birds on day 20 and day 21. Meanwhile, LPS injection increased (P < 0.05) the relative mRNA expression of interleukin-6 (IL-6) in the duodenal mucosa of broilers on day 21. However, dietary supplementation with PQQ·Na2 decreased (P < 0.05) the concentration of IL-6 in serum of birds on day 20 and the levels of IL-1ß, IL-6, and interleukin-10 (IL-10) in serum of broiler chickens on day 21. Besides, supplementation of PQQ·Na2 within diet decreased (P < 0.05) the mRNA expressions of IL-1ß and IL-10 in the duodenal mucosa of birds on day 20. Relative to saline injection, the activity of glutathione peroxidase (GSH-Px) in serum and the activities of total superoxide dismutase (T-SOD) and catalase (CAT) in liver were found to be lower (P < 0.05) in broilers after LPS challenge on day 21. However, birds fed with PQQ·Na2 showed higher (P < 0.05) GSH-Px activity in serum and higher (P < 0.05) T-SOD activities in liver on day 21 and day 42. Pyrroloquinoline quinone disodium also significantly attenuated the LPS-induced decreases in villus height to crypt depth ratio in the duodenum of broilers. In conclusion, dietary PQQ·Na2 supplementation significantly exerted protective effects on inflammation damage and oxidant stress of broilers under LPS challenge by regulating the expression of inflammatory cytokines (IL-1ß, IL-6, and IL-10) and activities of antioxidant enzymes (GSH-Px, T-SOD, and CAT). Moreover, dietary PQQ·Na2 supplementation significantly ameliorated the LPS-impaired intestinal morphology in broilers. Therefore, it has been considered that PQQ·Na2 can be used as a potential feed additive in broiler production.

Protective Effect of Vitamin E on laying performance, antioxidant capacity, and immunity in laying hens challenged with Salmonella Enteritidis.

Vitamin E (VE) has proven to function as potent lipid-soluble antioxidant, a signaling molecule, and a regulator of the immune system. The objective of the study was to assess the protective effect of VE on laying performance, antioxidant capacity, and immunity in laying hens exposed to Salmonella Enteritidis (SE). A total of 80 32-week-old salmonella-free double negative Hy-Line brown laying hens were randomly assigned to 4 treatments with 20 replicates each (1 bird per replicate) according to a 2 × 2 factorial design with 2 VE supplementation levels [0 IU/kg (VE0) vs. 30 IU/kg (VE30)], and 2 challenge treatments [SE vs. physiological saline solution (PS)]. During the last 3 D of week 43 of age, birds were orally challenged with 1.0 mL suspension of 109 cfu/mL S. Enteritidis daily, whereas the birds of negative treatments (VE0) received the same volume of PS. The egg mass of VE0 treatment decreased (P < 0.05) in contrast to VE treatment after challenge. The serum concentrations of interleukins (IL-1ß and IL-6) and malondialdehyde (MDA) levels of SE treatments increased (P < 0.05) at week 44 and week 46, respectively. In both VE30 treatments, the decrease (P < 0.05) in birds' mortality was associated with higher IgA, IgG, IgM concentrations at week 44, and higher IgA, IgM concentrations at week 46. There is an interaction (P < 0.05) between SE challenge and VE levels with regard to feed conversion, daily egg mass, and serum MDA, IgA, and IgM levels. It can be concluded that supplemental VE (30 IU/kg) in diets for laying hens may alleviate oxidative and immune stress due to SE challenge.

Evaluation of the overall impact of antibiotics growth promoters on broiler health and productivity during the medication and withdrawal period.

The effectiveness of some common combination of antibiotic growth promoters (AGP) on growth performance, gut health, and meat quality was evaluated during the medication and withdrawal period in broilers. A total of 540 male Arbor Acre broilers at 0 D of age were randomly assigned to 5 treatments, with 6 replicates of 18 chicks. Broilers received diets during the medication period (0 to 42 D) as follows: NC (control diet without AGP), EN (NC + enduracidin 8 ppm + colistin sulfate 8 ppm), BZ (NC + bacitracin zinc 40 ppm + colistin sulfate 8 ppm), CT (NC + chlortetracycline 50 ppm + colistin sulfate 8 ppm), and VG (NC + virginiamycin 20 ppm + colistin sulfate 8 ppm). Broilers were switched to the same finisher diet without AGP during the withdrawal period (43 to 49 D). The feed:gain ratio in EN, BZ, CT, and VG groups were significantly decreased by 0.07, 0.10, 0.06, and 0.05 during 0 to 42 D (P < 0.05), but increased by 0.19 (P > 0.05), 0.33 (P > 0.05), 0.49 (P < 0.05), and 0.69 (P < 0.05) during the withdrawal period, respectively. The jejunum villus height (VH) increased in EN group (P < 0.05) and crypt depth (CD) reduced in BZ, CT, and VG groups (P < 0.05) at 42 D, while jejunum VH increased in EN and BZ groups (P < 0.05) at 49 D compared to NC group (P < 0.05). Meat quality detection at 49 D found all AGP groups with the higher cook loss of the breast muscle, while CT group with the higher cook loss of thigh muscle. Consequently, the overall effects of 4 AGP combinations in the whole period were not significant on growth performance. Their poor growth performance during the withdrawal period should be partly attributed to the falling off a cliff of most digestive enzyme activities from 42 to 49 D. Attention should be paid to the adverse effects of AGP supplementation on meat quality, especially cook loss.

Interactions between the cecal microbiota and non-alcoholic steatohepatitis using laying hens as the model.

Chronic liver disease has caused increasing numbers of deaths worldwide. Fatty liver hemorrhagic syndrome, one of the chronic liver diseases in laying hens, has great similarity to non-alcoholic fatty liver disease (NAFLD) in humans. It is characterized by the pathological accumulation of liver fat. Non-invasive techniques are needed for early identification of fibrosis. As primary de novo lipogenesis in the liver of chicken is similar to that of humans, mature chicken is an ideal animal model for the understanding of NAFLD. This study was aimed to evaluate the relationships between gut microbiota and natural chronic liver disease (i.e., non-alcoholic steatohepatitis [NASH] and fibrosis stages) in a well-characterized laying hen population. One hundred 20-wk-old Hy-Line Brown laying hens were used and fed with basal diets until 52 wk of age. At the end of the experiment, birds were killed for sampling blood, liver, and cecal contents, and then classified by liver histology measurement into different groups. We investigated microbial community structure of cecum using 16S rRNA gene sequencing. Subjects in stage 0 fibrosis without NASH were classified as low NAFLD (Group A), subjects in stage 1-2 fibrosis with mild to moderate NASH were defined as low NASH (Group B), and subjects in stage 3 fibrosis were defined as severe NASH (Group C). The abundance of Firmicutes was reduced in Groups B and C (P < 0.001), whereas opposite results were observed for the abundance of Bacteroidetes. Additionally, the families Bacteroidaceae, Ruminococcaceae Lachnospiraceae, and lactobacillae were significantly different between groups of differing fibrosis stages (P < 0.001), driven entirely by alterations of Bacteroides and lactobacillus and lachnospiraceae genera (P < 0.001), were observed. Results indicated that cecal dysbiosis was linked with the severity of fibrosis and NASH; importantly, increased levels of serum AST, alkaline phosphatase, and uric acid were accompanied with liver fibrosis and NASH severity. Collectively, these data highlight the role of gut-liver axis and associations between the gut microbiota and fibrosis and NASH severity.

Effects of dietary inosinic acid on carcass characteristics, meat quality, and deposition of inosinic acid in broilers.

An experiment was conducted to evaluate the effects of dietary inosinic acid (inosine 5'-monophosphate, IMP) on carcass characteristics, meat quality, and deposition of IMP in Arbor Acres broilers. A total of two hundred forty 1-d-old male Arbor Acres broilers were allocated to 4 inosinic acid treatments (0, 0.25, 0.50, and 0.75% dietary IMP supplementation). Birds were slaughtered at 42 d old. Dietary IMP did not significantly affect the carcass characteristics of broilers. No significant difference among treatments was observed in muscle pH within 1 h or at 24 h postmortem (PM), or in the decrease of muscle pH within 24 h PM. Inosinic acid had no marked effect on the color of breast muscle or Hunter L* and a* values of thigh muscle. Hunter b* values in thigh muscle were lower (P < 0.05) in the 0.75% IMP supplementation group than in the control group. Both breast and thigh muscle of birds fed with 0.25% IMP diet resulted in a lower (P < 0.05) shear force value compared with those fed with the other diets. All of the test groups had greater (P < 0.05) deposition of IMP in breast and thigh muscle than that of the control group with the exception of the 0.75% IMP supplementation group for thigh muscle. Greater (P < 0.05) corrected IMP value in breast muscle was detected for the test groups compared with the control group. These results suggest that extraneous IMP addition may contribute to the improvement of growth, meat quality, and deposition of IMP in broilers.

No copper supplementation in a corn-soybean basal diet has no adverse effects on late-phase laying hens under normal and cyclic high temperatures.

Over supplementation of copper (Cu) in animal diets may cause serious pollution in soil, water and harvested crops. To minimize the potential pollution, the effects of corn-soybean basal diet with or without supplementation of 8 mg Cu/kg on laying performance, plasma biochemical metabolic indices, and antioxidant status in laying hens were evaluated under normal and cyclic high temperatures. A total of 240 Hy-Line Brown laying hens were randomly allotted to 4 treatments with 6 replicates of 10 hens per replicate according to factorial design involved in 2 temperatures [normal temperature (NT) vs. cyclic high temperature (CHT)] and 2 dietary Cu addition amount [Cu0 (0 mg/kg) vs. Cu8 (8 mg/kg in the form of CuSO4·5H2O)]. The experimental period included 1-week adaptation, 2-week heat stress and 2-week convalescence. The temperatures of NT groups in the same period or any groups during other periods were kept at 26 ± 2°C except that of CHT groups were 26 ± 2°C∼33 ± 2°C cyclically during heat stress period. CHT groups increased (P < 0.05) the rectal temperature and plasma glucose content under heat stress, but decreased (P < 0.01) the egg yield at the second week of heat stress and the first week of convalescence, and the plasma triglyceride, uric acid, and triiodothyronine levels under heat stress. Cu8 groups increased (P < 0.05) egg weight at the first week of convalescence, and plasma thyroxin level during the whole convalescence. Interactions between temperature and Cu content existed (P < 0.05) in the laying rate at the first week of convalescence, and the plasma lactic dehydrogenase level under heat stress. Conclusively, the CHT impaired laying performance. The Cu content (10.3 mg/kg) in corn-soybean basal diet might be sufficient for meeting the maintenance and production requirements of late-phase laying hens, and no Cu supplementation had no adverse effects on egg production and antioxidant indices under cyclic high (26 ± 2°C∼33 ± 2°C) or normal (26 ± 2°C) temperatures.

Influence of acidified drinking water on growth performance and gastrointestinal function of broilers.

The ban on the use of antibiotic feed additives as growth promoters compelled the researchers for exploring the future utility of other alternatives. This experiment was designed to evaluate the effect of acidified drinking water on growth performance, gastrointestinal pH, digestive enzymes, intestinal histomorphology, and cecum microbial counting of the broiler chicken. A total of 540 one-day-old male broilers (Arbor Acre) were randomly assigned to 5 treatments, with 6 replicates of 18 chicks per replicate. Broilers received diets and water as follows: NC (negative control, basal diet, normal water), PC (positive control, basal diet + 8 ppm colistin sulfate + 8 ppm enduracidin, normal water), A1 (basal diet, continuous supply of acidified water during whole experiment period), A2 (basal diet, intermittent acidification of water during 0 to 14 d, 22 to 28 d, and 36 to 42 d), and A3 [basal diet, intermittent acidification of water (24 h/d from 0 to 14 d and from 10:00 am to 4:00 pm on d 15 to 42)]. During the entire period, the acidified groups (A1, A2, and A3) and PC group showed improve on weight gain, average daily gain and feed conversion ratio compared to NC group (P < 0.05). The pH in crop, proventriculus and ileum at 43 d declined by 0.04, 1.03, 1.23; 0.55, 0.69, 0.70; and 0.63, 0.74, 1.21 in A1, A2, and A3 group, respectively. There was a significant decline of lipase activity in the PC and acidified groups compared to NC group. The A2 group had higher villus height in jejunum than NC group. The PC and acidified groups reduced (P < 0.05) the total aerobic bacteria count of cecum when contrasted to NC group. Therefore, we conclude that acidified drinking water can improve growth performance, compensate for gastric acidity, and control pathogenic bacteria in broilers and may be considered as a potential alternative to improve production parameters. Discontinuous supply of acidified water had the same or even better influence on broilers compared to continuous supply.

Development of breast muscle and meat quality in Arbor Acres broilers, Jingxing 100 crossbred chickens and Beijing fatty chickens.

The objective of this experiment was to examine development of breast muscle and myofiber of M. pectoralis superficialis in three chicken breeds. Commercial broiler chickens (Arbor Acres broilers, AA), crossbred chickens (Jingxing 100 crossbred chickens, JXC) and Chinese native chickens (Beijing fatty chickens, BJF) were grown up to 98d to estimate myofiber density, and size (area, and diameter of myofibers) in P. superficialis. At 42, 56, 70, 84, and 98d of age, Pectoralis muscle was used to evaluate breast muscle weight, breast yield, and tenderness (shear force value). Results indicate that commercial broilers have higher breast weight, and higher shear force value than crossbred chickens and Chinese native chickens, that may be due to an increased myofiber diameter and area in Pectoralis muscle. It is suggested that histological properties of myofibers play an important role in increasing the shear force value of meat.

Effect of sodium selenite and selenium yeast on performance, egg quality, antioxidant capacity, and selenium deposition of laying hens.

This study compared the effects of sodium selenite and selenium yeast and their combination on laying performance, egg quality, antioxidant capacity, and selenium (Se) contents in tissues and eggs. Two-hundred-eighty-eight Jing Hong layers that were similar in laying rate (87.5 ± 0.38%) and body weight (1.70 ± 0.02 kg) were randomly distributed into 4 treatments for 11 wk (from 203 d old to 279 d old) with 9 replicates of 8 hens per replicate. The diets (corn-soybean meal diet) were supplemented with 0 [blank control (BC)], 0.3 mg/kg Se from sodium selenite (SS), 0.15 mg/kg Se from sodium selenite and 0.15 mg/kg Se from Se yeast (SS+SY), or 0.3 mg/kg Se from Se yeast (SY). Results showed that the laying rate of the SS+SY group increased significantly (P < 0.05) compared to the BC and SY groups. There were no differences (P > 0.05) in egg quality between the Se-supplemented diets and the BC diet. The serum glutathione peroxidase (GSH-Px) activity was increased (P < 0.01) in hens fed Se-supplemented diets compared to the BC diet. The liver superoxide dismutase (SOD) activity of the SY group was increased significantly (P < 0.05) compared to the BC group. Significant increase (P < 0.01) due to SY supplementation was noted in the serum vitamin E content compared to BC and SS. Layers fed Se-supplemented diets had higher (P < 0.01) contents of Se in the serum, liver, and kidney compared to the BC diet. Compared to BC, Se content in eggs was significantly increased (P < 0.05) by feeding supplementary Se. In conclusion, the effects of SS and Se yeast were approximately equal in promoting antioxidant capacity of laying hens, while Se yeast is easier to deposit into eggs and tissues. The diet with added equal amounts of the 2 sources of Se was more cost effective and affordable than a comparable amount of Se yeast to obtain the promising production performance and nearly similar Se deposition.