Protective effects of γ-irradiated Astragalus polysaccharides on intestinal development and mucosal immune function of immunosuppressed broilers.

This study was aimed to assess the protective effects of γ-irradiated Astragalus polysaccharides (IAPS) on the development of small intestine and intestinal mucosal immunity of immunosuppressed broilers induced by cyclophosphamide (CPM). A total of 384 one-day-old broiler chicks with similar initial weight were randomly assigned into 6 groups: non-treated group (control), and CPM-treated groups fed either a basal diet or the diets containing 900 mg/kg APS, or 900, 600, 300 mg/kg IAPS, respectively. On days 16, 18, and 20, all broilers except for control group were intramuscularly injected with 0.5 mL CPM (40 mg/kg of BW). Broilers in the control group were intramuscularly injected with 0.5 mL sterilized saline (0.75%, wt/vol). This trial was lasted for 21 d. The results revealed that both APS and IAPS treatment elevated the duodenal IgA-producing cells number and the jejunal mRNA expression of interleukin-2 (IL-2), interleukin-10 (IL-10), and interferon γ of CPM-injected broilers (P < 0.05). The decreased jejunal villus height (VH), the ratio of VH to crypt depth (V/C), as well as the intestinal intraepithelial lymphocytes (IELs) and goblet cells number in CPM-injected broilers were elevated by dietary supplementation with 900 mg/kg APS or 900, 600 mg/kg IAPS (P < 0.05). The CPM-induced decrease in jejunum index, the duodenal VH and the jejunal IgA-producing cells number were only improved in the 900 mg/kg IAPS group (P < 0.05). Furthermore, the number of IELs and IgA-producing cells in duodenum, VH, V/C, the number of goblet cells, and mRNA expression of IL-2 and IL-10 in jejunum were higher in the 900 mg/kg IAPS group than those in the 900 mg/kg APS group (P < 0.05). In summary, IAPS possessed stronger immunomodulatory effect than APS at the same supplementation level. Therefore, gamma irradiation can be used as an alternative treatment to enhance the immunomodulatory activity of APS.

Attenuating effects of guanidinoacetic acid on preslaughter transport-induced muscle energy expenditure and rapid glycolysis of broilers.

This study evaluated the effects of dietary guanidinoacetic acid (GAA) supplementation on growth performance, plasma variables, muscle energy status, glycolytic potential, and meat quality of broilers experiencing transport stress during the summer. A total of 320 28-day-old male Arbor Acres broilers were randomly allotted to 3 dietary treatments, including a GAA-free basal control diet (160 birds) and basal diet supplementation with 600 (80 birds) or 1,200 mg/kg (80 birds) GAA for 14 D. On the morning of day 42, after an 8-h fast, the birds fed basal diets were divided into 2 equal groups, and all birds in the 4 groups of 80 birds were transported according to the following protocols: 1) a 0.5-h transport of birds on basal diets (as a lower-stress control group), 2) a 3-h transport of birds on basal diets, and a 3-h transport of birds on basal diets supplemented with either 3) 600 or 4) 1,200 mg/kg GAA. The results revealed that dietary supplementation with GAA at 600 and 1,200 mg/kg for 14 D prior to slaughter did not affect growth performance, carcass traits, and most textural characteristics and chemical composition of the pectoralis major (PM) muscle (P > 0.05). In the GAA-free group, a 3-h transport increased the broiler live weight loss, elevated the plasma corticosterone concentration, decreased the plasma glucose concentration, muscle concentrations of ATP, creatine and energy charge value, increased the muscle AMP concentration and AMP/ATP ratio, and accelerated glycolysis metabolism, which resulted in inferior meat quality (lower pH and higher drip loss, P < 0.05). However, dietary addition of GAA at 1,200 mg/kg increased the mRNA expression of S-adenosyl-l-methionine: N-guanidino-acetate methyltransferase in the liver and creatine transporter in both the liver and PM muscle. It also elevated muscle concentrations of creatine and phosphocreatine (P < 0.05), which helps improve meat quality by ameliorating the 3-h transport-induced muscle energy expenditure and delaying anaerobic glycolysis of broilers.

The alleviative effects and related mechanisms of taurine supplementation on growth performance and carcass characteristics in broilers exposed to chronic heat stress.

To investigate the alleviative effects and molecular mechanisms of taurine supplementation on growth performance and carcass characteristics in broilers exposed to chronic heat stress, 144 male Arbor Acres broilers (28 d old) were randomly distributed to positive control (PC, 22°C, basal diet), heat stress (HS, consistent 32°C, basal diet), or heat stress + taurine (HS + T, consistent 32°C, basal diet + 5.00 g/kg taurine) groups, with 6 cages per group and 8 birds per cage. Chronic heat stress significantly decreased body weight, average daily gain, and average daily feed intake, and increased cloacal temperature and feed conversion ratio (FCR, P < 0.05). Though taurine supplementation tended to decrease the FCR in the HS + T group compared with the HS group after 14 d of heat exposure (P = 0.071), there were no significant alleviative effects of taurine supplementation on the increased cloacal temperature and decreased growth performance in chronic heat-stressed broilers (P > 0.05). After 7 and 14 d of heat exposure, taurine supplementation significantly increased the proportion of breast muscle and hormone-sensitive lipase activity in the abdominal fat (P < 0.05), and decreased the mRNA expressions of muscle atrophy F-box protein (MAFbx) and muscle ring-finger protein-1 (MuRF1) in breast muscle compared with the HS group (P < 0.05). After 7 d of heat exposure, taurine supplementation significantly increased serum non-esterified fatty acid concentration (P < 0.05), and decreased the mRNA expressions of acetyl-CoA carboxylase 1c (ACC) and muscular isoform of carnitine palmitoyl transferase 1 (M-CPT1) compared with the HS group (P < 0.05). In addition, the mRNA expressions of M-CPT1 and ribosomal protein S6 kinase, 70 kDa (p70S6K) in the HS + T group were significantly higher than those of the other two groups after 14 d of heat exposure (P < 0.05). In conclusion, taurine supplementation can improve carcass characteristics of chronic heat-stressed broilers by facilitating lipolysis for energy, enhancing protein synthesis, and suppressing protein degradation of the breast muscles.

Effects of Different Selenium Sources on Growth Performance, Antioxidant Capacity and Meat Quality of Local Chinese Subei Chickens.

Despite increasing evidence indicating the essential involvement of selenium (Se) on growth performance, antioxidant capacity, and meat quality of commercial broilers, the effects of different Se sources on local Chinese Subei chickens is unclear. A total of 360 50-day-old male chickens were individually weighed and randomly allocated to four treatment groups. Chickens in each of the four groups were fed diets supplemented with 0.3 mg Se/kg as sodium Se (SS), Se-enriched yeast (SY), selenomethionine (Met-Se), or nano red element Se (Nano-Se) for 40 days. At the end of the experiment, one bird of approximately average weight from each cage was selected and slaughtered, and blood and breast muscles samples were collected. The results showed that there was no significant difference in feed intake, body weight gain, or feed to gain ratio among treatments (P > 0.05). Dietary SY, Met-Se, and Nano-Se supplementation increased the activity of glutathione peroxidase in serum and breast muscles and decreased the concentration of malondialdehyde in serum and carbonyl in breast muscles compared with the SS group (P < 0.05). Moreover, SY, Met-Se, and Nano-Se supplementation increased pH45min, total protein solubility, and myofibrillar protein solubility, as well as decreased the shear force value compared with the SS group (P < 0.05). In addition, birds in the SY and Met-Se groups exhibited lower cooking loss compared with the SS group (P < 0.05). In conclusion, organic Se and Nano-Se supplementation resulted in an improvement of antioxidant capacity and meat quality in local Chinese Subei chickens relative to inorganic Se.

In ovo feeding of creatine pyruvate alters energy reserves, satellite cell mitotic activity and myogenic gene expression of breast muscle in embryos and neonatal broilers.

We investigated the effects of in ovo feeding (IOF) of creatine pyruvate (CrPyr) on energy reserves, satellite cell mitotic activity (SCMA) and myogenic gene expression in breast muscle of embryos and neonatal broilers. A total of 960 eggs were randomly allocated into three treatments: 1) non-injected control group, 2) saline group injected with 0.6 mL of physiological saline (0.75%), and 3) CrPyr group injected with 0.6 mL of physiological saline (0.75%) containing 12 mg CrPyr/egg at 17.5 d of incubation. After hatching, a total of 120 male chicks were randomly assigned to each treatment group, with eight replicate sets per group. Selected chicks had body BW close to the average of their pooled group. Our results showed that the total and relative breast muscle weights of broilers subjected to CrPyr treatment were higher than those in the control and saline groups on 19 d of incubation (19 E), the day of hatch, 3 and 7 d post-hatch (P < 0.05). The myofiber diameter and cross-sectional area of individuals in the CrPyr group were higher than those in other treatments on 3 and 7 d post-hatch (P < 0.05). Moreover, IOF of CrPyr increased (P < 0.05) creatine concentrations on 19 E, the day of hatch and 3 d post-hatch, the same treatment increased phosphocreatine concentrations on 19 E. Broilers in the CrPyr group showed higher expression of myogenic differentiation 1 (MyoD) (P < 0.05), myogenin and paired box 7 (Pax7), as well as higher index of SCMA on 3 d post-hatch. However, myostatin mRNA expression in CrPyr-treated broilers was down-regulated on 3 d post-hatch (P < 0.05). These results indicated that IOF of CrPyr increased energy reserves of embryos and SCMA of broilers on 3 d post-hatch, which led to enhanced muscle growth in the late embryos and neonatal broilers. Additionally, IOF of CrPyr increased the activity of satellite cells possibly through up-regulating MyoD, myogenin, and Pax7 mRNA expression and down-regulating myostatin mRNA expression.

Effect of dietary creatine monohydrate supplementation on muscle lipid peroxidation and antioxidant capacity of transported broilers in summer.

This experiment was to evaluate the effect of dietary supplementation with creatine monohydrate (CMH) during the finishing period on the muscle lipid peroxidation and antioxidant capacity of broilers that experienced transport stress in summer. A total of 320 male Arbor Acres broilers (28 d in age) were randomly allotted to 3 dietary treatments including a basal control diet without additional CMH (160 birds), or with 600 (80 birds) or 1,200 mg/kg (80 birds) CMH for 14 d. On the morning of d 42, after an 8-h fast, the birds fed the basal diets were divided into 2 equal groups, and all birds in the 4 groups of 80 birds were transported according to the following protocols: 1) a 0.75-h transport of birds on basal diets (as a lower-stress control group), 2) a 3-h transport of birds on basal diets, 3) a 3-h transport of birds on 600 or 4) 1,200 mg/kg CMH supplementation diets. The results showed that the 3-h transport decreased the concentration of creatine (Cr) in both the pectoralis major (PM) and the tibialis anterior (TA) muscles, increased the concentration of phosphocreatine (PCr) and PCr/Cr ratio in PM muscle, and elevated the concentrations of thiobarbituric acid-reactive substances and the activities of total superoxide dismutase and glutathione peroxidase in both the PM and TA muscles of birds (P < 0.05). In addition, transport also upregulated mRNA expression of avian uncoupling protein and heat shock protein 70 in both the PM and TA muscles, as well as avian peroxisome proliferator-activated receptor γ coactivator-1α in the TA muscle (P < 0.05). Dietary supplementation with 1,200 mg/kg CMH increased the concentrations of Cr and PCr in PM muscle, and Cr in TA muscle than those in the 3-h transport group (P < 0.05). However, contrary to our hypothesis, dietary CMH did not alter the measured parameters in relation to muscle lipid peroxidation and antioxidant capacity affected by 3-h transport (P > 0.05). These results indicate that dietary CMH supplementation does not provide any significant protection via directly scavenging free radicals or increased antioxidant capacity of transported broilers.

Effects of dietary supplementation with ferulic Acid or vitamin e individually or in combination on meat quality and antioxidant capacity of finishing pigs.

This study aimed to evaluate the effects of vitamin E (VE), ferulic acid (FA) and their combination supplementation on meat quality and antioxidant capacities of finishing pigs. Sixty barrows were randomly allocated to four experimental diets using a 2×2 factorial arrangement with 2 VE supplemental levels (0 or 400 mg/kg) and 2 FA supplemental levels (0 or 100 mg/kg) in basal diets. After 28 days, six pigs per treatment were slaughtered. The results showed that VE supplementation increased loin eye area of pigs (p<0.05) and FA supplementation increased pH45min value (p<0.05). The interaction of FA×VE was observed in shear force of longissimus dorsi muscle (p<0.05). Moreover, supplementation with VE decreased hepatic and sarcous malondialdehyde (MDA) content, increased hepatic glutathione (GSH) content and sarcous glutathione peroxidase (GSH-Px) activity (p<0.05). Additionally, supplementation with FA increased hepatic GSH-Px activity and decreased sarcous MDA content (p<0.05). However, dietary treatment did not affect the expression of genes related to nuclear factor, erythroid 2-like 2 (NFE2L2) pathway. These results suggest that dietary FA and VE could partially improve meat quality and antioxidant capacity of finishing pigs, but not by activating NFE2L2 pathway under the normal conditions of farming.

Effects of alpha-lipoic acid supplementation in different stages on growth performance, antioxidant capacity and meat quality in broiler chickens.

This experiment was conducted to investigate the effect of basal dietary supplementation with 500 mg/kg alpha-lipoic acid (LA) on growth performance, antioxidant capacity and meat quality in different stages in broiler chickens. A total of 240 Arbor Acre chickens were randomly assigned into 4 treatment groups, each treatment containing 6 replicates of 10 chickens each. Group 1 was the control group without LA supplementation; Group 2 was supplied with LA in the starter period; Group 3 was supplied with LA in the grower period; and Group 4 was supplied with LA in the whole period. The results showed that LA supplementation improved average feed intake and body weight gain in all three experimental groups, especially in Group 2. LA supplementation significantly decreased abdominal fat yield in Groups 3 and 4. LA supplementation all improved hepatic total antioxidant capacity, the level of glutathione, the activities of total superoxide dismutase, catalase (CAT) and glutathione peroxidase, in particular in Group 4. LA supplementation decreased the activity of liver xanthine oxidase (XO) in all experimental groups, and that of liver monoamine oxidase in Group 3. The activities of liver CAT and XO in Group 2 were higher than that in Group 3. LA supplementation elevated the pH24 h and decreased drip loss in breast meat in Groups 3 and 4. In conclusion, LA supplementation can improve growth performance, antioxidant properties and meat quality in broiler chicken. LA supplementation in the starter period can improve growth performance and supplementation in the grower - and in the whole period can improve carcass characteristics. There was no significant difference in meat quality of broiler chickens fed on LA-supplemented diet in different stages.

Effects of dietary supplementation with creatine monohydrate during the finishing period on growth performance, carcass traits, meat quality and muscle glycolytic potential of broilers subjected to transport stress.

A total of 320 male Arbor Acres broiler chickens (28 days old) were randomly allotted to one of the three experimental diets supplemented with 0 (160 birds), 600 (80 birds) or 1200 mg/kg (80 birds) creatine monohydrate (CMH) for 14 days. On the morning of 42 day, after an 8-h fast, the birds of CMH-free group were divided into two equal groups, and all birds of these four groups were transported according to the follow protocol: 0.75-h transport without CMH supplementation (as a lower stress control group), 3-h transport without CMH supplementation, 3-h transport with 600 or 1200 mg/kg CMH supplementation. Each treatment group was composed of 8 replicates with 10 birds each. The results showed that supplementation of CMH for 14 days before slaughter did not affect the overall growth performance and carcass traits of stressed broilers (P>0.05). A 3-h transport decreased plasma glucose concentration, elevated plasma corticosterone concentration, increased bird live weight loss, breakdown of muscle glycogen, as well as the accumulation of muscle lactate (P<0.05), which induced some detrimental changes to breast meat quality (lower ultimate pH and higher drip loss, P<0.05). Nevertheless, supplementation of 1200 mg/kg CMH reduced chicken weight loss, decreased the contents of lactate and glycolytic potential in pectoralis major of 3-h transported broilers (P<0.05), which is beneficial to maintain breast meat quality by reducing the drip loss (P<0.05). These findings suggest that the reduction of muscle glycolysis is probably the reason for maintainance of meat quality by supplementation of CMH in transported broilers.

Effects of dietary glutamine and gamma-aminobutyric acid on meat colour, pH, composition, and water-holding characteristic in broilers under cyclic heat stress.

1. An experiment was conducted to evaluate the effects of dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on raw breast meat colour, pH, composition and water-holding characteristic of broilers under cyclic heat stress (HS). 2. A total of 360 21-d-old Arbor Acres male chicks were randomly assigned to 5 treatment groups (6 replicates of 12 birds per cage). The positive control (PC) broilers were kept in a thermoneutral chamber (22-24°C) and fed on the basal diet. The other 4 groups were kept in a cyclic HS chamber (30-34°C) for 9 h (from 09:00 to 18:00). 3. A significant increase was observed in breast meat lightness at 28, 35 and 42 d; and pH values at 28, 35 and 42 d; while a significant decrease was observed in breast meat cooking loss (CL) and contents of moisture, crude protein (CP), crude fat (CF) and crude ash (CA) due to HS. 4. The supplementation with 0·5 g Gln/kg decreased lightness at 28, 35 and 42 d; while increasing redness at 28 d, yellowness at 35 d, contents of CP, CF and CA, thawing loss (TL) and drip loss (DL). The addition of 100 mg GABA/kg decreased lightness at 28 and 35 d, pH value at 28, 35 and 42 d, and TL; while increasing redness at 28 d, 35 and 42 d, contents of moisture, CP and CF. 5. The lightness, redness, and pH value; contents of moisture, CP, CF and CA; and TL, DL and CL of breast meat of broilers fed with the mixture of Gln and GABA under cyclic HS were similar to those of the broilers in the PC group. 6. Significant interactions were found between Gln and GABA for yellowness at 28 and 35 d; pH at 28, 35 and 42 d; moisture content, CP content, water-holding capacity and TL. 7. These results demonstrated that dietary Gln and GABA offer a potential nutritional strategy to prevent cyclic HS-related depression in broiler meat chemical composition and quality.

Dietary sodium butyrate alleviates the oxidative stress induced by corticosterone exposure and improves meat quality in broiler chickens.

The present study was to investigate the effects of dietary microencapsulated sodium butyrate (SB) and acute pre-slaughter stress, mimicked by subcutaneous corticosterone (CORT) administration, on BW, carcass characteristics, muscle antioxidant status, and meat quality of broiler chickens. A total of 120 1-d-old broiler chickens were fed a control diet (without SB) or a 0.4-g microencapsulated SB/kg diet. On 42 d, half of the birds from each treatment were given 1 single subcutaneous injection of CORT (4 mg/kg of BW in corn oil) to mimic acute stress, whereas the other half were injected with the same amount of corn oil (sham control). Three hours later, BW loss was determined and breast meat samples were collected. The results showed that the BW of the CORT-challenged groups lost much more than the sham control group (P < 0.001), whereas it was alleviated by the dietary microencapsulated SB (P < 0.05). Meanwhile, the catalase activity was decreased and malondialdehyde level was increased by the stress (P < 0.05), and the microencapsulated-SB diet significantly inhibited this effect (P < 0.05). Lower pH values and higher yellowness values were also observed in CORT-challenged chickens (P < 0.05), and the microencapsulated-SB diet treatment partially exerted a preventive effect. Microencapsulated SB significantly decreased the contents of saturated fatty acids and C18:0 (P < 0.01 and P < 0.001), and increased C20:0 and C20:4 contents. However, the effect of the stress treatment on fatty acid composition was insignificant (P > 0.05). In addition, diet and stress did not significantly influence carcass characteristics and the chemical composition of breast meat (P > 0.05). These results suggest that microencapsulated SB was favorable for chickens in the presence of stress, which may be partially ascribed to the ability of SB to decrease catabolism and oxidative injury of tissues.

Sodium butyrate maintains growth performance by regulating the immune response in broiler chickens.

1. The experiment was conducted to investigate the effects of dietary sodium butyrate on the growth performance and immune response of broiler chickens. In experiment 1, 240 1-d-old chickens were allocated into 4 dietary groups (0, 0·25, 0·50 or 1·00 g sodium butyrate/kg) with 6 replicates each. In experiment 2, 120 1-d-old chickens were fed a control diet (without sodium butyrate) or 1·00 g sodium butyrate/kg diet. Half of the chickens fed on each diet were injected intra-peritoneally with 0·5 g/kg body weight of Escherichia coli lipopolysaccharide (LPS) at 16, 18 and 20 d of age. 2. There was no effect of dietary sodium butyrate on growth performance. On d 21, serum interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) were decreased in chickens given 1·00 g sodium butyrate/kg, serum superoxide dismutase (SOD) and catalase activities were significantly increased, and malondialdehyde (MDA) was decreased by dietary sodium butyrate at 0·50 or 1·00 g/kg. On d 42, serum IL-6 was markedly decreased by dietary sodium butyrate, while 1·00 g sodium butyrate/kg greatly reduced MDA and increased catalase. 3. LPS challenge significantly reduced the growth performance of chickens. Serum IL-1ß, IL-6, TNF-α, corticosterone, alpha-1 acid glycoprotein (AGP) and prostaglandin E(2) (PGE(2)) were increased in LPS-challenged chickens. Dietary sodium butyrate supplementation maintained the body weight gain and feed intake. Sodium butyrate supplementation inhibited the increase in IL-6 and AGP in serum at 16 d of age and TNF-α, corticosterone, AGP and PGE(2) at 20 d of age. Similar inhibitory effects of sodium butyrate in serum glucose and total protein concentrations were also found at 20 d of age. 4. The results indicated that dietary sodium butyrate supplementation can improve the growth performance in chickens under stress and that this may be used to moderate the immune response and reduce tissue damage.

Use of natural antimicrobials to improve the control of Listeria monocytogenes in a cured cooked meat model system.

Concern about nitrite in processed meats has increased consumer demand for natural products manufactured without nitrite or nitrate. Studies on commercial meat products labeled as "Uncured" and "No-Nitrite-or-Nitrate-Added" have shown less control of nitrite in these products and greater potential growth of bacterial pathogens. To improve the safety of the "naturally cured" meats, several natural ingredients were studied in a cured cooked meat model system (80:20 pork, 10% water, 2% salt, and 150 or 50 ppm ingoing sodium nitrite) that closely resembled commercial frankfurters to determine their inhibitory effect on Listeria monocytogenes. Results showed that cranberry powder at 1%, 2% and 3% resulted in 2-4 log cfu/g less growth of L. monocytogenes compared to the control with nitrite alone (P<0.05). Other natural compounds, such as cherry powder, lime powder and grape seed extract, also provided measureable inhibition to L. monocytogenes when combined with cranberry powder (P<0.05).

Methionine and selenium yeast supplementation of the maternal diets affects antioxidant activity of breeding eggs.

Four hundred fifty 52-wk-old Langshan layer hens (dual-purpose type, an indigenous poultry breed of China) were randomly divided into 9 treatments with 5 replicates in each treatment. Birds were fed corn-soybean diets (0.13 mg of Se/kg) supplemented with 0, 0.30, and 0.60 mg/kg of Se from Se yeast and 3.2, 4.0, and 5.4 g of dl-Met/kg, respectively. Increasing Se yeast supplementation significantly increased Se concentration in the egg yolk (P < 0.01) and the Se concentration of the 3.2 g of Met/kg treatment was higher than those of the 4.0 and 5.4 g of Met/kg treatments. Adding 0.3 mg of Se/kg to the diet significantly increased glutathione peroxidase (GSH-Px) activity in the egg yolk compared with 0 and 0.6 mg of Se/kg (P < 0.01) and increasing Se yeast supplementation significantly increased the GSH-Px activity in the egg albumen (P < 0.01). Increasing Met supplementation significantly decreased the GSH-Px activity in both the yolk and the albumen of the eggs (P < 0.01). Methionine supplemented at 3.2 and 4.0 g/kg significantly increased glutathione concentration in the egg yolk compared with 5.4 g of Met/kg (P < 0.01) and increasing Met supplementation increased the glutathione concentration in the egg albumen. Increasing Met supplementation significantly decreased malondialdehyde concentration in the egg yolk (P < 0.01) and Se supplemented at 0 and 0.6 mg/kg increased the malondialdehyde concentrations in the egg yolk compared with 0.3 mg of Se/kg (P < 0.01). Methionine supplemented at 4.0 and 5.4 g/kg significantly decreased carbonyl concentration compared with 3.2 g of Met/kg. The conclusion was drawn that Se yeast and Met supplementation of the maternal diets could enhance antioxidant activity of breeding eggs.

Methionine and selenium yeast supplementation of the maternal diets affects color, water-holding capacity, and oxidative stability of their male offspring meat at the early stage.

Four hundred fifty 52-wk-old Lang-shan breeding hens (dual-purpose type, an indigenous poultry breed of China) were randomly divided into 9 treatments with 5 replicates each treatment. They were fed corn-soybean diets with 0, 0.30, and 0.60 mg of Se/kg from Se yeast and 3.2, 4.0, and 5.4 g of dl-Met/kg, respectively. After incubation, 250 chickens each treatment were randomly divided into 5 replicates and fed the same diet. At 21 d old, 10 male chicks in each treatment were slaughtered. There results were as follows. (1) The Se content significantly increased with the increase of Se yeast supplementation (P < 0.01). (2) The carbonyl content of the myofibrillar protein significantly decreased with the increase of Met supplementation (P < 0.01) and the carbonyl content of the 0 mg of Se/kg treatment was higher than the 0.3 mg of Se/kg treatment (P < 0.01). (3) Selenium supplementation at 0.30 and 0.60 mg/kg significantly decreased malondialdehyde content compared with that of 0 mg of Se/kg (P < 0.01) and 4.0 and 5.4 g of Met/kg supplementation significantly decreased malondialdehyde content compared with that of 3.2 g of Met/kg (P < 0.01). (4) Supplementation of Met at 5.4 g/kg significantly increased International Commission on Illumination a* value compared with 3.2 and 4.0 g of Met/kg (P < 0.01). Supplementation of Se at 0.6 mg/kg significantly increased a* value compared 0 and 0.3 mg of Se/kg (P < 0.01) and 0 mg of Se/kg significantly increased b* value compared with 0.30 and 0.60 mg of Se/kg (P < 0.01). (5) Selenium supplemented at 0.30 and 0.60 mg/kg decreased drip loss compared with 0 mg of Se/kg and 4.0 and 5.4 g of Met/kg decreased drip loss compared with 3.2 g of Met/kg, respectively. The conclusion was drawn that Met and Se yeast supplementation of the maternal diets could improve color, water-holding capacity, and oxidative stability of male offspring meat to an extent.

Pre-column derivatization and gas chromatographic determination of alkaloids in bulbs of Fritillaria.

A method of precolumn derivatization GC with FID detection was developed for a simultaneous analysis of five major steroidal alkaloids of Fritillaria species, namely ebeiedine, ebeiedinone, verticine, verticinone and imperialine. Derivatization was carried out by trimethylsilylation of the hydroxyl-containing Fritillaria alkaloids to the corresponding trimethylsilylates with trimethylsilylimidazole. Reaction conditions were optimised and the alkaloids derivatives were characterised by on-line GC-MS. The validated GC method demonstrated a good linearity at the sampling ranges used. This analytical method is simple, convenient and reproducible. The developed assay was successfully applied to the determination of the major pharmacologically active alkaloids in three commonly used antitussive Fritillaria species: F. cirrhosa, F. thunbergii and F. pallidiflora.

Effects of dietary supplementation of beta 2-adrenergic agonist clenbuterol on carcase characteristics and some metabolites in ducks.

1. Ducks (622 in total) aged 25 d were given diets supplemented with clenbuterol (CL) at 0 (control), 0.5, 1, 2, 3 and 5 mg/kg for 25 d to investigate the effect of dietary CL on muscle and fat deposition and some metabolites in ducks. 2. The mass of the breast muscles was increased by 10 to 31%, while subcutaneous fat plus skin and abdominal fat pad were reduced by 8 to 23% and 20 to 37%, respectively, in the ducks supplemented 1 to 5 mg CL/kg diet. 3. Increased RNA:DNA ratios in the breast muscle, reduced uric acid and increased free fatty acid concentrations in the serum were observed in clenbuterol-fed ducks.