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This study aimed to evaluate the effects of vitamin C and vitamin E on antioxidant capacity and immune function in oxidative-stressed breeder roosters. One hundred twenty 45-week-old Lveyang black-boned breeder roosters were randomly assigned to 5 dietary treatments, including negative control group (NC), positive control group (PC), and 3 trial groups, which were fed the diets containing 300 mg/kg VC, 200 mg/kg VE, or 300 mg/kg VC and 200 mg/kg VE (VC+VE). At 47 wk of age, the positive control and trial groups were subcutaneously injected 3 times every other d with dexamethasone (DEX) 4 mg/kg of body weight, the negative control group was injected with saline. The experiment lasted for 35 d. The results showed that at 50 wk of age, average daily feed intake of birds challenged with DEX significantly increased (P0.05). During post-stress recovery period (52 wk of age), dietary supplemental VE or VC+VE notably increased body weight under oxidative stress (P0.01). Oxidative stress induced by DEX could significantly decrease superoxide dismutase (SOD), IgM, antibody titer of ND and mRNA expression of SOD or glutathion peroxidase activity (GSH-Px), increase serous malondialdehyde (MDA) (P0.05). Supplementation of VC or VE significantly decreased serous MDA, and increased SOD under oxidative stress (P0.05). Supplementation of VC or VE, or their combination significantly increased the relative expression of GSH-Px mRNA when compared to the oxidative-stressed control treatment (P0.05), whereas did not alleviate the relative expression of SOD mRNA (P0.05). Therefore, the results suggest that addition of 300 mg/kg VC, 200 mg/kg VE or their combination could improve antioxidant ability and immune performance in oxidative-stressed breeder roosters through up-regulating the expression of GSH-Px gene.

Effects of preslaughter immunological stress induced by lipopolysaccharide (LPS) on antioxidant performance and meat quality of broilers were investigated. Twenty-four broiler chickens (39 days old) with near-mean body weight (BW) were randomly divided into three following treatments: sham injection of saline (control), daily subcutaneous (s.c.) injection of LPS (3 mg/kg or 6 mg/kg of BW, respectively.) for three days. The results showed that average daily feed intake and daily gain of chickens were significantly decreased in the LPS treatment (P 0.05). The LPS treatment significantly decreased the pH at 24 h postmortem in breast muscle (P < 0.05) and significantly increased the water-holding capacity (WHC) of breast muscle (P < 0.01). It was the same as the change of yellowness (b*) at day 3 postmortem and lightness (L*) at day 6 postmortem in breast muscle (P < 0.05), but ha...

SUMMARY Distillers dried grains with solubles (DDGS) from corn contain relatively large amounts of polyunsaturated fatty acids and some yeast components, which may increase oxidative stress and alter immune function, respectively, when fed to broilers. Therefore, the study was undertaken to assess the effects of distillers dried grains with soluble (DDGS) on broilers under immunosuppressive challenge. One-day-old male broiler chickens (300) were assigned to 2 treatments with 6 replicates pretreatment. Birds were fed diets formulated to contain 0, 15% corn-based DDGS, respectively. The experimental diets were fed for 6 weeks in 2 phases. On day 21, serum IgA, IgG content and malondialdehyde (MDA), glutathione peroxidase (GSHPx), total superoxide dismutase (T-SOD), and total antioxidant activity (T-AOC) capacity were analyzed. Chickens were then randomly allotted to 1 of 4 treatment groups: negative control (NC) corn-soybean meal diet without dexamethasone (DEX) challenge, positive control (PC) corn-soybean meal diet with (DEX) challenge, 15% DDGS without DEX challenge (D), 15% DDGS with DEX (D+DEX). Based on these results, dietary DDGS did not influence ADG, ADFI and F:G of 21 d, 28 da nd 42 dc hicks (P > 0.05), however, DEX affected ADG and F:G of 28 d chicks remarkably (P < 0.05). Relative weights of liver, abdominal fat, spleen, thymus, and bursawereinfluencedbyDEXchallengeond28(P

SUMMARY This experiment was conducted to evaluate the effects of distillers dried grains with solubles (DDGS) on the meat quality and antioxidant status and capacity of broiler chickens. One-dayold male broiler chickens (720) were assigned to 6 treatments, with 4 replicates per treatment. Birds were fed diets formulated to contain 0, 5, 10, 15, 20, and 25% corn-based DDGS, respectively, for a period of 6 wk. The addition of DDGS influenced the general meat quality by affecting the b* (yellowness) values, cooking loss, and shear force (P 0.05), but feeding DDGS significantly increased the ratio of polyunsaturated to saturated fatty acids (P 0.05) by dietary DDGS concentrations; however, liver malondialdehyde production was influenced significantly (P < 0.01) by dietary DDGS levels. Overall, including DDGS at concentrations up to 15% in the broiler diet is feasible and can result in ideal meat quality.

An experiment was conducted to investigate the effects of dihydropyridine supplementation on growth performance and lipid metabolism of broilers. A total of 480 one-day-old female Arbor Acres broiler chicks were randomly divided into four groups, each group had six replications of 20 birds. Each group was fed a maize-soybean meal diet supplemented with 0, 100, 200, 300 mg/kg dihydropyridine, respectively, for six weeks. At 42 days of age, body weight and feed intake were not affected by dihydropyridine, while feed efficiency was significantly increased by 8.4%, 15.0% and 12.0%, respectively ( P < 0.05). The percentage of abdominal fat and the percentage of liver fat were reduced by 24.5%, 25.9%, 23.3%, and 23.6%, 26.7%, 26.0%, respectively (P < 0.05). The higher level of dietary dihydropyridine (200 or 300 mg/kg) increased the hormone- sensitive triglyceride lipase activity in liver and abdominal fat ( P < 0.05). The lipoprotein lipase activity in abdominal fat was significantly decreased by dihydropyridine ( P < 0.05). The activity of glucose-6-phosphate dehydrogenase and malic dehydrogenase in liver was significantly reduced, whereas the isocitrate dehydro - genase activity in liver was not affected by dietary dihydropyridine. The content of cAMP was significantly increased by dihydropyridine, but malondialdehyde content was decreased ( P < 0.05). Dihydropyridine at doses of 100 and 200 mg/kg increased apolipoprotein B ( P < 0.05), but 300 mg/kg dihydropyridine had no effect on apolipoprotein B compared with the control group. Triiodothyronine was significantly increased by dietary dihydropyridine ( P < 0.05). There were no differences in apolipoprotein A, cholesterol, trigly- cerides, high density lipoprotein-cholesterol, very low density lipoprotein-cholesterol, thyroxine and insulin among dietary treatments. It is concluded that supplementing dihydropyridine has a beneficial effect on feed efficiency and lipid metabolism of broilers, and that 200 mg/kg dihydropyridine supplementation is the optimum dose.

Glycerin, known as glycerol or glycerine, is the principal co-product of biodiesel production, produced through a NaOHor KOH-catalyzed transesterification of the triacylglycerols in oils or fats with an alcohol. Glycerin is known to be a valuable ingredient for producing food, soaps, cosmetics and pharmaceuticals. Currently, with plenty of glycerin available to the world market, more uses are expected to develop, especially as a potential energy source for poultry diets, with approximately 4,100 kcal/kg of gross energy. Moreover, glycerin also plays a critical role in body cellular metabolism. Results from different laboratories on the use of glycerin as feed energy source for poultry are discussed in this article. Positive responses are obtained with glycerol content up to 10% in poultry diets. The AMEn also has been measured in several experiments. However, more indices such as carcass performance and blood parameters need to be determined in further studies.

SUMMARY Two trials of similar experimental design were conducted to assess the effects of various dietary enzymes on energy digestibility of diets high in distillers dried grains with solubles (DDGS) for broilers. A 2 × 4 factorial arrangement of treatments was used in which a cornsoybean meal control diet and a diet with 30% DDGS were supplemented with 2 different commercial enzyme products. In addition to the unsupplemented control, each enzyme was fed at the level suggested by the manufacturer, twice the recommended level, and 4 times the recommended level. Allzyme SSF (Alltech, Nicholasville, KY) was used in the first experiment, and Rovabio Excel (Adisseo, Alpharetta, GA) was used in the second experiment. Male commercial strain chicks that were 15 (trial 1) or 20 (trial 2) d old were randomly assigned to the experimental diets, with each treatment replicated 3 times. Celite (Celite Corp., Santa Barbara, CA) was used as an indigestible marker. After a 5-d period of acclimation to the diets, excreta samples were collected. The energy contents of the diet and excreta were determined and digestibility of dietary energy was calculated. In both trials, there was a significant (P < 0.05) difference in gross energy digestibility between the corn-soybean meal control diets and diets with 30% DDGS. However, no significant improvement in gross energy digestibility was obtained by adding any level of the 2 enzymes. Moreover, no significant interactions were found between the basal diets and various enzyme levels. Therefore, addition of the enzymes used in these studies had no apparent beneficial effect on energy digestibility of corn-soybean meal diets or diets with a high level of DDGS.

SUMMARY The development of the fuel ethanol industry has resulted in large quantities of distillers dried grains with solubles (DDGS). This can partially replace corn and soybean meal in broiler diets, but the amino acids in DDGS are not balanced. Canola meal (CM) is a good protein source with a high amino acid content, so the combined use of DDGS and CM may improve the amino acid balance. A study was conducted to evaluate the use of DDGS in combination with CM in broiler diets. In a 6 × 6 factorial arrangement, 1,080 one-day-old male broilers were randomly assigned to diets with 0, 5, 10, 15, 20, and 25% DDGS of known composition; within each level of DDGS, diets contained 0, 5, 10, 15, 20, or 25% CM from 0 to 18 d of age. Each treatment was replicated 6 times. Diets were formulated to meet digestible amino acid requirements and were fed as a 3.17-mm pellet. Body weight and feed consumption were measured at 18 d of age. In addition, feed bulk density and percentage of fines were evaluated. The DDGS and CM levels as well as their interaction significantly affected feed intake and BW (P

A 3x4 factorial arrangement with three Metabolizable Energy (ME) levels (12.13, 12.55, 12.97 MJ/kg) and four Crude Protein (CP) levels (20.0, 21.0, 22.0 and 23.0%), respectively, was undertaken to investigate the influence of varying levels of dietary energy and protein on broiler performance and carcass quality from 1-21 d aysof age. Six hundred 1 day old broiler chicks were randomly divided into 12 treatments, each of which had five replicates of 10 birds. BW of 21 days of age was significantly increased with an increase in dietary ME (p 0.05). Both ME and CP significantly improved feed efficiency (P

This experiment was undertaken to evaluate the effect of dietary vitamin A on the performance and immune competence of broilers under heat stress (HS). A total of 180 birds, at 22 days of age, were randomly assigned to be reared either at 24°C (thermoneutral, TN, 24°C, constant) or 24°C to 38°C (heat stress, HS, cycling) until the age of 42 days. Birds were then supplemented with vitamin A at 750, 1500, 15 000 IU/kg. Each of the 2 × 3 factorially arranged treatments were replicated in six cages, each containing five birds. Humoral immunity was assessed by intravenous injection of 7% sheep red blood cells (SRBC) followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed by using a Sephadax stimulation method to recruit abdominal exudate cells (AEC) to evaluate macrophage phagocytic ability. Body weight (BW) and feed conversion were significantly affected by dietary vitamin A (P < 0.05). HS significantly reduced BW, feed intake and feed conversion (P < 0.05). Numbers of AEC, percentage of macrophages in AEC, phagocytic macrophages, internalized opsonized and unopsonized SRBC were increased by dietary vitamin A (P < 0.05). Both primary and secondary antibody responses were characterized by increasing titers of antibody to SRBC by dietary vitamin A when birds were exposed to HS (P < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC and phagocytic ability of macrophages were all significantly reduced under HS. These results indicated that HS severely reduced performance and immunocompetence of broilers, whereas the immune response of broilers improved by dietary vitamin A supplementation under HS.

2 Abstract: An experiment was conducted to evaluate the use of distillers dried grains with solubles (DDGS) combined with glycerin in broiler diets. In a 3×2 factorial arrangement, 600 one-day-old commercial strain Cobb 500 broilers were randomly assigned to experimental diets with 0, 15 and 30% DDGS of know n composition; within each level of DDGS the diets contained 0 or 5% glycerin, respectively, from 0-42 days of age. Diets were formulated to meet digestible amino acid requirements and were fed in pelleted form. Each dietary treatment was replicated 4 times. Body weight gain and feed consumption were measured and carcass characteristics were evaluated at 42 days of age. Inclusion of 30% DDGS had no adverse effect on body weight of chicks; however birds fed diets with 30% DDGS had greater feed intake and poorer feed conversion than birds fed the control diet at most age periods. This was highly correlated to the reduced pellet quality of diets containing the high levels of DDGS. Birds fed diets with 30% DDGS also had significantly reduced dressing percentage compared to birds fed the control diet with no DDGS. However, there was no adverse effect on breast meat yield related to the higher levels of DDGS inclusion. Addition of 5% glycerin from biodiesel production to the diets had no significant effect on body weight, feed intake, or feed conversion. There was no significant effect of the addition of glycerin on dressing percentage or yield of various carcass parts. With one minor exception, there was no significant interaction between addition of glycerin and level of DDGS in the diet, even though pellet quality declined when glycerin was added to the diets. Overall, the results of this study demonstrates that 15% DDGS of known nutritional quality can be utilized in diets for growing broilers with no adverse effects provided diets are formulated on a digestible amino acid basis and meet the nutritional requirements of the broiler. Higher levels may be tolerated but there may be a loss in feed conversion unless pellet quality can be improved. A loss in dressing percentage at higher levels of DDGS has been consistently noted in this and previous studies. Incorporation of 5 % glycerin from biodiesel production as a source of energy appears satisfactory.

This experiment was conducted to compare carcass characteristics of native quality chicken white Lueyang (WL), modern commercial broiler strain Arbor Acres breeder (AA) and their respective F cross when 1 achieve a common live body weight. A total of 300 day-old chicks were allotted to three groups and reared under the same conditions until they reached market weight (1800±20 g) respectively, then ten of individual male birds from each group were killed for measuring. There were significant differences in carcass and meat characteristics for breeds at a common market weight. WL had a large age to market weight, lower abdominal fat weight, lower breast meat yield, higher leg meat yield (P

The study was undertaken to assess dietary CP and ME concentrations for optimum growth performance and carcass characteristics of goslings. In a 5 x 3 factorial arrangement, 360 one-day-old commercial generation Huoyan goslings were randomly assigned to experimental diets with 10.87, 11.37, 11.87, 12.37, and 12.87 MJ of ME/kg of diet; each contained 15.0, 17.5, and 20.0% CP, respectively, from 0 to 4 wk of age (WOA). Each dietary treatment was replicated 6 times. Body weight and feed consumption were measured, and carcass characteristics were evaluated at 4 WOA. The result showed that birds on a diet with 11.87, 12.37, and 12.87 MJ of ME/kg at 0 to 4 WOA exhibited greater BW gain than those on a diet with 10.87 and 11.37 MJ of ME/kg (P0.01), though BW gain was not different among 11.87, 12.37, and 12.87 MJ of ME/kg of diet. Mean BW gain of birds fed 17.5 and 20.0% CP diets was not different (P0.05), but they were higher than those on 15.0% dietary CP concentration (P0.001). Feed intake was not influenced by dietary ME levels (P0.05). Feed intake of birds fed 17.5 and 20.0% CP diets was higher than those of birds on 15.0% CP diets (P0.01). Feed conversion ratios of birds fed on 11.87, 12.37, and 12.87 MJ of ME/kg of diet were better than those fed on 10.87 and 11.37 MJ of ME/kg (P0.001). Feed conversion ratios of birds fed on 17.5 and 20.0% CP diets were better than those fed on 15.0% CP diets. Moreover, there were no significant interactions between CP and ME on growth performance. There was a direct relationship between dietary ME levels and eviscerated carcass percentage, abdominal fat percentage, and liver relative weight (P0.01). Breast and leg meat percentage were influenced by dietary CP concentrations significantly (P0.001). Thus, diets with 11.87 MJ of ME/kg and 17.5 to 20.0% CP were used more efficiently from 0 to 4 WOA by Huoyan goslings.

This study was conducted to determine the effect of supplemental dietary vitamin C (VC) and vitamin E (VE) on improving semen quality and antioxidative status in breeder roosters challenged with dexamethasone (DEX). 120 45-week-old Lveyang black-boned breeder roosters were divided into 5 experimental treatments, including negative group, positive group, and three trial groups, which were fed basal diet supplemented with 300mg/kg VC, 200mg/kg VE, or 300mg/kg VC and 200mg/kg VE (VC+VE). At 49 weeks of age, the positive control and trial groups were subcutaneously injected 3 times every other day with DEX 4 mg/kg body weight, the negative control group was sham injected with saline. At 50 weeks of age, average daily feed intake of birds challenged with DEX significantly increased (P

Three experiments were carried out to determine optimal feed input and excreta collection time in bioassay of feedstuff true metabolizable energy for ducks. In experiment 1, 20 drakes had been food withdrawn and were allocated to 4 groups, each of which contained 5 birds. Birds of each group were force- fed 50 g complete feed, approximately 48 h after food withdrawal. The excreta voided during the exact 56 h following feeding were collected. In experiment 2, 28 drakes were force-fed 50 g complete feed, approximately 48 h after food withdrawal. 4 birds were killed by an intravenous dose of sodiu m pentobarbitone 4 h, 8 h, 14 h, 24 h, 32 h, 38 h and 48 h after feeding. The residues in alimentary canal were collected and dried in an oven at 65 C. In experiment 3, 70 mature drakes were allocated to 7 groups. The o treatments comprised an unfed negative control and five levels of feed input (30, 50, 70, 90, 110 and 150 g complete feed). The birds were force-fed at approximately 48 h after food withdrawal. The excreta voided during the exact 36 h following feeding were collected. The results indicated that the time prior to force - feeding and excreta collection period should be 32-36 h when evaluating feed metabolizable energy and 50- 70 g feed per bird is feasible for evaluating feed metabolizable energy.

The experiment was conducted to investigate the effects of dihydropyridine supplementation on the laying performance and lipid metabolism of broiler breeder hens. A total of 720 forty-five week old broiler breeder hens were randomly divided into four experimental groups, each group consisting of six replicates of 30 birds. For 10 weeks the birds were fed a maize-soybean meal diet containing 0, 100, 200, 300 mg dihydropyridine/kg, in the respective treatment groups. The daily egg weight and daily feed intake were not affected by dihydropyridine supplementation, but the laying rate and feed efficiency were significantly increased. The percentage of abdominal fat and percentage of liver fat were significantly decreased by dietary dihydropyridine. A level of 100 mg dihydropyridine/kg had no effect on the hormone-sensitive triglyceride lipase (HSL) activity in the liver or abdominal fat, though higher levels of dietary dihydropyridine (200 mg/kg or 300 mg/kg) increased HSL activity in the liver and abdominal fat. The concentration of cyclic adenosine monophosphate (cAMP) and superoxide dismutase activity were significantly increased by dihydropyridine, but the malondialdehyde content decreased. The apolipoprotein B concentration was increased at levels of 100 and 200 mg dihydropyridine/kg, but the 300 mg level had no effect on apolipoprotein B, compared with the control group. The triiodothyronine concentration was significantly increased by dietary dihydropyridine. It is concluded that supplementing dihydropyridine in the diet has a beneficial effect on the laying performance and regulates the fat metabolism of broiler breeder hens. The results suggest that the supplementation of 200 mg dihydropyridine/kg diet is the optimal dose for broiler breeder hens.Keywords: Abdominal fat, fatty liver syndrome, lipogenesis, lipolysis

This experiment was undertaken to evaluate the effect of dietary vitamin E on growth performance and immune response of broilers under heat stress (HS). Birds raised in either a thermoneutral (23.9 degrees C constant) or HS (23.9 to 38 degrees C cycling) environment were fed a corn-soybean meal basal diet supplemented with vitamin E at 0, 100, or 200 mg/kg, respectively. Two hundred forty 1-d-old male broiler chicks were randomly assigned to 6 groups; each group had 4 replicates of 10 birds. Humoral immunity was assessed by i.v. injection of 7% SRBC followed by evaluation of serum for antibody titers in primary and secondary responses. Cell-mediated immunity was assessed by using a Sephadex stimulation method to recruit abdominal exudate cells (AEC) to evaluate macrophage phagocytic ability. Body weight and feed intake were not significantly influenced by dietary vitamin E (P>0.05), whereas feed conversion was significantly affected by vitamin E at 100 mg/kg (P

An experiment was undertaken to evaluate the effect of dietary selenium (Se) levels on growth performance and immune competence of broilers under heat stress. Birds were raised in either a thermoneutral (TN, 23.9 degrees C constant) or heat stress conditions (HS, 23.9 degrees C to 38 degrees C cycling) and were fed a corn-soybean meal basal diet supplemented with Se at 0, 0.2 and 0.4 mg/kg. A total of 240 one-day-old male broiler chicks were randomly assigned to six groups; each group had four replicates of 10 birds. Body weight and feed intake were not influenced by dietary Se, while feed conversion was significantly improved by a Se-supplementation of 0.2 mg/kg. HS significantly reduced body weight, feed intake and feed conversion. Numbers of abdominal exudate cells (AEC), percentage of macrophages in AEC, phagocytic macrophages, internalized opsonised and unopsonised sheep red blood cells (SRBC) were significantly increased by dietary Se. Both primary and secondary antibody responses were characterised by increasing titres of antibody to SRBC by dietary Se when birds were exposed to HS (p < 0.05). Lymphoid organ weights, antibody responses, incidence of macrophages in AEC, and phagocytic ability of macrophages were also significantly reduced under HS. These results indicated that HS severely reduced growth performance and immunocompetence of broilers, whereas the immune response of broilers improved by dietary Se supplementation under HS.