F Z Liu

University of Arkansas, Fayetteville, Arkansas, United States

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Publications (12)5.22 Total impact

  • South African Journal Of Animal Science 12/2010; 41(4):331-336. · 0.54 Impact Factor
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    ABSTRACT: Glycerin, known as glycerol or glycerine, is the principal co-product of biodiesel production, produced through a NaOH- or 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.
    International Journal of Poultry Science. 01/2010;
  • Z Y Niu, F Z Liu, Q L Yan, W C Li
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    ABSTRACT: 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<0.05). Heat stress significantly reduced BW, feed intake, and feed conversion (P<0.05). Numbers of AEC, percentage of macrophages in AEC, phagocytic macrophages, and internalized opsonized and unopsonized SRBC were increased by dietary vitamin E (P<0.05). Both primary and secondary antibody responses were significantly increased by dietary vitamin E 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 growth performance and immune response of broilers, whereas the immune response of broilers could be improved by dietary vitamin E supplementation under HS.
    Poultry Science 10/2009; 88(10):2101-7. · 1.52 Impact Factor
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    ABSTRACT: 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.
    animal 10/2009; 3(10):1442-8. · 1.65 Impact Factor
  • Journal of Applied Poultry Research - J APPL POULTRY RES. 01/2009; 18(4):734-740.
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    ABSTRACT: 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 < 0.05). Moreover, feed intake and BW declined dramatically with the increasing inclusion of CM. However, no significant difference was noted in FCR due to dietary DDGS and canola levels. Percentage of fines and diet bulk density were influenced significantly by dietary DDGS and CM levels as well as by their interaction. The percentage of fines increased with increasing combinations of DDGS and CM. However, the effect of dietary DDGS and canola concentrations on feed bulk density did not show a clear trend. By regression analysis, percentage of fines had a significant impact on feed intake and BW gain but failed to show any clear-cut relationship between bulk density and performance factors. Therefore, when DDGS and CM are used in combination, the total level of the 2 ingredients in the formulation should be considered.
    Poultry Science Association J. Appl. Poult. Res. 01/2009; 18:725-733.
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    ABSTRACT: An experiment was conducted to evaluate the use of distillers dried grains with solubles (DDGS) combined with glycerin in broiler diets. In a 3x2 factorial arrangement, 600 one-day-old commercial strain Cobb 500 broilers were randomly assigned to experimental diets with 0, 15 and 30% DDGS of known 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.
    International Journal of Poultry Science. 01/2008;
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    ABSTRACT: 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 (P < 0.01), 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 (P > 0.05), but they were higher than those on 15.0% dietary CP concentration (P < 0.001). Feed intake was not influenced by dietary ME levels (P > 0.05). Feed intake of birds fed 17.5 and 20.0% CP diets was higher than those of birds on 15.0% CP diets (P < 0.01). 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 (P < 0.001). 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 (P < 0.01). Breast and leg meat percentage were influenced by dietary CP concentrations significantly (P < 0.001). 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.
    Poultry Science 05/2007; 86(4):661-4. · 1.52 Impact Factor
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    ABSTRACT: Three experiments were conducted to determine the optimal feed input and excreta collection time by a bioassay of dietary true metabolisable energy ( TME) for ducks. In experiment 1 and experiment 2, the time for the unabsorbed feed passage through the alimentary canal was determined by measuring the DM and energy of excreta and feed residues in the alimentary canal at different periods. In experiment 3, the feed input of force-feeding was studied and a total of 70 mature Pekin drakes were allotted to 7 groups, each group containing 10 birds. After fasting for 36 h, one group served as a negative control to measure metabolic faecal energy plus endogenous urinary energy and the drakes of the other 6 groups were force-fed pelleted feed 30 g, 50 g, 70 g, 90 g, 110 g, and 150 g per bird, respectively. Energy excretion of the periods of 16-28 h after force-feeding was significantly higher than that of the periods after 32 h, and the total energy excretion of the periods after 32 h (P < 0.05). When the feed input increased from 30 g to 70 g, the value of TME was constant ( P > 0.05). Metabo- lisable energy decreased significantly with an increase in feed input when the feed input was higher than 70 g (P < 0.05). It was concluded that the optimal time of feed withdrawal before tube-feeding and during excreta collection would be 32-36 h. The optimal feed input was 50 g to 70 g per drake.
    01/2007;
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    Han X.F, Niu Z.Y, Liu F.Z, Yang C.S
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    ABSTRACT: A series of sequential experiments were carried out to determine optimum diluents, cryoprotectants, equilibration time, and thawing temperature for frozen duck semen in order to set up the commercial semen cryopreservating techniques which could be applied to the conservation of genetic resources, breeding, and commercial production in domestic ducks. In experiment 1, the seven semen extenders were studied to determine efficacy of the diluent on cryopreservation of duck Semen. The result showed that the diluent which contains 0.14% potassium citrate, 1.40% sodium glutamate, 0.98% disodium hydrogen phosphate, 0.21% sodium dihydrogen phosphate, 0.7% glucose, and 0.7% inositol was better than other six semen diluents. In experiment 2, the effects of various concentrations of cryoprotectants including glycerol, dimethyl sulphoxide (DMSO), dimethyl acetamide (DMA), and dimethyl formamide (DMF) on cryopreservation of bird semen were evaluated. The results showed that the cryoprotectant containing 10% DMSO was better than others. The experiment 3 was conducted to determine the effect of equilibration time and thawing temperature on cryopreservation of bird semen. The optimum equilibration time was 15 min and the optimum thawing temperature was 40°C
    International Journal of Poultry Science 01/2005;
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    ABSTRACT: This experiment was conducted to evaluate the accuracy of a bioassay method for metabolizable energy for domestic duck, which was previously developed by our research group. 110 adult Peking drakes with similar weight were randomly allotted to 2 groups in each of 55 birds, one was treatment group and another was control group. Prior to trial, all birds were fasted for 12h, but water were provided ad libitum . And 5 birds from each group were web-bled from their venous in wings. At the same time, each bird of the tow groups was force-fed by pelleted feed 50g, then they were fasted but water was provided ad libitum . 4h later, drakes of the trial group were intake glucose saturated solution once every 6h for 15 minutes. At 2h, 12h, 24h, 36h, 48h after force-feeding, ten birds from each group were web-bled and discarded, respectively. Contents of glucose, uric acid, total protein, triglyceride, insulin, triiodothyronine, corticosteroid in plasma were measured. The results indicated that contents of glucose, uric acid and total protein in plasma didn`t fluctuate during the starvation of 48h. However, the content of triiodothyronine in plasma tended to decline, but it showed nonsignificant (p>0.05). Therefore, those drakes weren`t in abnormal conditions. Feeding glucose saturated solution to fasted drakes could alleviate the decrease of triiodothyronine in plasma. Fast resulted in the decease of insulin content in plasma. The plasma insulin content of fasted drakes fed glucose saturated solution is steady. Force feeding and fast didn`t cause the change of the corticosteroid content in plasma, which indicated that forementioned treatments didn`t make ducks under stress.
    International Journal of Poultry Science. 01/2005;
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    Z. Y. Niu, F. Z. Liu, Y. N. Min
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    ABSTRACT: 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.