Inaugural ASAS–CAAV Asia Pacif ic Rim Conference Abstracts

5 Effects of in ovo feeding with carbohydrates and arginineon hatchability, BW, energy metabolism and perinatal growth in duckembryos and neonates. T. Moussa, W. Chen, J. Xu, F. R. Huang, and J. Peng*,Department of Animal Nutrition and Feed Science, Huazhong AgriculturalUniversity, Wuhan, Hubei, P. R. China.The perinatal periods in ducks present an enormous challenge in the utilizationof energy substrate, and ducks may be particularly exposed to metabolicstresses that can adversely affect their growth and developmental potential,both pre- and postnatally. The objective of the present study was to test thehypothesis that supplementing the duck embryos with nutrients might improvethe glycogen store and body growth. At 21 d of incubation, 650 viable embryosin eggs were randomly divided into 5 groups: 1) uninjected control; 2) sodiumchloride (NaCl); 3) sucrose + maltose (CHO); 4) arginine (Arg); and 5) sucrose+ maltose + arginine (CHO + Arg). At 23 d of incubation, each group of eggswas injected with 1.2-mL solutions using a 22-gauge needle. On the day ofhatch, the number of hatched eggs was determined. Ducklings were given adlibitum access to water and feed. At 25 d of incubation, hatch, 3 d, and 7 d, a totalof 10 eggs/duckling per treatment were weighed and sampled to determine liverand muscle glycogen values, the glycogen index, and glucose-6-phosphataseactivity. Hatchability was 86% in the uninjected control, 74% in NaCl, 69% inCHO, 87% in Arg, and 93% in CHO + Arg. All the ovo-fed ducklings improvedtheir BW from 3 to 7 d. Liver glycogen in the CHO treatment was significantlyenhanced from hatch to 3 d (P < 0.05). The main effects on increasing muscleglycogen were observed in the CHO and Arg treatments at 25 d of incubation (P< 0.05). Ducklings in the CHO treatment had an increased glycogen index fromhatch to 7 d age (P < 0.05). Glucose-6-phosphatase activity increased at 25 dof incubation in the Arg and CHO + Arg treatments (P < 0.05). Liver glycogenwas positively correlated with BW (P < 0.01) but negatively correlated withglucose-6-phosphatase activity (P < 0.05). Muscle glycogen was positivecorrelated with hepatic glucose-6-phosphstase activity (P < 0.05). The presentstudy suggests that in ovo supplementation with carbohydrates and argininemay help enhance the glycogen store in duck embryos. Further, these resultsraise the question of the benefits of in ovo feeding of ducks to improve thehatchability and posthatch performance of ducklings.Key Words: duck, in ovo feeding, energy6 Developmental changes in the plasma proteins ofperiparturient dairy cattle. Y. X. Yang*, J. Q. Wang, D. P. Bu, L. Y. Zhang,S. S Li, C. L. Zhang, and L. Y. Zhou, State Key Laboratory of Animal Nutrition,Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing,China.To investigate the mechanism by which the immune system of dairy cows issuppressed during the transition period, changes in the levels of plasma proteinswere detected during the last phase of pregnancy, at parturition, and postpartumusing 2-dimensional electrophoresis, providing a platform for parallel analysis.After visualizing proteins with SYPRO ruby, differential expression of proteinswas detected by ImageMaster 2D platinum 6.0 software and identified byHPLC tandem ion-trap spectrometry. Results showed that transthyretin wasdownregulated at 1 d of parturition compared with 21 d before and after calving.Haptoglobin and α-1 acid glycoprotein were upregulated, with a much largerand more abrupt variation at parturition, compared with 21 d prepartum andpostpartum. At 21d postpartum, the expression abundance of apolipoproteinA-I presented an increase compared with prepartum levels and levels atcalving. These proteins were involved in the acute-phase reaction, transport,and metabolism. The findings may provide valuable information for exploringhow the immune function is decreased in periparturient dairy cattle.Key Words: periparturient, 2-dimensional electrophoresesis, spectrometry7 Expression of immunologically active recombinant ninetandem repeats of porcine cholecystokinin-33. Z. Y. Gou, H. F. Luo, J.Wang, S. W. Jiang, and J. Peng*, Huazhong Agricultural University, Wuhan,Hubei, China.To gain recombinant cholecystokinin (CCK) protein, which is immunoactive, amethod based on an isocaudamer technique to tandemly repeat porcine CCK-33, was designed for increasing antigenic determinants with large molecularweights of CCK. The gene sequence (5′-aaa gct ccg tct ggt cgt gtg tct atg attaaa aac ctg cag tct ctg gac ccg tct cat cgt att tct gat cgt gat tat atg ggt tgg atggat ttt-3′, 99 bp) coding for the porcine CCK-33, which was partly optimized,was designed and synthesized based on the porcine CCK-33 gene sequencepublished in GenBank (K01940) and preferred codons of Escherichia coli. Theprokaryotic expression vector pRSET B, which carries a pair of isocaudamerBamHI and BglII sites, was used for construction of the expression vectorpRSET-Z9CCK, in which 9 repeated copies of optimized CCK-33 DNAfragments were tandemly connected, was constructed. After that, Z9CCKrecombinant protein was overexpressed in E. coli BL21, and the expressionlevel reached 35.6% of the cell total protein. In addition, the immunoactivityof the Z9CCK protein was analyzed by antigenicity prediction (antigenicepitopes were determined using the method of Kolaskar and Tongaonkar;http://tools.immuneepitope.org/tools/bcell/iedb_input), Western blot, animalimmunization, and ELISA. Antigenicity prediction indicated that 9 repeatedcopies of antigenic determinant of SGRVSMIKNLQSLDPSHRI peptidesexisted in the Z9CCK protein, and Western blot analysis showed that in theZ9CCK protein, approximately 42.1 kD reacted specifically with the rabbitanti-CCK-8 antiserum (Sigma, St. Louis, MO). Additionally, layer hens wereimmunized with the purified Z9CCK protein and the ELISA results showedthat Z9CCK induced a good anti-Z9CCK response. Another ELISA assayusing a CCK-8 standard (Sigma) as coated antigen demonstrated that anti-Z9CCK antibodies were able to bind with the CCK-8. All the immunogenicityassays tested showed Z9CCK had good antigenicity and had similar antigenicdeterminants and immunoactivity as CCK-8.Key Words: cholecystokinin, recombinant, tandem repeat8 The effect of active immunization against cholecystokininwith porcine cholecystokinin-33 multiple concatamers on performance,and the dynamic change in parts of blood biochemical indices in growingpigs. Z. Y. Gou, H. F. Luo, S. W. Jiang, and J. Peng*, Huazhong AgriculturalUniversity, Wuhan, Hubei, China.Because reduced food intake is associated with increased circulatingcholecystokinin (CCK) concentrations, we investigated the effects of CCKsuppression by inducing a humoral immune response to 9 porcine CCK-33 concatamers (9CCK protein) on physiological and production variablesin growing pigs. The 9CCK protein, which was a recombinant protein andexpressed in Escherichia coli BL21, was gained in a previous study in ourlaboratory. Grower pigs (22.85 ± 1.84 kg) were immunized with 9CCK proteinemulsified with oil adjuvant or adjuvant alone (control) on d 1, 29, and 57. TheCCK-specific antibody titers were highly variable throughout. The mean titerreached a peak on d 43 and then declined. Body weight gains during the last42 d, the period during which titers were expressed, were compared by t-test.The CCK immunization stimulated food intake and growth of pigs by 5.10 and5.27%, respectively, in the study. The process of food intake and postprandialperiod were a dynamic state of blood biochemical indices and metabolism thatcould be influenced by CCK immunization. Another objective of this studywas to determine whether the 9CCK protein immunization had effects onthe dynamic change of blood CCK, insulin, and glucose in the pigs. Bloodsamples were drawn at the times of 0 min, 15 min, 30 min, 1 h, and 2 h frompigs that began taking food. The CCK concentration was suppressed by CCKspecificantibodies during the food intake and postprandial period in the CCKimmunegroup. Plasma insulin concentration decreased by 31.62% (P < 0.05)at the time of 15 min (CCK-immune = 9.06 ± 1.83 μIU/mL; control = 13.25± 1.88 μIU/mL), presumably because of a decrease from CCK. Blood glucoseconcentrations were higher during the food intake and postprandial period thanin control pigs (except at baseline, 0 min). In summary, the suppression of CCKinducedsatiety responses through CCK immunization increased food intakeand BW gain. Blood CCK, insulin, and glucose were affected simultaneously.Key Words: pig, cholecystokinin immunization, food intake6