Inaugural ASAS–CAAV Asia Pacif ic Rim Conference Abstracts

9 Pig personality, meat quality, and metabolic programming.R. Zhao*, L. Li, S. Wei, X. Yang, and Q. Sun, Key Laboratory of AnimalPhysiology and Biochemistry, Nanjing Agricultural University, Nanjing,Jiangsu, China.Different breeds of pigs differ in personality, growth rate, and carcass quality,yet the mechanism underlying the formation and integration of breed-specifictraits is elusive. In the present study, Chinese Erhualian (EHL) and EuropeanPietrain (PIE) pigs were subjected to a coping characteristic test, the Backtest,at 3, 10, and 17 d of age, and a 2-hr transport trial was conducted when pigswere at a BW of 20 kg. We observed distinct breed differences, not only ingrowth and obesity, but also in stress-coping styles. The EHL pigs demonstratedgreater stress resistance compared with PIE pigs, which was associatedwith 2-fold higher basal plasma cortisol concentrations yet lower cortisolincreases in response to stress. A higher adrenocortical steroidogenic capacity,characterized by enhanced ACTH signaling and augmented expression ofStAR and steroidogenic enzymes, may result in a higher basal cortisol level,whereas higher expression of GR, MR, and 11-HSD1, but lower expression of11-HSD2 in the hippocampus may account for higher stress tolerance in theEHL pigs owing to a more effective negative feedback regulation of HPA axisactivity. Expression of GR was found to be breed specific in other peripheraltissues, including the liver, muscle, and fat, which is associated with breedspecificproperties in hepatic gluconeogenesis, muscle energy metabolism, andfat deposition. To test the hypothesis that the breed-specific phenotypes andpattern of GR expression in EHL pigs is a result of natural selection under thepressure of a low-protein diet because they have been traditionally raised undera low-protein diet, we investigated the effect of maternal protein restrictionduring pregnancy and lactation on offspring performance and GR expressionin various tissues. Indeed, maternal protein restriction modified offspring GRexpression in the hippocampus, liver, and muscle, which was accompanied byalterations in growth and metabolism. Moreover, both messenger RNA andprotein contents of DNMT1 in the hippocampus and liver were found to bedifferent between breeds and were also affected by maternal protein restriction,implying that an epigenetic mechanism may be involved in the formation ofbreeds and in metabolic programming.10 Effect of dbcAMP on growth performance and growth axishormones in finishing pigs. W. Fang* 1,2 , Z. Jiang 1 , X. Ma 1 , C. Zheng 1 , and S.Jiang 1 , 1 Key Laboratory of Animal Nutrition and Feed (South China), Ministryof Agriculture of P. R. China, Institute of Animal Science, Guangdong Academyof Agricultural Sciences, Guangzhou, Guangdong, P. R. China, 2 School of LifeSciences, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China.The effect of dietary inclusion of dbcAMP on growth performance and growthaxis hormones in finishing pigs was studied. Eighteen crossbred (Duroc ×Landrance × Large White) barrows (49.75 ± 0.75 kg of BW) were equallyrandomly assigned to 2 groups. Pigs were fed a control diet or the control dietsupplemented with 15 mg of dbcAMP/kg for a 35-d period. On d 36, 6 pigsfrom each group were slaughtered, and growth performance data and blood andtissue (hypothalamus, pituitary gland, and liver) samples were collected. Serumconcentrations of GH, IGF-1, and IGFBP3 was determined by enzyme-linkedimmunosolid assay, and messenger RNA (mRNA) abundance for GHRH in thehypothalamus and GHRH receptor (GHRHR), GH in the pituitary gland andGH receptor (GHR), and IGF-1 and IGF-1 receptor (IGF-1R) in the liver wasdetermined by a real-time fluorescent quantitative PCR method. Results showedthat dietary dbcAMP inclusion decreased (P > 0.05) ADFI and to feed-to-gainratio by 3.02 and 9.23%; increased (P > 0.05) ADG by 1.37%; increased serumconcentrations of GH (P < 0.05), IGF-1 (P < 0.05), and IGFBP3(P > 0.05) by24.23, 27.76, and 35.78%; increased hypothalamus GHRH mRNA abundance (P< 0.01) and pituitary gland GHRHR (P < 0.05); increased GH mRNA abundance(P < 0.01); and increased liver GHR (P < 0.01), IGF-1 (P < 0.01), and IGF-1RmRNA abundance (P > 0.05). It implied that dbcAMP as a growth promotormight improve growth performance by increasing the mRNA abundance forGHRH in the hypothalamus; GHRHR and GH in the pituitary gland; GHR andIGF-1 in the liver; and the concentrations of GH, IGF-1, and IGFBP3, therebyimproving the anabolic effect and protein synthesis in the skeletal muscle.Key Words: growth axis hormones, dbcAMP, finishing pigKey Words: pig, personality, metabolic programming11 The importance of feed safety for animal health and foodsafety: Accepted principles for producing safe feed. R. S. Sellers*, AmericanFeed Industry Association, Arlington, VA, USA.This presentation presents an overview of generally accepted principles forproducing safe feed based on the Codex Alimentarius Commission’s Codeof Good Animal Feeding Practices and FAO/WHO Report of the Experts’Meeting on the Impact of Feed on the Food Safety. Many of these principlesare common sense, as there are very few chemical or microbiologicalhazards that may be passed through meat, milk, eggs, or fish from feed thatwill cause serious harm to humans consuming these products. Generally,the principles involve having a system for identifying hazards, ranking thehazards based on seriousness of impact and exposure, and then developing arisk management plan to reduce the hazards to low or no impact level. Thiscan be done by either eliminating the hazards or processing the product sothat the hazards are reduced to an acceptable level. This process requireshaving a feed process control plan that identifies control points to eliminateor reduce hazards or critical control points in each feed manufacturing plan.Key Words: feed safety, hazards, risk managementBiosecurity and Food/Feed Security12 Human food safety of veterinary substances: The linkbetween the acceptable daily intake, the maximum residue limit in tissues,and the analytical method. T. J. Burnett* 1 and L. A. Stobbs 2 , 1 Elanco AnimalHealth, Greenfi eld, IN, USA, 2 Anson Group, Pendleton, IN, USA.Veterinary substances administered to food animals are highly regulated in orderto assure safety to consumers. The risk of unsafe residues of these approvedsubstances is assessed by regulators who set acceptable daily intakes (ADI)and maximum residue limits (MRL) for veterinary drugs in food commoditiessuch as meat, fat, liver, kidney, milk, and eggs so that the risk can be managedthrough residue monitoring. The methods used to monitor residues are specificfor a marker residue. The marker residue relates the MRL to the ADI by using aratio of the marker to total residue and consumption factors to calculate potentialexposure. The relationship of the no observed adverse effect level, ADI,consumption factors, MRL, and marker residue is presented to demonstrate themagnitude of the safety factors that are used to protect the consumer. Variousmethods of risk assessment used by various regulatory bodies were comparedand discussed in order to understand the role of analytical methods in the contextof human food safety. As an example, analytical methods for ractopamine andtheir effect on food safety calculations are presented.Key Words: maximum residue limit, food safety, marker residue method7