Inaugural ASAS–CAAV Asia Pacif ic Rim Conference Abstracts

T313 Study of lysine requirement of weaning piglets fedlow-protein diets. L. Yue*, M. Ren, and S. Qiao, National Key Laboratory ofAnimal Nutrition, Beijing, China.Study of the of low-protein diet has become a hot issue in view of the alleviation ofdiarrhea of weaning piglets, reduction of feed cost, and reduction of environmentalpollution by the swine industry. A low-protein diet refers to any diet in which thedietary protein level is reduced by 2 to 4% and the type, ratio, and requirementof AA in livestock feed are met, but the growth performance, feed conversion,N retention, and excretion of animals and the ability to withstand heat stress areimproved. Furthermore, a low-protein diet is beneficial to the intestinal tracthealth of weanling piglets. Most studies on the dietary lysine requirement havebeen conducted based on a protein level of more than 21%; however, the actualprotein level in the diets of weanling piglets in China is approximately 19 to 21%.Therefore, study of the lysine requirement in diets with a lower protein level is notsystemic. This study was conducted to study the lysine requirement of weanlingpiglets fed low-protein diets, which can be used for reference in practice. Thisstudy was carried out under conditions of a commercial pig farm. A total of 360weanling piglets (Duroc × Landrace × Yorkshire) were used in this study and wereallocated into 6 treatments, with 6 replicates (pen) per treatment and 10 weanlingpiglets per pen. The control group was fed a high-protein diet with a proteinlevel of 21% and a digestible lysine level of 1.41%. Moreover, 5 treatments wereincluded in the low-protein group (19% CP), with digestible lysine levels of 1.29,1.35, 1.41, 1.47, and 1.53%, respectively, to study the lysine requirement undera low-protein level and its change in comparison with the requirement under arelatively high-protein level. The growth performance of weanling piglets wasmeasured during a 2-week experiment, and all data were analyzed using SAS.Results of the regression analysis with daily BW gain and lysine level, and feedto-gainratio and lysine level showed that the digestible lysine requirement ofweanling piglets (7 to 10 kg) was 1.50 and 1.47%, respectively, when the dietaryprotein level was 19%.Key Words: weanling piglet, low-protein diet, lysine requirementSwine Species PostersT315 The development of T lymphocytes in piglets withintrauterine growth retardation from birth to weaning. Y. Lin*, J. Wang, X.Wang, W. Wu, and C. Lai, State Key Laboratory of Animal Nutrition, College ofAnimal Science and Technology, China Agricultural University, Beijing, China.Intrauterine growth retardation (IUGR), showing a lower immune function andresistance to pathogens, is a major concern in domestic animal production. Thisexperiment was conducted to evaluate the development of T cells in pigletswith IUGR from birth to weaning. A total of 30 Dhahran primiparous sows withsimilar BW and gestation periods were selected. After parturition, 1 normal and 1IUGR piglet were selected from each litter and slaughtered at d 1, 7, 14, 21, and28, with 6 replicates for each treatment. The thymus of each piglet was collectedto isolate T cells. The numbers of CD3, CD4, and CD8 T cells were determinedby flow cytometry. The results showed that the percentages of CD4 + CD8 + Tcells (double-positive T cells) in the total T cells of IUGR and normal pigletsat d 1 were 53.18 and 63.23% (P < 0.05), respectively. Double-positive T cellsare the precursor cells of CD4 + +CD8 – (CD4 cells) and CD4 – CD8 + (CD8 cells).Moreover, CD4 and CD8 cells are the main cells in cellular immunity. The resultssuggest that the normal piglets were more capable of differentiating into CD4and CD8 cells than the IUGR piglets, and they had a stronger immune functionand greater ability to resist pathogens than the IUGR piglets. The percentagesof CD4 cells in the total T cells of IUGR and normal piglets at d 7 were 0.68and 0.23% (P < 0.01), respectively. The percentage of CD4 cells at d 1 was notsignificant. Consistent with the development of double-positive cells, a differencein CD4 T cells of IUGR and normal piglets was not observed. In the later days,there was no difference in T-cell subsets between IUGR piglets and normalpiglets. Our investigation suggests that complex factors in the uterus caused thepostnatal hypogenesis of T-cell subsets at an early stage in IUGR piglets, whichcould explain why the postnatal immunity in IUGR piglets in the early days waslower.Key Words: intrauterine growth retardation, flow cytometry, T-celldevelopmentT314 Effects of dietary cysteamine and chromium yeaston performance and on serum physiobiochemical parameters in growingfinishingpigs. Z. S. Xia* 1 , W. X. Feng 2 , S. H. Huang 1 , Z. C. Liao 1 , and J. H.Xie 2 , 1 College of Animal Science and Technology, Guangxi University, NanningGuangxi, P. R. China, 2 Guangxi Peter Hand Premix Feed Company Ltd., NanningGuangxi, P. R. China.This study was conducted to investigate the effects of cysteamine (CS) andchromium yeast(Cr) on performance and on serum parameters in growingfinishingpigs. A total of 96 growing pigs (DLY), with an average BW ofapproximately 25 kg, were selected and randomly divided into 4 groups(24 pigsper group, with an equal number of males and females), with 6 replicates in agroup, each of which including 4 pigs, in a 2 × 2 factorial design. These pigs werefed for a period of 90 d, and were raised, respectively, with a basal diet (groupCT), the basal diet with added Cr (Cr group), the basal diet with added CS (CSgroup), and the basal diet with added CS and Cr (CS × Cr group). During thegrowing and finishing periods, the diets were CS added at 120 and 170 mg/kg,and Cr added at 200 and 300 μg/kg, respectively. The results were as follows:(1) The diets with added CS, Cr, or both had no influence on ADG (P > 0.05),and showed a trend of increasing ADG and slowing the feed-to-gain ratio ingrowing and finishing pigs. In all the periods of the experiment, there was a trendof increasing ADG (P > 0.05) and slowing feed-to-gain ratio, in the order Cr × CSgroup > CS group > Cr group > CT group at ADG; the CS group excelled overthe Cr group and the CS × Cr group at feed-to-gain ratio. (2)The diets with addedCS, Cr, or both showed no significant difference in serum blood urea nitrogen,TP, ALB, Glo, A/G, AST, ALT, LDH, and AST/ALT (P > 0.05). (3) The diet withadded CS showed a trend of decreasing serum TC, TG, and vLDLc (P > 0.05) ingrowing pigs, whereas added Cr reduced serum TG and vLDLc significantly (P 0.05) in serum GH,INS, IGF-I, T3, and T4 between the diets with added CS and those with addedCr. Adding CS and Cr increased T4 significantly (P < 0.05), but there were nosignificant differences (P > 0.05) in GH, INS, IGF-I, or T3 between the diets withadded CS and the diets with added Cr.T316 Gonadotropin regulation of porcine NR4A1 expressionduring ovarian follicle development in vitro. L. Q. Liu* 1,2 , C. Y. Deng 1 , L.Tao 2 , F. E. Li 1 , and Y. Z. Xiong 1 , 1 Key Laboratory of Pig Genetics and Breeding,Ministry of Agriculture, Hubei, China, 2 Institute of Husbandry and VeterinaryMedicine, Anhui, China.Nuclear receptor subfamily 4, group A, member 1(NR4A1), otherwise known asNGFI-B, is an immediate-early gene that encodes an orphan nuclear receptor,which plays a potential role in the ovulatory process. The present study wasdesigned to examine gonadotropin regulation of porcine NR4A1 expression duringovarian follicle development. Ovarian follicles obtained from 3 immature pigs andisolated between 0 and 24 h after PMSG/hCG treatment. Reverse transcription-PCR analysis was performed to study the expression of NR4A1 during ovarianfollicle development in vitro. Results demonstrated that NR4A1 reached a peak at2 h after PMSG/hCG treatment. Subsequently, it declined sharply and a limitedamount of NR4A1 was expressed randomly in the granulosa layer at 4 to 24 h afterPMSG/hCG treatment, at the time when the ovarian follicles gradually mature,begin to rupture (ovulation), and form corpora lutea. These results demonstratethat induction of porcine NR4A1 expression by PMSG/hCG in granulosa cellsof preovulatory follicles is rapid and transient, and play an important role in theovulatory and corpora luteal formation process.Key Words: NR4A1, ovarian follicle, pregnant mare’s serum gonadotropin/human chorionic gonadotropinKey Words: cysteamine, chromium yeast, growing-finishing pig91