16 t h International Congress on Animal <strong>Reproduction</strong> 28 Poster Abstracts POSTER ABSTRACTS Poster 01 - Bov<strong>in</strong>e <strong>Reproduction</strong> P001 New Trends for Estrus Synchronization <strong>in</strong> Lactat<strong>in</strong>g Dairy Cows Amer, HA 1 , Abaza, F 2 * 1Department of Theriogenology, Faculty of Veter<strong>in</strong>ary Medic<strong>in</strong>e, Zagazig University; 2 Department of Military Veter<strong>in</strong>ary Services, M<strong>in</strong>istry of Defense, Egypt This study was conducted to through the light on estrus synchronization <strong>in</strong> dairy cows. Four treatments were performed on sixty Holste<strong>in</strong> Friesian cows. In treatment 1 (PP), cows received 2 <strong>in</strong>jections of PGF2α on days 0 and 11 (n=14). In treatment 2 (PGP), cows <strong>in</strong>jected twice PGF2α on days 0 and 11 and 100 ug of GnRH on day 3 after 1st <strong>in</strong>jection (n=14). In treatment 3 (PGPE-0), cows treated with PGP and 1 mg of estradiol cypionate (ECP) at same time of 2nd PGF2α dose (n=16). In treatment 4 (PGPE-1), cows were treated with PGP and 1 mg ECP one day after 2nd PGF2α <strong>in</strong>jection (n=16). Cows were exam<strong>in</strong>ed rectally and ultrasonographically by B-mo<strong>de</strong> System [Pie-Medical Scanner-240] with a 6-8 MHz l<strong>in</strong>ear probe. Every cow was blood sampled at selected <strong>in</strong>tervals for progesterone and estradiol assay and <strong>in</strong>sem<strong>in</strong>ated at estrus. The results showed a higher percentage of GnRH-treated cows (PGP) ovulated after 1 st PGF2α <strong>in</strong>jection than non treated (PP) cows (64.3% vs 50%; P
16 t h International Congress on Animal <strong>Reproduction</strong> Poster Abstracts 29 hyperimmune serum were produced aga<strong>in</strong>st Arcanobacterium pyogenes and E. coli that were isolated <strong>in</strong> Iranian dairy farms. Cows <strong>in</strong> group oxytetracycl<strong>in</strong>e (n=39) were treated with one <strong>in</strong>trauter<strong>in</strong>e <strong>in</strong>fusion of 5gr oxytetracycl<strong>in</strong>e (10%). Cows that did not show any cl<strong>in</strong>ical signs of postpartum endometritis were regar<strong>de</strong>d as healthy control group (HC, n =91). In group hyperimmunue serum and oxytetracycl<strong>in</strong>e (OTC), all cows were re-exam<strong>in</strong>ed 39–49 DIM. In group hyperimmunue serum and OTC, cows were re-treated with hyperimmunue serum if signs of endometritis were found. Cure rate after the first treatment, <strong>de</strong>f<strong>in</strong>ed as the absence of vag<strong>in</strong>al discharge at the re-exam<strong>in</strong>ations, was 64.3 % and 61.5% <strong>in</strong> groups hyperimmunue Serum and OTC (P > 0.05). Reproductive performance measures showed no significant differences (P > 0.05) between the two treatment groups. There was no significant difference (P > 0.05) Service rate between treatments groups hyperimmunue Serum and OTC, compared to HC. Conception rates to all services and percentages of cows pregnant by 180 DIM were 90.48, 86.49 and 92.13 <strong>in</strong> groups hyperimmunue Serum, OTC and HC, respectively (P > 0.05). In both treatment groups, cure rate and reproductive performance measures were better for cows categorized E1 or E2, than for cows categorized E3 but the differences were not significant. Conception rate to all services for cows with endometritis (category E1, E2 and E3) was 52.94 <strong>in</strong> group hyperimmunue Serum and 57.14 <strong>in</strong> group OTC compared 66.67 <strong>in</strong> HC (P > 0.05). The results of this field trial suggest that hyperimmunue serum could be the alternative no antibiotic treatment of choice for postpartum endometritis <strong>in</strong> dairy cattle. P005 GnRH-<strong>in</strong>duced LH and ovulatory responses <strong>in</strong> dairy heifers dur<strong>in</strong>g diestrus and proestrus Ambrose, DJ 1 *, Colazo, MG 1 , Bhuwanee, A 2 , Kumpula, B 2 , Lamont, AL 2 , Salmon, F 2 , Suddaby, P 2 , Terletski, S 2 1Agriculture Research Division, Alberta Agriculture and Food, Canada; 2Agricultural Food and Nutritional Science, University of Alberta, Canada The objective was to <strong>de</strong>term<strong>in</strong>e whether pituitary LH response to GnRH <strong>in</strong> Holste<strong>in</strong> heifers differed between diestrous and proestrous stages of the estrous cycle. Fifteen postpuberal heifers (13 to 14 mo of age, 404 to 479 kg body weight) were given 25 mg of d<strong>in</strong>oprost trometham<strong>in</strong>e (PGF; Lutalyse, Pfizer Animal Health) im. Estrus <strong>de</strong>tection was done twice daily for 4 d after PGF treatment and ovulation (Day 0) confirmed by ultrasonography. On Day (Mean ± SE) 8.5 ± 0.6 after ovulation, 100 µg of gonadorel<strong>in</strong> acetate (GnRH; Fertil<strong>in</strong>e, Vetoqu<strong>in</strong>ol Canada Inc.) was given im to all heifers (Diestrous stage treatment). Blood samples (n=15/heifer; from 15 m<strong>in</strong> before to 8 h after GnRH) were collected and plasma analyzed for LH concentration. One blood sample taken prior to GnRH was analyzed for progesterone. Ovulation was <strong>de</strong>term<strong>in</strong>ed by ultrasonography 48 h follow<strong>in</strong>g GnRH treatment and heifers received an <strong>in</strong>travag<strong>in</strong>al progesterone (P4; 1.9 g) <strong>in</strong>sert (CIDR; Pfizer Animal Health) for 7 d, with PGF adm<strong>in</strong>istered at CIDR removal. Twenty-four h after CIDR removal (Day 15.9 ± 0.6), GnRH was given im (Proestrous stage treatment). Ovulatory response, P4 and LH concentrations were <strong>de</strong>term<strong>in</strong>ed as <strong>in</strong> Diestrus. Data were analyzed by Proc MIXED, ANOVA, and Chi-square. Two heifers did not respond to PGF treatment; both were exclu<strong>de</strong>d from the study. Plasma P4 concentration (ng/mL) at GnRH treatment was higher (P < 0.01) <strong>in</strong> heifers treated dur<strong>in</strong>g diestrus (5.7 ± 0.7) than dur<strong>in</strong>g proestrus (1.0 ± 0.2). The ovulatory response to GnRH treatment was higher dur<strong>in</strong>g proestrus than diestrus (P < 0.02; 61.5 vs 15.4%). GnRH-<strong>in</strong>duced LH peak was lower (P < 0.04; 5.7 ± 0.8 vs 13.6 ± 3.0 ng/mL) and of shorter duration (P < 0.01; 5.4 ± 0.3 vs 6.8 ± 0.3 h) <strong>in</strong> heifers treated dur<strong>in</strong>g diestrus than dur<strong>in</strong>g proestrus. Regardless of the stage of the estrous cycle at treatment, heifers that ovulated after GnRH had a significantly longer <strong>in</strong>terval from GnRH treatment to LH peak than those that did not ovulate (P < 0.01; 1.7 ± 0.1 vs 1.0 ± 0.1 h). However, <strong>in</strong> heifers treated with GnRH dur<strong>in</strong>g proestrus, LH concentrations did not differ (P = 0.60) between those that ovulated and those that did not. In conclusion, heifers treated with GnRH dur<strong>in</strong>g diestrus had lower peak LH concentrations, <strong>de</strong>layed atta<strong>in</strong>ment of LH peak, shorter duration of elevated LH concentrations, and lower ovulatory responses than those treated dur<strong>in</strong>g proestrus. P006 The Effect of Add<strong>in</strong>g Cholesterol, Vitam<strong>in</strong> A, Cod Liver or Flax Oil Loa<strong>de</strong>d Cyclo<strong>de</strong>xtr<strong>in</strong> on Bull Sperm Cryosurvival Amorim, EAM 1,2 *, Graham, J 2 , Spizziri, B 2 , Meyers, M 2 , Amorim, LS 1,2 , Torres, CAA 1 1Department of Animal Science, Fe<strong>de</strong>ral University of Vicosa, Brazil; 2Department of Biomedical Sciences, Colorado State University, USA Introduction Damage occurr<strong>in</strong>g to spermatozoa dur<strong>in</strong>g cryopreservation results <strong>in</strong> a loss of motile cells and cells that are functionally normal, compared to fresh sperm samples. Treat<strong>in</strong>g bull sperm with cholesterol-loa<strong>de</strong>d cyclo<strong>de</strong>xtr<strong>in</strong>s (CLCs) prior to cryopreservation results <strong>in</strong> <strong>in</strong>creased sperm cryosurvival, however, add<strong>in</strong>g cholesterol to bull sperm membranes alters their ability to capacitate <strong>in</strong> vitro. This study compared the effect of add<strong>in</strong>g four compounds, which should <strong>in</strong>corporate <strong>in</strong>to and <strong>in</strong>crease membrane fluidity at low temperatures thereby <strong>in</strong>creas<strong>in</strong>g cryosurvival. Method Twenty-five ejaculates from four bulls were collected us<strong>in</strong>g artificial vag<strong>in</strong>a and exten<strong>de</strong>d with Tris, and then sub-divi<strong>de</strong>d <strong>in</strong>to 11 treatments: No additive (negative control); 1.5 mg CLC/120 million sperm (positive control); and 0.75 mg, 1.5 mg and 3.0 mg/120 million sperm of cyclo<strong>de</strong>xtr<strong>in</strong> pre-loa<strong>de</strong>d with vitam<strong>in</strong> A or Cod Liver oil or Flax oil. Methyl-β-cyclo<strong>de</strong>xtr<strong>in</strong> was preloa<strong>de</strong>d with cholesterol as <strong>de</strong>scribed by Purdy and Graham (2004). Spermatozoa were <strong>in</strong>cubated for 15 m<strong>in</strong> at 22 o C. Then, samples were diluted 1:1 (v:v) <strong>in</strong> Tris with 20% Egg Yolk (EY) and cooled to 5 o C. After dilution 1:1 (v:v) with Tris conta<strong>in</strong><strong>in</strong>g 10% EY and 16% glycerol, samples were allowed to equilibrate for 15 m<strong>in</strong> before packag<strong>in</strong>g <strong>in</strong>to 0.5 ml straws, freez<strong>in</strong>g <strong>in</strong> static liquid nitrogen vapor (4.5 cm above the liquid nitrogen) for 20 m<strong>in</strong> and plung<strong>in</strong>g <strong>in</strong>to liquid nitrogen for storage. Straws were thawed <strong>in</strong> a water bath at 37ºC for 30 sec and the percentages of total motile <strong>in</strong> each sample were <strong>de</strong>term<strong>in</strong>ed us<strong>in</strong>g a computer-assisted sperm analysis (Hamilton Thorne Motility Analyser). Results The percentages of motile total sperm cells were ma<strong>in</strong>ta<strong>in</strong>ed after thaw<strong>in</strong>g for bull sperm treated with CLC (45%) compared to all other treatments (26-41%; P0.05). Conclusion Therefore, <strong>in</strong>creas<strong>in</strong>g membrane cholesterol levels by add<strong>in</strong>g CLCs to bull sperm, prior to freez<strong>in</strong>g, is a simple technology that improved cell cryosurvival, whereas treatments with cyclo<strong>de</strong>xtr<strong>in</strong>s preloa<strong>de</strong>d with other molecules did not. Acknowledgments Supported by Colorado State University Experiment Station and CNPq/Brazil. P007 Bypass fat supplementation <strong>in</strong> zebu cows (Bos <strong>in</strong>dicus) <strong>in</strong> the early postpartum: an alternative to <strong>de</strong>crease the open days period Mesa, C 1 ; Mahecha, L 2 ; Ruiz, ZT 1 ; Gallo, J 3 ; Angulo, J 1,2 *; Olivera-Angel, M 1 1Grupo <strong>de</strong> Reproducción - Fisiología y Biotecnología, <strong>Facultad</strong> <strong>de</strong> <strong>Ciencias</strong> Agrarias, Universidad <strong>de</strong> Antioquia, Colombia; 2 Grupo Grica, <strong>Facultad</strong> <strong>de</strong> <strong>Ciencias</strong> Agrarias, Universidad <strong>de</strong> Antioquia, Colombia; 3 Soluciones Nutricionales S.A., Me<strong>de</strong>llín, Colombia Introduction Traditional beef cattle production <strong>in</strong> tropical South America is extensive and based primarily on Bos <strong>in</strong>dicus cattle and its crosses. This productive system <strong>in</strong>volves the permanent contact of the cow with its calf, feed<strong>in</strong>g with low nutritional value grass and the highly seasonal supply of forage. These characteristics are the ma<strong>in</strong> causes of postpartum anoestrus and the long calv<strong>in</strong>g to conception period (open days). Nowadays, there are some management strategies which help to <strong>de</strong>crease the postpartum anoestrus and the open days. The use of bypass fat <strong>in</strong> or<strong>de</strong>r to <strong>in</strong>crease the energetic contribution of the diet, and the restricted suckl<strong>in</strong>g practices, are some of them. However, these practices are usually used <strong>in</strong> a separated way. The objective of this study was to evaluate the effect of mix<strong>in</strong>g a temporal