Artificial insemination, hybridization and pregnancy detection in sika deer (Cervus nippon )

Artificial insemination (AI) was performed on sika hinds (Cervus nippon ) receiving various dosages of pregnant mare serum gonadotropin (PMSG; Year 1: 0, 50 and 100 IU; Year 2: 100 and 150 IU) and using semen collected from elk and 1 2 elk x 1 2 sika stags. The time from synchronization device removal (CIDR vs norgestomet) to estrus was determined through observations of mounting activity. Methods for pregnancy detection, serum progesterone (P4), estrone sulfate (E1S), pregnancy-specific protein B (PSPB) and ultrasonography, following AI (Year 1: AI, Days 28 and 48 after AI; Year 2: AI, Days 42, 53 and 100 after AI) and a 90-d natural breeding season were investigated. From available production data, body weights were compared among sika and 1 4 elk x 3 4 sika hybrids relative to age. Pregnancy rates tended (P < 0.10) to differ relative to PMSG treatment and sire; administration of 0 IU PMSG resulted in fewer hinds becoming pregnant to AI than 50 or 100 IU of PMSG. Hinds receiving 100 IU of PMSG had higher (P < 0.05) pregnancy rates than hinds receiving 150 IU PMSG. Time to standing estrus did not differ (P > 0.10) between the CIDR and norgestomet groups. Pregnancy rates 50 d after a 90-d breeding season were similar (P > 0.10) between ultrasound (70.9%) and PSPB (61.6%). Serum P4 after 90 d in breeding groups and 50 d after stag removal were higher (P < 0.05) for pregnant than open hinds. Pregnancy rates (Year 1) 48 d after AI were similar (P > 0.10) between ultrasound (49.0%) and PSPB (37.3%). Serum P4 28 and 48 d after AI were higher (P < 0.05) for pregnant than open hinds. Serum E1S was higher (P < 0.01) for pregnant than open hinds 48 d after AI. Pregnancy rates (Year 2) 100 d after AI did not differ (P > 0.10) between ultrasound and PSPB (66.7%). Serum P4 was higher (P < 0.03) in pregnant than open hinds at 42, 53 and 100 d after AI. At 100 d after AI, pregnant hinds had higher (P < 0.002) serum E1S than open hinds. At 6 to 8 and 11 to 13 mo of age, 1 4 elk x 3 4 sika males tended (P < 0.08) to be heavier than sika males, while 1 4 elk x 3 4 sika females were heavier (P < 0.05) than sika females at all ages. In summary, this study documents the use of AI and methods for pregnancy detection in sika hinds as well as preliminary information regarding the production of elk-x-sika hybrids.     

Early pregnancy detection and the hormonal characterization of embryonic-fetal mortality in fallow deer (Dama dama)

The objectives of this investigation were to 1) determine serum concentrations of progesterone (P4), estrone sulfate (E1S) and pregnancy-specific protein B (PSPB) from estrus synchronization through mid-gestation in the fallow doe (Dama dama) and 2) characterize the hormonal profiles of does whose embryos or fetuses died in utero. Ten fallow does were synchronized for 14 d with an intravaginal P4-releasing device (CIDR) and were naturally mated after CIDR removal. Blood samples were collected at CIDR insertion, CIDR removal and at intervals through Day 203 post-CIDR removal for analysis of P4, E1S and PSPB by radioimmunoassay (RIA). Ultrasonography was performed on Days 49 and 69 post-CIDR removal. Serum P4 at the time of CIDR insertion was 4.8 +/- 0.6 ng/ml, and at CIDR withdrawal it was 6.2 +/- 0.3 ng/ml. Concentrations of E1S and PSPB were nondetectable at CIDR insertion. Serum E1S was highest at Day 93, and PSPB was first detectable in pregnant does at Days 27 to 30 post-CIDR withdrawal. Ultrasonography on Day 49 revealed that 6 does were pregnant, 2 were not pregnant and 2 others were diagnosed originally as early pregnant. At Day 69, ultrasonography revealed that 6 does (60%) were pregnant and 4 (40%) were not. A comparison of the ultrasonographic and hormonal data indicated that the 2 does diagnosed as early pregnant on Day 49 had conceived but had lost the pregnancy. A third doe which was pregnant on Day 69 lost the fetus later in gestation. Hormonal profiles of does whose embryo or fetus had died were characterized by erratic P4 and E1S profiles, with PSPB becoming undetectable in the 3 does by Days 49, 65 and 80 post-CIDR removal. These data 1) demonstrate the timing for the collection of serum samples for determining early pregnancy in fallow does using 3 hormonal methods and 2) characterize the hormonal profiles of 3 fallow does with embryonic-fetal loss.     

Detection of pregnancy by radioimmunoassay of a novel pregnancy-specific protein in serum of cows and a profile of serum concentrations during gestation

The development of a double antibody radioimmunoassay for a bovine pregnancy-specific protein (pregnancy-specific protein B; PSPB) is presented. By means of this assay, PSPB could be measured in serum of pregnant cows. Five dairy cows were bled throughout gestation to measure serum levels of PSPB. Serum concentrations (means +/- SE) exceeded 1 ng/ml by 30 days postbreeding and increased gradually through three months (9 +/- 0.6 ng/ml), six months (35 +/- 6 ng/ml), and nine months (150 +/- 75 ng/ml) of gestation. Maximum levels of PSPB (542 +/- 144 ng/ml) were reached two days before parturition and then steadily declined to less than 78 ng/ml by 21 days postpartum. In 21 cows bled daily from 15 through 30 days postbreeding, PSPB could be measured in a few cows before and in most cows by 24 days after breeding. In a commercial herd of 102 beef cows, the assay could detect pregnancy earlier and more accurately than the routine method of rectal palpation. This radioimmunoassay measures a unique antigen that, for the first time, provides a serological method for detecting pregnancy in cows.     

Use of pregnancy-specific protein-B and estrone sulfate for determination of pregnancy on Day 49 in fallow deer (Dama dama )

The objective of this study was to determine if pregnancy specific protein-B (PSPB) and estrone sulfate (E(1)SO(4)) could be used to determine pregnancy status in fallow deer (Dama dama ). Forty mature does were synchronized for estrus with an intravaginal progesterone-releasing device (CIDR) and then artificially inseminated via laparoscopy with frozen semen on one day. Ultrasound examination and jugular blood sampling were done 49 days later. Transrectal ultrasonography was done to presumptively determine the pregnancy status at the time of blood sampling. Serum estrone sulfate concentrations were significantly (P < 0.05) greater in pregnant (n=31) than nonpregnant (n=9) females at 49 days of gestation (166.7 +/- 25.9 pg/ml vs 36.3 +/- 11.1 pg/ml, respectively). The percentage of [(125)I]PSPB bound was significantly (P < 0.01) lower when sera of pregnant (n=29) versus nonpregnant (n=9) females was added to RIA tubes (63.7 +/- 1.6% vs 98.1 +/- 1.6%, respectively). There were 30 fawns born from the group of females that were diagnosed pregnant based on ultrasound. We conclude that estrone sulfate and PSPB can be used to determine pregnancy status in fallow deer at 49 days of gestation.     

Pregnancy-specific protein B and progesterone concentrations in French Alpine goats throughout gestation.

The 34 French Alpine dairy goats originated from a single flock and were artificially inseminated 44 h after synchronization of oestrus. They were bled daily at the jugular vein from 15 to 27 days after AI. An early pregnancy diagnosis by RIA of progesterone concentration was performed 21 days after AI. In pregnant goats (greater than 1.5 ng progesterone/ml) daily sampling was extended until 30 days after AI and, from those, 9 were bled every 2 weeks until the end of pregnancy and at 50 and 63 days post partum. Pregnancy-specific protein B (PSPB) was also assayed. The kidding rate was 67.6% (23/34). PSPB concentrations (ng/ml) in pregnant goats were significantly different from those of non-pregnant goats at 24 days after AI (0.82 +/- 0.18 vs 1.78 +/- 0.19; mean +/- s.e.m.) and rose to 40 ng/ml at the end of pregnancy. From Day 25 and throughout gestation, females with 2 fetuses had higher PSPB concentrations than did those with a single fetus (P less than 0.05). In the 2 goats exhibiting late embryonic mortality according to progesterone concentrations, one had a PSPB profile very similar to those of pregnant goats until 30 days while the other did not show any elevation of PSPB concentration. It is concluded that PSPB profiles in goats are similar to those found in cows throughout pregnancy and that PSPB RIA may be useful for pregnancy diagnosis or diagnosis of late embryonic mortality.     

Administration of human chorionic gonadotropin at embryo transfer induced ovulation of a first wave dominant follicle, and increased progesterone and transfer pregnancy rates

We hypothesized that administration of hCG to recipients at embryo transfer (ET) would induce accessory CL, increase serum progesterone concentrations, and reduce early embryonic loss (as measured by increased transfer pregnancy rates). At three locations, purebred and crossbred Angus, Simmental, and Hereford recipients (n = 719) were assigned alternately to receive i.m. 1,000 IU hCG or 1 mL saline (control) at ET. Fresh or frozen-thawed embryos were transferred to recipients with a palpable CL on Days 5.5 to 8.5 (median = Day 7) of the cycle (Locations 1 and 2), or on Day 7 after timed ovulation (Location 3). Pregnancy diagnoses (transrectal ultrasonography) were done 28 to 39 d (median = 35 d) and reconfirmed 58 to 77 d (median = 67 d) post-estrus. At Location 1 (n = 108), ovaries were examined at pregnancy diagnosis to enumerate CL. More (P < 0.001) pregnant hCG-treated cows (69.0%) had multiple CL than pregnant controls (0%). Serum progesterone (ng/mL) determined at Locations 1 and 2 (n = 471) at both pregnancy diagnoses in pregnant cows was greater (P ≤ 0.05) after hCG treatment than in controls (first: 8.1 ± 0.9 vs 6.1 ± 0.8; second: 8.8 ± 0.9 vs 6.6 ± 0.7), respectively. Unadjusted pregnancy rates at the first diagnosis were 61.8 and 53.9% for hCG and controls. At the second diagnosis, pregnancy rates were 58.6 and 51.3%, respectively. Treatment (P = 0.026), embryo type (P = 0.016), and BCS (P = 0.074) affected transfer pregnancy rates. Based on odds ratios, greater pregnancy rates occurred in recipients receiving hCG, a fresh embryo (66.3 vs 55.5%), and having BCS >5 (62.3 vs 55.3%). We concluded that giving hCG at ET increased incidence of accessory CL, serum progesterone in pregnant recipients, and transfer pregnancy rates. Furthermore, we inferred that increased progesterone resulting from hCG-induced ovulation reduced early embryonic losses after transfer of embryos to recipients.     

Sources of variation of post-partum cyclicity, ovulation and pregnancy rates in primiparous Charolais cows treated with norgestomet implants and PMSG

In this study, sources of variation of postpartum cyclicity, ovulation and pregnancy rates were analyzed for 723 primiparous suckled Charolais cows treated with combined norgestomet implants (Crestar) and 600 IU PMSG (Chronogest) injected at the time of implant removal. The cows were inseminated 48 and 72 h after implant removal. Cyclicity and ovulation rate were estimated by progesterone assay and pregnancy rate by ultrasonography. At time of implant insertion, difficulty of previous calving, body condition score (BCS, from 1 to 5), interval from calving to implant insertion and herd related factors were recorded and their effects analyzed by logistic regression models. Cyclicity, ovulation and pregnancy rates were, respectively, 14.7% (106/723 ), 67.1% (381/568 ) and 42% (303/722 ) and were affected by BCS, calving conditions and interval from calving to implant insertion (P values from < 0.01 to < 0.0001). For ovulation and pregnancy rate, an interaction between BCS and interval from calving to implant insertion was found (P < 0.01). No other main factor or interaction was found to be significant. Cyclicity rate was lower in BCS1 (score < 2.5) cows (9.6%) than in BCS2 (19.8%) or BCS3 (score > 2.5) cows (22.4%), and decreased as difficulty of calving increased (23.2, 13.6 and 10.1%, respectively, for calving conditions 1, 2 and 3 cows). Cyclicity rate increased with interval from calving to implant insertion (8.2, 10.2 and 19.5%, respectively, for interval from calving to implant insertion < 60 d, between 60 and 70 d and > 70 d). Similar trends were found for ovulation rate. Previous difficult calving conditions influenced pregnancy rate negatively (47.9, 43.8 and 32.5% for calving conditions 1, 2 and 3 cows, respectively; P < 0,005).     

Observed and expected combined effects of clinical mastitis and low body condition on pregnancy loss in dairy cows

The objective was to compare the observed and expected combined effects of clinical mastitis before timed artificial insemination (TAI) and low body condition at 70 d postpartum (dpp) on pregnancy loss in dairy cows. Cows were examined for pregnancy by ultrasonographic examination 28-32 d after TAI; the presence of an embryo with a heartbeat was the criterion used to determine pregnancy. Cows diagnosed pregnant were re-examined by transrectal palpation of the uterus and its contents 28 d later to confirm pregnancy status and to identify pregnancy loss. Eighty-eight (17%) of 512 cows were diagnosed with pregnancy loss. Cows affected with clinical mastitis before insemination and a body condition score (BCS) ≤ 2.75 at 70 dpp were 2.03 times more likely to experience pregnancy loss, compared to cows without clinical mastitis and with a BCS > 2.75 (RR = 2.03; 95% CI = 1.15, 3.60; P = 0.01). This observed combined effect for pregnancy loss (RR = 2.03) was higher than the expected combined effect based on adding (RR = 1.39) or multiplying (RR = 1.42) absolute independent excesses due to clinical mastitis or low body condition.     

A comparison between plasma oestrone sulphate concentration and doppler ultrasound as methods for pregnancy diagnosis in sows

Plasma oestrone sulphate (E(1)S) concentration and doppler ultrasound as methods of pregnancy diagnosis in sows were compared. Using either method, pregnancy was accurately detected (test sensitivity > 94% for pregnant sows). E(1)S was a better predictor of nonpregnant animals (test specificity 78 vs 66%, respectively; P < 0.01) and could be used at least 1 wk earlier than doppler ultrasound (24 to 30 d vs 35 d postservice, respectively). E(1)S concentration was not an accurate predictor of litter size.     

Characterization of estrus detection, conception and pregnancy risk of Holstein cattle from the central area of Chile

The objectives were to characterize the estrus detection risk (HDR), conception risk (CR), and pregnancy rate (PR) of postpartum (pp) Holstein cattle from the central area of Chile. The study used records of 2269 lactations from six dairy farms in central Chile (Mediterranean-type climate) during 2004. Three 21-d periods for estrus detection were considered (50-70, 71-91, and 92-112d pp). Estrus detection risk, CR, and PR at the first, second, and third periods were analyzed by logistic regression, whereas overall PR at the end of the 63-d study (112d pp) was assessed with survival analysis. The overall HDR was 51.1%. The HDR, CR, and PR were 48.4, 42.2, and 17.3%, respectively, during the first period; 52.8, 41.8, and 20.5% during the second period; and 52.9, 39.2, and 19.7% during the third period. The HDR was lower during Period 1 than during Periods 2 and 3 (P< or =0.05). Conception risks were not different among periods (P>0.05); however, PR was lower during Period 1 than during Periods 2 and 3 (P< or =0.05). Overall PR over time differed among parities, but was not significantly different among seasons. There were no significant interactions among parity, season and herd for HDR, CR and PR for the three 21-d periods. Parity 1 had higher CR and PR than Parity 2 and 3+ during Period 3. Overall, survival curves for the risk of non-pregnancy among parities (1, 2, 3 or greater) were different over time (P< or =0.05). Cows of Parity 1 became pregnant earlier than cows of Parity 2, and Parity 3 or greater. Survival curves for the risk of non-pregnancy among seasons (summer, fall, winter, and spring) were not different over time (P>0.05).     

Comparison of ultrasonography, bovine pregnancy-specific protein B, and bovine pregnancy-associated glycoprotein 1 tests for pregnancy detection in dairy cows

At Days 26 to 58 after AI, 138 Holstein-Friesian dairy cows were repeatedly examined by ultrasonography, using a 7.5 MHz linear-array rectal transducer. The total calving rate was 37.6% (52/138), and late embryonic mortality occurred 8.6% of the cows (12/138). On the days of ultrasound scanning, blood samples were drawn from the jugular vein for measuring the concentration of bovine pregnancy-specific protein B (bPSPB) and bovine pregnancy-associated glycoprotein 1 (bPAG 1). When compared with calving results, there were no significant differences in accurate diagnosis of pregnant cows were found between the 3 methods. However, when recognition of an embryo proper with a beating heart was used as the criterion for positive ultrasonographic diagnosis significantly fewer (P < 0.001) pregnant cows were correctly identified than by the other 2 tests. When compared with the noncalving cows, significantly fewer (P < 0.001) false positive diagnoses were made by the 2 ultrasonographic tests than by the PSPB and bPAG 1 tests, while significantly fewer (P < 0.001) false positive diagnoses were made by the bPSPB test than by the bPAG 1 test. The accuracy of detecting nonpregnant animals by both protein tests was limited by the relatively long half-life of these proteins after calving and by early embryonic mortality.     

Lactate dehydrogenase isoenzyme patterns as a method of pregnancy detection in cattle

The objective of this study was to evaluate serum lactate dehydrogenase isoenzyme patterns in open and pregnant Holstein and Hereford cows as a method of detecting pregnancy. Serum samples were collected from 26 Holstein and 13 Hereford cows and lactate dehydrogenase isoenzyme patterns were examined by electrophoresis and quantitated by scanning densitometry. Lactate dehydrogenase isoenzyme(4) and LDH(5) were found in higher concentration (P 相似文献   

Effects of embryo size at transfer (whole versus demi) and early pregnancy progesterone supplementation on embryo growth and pregnancy-specific protein bovine concentrations in recipient dairy heifers

The objectives of this study were to evaluate embryonic size and survival, plasma progesterone (P4) and pregnancy-specific protein bovine (PSPB) concentrations in early pregnancies (n = 99) following the transfer of one whole (n = 66) or one demi (n = 33) embryo to recipient virgin dairy heifers. The experiment was designed to evaluate the fixed effects of embryo size at transfer (whole or demi embryo) on Day 7 of the estrous cycle (Day 0 = estrus) and P4 supplementation between Days 7 to 19 through an intravaginal device (yes or no) on plasma P4 and PSPB concentrations and on embryo measurements. Plasma P4 concentrations were measured by RIA on Days 0, 7, 14, 19, 21, 25, 35, 42, 49, 56 and 63 of pregnancy and, PSPB concentrations were measured by ELISA on Days 7, 21, 25, 35, 42, 49, 56 and 63. The presence of an embryonic vesicle was detected on Day 25, embryonic/fetal movements and heartbeat were evaluated on Days 42 and 63 and embryo measurements [crown-rump length (CRL) and width at mid body] were obtained on Day 42 through ultrasonography.In non-supplemented pregnancies, Day 42 whole embryos had higher (P < 0.05) CRL and width than demi embryos, but the difference averaged only 1 to 2 mm. In P4 supplemented pregnancies, whole and demi embryos attained a similar size on Day 42 of pregnancy. Embryo size at transfer, early exogenous P4 supplementation and their interactions had no effects (P > 0.05) on plasma P4 concentrations. However, the post-hoc LSD evaluation showed that plasma P4 concentrations on Day 25 were higher (P < 0.001) in whole than in demi embryo derived pregnancies and, that exogenous P4 supplementation increased (P < 0.05) plasma P4 concentrations on Day 19 of pregnancy. The plasma PSPB detection rate on Days 7 to 63 of pregnancy was similar in pregnancies resulting from the transfer of whole and demi embryos. From a total of 93 recipients remaining pregnant until Day 63, plasma PSPB was constantly undetectable on Day 7, was detected in 4% of Day 21 samples, 41% of Day 25, 95% of Day 35, 96% of Day 42, 99% of Day 49 and in 100% of samples of Days 56 and 63. Concentrations of PSPB increased (P < 0.05) from Days 21 to 42 and from Days 56 to 63, with a plateau between Days 42 to 56. Demi embryo pregnancies had higher (P < 0.05) plasma PSPB concentrations on Days 35 and 42 than whole embryo pregnancies. Progesterone supplementation had a positive effect (P < 0.01) on PSPB concentrations from Days 35 to 63. Concentrations of PSPB were similar in non-supplemented whole and demi embryo pregnancies from Days 7 to Day 63. In contrast, in supplemented recipients, demi embryo pregnancies had higher (P < 0.05) PSPB concentrations on Days 25 to 42 than whole embryo pregnancies. No significant correlation was found between P4 and PSPB concentrations or between the concentrations of these hormones and embryonic measurements on Day 42. In conclusion, demi embryos experienced a compensatory growth until Day 42 of pregnancy, attaining a similar size to that of whole embryos and originating conceptuses producing similar plasma PSPB concentrations to those of whole embryo derived conceptuses. Embryonic growth and conceptus secretion of PSPB were positively stimulated by early pregnancy exogenous P4 treatment.     

Relationship of pregnancy rate to peripheral concentrations of progesterone and estradiol in beef cows

The relationship between pregnancy rate and concentrations of progesterone (P(4)) and estradiol-17beta (E(2)) in serum was examined in inseminated beef cows. Jugular blood was collected twice daily on Days 4 through 7 and Days 14 through 17 after estrus to establish patterns of secretion of P(4) and E(2). Pregnancy rate was determined by palpation per rectum at 45 d. Mean concentrations of each hormone, ratio of E(2):P(4) and regressions of hormone on day were the variables measured for each of the 2 periods. Cows were classified into low (n=26), medium (n=50) and high (n=26) groups for each variable. The relationship of pregnancy rate to each variable was tested using Chi-square analyses. Pregnancy rates to the first service decreased linearly as relative mean concentrations of E(2) increased on Days 14 through 17 (P<0.05) but were not affected by any of the other hormonal variables studied during either period. Pregnancy rates to the second service were not related to concentrations of P(4) or E(2) during the luteal phase before mating (Days 14 through 17). The effects of pregnancy on concentrations of E(2) and P(4) also were tested. On Days 14 through 17, P(4) increased slightly in pregnant cows and declined slightly in nonpregnant cows (P<0.05), but pregnancy did not affect E(2) during either period or P(4) on Days 4 through 7. In summary, pregnancy rate to the first service decreased significantly as concentrations of E(2) increased on Days 14 through 17.     

Relationship of body condition score and blood urea and ammonia to pregnancy in Italian Mediterranean buffaloes

The relationship of body condition score (BCS) and blood urea and ammonia to pregnancy outcome was examined in Italian Mediterranean Buffalo cows mated by AI. The study was conducted on 150 buffaloes at 145 +/- 83 days in milk that were fed a diet comprising 14.8% crude protein, 0.9 milk forage units.kg-1 dry matter and a non-structural carbohydrate/crude protein ratio of 2.14. The stage of the oestrous cycle was synchronised by the Ovsynch-TAI programme and blood urea and ammonia levels were assessed on the day of AI. Energy corrected milk (ECM) production and BCS were recorded bi-weekly. The pregnancy risk was 46.7% and was slightly lower in buffaloes with BCS < 6.0 and BCS > 7.5. There were no significant differences in ECM, urea and ammonia between pregnant and non-pregnant buffaloes. However, pregnancy outcome was higher (P = 0.02) in buffaloes with blood urea < 6.83 mmol.L-1. The likelihood of pregnancy for buffaloes with low urea blood level was 2.6 greater than for high urea level and exposure to a high urea level lowered the probability of pregnancy by about 0.25. The findings indicate that buffaloes are similar to cattle and increased blood levels of urea are associated with reduced fertility when animals are mated by AI.     

Effect of fetal mass, number and stage of gestation on pregnancy-specific protein B concentrations in the bovine

In this study we characterized the peripheral plasma pregnancy-specific protein-B (PSPB) profile throughout gestation and examined the effect of stage of gestation, fetal mass and number on this profile in Holstein cows after non surgical embryo transfer. Cows (n = 12) were divided into 2 groups: Group 1 = single embryo recipient cows (n = 5), Group 2 = twin-embryo recipient cows (n = 7). Blood was collected approximately every third day from Day 0 (Day 0 = first day of standing estrus), then daily for the last 10 d of gestation, and sampling was stopped 1 d post partum. Two twin-embryo recipient cows had abnormal pregnancies; therefore, their data were excluded from the group. The time trend concentrations of plasma PSPB were significantly affected by the stage of gestation (P < 0.001) and fetal number (P < 0.001). In both groups PSPB increased gradually, with the mean levels being significantly higher (P < 0.01) in the twin-bearing group from Day 50 onwards (0.7 +/- 0.2 vs 9.2 +/- 4.5 ng/ml, singleton and twin-bearing cows, respectively) except for Day 10 pre-partum. By mid-gestation (Day 140), mean PSPB levels increased in the singleton (P < 0.001) cows by thirty-fold (21.2 +/- 3.2 ng/ml) as opposed to a ten-fold (98.4 +/- 13.2 ng/ml) increase in the twin-bearing (P < 0.001) group. The mean PSPB concentrations between Days 30 to 20 prepartum dramatically increased by about 700 to 200% in singleton (128.8 +/- 46.3 to 745.6 +/- 66.7 ng/ml) and twin-bearing cows (375.6 +/- 130.4 to 861.5 +/- 127.9 ng/ml), respectively. The PSPB levels between Day 10 prepartum to parturition were significantly higher (P < 0.001) in the twin-bearing group than in the singleton group (745.6 +/- 66.7 to 1627.4 +/- 238.9 ng/ml vs 861.5 +/- 127.9 to 3103.0 +/- 643.0 ng/ml in singleton and twin-bearing groups, respectively). Calf birthweight was correlated (P < 0.01) to peripheral PSPB concentration in singleton cows; however, this relationship decreased with the subsequent increase in fetal number. Cows giving birth prematurely to stillborn calves or to a schistosomus reflexus calf exhibited abnormal PSPB profiles. These results indicate that peripheral PSPB levels are correlated to the stage of gestation and fetal number. In addition, the peripheral pattern of PSPB is a valuable guage for predicting fetoplacental viability.     

Endocrine profiles of somatic nuclear transfer-derived pregnancies in dairy cattle

In cattle, several hormones and proteins are necessary for maintenance of a normal pregnancy that will result in a viable calf. Deviation from the normal cascade or expected profile of reproductive hormones and proteins may be associated with impairment of somatic nuclear transfer-derived pregnancies and the high rate of fetal loss. The objectives of this study were to characterize maternal plasma concentrations of pregnancy-specific protein B (PSPB), progesterone (P4), estrone sulphate (E₁S), and estradiol (E2) during the last two-thirds of pregnancy (cloned calves), and to determine associations with gestational abnormalities. Cows with cloned fetuses, produced by either commercial (N = 16) or zona-free (N = 4) cloning techniques, were compared with pregnant animals derived from traditional embryo transfer (N = 6) or AI (N = 6), at various stages of gestation (Days 80, 120, 150, 180, 210, and 240; Day 0 = estrus). Fetal well-being was monitored with ultrasonography throughout gestation. At Day 80, progesterone concentration was lower (P < 0.0001) in nuclear transfer (NT) recipients than in control groups. Mean estrone sulphate concentrations did not vary significantly between NT and control groups. At Day 150, pregnancy-specific protein B concentrations were elevated (P < 0.002) in NT cows. Estradiol concentration was higher in NT recipients than control cows throughout the study period.     

Accuracy of pregnancy specific protein-B test for early pregnancy diagnosis in dairy cattle

The objective was to evaluate the accuracy of an ELISA for pregnancy specific protein B (PSP-B) for early pregnancy diagnosis in dairy cattle. Blood from lactating (>100 d postpartum) dairy cows (n = 738), was collected on Days 28, 30, and 35 (Day 0 = estrus), analyzed with an ELISA for PSP-B, and the cows designated as pregnant, probable, unlikely, or non-pregnant. Immediately after blood collection, transrectal ultrasonography (TRUS) was done for pregnancy diagnosis, and the results used as a criterion standard test for comparison with PSP-B. At Day 28, 46.3% were diagnosed by TRUS as pregnant. The PSP-B sensitivity was 93.9% on Day 28 and similar on Days 30 and 35. The PSP-B specificity, positive predictive value, negative predictive value, and accuracy were all >94% on Day 28 and similar on Days 30 and 35. However, the accuracy was significantly less compared to TRUS (P < 0.01). The percentage of all samples from cows that were probably pregnant or unlikely to be pregnant was 5.6%. At Days 28, 30, and 35, percentages of uncertain samples were 8.5, 4.8, and 3.3%, respectively (P < 0.01), and Kappa values were 0.92, 0.92, and 0.95. False negative and false positive results were attributed to low concentrations of PSP-B in pregnant animals and to persistence of pregnant concentrations of PSP-B in females with pregnancy loss, respectively. In conclusion, PSP-B ELISA was a sensitive, specific, and accurate test for pregnancy diagnosis (relative to TRUS) at Days 28, 30, and 35 after breeding.     

Correlation between reproductive efficiency, as determined by new mathematical indexes, and the body condition score in dairy cows

The aim of this work was to study a new mathematical model based on dynamic indexes designed to evaluate reproductive efficiency in dairy herds and to correlate the new index with the body condition score (BCS) in order to evaluate the reproductive state of the cows post partum. Four groups of dairy cows were used: 1) loose-housed Italian Friesian (loose Friesian, n = 190); 2) stanchioned Italian Friesian (stanchioned Friesian, n = 121); 3) stanchioned Italian Simmental (stanchioned Simmental, n = 120); and 4) loose-housed selected Italian Friesian cows (BCS test, n = 117). The first 3 herds were used to develop the new mathematical model while the fourth was used to correlate the method with the BCS. The new model was developed from the analysis of progesterone (P4) concentrations in whey and the frequency distribution of the cows in 3 reproductive states: cyclicity, acyclicity and pregnancy. The frequency distribution generated 3 curves, the intersections of which form a closed area. The barycenter of this closed area gives a simple static representation of the reproductive efficiency of each herd. We also studied the movement of the barycenter with time (dynamic index) for each reproductive status curve. The dynamic index allowed for evaluation of the reproductive efficiency of a group of cows at 40 d after calving, by analyzing the evolution of the different reproductive states post partum. A reproductive index called Cycle Time was characterized in a 240-d period of observation as the interval needed to bring all the animals from acyclic to pregnant status. The loose Friesian cows had the best reproductive efficiency. The BCS test was used to divide cows into 3 groups depending on the percentage loss of BCS due to the negative energy balance at 30 d post partum. Cows which lost more than 20% in BCS had the lowest reproductive efficiency. The following protocol was devised to monitor herds in order to identify cows that were likely to have reproductive problems: 1) measure BCS 10 d before calving; 2) monitor progesterone in whey starting 5 d after calving; 3) measure BCS 30 d after calving; 4) isolate cows that lost more than 20% of BCS; 5) measure progesterone only in the cows that lose more than 20% of BCS; 6) activate appropriate feeding strategies to help prevent excessive mobilization of body fat reserves.     

Effect of archer density on elk pregnancy rates and conception dates

Archery hunting in Oregon has increased dramatically over the past 2 decades. At the same time, spring juvenile to adult female ratios of Rocky Mountain elk (Cervus elaphus) have been declining. This has raised concern that archery seasons may be disrupting elk breeding and contributing to the decline in recruitment. Two mechanisms could contribute to reduced juvenile:female ratios: 1) reduced pregnancy rates, and 2) delayed conception dates because of human disturbance during the rut. We varied the number of archery hunters at the Starkey Experimental Forest and Range over 13 years to evaluate effects of archer density on reproduction of elk. Archer densities were maintained at high densities during 4 years , low densities during 3 years , and no archers during 6 years. We determined pregnancy status, age, kidney fat index (KFI), lactation status, and fetus conception dates for 622 female elk harvested in December. We found pregnancy rate differences of 0.105, 0.080, and 0.021 between high and no archer density years (P = 0.004), high and low archer density years (P = 0.054), and low and no archer density years (P = 0.616), respectively. Conception dates were 4 days later for high archer density compared to low archer density (P = 0.006), but did not differ between high and no archer years (2 days; P = 0.136) or between low and no archer years (2 days; P = 0.108). We compared generalized linear model estimates of pregnancy rates and determined pregnancy rates for 28% of the lactating female elk to be affected by high archer density, whereas archer densities had no significant affect on pregnancy rate estimates for non-lactating females. We found no difference in conception dates among archer densities when comparing model estimates. Our results suggest that archer density and its interaction with nutritional condition of elk influence pregnancy rates of lactating females with low KFI levels; however, the effect of archer density alone does not explain the magnitude of decline in juvenile to female ratios observed in Oregon. © 2012 The Wildlife Society.