首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 234 毫秒
1.
Electrolytes, metabolites, cortisol and reproductive hormones were measured in maternal plasma taken at least twice daily from three cases of bovine hydrops before, during and after parturition induced by dexamethasone or prostaglandin. Caesarean operations were required for two of the cases. Maternal plasma electrolytes remained within the normal range, but average potassium and creatinine concentrations were higher (9.2 and 0.68 mmol/litre, respectively) than normal (4.7 and 0.42 mmol/litre) in samples of amniotic fluid obtained at calving. Sodium (100 mmol/litre) and chloride (67 mmol/litre) in allantoic fluid were also higher than normal (53 and 20 mmol/litre, respectively). Conversely, creatinine concentrations were lower than normal in allantoic fluid (2.2 vs 13.8 mmol/litre). Oestradiol concentrations were lower than normal in maternal plasma (ranges: less than 20 to 140 pg/ml vs 30 to 440 pg/ml); maximum prostaglandin F metabolite (PGFM) concentrations were slightly elevated (ranges 1.1 to 2.0 ng/ml vs 0.4 to 0.9 ng/ml). Progesterone and cortisol concentrations remained within the normal range; the latter hormone increased markedly in parallel with raised PGFM concentrations. In two cases, the concentrations of reproductive hormones tended to be lower in the amniotic fluid than in the allantoic fluid. For example, progesterone concentrations were 42.8 and 14.9 ng/ml in the amniotic fluids vs 64.2 and 29.8 ng/ml in the allantoic fluids of the two cows; PGFM concentrations were 27.7 and 4.3 ng/ml vs 34.6 and 5.0 ng/ml, and oestradiol concentrations were 1.5 and 3.5 ng/ml vs 1.1 and 6.4 ng/ml in the two fluids, respectively.  相似文献   

2.
Pregnancy‐associated glycoproteins (PAG) constitute a large family of glycoproteins found in the outer placental epithelial cell layer of the placenta in Eutherian species. In ruminants, they are noted to be structurally closely related among the different species. This study was designed to determine PAG concentrations in maternal and fetal plasma, allantoic and amniotic fluids in buffalo species. Antisera (AS) generated in rabbits against distinct PAG molecules were used in three radioimmunoassay (RIA)‐PAG systems: RIA‐1 (antiserum raised against bovine PAG67kDa; AS#497), RIA‐2 (antiserum raised against caprine PAG55 + 62 kDa; AS#706) or RIA‐3 (antiserum raised against buffalo PAG; AS#859). Samples were collected at a slaughterhouse (n = 67). PAG concentrations determined by RIA‐2 gave significantly higher results in both allantoic and amniotic fluids (12.7 ± 2.1 ng/mL and 24.0 ± 7.3 ng/mL, respectively). Regarding maternal and fetal plasma, PAG concentrations obtained by RIA‐2 (21.8 ± 2.4 ng/mL and 20.2 ± 2.5 ng/mL, respectively) and RIA‐3 (25.0 ± 2.2 ng/mL and 21.9 ± 3.2 ng/mL, respectively) were higher than those obtained by RIA‐1 (15.5 ± 1.4 ng/mL and 16.1 ± 1.8 ng/mL, respectively). The correlation among the three systems was very high. The study clearly reveals the ability of different PAG‐RIA systems to measure PAG concentration in swamp buffalo samples.  相似文献   

3.
为了研究日粮中添加NCG(N-氨甲酰谷氨酸)对妊娠前期鄂尔多斯细毛羊血液、尿囊液和羊水中氨基酸浓度的影响,试验选择年龄、胎次和体况相近、平均体重为50.62±0.52 kg的受孕鄂尔多斯细毛羊母羊40只,随机分为3组(NCG1组饲喂基础日粮+0.30 g NCG/d(n=13),NCG2组饲喂基础日粮+0.40 g N...  相似文献   

4.
Fetal fluids have different vital functions that sustain both pregnancy and normal parturition. The biochemical composition of amniotic fluid during gestation is not well established; thus the purpose of the present study was to determine the biochemical profile of both amniotic and allantoic fluids from mares during initial, mid, and latter third phases of pregnancy. Samples were collected after slaughter, using allantocentesis and amniocentesis. Sixty samples of fetal fluids were analyzed. Alkaline phosphatase (AP), glucose, total protein (TP), urea, creatinine, Ca, chloride (Cl), Na, and K concentrations were measured using commercially available kits. The AP concentration in amniotic fluid was higher than that in allantoic fluid during the three gestational phases (P < .05). There were no differences between glucose mean values of allantoic and those of amniotic fluids (P < .05). However, glucose values were higher in the allantoic fluid in the last trimester of pregnancy. TP was higher in the amniotic fluid than in allantoic fluid (P < .05). Urea values varied among the phases; however, there were no differences between the amniotic and allantoic fluid values (P > .05). Creatinine values were higher in allantoic fluid (P < .05). Na and Cl concentrations were higher in amniotic fluid (P < .05). However, Ca and K concentrations were higher in the allantoic fluid.  相似文献   

5.
The amniotic and allantoic fluid compartments in the mare serve essential roles throughout pregnancy and parturition. Although the global metabolomic profile of amniotic fluid in women has been extensively characterized, current data for equine fetal fluids are limited. Therefore, the goal of this study was to characterize the global metabolomic profile of equine allantoic and amniotic fluid through nuclear magnetic resonance spectroscopy. Fetal fluids were collected between 270 and 295 days of gestation from 12 pregnancies through ultrasound-guided transabdominal puncture. A total of 24 samples (n = 10 allantoic fluid; n = 9 amniotic fluid; n = 5 admixed fluid) were analyzed by one-dimensional proton (1H) and two-dimensional (1H-13 C) nuclear magnetic resonance spectroscopy. Metabolites were integrated and compared between fluid types using a Kruskal–Wallis test at P < .05 significance. A total of 28 distinct metabolites were found in allantoic and admixed fluid, whereas 23 metabolites were identified in amniotic fluid. Allantoic fluid contained significant elevations (P < .05) in the metabolites betaine, creatine, creatinine, citrate, histidine, nitrophenol, tryptophan, π-methylhistidine, and unknown metabolite #1 compared with amniotic fluid, whereas amniotic fluid contained statistically increased concentrations of the metabolite lactate compared with allantoic fluid (P = .003).  相似文献   

6.
A complex organ, the equine placenta is responsible for fetal nourishment, protection from external and internal insults, and the production and/or metabolisation of various hormones. The endometrial cups are unique structures of the equine placenta that are responsible for producing an essential hormone for equine pregnancy, equine chorionic gonadotropin. Since mares have epitheliochorial placentae, with 6 layers of tissue separating maternal from fetal circulation, almost the entire surface of the chorioallantois must be attached to the maternal endometrium in order to support a developing fetus adequately. The only avillous areas of the normal chorioallantois are: the cervical star, sites of the endometrial cups, areas facing oviductal papillae, folds overlying major allantoic vessels, and fetal foot PADs (placental areas of degeneration). There are characteristic differences between the gravid and the nongravid horn of the chorioallantois. Allantoic vesicles, allantoic pouches, hippomanes, amniotic plaques and yolk sac remnants are normal features of the equine placenta. The clinician should thoroughly examine the entire placenta immediately after its expulsion. The most important aspect of this evaluation is to check for completeness of the chorioallantois, along with identifying any pathological lesions on the fetal membranes or the umbilical cord.  相似文献   

7.
Bovine placenta produces an array of proteins that are structurally and functionally similar to pituitary prolactin. Bovine placental lactogen (bPL) is a glycoprotein hormone that has lactogenic and somatogenic properties. Purified bPL contains several kinds of isoforms that are created by alternative splicing and/or multiple glycosylation patterns. bPL can activate the prolactin (PRL) receptor‐mediated signaling pathway as well as PRL does. The bPL mRNA is transcribed in trophoblast binucleate cells, and synthesized bPL protein is stored in membrane‐bound secretory granules. The message encoding bPL is first detectable in trophoblast binucleate cells at approximately day 20 of gestation at, or shortly after, the appearance of binucleate cells in the trophoblast. Most binucleate cells are detected as expressed bPL in the placenta. Bovine PL may be the determinant in trophoblast differentiation. Although the biological activities of bPL have long been studied, the precise role of bPL is still largely unclear. This article reviews and discusses the biological roles of bPL, focusing on luteal function, fetal growth and pregnancy‐associated maternal adaptation, mammogenesis and lactogenesis, and placental angiogenesis. The precise biological function of bPL needs to be further evaluated.  相似文献   

8.
Sulfate is important for growth and development, and is supplied from mother to fetus throughout pregnancy. We used NaS1 sulfate transporter null (Nas1(-/-)) mice to investigate the role of NaS1 in maintaining sulfate homeostasis during pregnancy and to determine the physiological consequences of maternal hyposulfataemia on fetal, placental and postnatal growth. We show that maternal serum (≤0.5 mM), fetal serum (<0.1 mM) and amniotic fluid (≤0.5 mM) sulfate levels were significantly lower in pregnant Nas1(-/-) mice when compared with maternal serum (?2.0 mM), fetal serum (?1.5 mM) and amniotic fluid (?1.7 mM) sulfate levels in pregnant Nas1(+/+) mice. After 12 days of pregnancy, fetal reabsorptions led to markedly reduced (by ≥50%) fetal numbers in Nas1(-/-) mice. Placental labyrinth and spongiotrophoblast layers were increased (by ?140%) in pregnant Nas1(-/-) mice when compared to pregnant Nas1(+/+) mice. Birth weights of progeny from female Nas1(-/-) mice were increased (by ?7%) when compared to progeny of Nas1(+/+) mice. These findings show that NaS1 is essential to maintain high maternal and fetal sulfate levels, which is important for maintaining pregnancy, placental development and normal birth weight.  相似文献   

9.
The objective of this study was to determine the effects of maternal treatment with porcine somatotropin (pST) during early gestation on embryonic survival, fetal development, and internal environment for fetal growth. Sixty-two crossbred gilts received daily injections of either 3 mL of a placebo (control, n = 31) or 6 mg of pST (n = 31) from d 10 to 27 of gestation. Representative gilts were slaughtered on d 28, 37, and 62 of gestation. The remaining gilts were allowed to farrow. It was found that embryonic survival was not influenced by pST treatment (P > 0.10). However, pST affected the growth and composition of the maternal (endometrium) and fetal (chorion) parts of the placenta. Thus, endometrial RNA concentration tended to be increased by pST at d 37 (P = 0.15), and it was increased at d 62 (P < 0.05) of gestation, which is indicative of increased capacity for protein synthesis. At birth, placental chorion weight (P < 0.10) and contents of DM and protein (P < 0.05) were increased due to pST treatment, but no effects were detectable up to d 62 of gestation. Maternal pST treatment was effective at increasing nutrient supply to the embryo as suggested from elevated glucose concentrations in amniotic and allantoic fluids (P < 0.05) at d 28 of gestation. With regard to prenatal growth, embryonic DNA concentration was slightly elevated at d 28 (P < 0.10), but pST did not induce any changes in average embryonic, fetal, or neonatal weights. However, within litters, the birth weights of piglets in the 25% lowest weight group (LW) were increased by pST treatment vs control LW pigs (1,241+/-55 vs 1,099+/-59 g, P < 0.10). Thirty-eight neonates from 15 litters divided among the three weight groups were examined for body composition. The weight of the intestinal tract was increased above average after maternal pST treatment (P < 0.01). Additionally, the amounts of tissues such as bone (P = 0.12) and s.c. fat (P = 0.06), and of protein, fat (P = 0.10), and ash (P < 0.05) were increased, whereas the relative body composition remained unchanged by pST (P > 0.10). On average, muscle protein concentration was elevated due to pST (P < 0.01), and, in LW piglets, plasma IGF-I concentration was increased (P < 0.10). The results suggest that maternal somatotropin is a critical factor in early pregnancy capable of influencing placental nutrient transfer and placental growth. It thereby selectively improves the growth conditions for the smaller littermates.  相似文献   

10.
Chlamydophila abortus, the aetiological agent of enzootic abortion of ewes (EAE), replicates in trophoblast cells leading to their destruction and dissemination of the bacterium to foetal organs. To further understand the pathogenesis of EAE, amniotic and allantoic fluids were collected from experimentally infected pregnant ewes at 30 (7 samples from each fluid), 35 (8 samples from each fluid), 40 (10 samples from each fluid) and 43 (6 amniotic fluids and 7 allantoic fluids) days post-infection to determine pathogen numbers and other markers of infection. Whilst experimentally infected ewes had characteristic placental lesions, only two amniotic and seven allantoic fluid samples were positive for C. abortus by real-time PCR. In contrast, all amniotic and allantoic fluids were positive for immunoglobulin. Immunoglobulins were generally detected earlier in allantoic fluid than in amniotic fluid and the numbers of samples containing immunoglobulins increased as infection progressed. IgG in amniotic and allantoic fluids was shown to be specific for C. abortus, and reacted with the major outer membrane proteins, polymorphic outer membrane protein and macrophage infectivity potentiator protein. A comparison of two-dimensional immunoblots using purified IgG from the allantoic fluid, amniotic fluid, ewe serum and foetal serum of a C. abortus infected animal at 40 days post infection indicated a pattern of reactivity intermediate between that of the ewe serum and the foetal serum. Results suggest that a maternal source of immunoglobulin is predominant at 30 days post-infection but that foetal derived antibodies may be contributed at a later stage.  相似文献   

11.
This study investigated placental progesterone production by bovine placentomes. Catheters were placed in the femoral artery (FA) and in the caruncular artery (CA), caruncular vein (CV) and lymphatic vessel of a prominent placentome of 13 cows at 200 d of gestation. Four of the 13 cows were given prostaglandin F2 alpha (PGF2 alpha) after surgery, and blood and lymph were collected for progesterone determination. After 24 h, progesterone was higher (P less than .01) in FA and CA plasma from control cows that FA and CA plasma from PGF2 alpha-treated cows (5.11 +/- .29 and 5.17 +/- .64 vs 1.41 +/- .08 and 1.15 +/- .08 ng/ml, respectively), but CV concentrations were similar (3.38 +/- .30 vs 2.56 +/- .24, respectively). There was a net uptake of progesterone by placentomes from control cows (P less than .01) but a net secretion in PGF2 alpha-treated cows (P less than .05). Lymph contained low progesterone concentrations regardless of treatment. Cows were slaughtered at 240 d of gestation. Placentomes were removed and perfused with pregnenolone through the maternal and fetal arteries. Fetal venous effluent contained more progesterone than maternal venous effluent (P less than .001) in both groups, and fetal venous effluent of placentomes from PGF2 alpha-treated cows contained more progesterone than that from control cows (P less than .05). Maternal and fetal components of other placentomes were cultured alone or in co-culture along with pregnenolone and (or) epostane. Fetal tissue produced more progesterone (P less than .001) than maternal tissue when each was cultured alone, but fetal tissue production declined when co-cultured with maternal tissue.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

12.
Toxoplasma gondii, an intracellular protozoan parasite, is one of the major causes of infectious abortion in sheep. To further understand the pathogenesis of toxoplasmosis, serum, amniotic and allantoic fluids and foetal stomach contents were collected from experimentally infected pregnant ewes to determine pathogen numbers and other markers of infection. Fifteen pregnant ewes (90 days of gestation) were each orally inoculated with 3000 sporulated oocysts of T. gondii. Serum samples were collected weekly following challenge. Amniotic and allantoic fluids and foetal stomach contents were collected at 21, 25, 28, 33 and 35 days post-infection. Characteristic placental lesions were detected in 1 of 4 challenged ewes at day 25, 3 of 4 challenged ewes at day 28 and in all challenged ewes at days 33 and 35 post-infection. T. gondii was detected only sporadically in amniotic and allantoic fluids before 35 days of infection, by real-time PCR, and only in ewes with placental lesions. At 35 days post-infection, high numbers of parasite were detected in both amniotic and allantoic fluids. An increase in the number of fluids from challenged animals with IgM and IgG was detected over time, except for IgG in allantoic fluid, which was detected in all samples from day 21 post-infection. IgG in amniotic and allantoic fluids was shown to be specific for T. gondii, and reacted with antigens with an apparent molecular mass of approximately 22 kDa and 30 kDa. Results suggest a maternal source of immunoglobulin in the allantoic fluid and a foetal source of immunoglobulin in the amniotic fluid early in infection but that both sources may contribute immunoglobulin to both fluids at a later stage.  相似文献   

13.
The transplacental exchange of moxidectin after maternal or fetal intravenous (i.v.) administration was studied using the chronically catheterized fetal sheep model. Nine pregnant Suffolk Down sheep of 65.7 ± 5.9 kg body weight (bw) were surgically prepared to insert polyvinyl catheters in the fetal femoral artery and vein and amniotic sac. The ewes were randomly assigned to two experimental groups. In group 1 (maternal injection) five ewes were treated with an i.v. bolus of 0.2 mg of moxidectin/kg bw. In group 2, (fetal injection) an i.v. bolus of 1 mg of moxidectin was administered to the four fetuses by femoral vein catheters. Maternal and fetal blood and amniotic fluid samples were taken before and after moxidectin administration for a 144 h post-treatment period. Samples were analyzed by liquid chromatography. A noncompartmental pharmacokinetic analysis was performed and statistical differences were determined by mean of parametric and nonparametric statistical tests. Pharmacokinetic differences observed in maternal variables were shorter elimination half-life and mean residence time compared with values previously reported for ivermectin. Drug diffusion from maternal to fetal circulation ( AUC 0– t  = 232.6 ± 72.5 ng·h/mL) was statistically not different ( P =  0.09) compared with fetal to maternal diffusion ( AUC 0– t = 158.0 ± 21.6 ng·h/mL). Fetuses showed significantly ( P  =   0.008) lower drug body clearance values compared with those observed in the maternal side. Considering the observed transplacental passages between materno-fetal or feto-maternal circulations, we conclude that the placental barrier is not effective in preventing the moxidectin diffusion between mother and fetus.  相似文献   

14.
To test the hypothesis that placental lactogen (PL) is a Immoral regulator of fetal growth, six singleton sheep fetuses received a continuous intravenous fusion of 1.2 mg/d of purified ovine PL (oPL) for 14 d, beginning on Day 122 of gestation. The plasma concentration of oPL was approximately four-fold higher in infused fetuses than in six control fetuses that received a continuous infusion of saline. The circulating insulin-like growth factor 1 (IGF-1) concentration was also significantly elevated in PL-infused fetuses (43.1 ± 1.7 vs. 31.9 ± 4.l ng/ml; P < 0.05). Animals were slaughtered on Day 136, and the placenta and all major fetal tissues were dissected, weighed, and subsampled for chemical analysis. Fetal weight and crown-rump length were not significantly affected by treatment; however, the aggregate weight of the brain, liver, lungs, and heart tended to be larger (85.3 ± 2.1 vs. 79.9 ± 1.5 g/kg fetus; mean ± SE, P = 0.07) and the thyroid gland was smaller (0.18 ± 0.l vs. 0.26 ± 0.02 g/kg fetus; P < 0.05) in the PL-infused fetuses. The livers of the PL-infused fetuses had also accumulated additional glycogen (13.1 ± l.7 vs. 8.4 ± 0.7 g; P < 0.05). In late gestation, PL within the fetal compartment increases fetal plasma IGF-1 concentration and hepatic glycogen deposition and may affect the growth of several vital organs.  相似文献   

15.
In pregnant sheep at 120–130 days of gestational age, a study was undertaken in order to characterize the pharmacokinetics and transplacental exchange of Ivermectin after maternal or fetal intravenous administration. Eight pregnant Suffolk Down sheep of 73.2 ± 3.7 kg body weight (bw) were surgically prepared in order to insert polyvinyl catheters in the fetal femoral artery and vein and amniotic sac. Following 48 h of recovery, the ewes were randomly assigned to two experimental groups. In group 1, (maternal injection) five ewes were treated with an intravenous bolus of 0.2 mg ivermectin/kg bw. In group 2, (fetal injection) three ewes were injected with an intravenous bolus of 1 mg of ivermectin to the fetus through a fetal femoral vein catheter. Maternal and fetal blood and amniotic fluid samples were taken before and after ivermectin administration for a period of 144 h post‐treatment. Samples were analyzed by liquid chromatography (HPLC). A computerized non‐compartmental pharmacokinetic analysis was performed and the results were compared by means of the Student t‐test. The main pharmacokinetic changes observed in the maternal compartment were increases in the volume of distribution and in the half‐life of elimination (t½β). A limited maternal‐fetal transfer of ivermectin was evidenced by a low fetal Cmax (1.72 ± 0.6 ng/mL) and AUC (89.1 ± 11.4 ng·h/mL). While the fetal administration of ivermectin resulted in higher values of clearance (554.1 ± 177.9 mL/kg) and lower values of t½β (8.0 ± 1.4 h) and mean residence time (8.0 ± 2.9 h) indicating that fetal‐placental unit is highly efficient in eliminating the drug as well as limiting the transfer of ivermectin from the maternal to fetal compartment.  相似文献   

16.
In order to determine the variability inherent in conceptus-related measurements in first trimester bovine pregnancies, conceptus and fetometric parameters from beef cattle pregnancies (n=103) estimated to be between Days 36 and 103 of gestation were examined. During this period, the protein concentration of amniotic fluid ranged between 0.181 and 0.501mg/mL. The amniotic fluid volume gradually increased from <1mL at Day 36 to 950mL at Day 103 (R(2)=0.9275) and amniotic compartment dimensions (length, R(2)=0.9713; width, R(2)=0.9802) increased predictably with fetal growth. Conversely, allantoic fluid protein concentration and volume correlated weakly with fetal age. A significant linear correlation existed between fetal crown rump length (CRL) and crown nose length (R(2)=0.9899) confirming that either measurement can be employed in the ultrasonographic estimation of fetal age. The amniotic compartment and fetometric data presented here have both research and clinical value, particularly in relation to fetal development evaluation and pregnancy viability diagnosis.  相似文献   

17.
The objective of this study was to describe the dynamic changes in protein composition and protein abundance in amniotic and allantoic fluids from buffaloes during gestation. Amniotic and allantoic fluids were collected during the first, second and third trimesters of gestation. The foetuses were measured and weighed. Fluid samples were centrifuged at 800 g for 10 min and then at 10,000 g for 60 min at 4°C. The supernatant was collected to determine the total protein concentration. Based on total protein concentration, an aliquot (50 μg) was used for in‐solution tryptic digestion, and mass spectrometry analysis (nano‐LC‐MS/MS) was performed. A multivariate statistical analysis of the proteomic data was conducted. Across the different stages of buffalo gestation, fifty‐one proteins were found in the amniotic fluid, and twenty‐one were found in the allantoic fluid. A total of twelve proteins were common among the stages, and four presented significant differences (VIP score α > 1). Fibronectin and alpha‐1‐antiproteinase were more abundant in the amniotic fluid than in the allantoic fluid. Alpha‐2‐macroglobulin and alpha‐2‐HS‐glycoprotein were more abundant in the allantoic fluid than in the amniotic fluid. Alpha‐2‐macroglobulin participates in remodelling and growth of the uterus at beginning of the gestation (first trimester), and these findings indicate that can serve as a potential tool for the early diagnosis of pregnancy in buffaloes.  相似文献   

18.
Ketone body concentrations were determined in six body fluids of cows in late pregnancy and their fetuses (blood plasma and urine of cows, amniotic and allantoic fetal fluids, and fetal blood serum and urine) using the head-space gas chromatographic method. Physiological ratios 0/T% of oxidized (acetone and acetoacetic acid) to total (acetone, isopropanol, acetoacetic and 3-hydroxybutyric acids) ketone bodies were below 10% in cow blood plasma and urine, fetal serum and urine, and allantoic fluid, and below 20% in amniotic fluid. A scheme for the evaluation of the degree and duration of ketosis based on the 0/T% ratio is proposed. The existence of a renal regulatory mechanism for excretion of ketone bodies is suggested by analogy with the renal acidobasic regulation.  相似文献   

19.
Ketone body concentrations were determined in six body fluids of cows in late pregnancy and their fetuses (blood plasma and urine of cows, amniotic and allantoic fetal fluids, and fetal blood serum and urine) using the head-space gas chromatographic method. Physiological ratios O/T% of oxidized (acetone and acetoacetic acid) to total (acetone, isopropanol, acetoacetic and 3-hydroxybutyric acid) ketone bodies were below 10% in cow blood plasma and urine, fetal serum and urine, and allantoic fluid, and below 20% in amniotic fluid. A scheme for the evaluation of the degree and duration of ketosis based on the O/T% ratio is proposed. The existence of a renal regulatory mechanism for excretion of ketone bodies is suggested by analogy with the renal acidobasic regulation.  相似文献   

20.
This study characterized the peripheral plasma placental lactogen (bPL) profile throughout gestation and examined the relationship between the stage of gestation, fetal mass, number, and postpartum lactation with circulating levels of bPL in Holstein cows after nonsurgical embryo transfer. Cows (n = 12) were divided into two groups: Group 1 = single embryo recipient cows (n = 5); Group 2 = twin embryo recipient cows (n = 7). Blood was collected about every third day from Day 0 (Day 0 was defined as the first day of standing estrus), then daily for the last 10 d of gestation, and sampling was stopped 1 d postpartum. The cows were milked twice daily at 0800 and 1800 hr. Two twin-embryo recipient cows had abnormal pregnancies; therefore, their data were excluded from that of the group and reported separately. The time trend concentrations of plasma bPL were significantly affected by the stage of gestation (P < 0.01) but not fetal number (P < 0.21). In both groups bPL levels remained low during the first two trimesters, then increased rapidly (P < 0.01) to peak concentrations between Days 200 and 220, and stabilized at this elevated level until parturition. Postpartum milk yields were indistinguishable between the singleton and twin-bearing cows. Calf birth weight and postpartum lactation were both correlated (P < 0.01) to peripheral bPL concentration in singleton cows, however, this relationship decreased with a subsequent increase in fetal number. Cows giving birth prematurely to stillborn calves or to a schistosomus reflexus calf exhibited a deviating bPL profile. These results indicate that peripheral bPL levels are positively associated with the stage of gestation but not with fetal number. Otherwise, the peripheral pattern of bPL is a valuable index for predicting feto-placental viability.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号