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1.
This study was performed to evaluate reproductive performance after non‐surgical embryo transfer (Ns‐ET) of 10–15 porcine expanded blastocysts (ExBs) that had been vitrified and warmed (V/W) using the micro volume air cooling (MVAC) method. The effect of asynchrony between the donor and recipient estrous cycle was investigated. Ns‐ET was conducted in recipients whose estrous cycle was asynchronous to that of donors by a delay of 2, 1, or 0 days. In the 2‐day and 1‐day groups, the similar farrowing rates (27.3% and 25.0%) and survival rates to term (13.9% and 15.7%) were obtained after Ns‐ET of V/W ExBs. None of the recipients in 0‐day group farrowed. Artificial insemination (AI) prior to Ns‐ET was then evaluated. Ten–15 V/W ExBs were transferred non‐surgically to 12 recipients whose estrous cycles were asynchronous to that of donors by a 2‐day delay. All of the recipients produced piglets, and all (100.0%) delivered piglets were derived from the transferred V/W ExBs. The survival rate of V/W ExBs to term was 25.2%. These results demonstrate that Ns‐ET of V/W ExBs using MVAC can facilitate piglet production, even if 10–15 embryos are transferred. Moreover, piglets were obtained stably when AI was performed prior to Ns‐ET.  相似文献   

2.
This study aimed to compare the efficiency of non‐surgical embryo transfer (ET) using a newly developed catheter, which enables transferring embryos into a proximal site of the uterus (mostly uterine body), and surgical ET of vitrified porcine embryos. In Experiment 1, the catheter was inserted into 12 gilts, with each half of the group allocated to skilled or novice operators. The time required for insertion into the uterus did not differ between skilled and novice operators (4 min 9 s and 4 min 6 s, respectively). In Experiment 2, 12 gilts were used as recipients for non‐surgical and surgical ET with vitrified embryos (n = 6, each). There was no significant difference in the rate of piglet production based on the number of transferred embryos between surgical and non‐surgical ET (25.8% vs. 15.4%, p = .098). The results suggest that non‐surgical ET catheter allowed for easy insertion and transfer of embryos without special training. Although the catheter is effective for deposition of embryos into the proximal site of uterus, the efficiency of piglet production is not enhanced compared with surgical ET. The ET method using this catheter, being labor‐saving and less‐invasive, may contribute to the improvement of ET in pigs.  相似文献   

3.
Non-surgical embryo transfer is a promising method for improving efficiency in the pork industry and also for biotechnology applications, such as in vitro embryo production, transgenesis and cloning. Several groups have reported successful piglet production using an artificial insemination catheter or flexible catheter designed for this procedure; however, the efficiency of the technique is still low. The critical points that need to be addressed in order to improve this procedure are (1) the embryo deposition site and (2) volume of transfer medium associated with the embryos; however, the latter has not yet been examined systematically. In the present study, we evaluated the effect of the volume of non-surgical embryo transfer medium on the ability of porcine embryos to survive to term by using a recently produced flexible catheter. The catheter consists of a guide and an injector. Blastocysts 200-230 mum in diameter were collected from donor gilts and transferred to recipient gilts. The time required for the completion of embryo transfer using this catheter was 14.6 +/- 3.9 min. The tip of the injector was determined by laparotomy to be located in a uterine horn 20-30 cm anterior from the branching point of the uterus body. We transferred 17.0-17.3 embryos with different volumes of medium (1.6, 3.2 and 10 ml) into each of 5, 4 and 4 recipients, respectively, and pregnancy was confirmed in 4, 3 and 1 of these recipients, respectively. Three recipients in the 1.6 ml group farrowed a total of 19 piglets (4, 5 and 10 piglets, respectively). These results suggest that successful non-surgical embryo transfer is affected by the volume of transfer medium.  相似文献   

4.
A system was designed to allow a small swine farm in a northern latitude to use its own boars for artificial insemination (AI) conveniently. Semen was collected twice weekly for 3 day use (days 0, 1 and 2), extended in an egg yolk extender and stored at 5°C. Farm personnel were trained to manage the entire AI programme. For simplicity all semen collected was used for insemination. In the first test 47 gilts and 15 sows were inseminated with semen from four boars. One boar was subfertile with a farrowing rate of 36%. The averages for the other boars ranged from 71 to 100%. Then semen was collected from seven boars and all was used to inseminate 70 gilts and 55 sows with 3 × 109 or more sperm. Overall 63% farrowed an average of 10.1 piglets per litter. Litter size for sows was 1.5 piglets larger than for gilts. There was no difference in farrowing rate when more than 3 × 109 sperm were inseminated. The feasibility of initiating a complete AI programme within a small herd using herd boars was established. However, selection of the boars, use of only high quality semen, and experience with detecting oestrus was required to increase the farrowing rate. The use of various agents to protect sperm against cold shock below 15°C is worthy of further investigation. A new type of electronic probe, which measures the conductivity of cervical mucus, could be helpful if a boar is not available for conventional detection of oestrus.  相似文献   

5.
With the development of the non‐surgical deep uterine (NsDU) embryo transfer (ET) technology, the commercial applicability of ET in pigs is now possible. There are, nevertheless, many factors that influence NsDU‐ET effectiveness that need to be addressed. The aim of this study was to evaluate the effects of the weaned recipients' parity on fertility and prolificacy following NsDU‐ET. The recipients (n = 120) were selected based on their reproductive history and body condition and grouped into three categories according to their parity: primiparous sows, sows of parity 2 and sows of parities from 3 to 5. Thirty fresh embryos (morulae and unhatched blastocysts) were non‐surgically transferred into one uterine horn of each recipient. It was possible to insert the NsDU‐ET catheter through the cervix along a uterine horn in 98.3% of the recipients. The parity had no influence on the difficulty grade of the insertions or on the percentage of correct insertions. The cervix and uterine wall were not perforated during the insertions, and vaginal discharge was not observed after transfer in any of the recipients. There were no differences in the pregnancy rates (74.8%), farrowing rates (71.2%) or litter sizes (9.6 ± 3.3) between groups. Also, there were no differences between groups regarding to the piglets' birthweights or piglet production efficiency. In conclusion, these results demonstrate that weaned sows from parity 1 to 5 are appropriate to be used as recipients in NsDU‐ET programs, which increase the possibilities for the utilization of ET in the recipient farms.  相似文献   

6.
This study was conducted to clarify the feasibility of newly developed vitrification techniques for porcine embryos using the micro volume air cooling (MVAC) method without direct contact with liquid nitrogen (LN2). Expanded blastocysts were vitrified in a solution containing 6 M ethylene glycol, 0.6 M trehalose and 2% (wt/vol) polyethylene glycol in 10% HEPES-buffered PZM-5. The blastocysts were collected from gilts and vitrified using the new device (MVAC) or a Cryotop (CT). Blastocysts were stored in LN2 for at least 1 month. After warming, cryoprotective agents were removed using a single step. Survival of the embryos was assessed by in vitro culture (Experiment 1) and by embryo transfer to recipients (Experiment 2). In Experiment 1, the embryos vitrified by the MVAC or CT and fresh embryos without vitrification (Control) were used. The survival rates of embryos in the MVAC, CT and Control groups were 88.9% (32/36), 91.7% (33/36) and 100% (34/34), respectively, after 48 h culture, and the hatching rates of embryos after 48 h incubation were 69.4% (25/36), 63.9% (23/36) and 94.1% (32/34), respectively. In Experiment 2, 64 vitrified embryos were transferred to 5 recipient gilts, and 8 healthy piglets were produced from 3 recipients in the MVAC group. Similarly, 66 vitrified embryos were transferred to 5 recipient gilts, and 9 healthy piglets were produced from 2 recipients in the CT group. These results indicated that porcine expanded blastocysts can be cryopreserved using the MVAC method without potential pathogen contamination from LN2.  相似文献   

7.
Scheduled breeding of gilts after estrous synchronization with altrenogest   总被引：2，自引：0，他引：2  
Fertility of 104 gilts artificially inseminated (AI) at a predetermined time (scheduled AI) after estrous synchronization with altrenogest (15 mg X gilt-1 X d-1 for 18 d) was compared with that of 103 gilts checked for estrus (estrus checked) and inseminated after altrenogest. Scheduled-AI gilts were inseminated once on d 5, 6 and 7 after the last altrenogest feeding (d 0). Estrus-checked gilts were exposed to a boar twice daily at 0830 and 1630 h and inseminated after the second and third estrous detection period following first detected estrus. Percentage of gilts assigned to treatment that farrowed (72.8 vs 67.3%), total pigs farrowed (11 +/- .4 vs 11.3 +/- .4) and pigs born alive (10.1 +/- .4 vs 10.5 +/- .4) were similar for estrus-checked and scheduled-AI gilts, respectively. We conclude that scheduled AI can be used with estrous synchronization for gilts and may have advantages in breeding herd management and the use of AI in swine.  相似文献   

8.
使用流式细胞仪分离精子进行仔猪性别控制的研究   总被引：2，自引：2，他引：0  
本研究旨在探索流式细胞仪分离精子在猪性别控制中的应用。使用流式细胞仪分离猪XY精子,而后通过母猪输卵管授精生产"预知"性别的仔猪,并使用吖啶橙染色法检测粗分离对精子核酸含量的影响。结果,成功利用分离获得的猪X和Y精子对母猪进行输卵管授精,母猪怀孕率、产仔率均为100%;输Y精子母猪产仔雄性率100%(♂6/6),对照母猪产仔雄性率57.14%(♂8/14);3头输X精子母猪产母仔率91.67%(♀11/12),对照母猪产雌性仔猪40%(♀2/5);使用性别分离精子不影响母猪的怀孕率、产仔率,但窝产仔数较低;吖啶橙染色法检测结果表明,流式细胞仪粗分离对猪精子核酸含量没有显著影响(P>0.05)。本研究结果提示,使用流式细胞仪分离精子授精可以有效改变仔猪的性别比例。本研究结果为猪分离精子性别控制技术的推广应用奠定了基础。  相似文献   

9.
Evaluation of the uterine environment and embryos of prepubertal gilts   总被引：1，自引：0，他引：1  
A series of three experiments was conducted to test the functional status of the uterus and embryos in prepubertal gilts. In Exp. 1, gilts were induced to ovulate by treating with gonadotropins followed by hCG 72 or 96 h later, and were artificially inseminated 24 h after hCG. Five of the 10 gilts treated at 120 d of age, but none of the gilts treated at 100 of age, maintained pregnancies. We next tested the function of the uterine environment by transferring embryos from postpubertal females into gilts of various ages that had been induced to ovulate but not inseminated (Exp. 2). Pregnancy rate at d 50 of gestation was 44% (4/9) for 100-d-old recipients, 67% (2/3) for 140-d-old recipients, and 60% (3/5) for postpubertal recipients (P > 0.20). Therefore, uteri of 100-d-old gilts are able to maintain pregnancies with conceptuses from postpubertal gilts. In Exp. 3, embryos from 100-d-old and postpubertal gilts were transferred into postpubertal recipients. Uterine horns of recipients were surgically separated before transfer, and embryos from 100-d-old and post-pubertal females were transferred to opposite horns of some recipients (experimental). Other recipients received embryos from postpubertal females in both uterine horns (control). When examined on d 50 to 60 of gestation, three of five control gilts were pregnant and three of seven experimental gilts were pregnant (P > 0.50). In experimental recipients, the survival of embryos from 100-d-old gilts was 38% (8/21) compared to 57% (15/26) for embryos from postpubertal gilts (P > 0.30). Because all uterine horns of pregnant recipients contained fetuses, these results support the hypothesis that embryos from 100-d-old gilts are able to initiate and maintain pregnancies in the uteri of postpubertal gilts. Therefore, the uterine environment of 100-d-old gilts provides an environment that supports development of embryos produced by postpubertal gilts, and the embryos produced by 100-d-old gilts can survive and develop in the uteri of postpubertal gilts. It was only the combination of embryos and uteri of 100-d-old gilts that did not permit pregnancy to be maintained.  相似文献   

10.
This experiment was conducted to study the relationship of oestrone excretion during late pregnancy to piglet viability, growth and mortality. Oestrone production was quantified by a radioimmunoassay of daily samples for urinary oestrone (UE) and expressed as a ratio of UE to urinary creatinine (UC). Following parturition and estimation of piglet viability (time from birth to suckling) six litters and their dams were divided into a high and low viability group for further analysis. The average birth to suckling interval for litters judged to have low viability was 96 ± 12 min and for those with high viability 42 ± 4 min. The dams of litters with high viability excreted > 2100 μg UE/g UC during the final 4 days of gestation, whereas the dams of the litters with low viability excreted < 1800 μg UE/g UC during the same period.Ten percent of the piglets produced by gilts who excreted < 1800 UE were stillborn, whereas a stillbirth was not observed in the litters from gilts excreting > 2100 UE. It was concluded that the data from this preliminary study would suggest that further research be conducted with regard to the association between UE and piglet losses pre- and postpartum.  相似文献   

11.
Twenty-five crossbred gilts and 25 crossbred sows were used in an experiment to estimate the riboflavin requirement of lactating swine. During gestation the females were fed a 12% crude protein, corn-soybean meal diet that was marginal in riboflavin content, i.e., 2.3 mg/kg. After farrowing, litter size was equalized across lactation diets within each parity category. The basal, 14% crude-protein corn-soybean meal lactation diet was supplemented to provide five levels of dietary riboflavin: 1.25, 2.25, 3.25, 4.25 and 5.25 mg/kg. Five gilts and five sows were fed each dietary treatment. Each dam was provided her assigned diet ad libitum during the 24-d lactation; piglets were not provided supplemental feed. The erythrocyte glutathione reductase activity coefficient (EGRAC), an indicator of riboflavin status, was measured on blood samples obtained from the dams and their piglets on d 1 and d 24 postpartum. On d 1, the mean EGRAC of gilts was slightly higher than that of sows, while piglet EGRAC was similar regardless of maternal age. On d 24 gilts and their piglets had higher average EGRAC (P less than .01) than did sows and their piglets. Thus, there was a treatment x dam age interaction (P less than .05). Lactation performance criteria gave further evidence of similar treatment x age group interactions. Gilts fed the diet containing 1.25 ppm riboflavin had higher piglet mortality, consumed less feed and lost more weight (P less than .05) for each criterion than did sows fed the same diet. Despite these observations, the broken-line estimates of the riboflavin requirement, based on EGRAC, for gilts and sows were 16.3 and 16.2 mg/d, respectively. The EGRAC values for piglets closely paralleled those of their dams regardless of treatment, suggesting that there is no mechanism to protect the nursing piglets from a maternal dietary deficiency of riboflavin.  相似文献   

12.
SUMMARY Laparoscopy was used to estimate ovulation rate at first mating in 460 Large White/Landrace gilts. For 385 gilts which farrowed litter size was recorded and the relationships between age and mating, maternal litter size, ovulation rate and reproductive performance were examined. The mean ovulation rate of the gilts which farrowed was 10.9 ± 0.14 corpora lutea and the mean first litter size was 8.0 ± 0.12 piglets born with 7.5 ≥.± 0.13 born alive. Ovulation rate was related to first litter size (r = 0.29, P < 0.001) but embryo loss was the major factor determining litter size, accounting for about 58% of the variation. None of the variable examined at the time of mating was sufficiently correlated with litter size to be useful as selection criteria for improving reproductive performance.  相似文献   

13.
Development of gilts that conceive early and continue to produce offspring is an objective of swine production. We investigated different patterns of growth on reproductive development and performance of gilts through the first farrowing. At 13 wk of age and 43 kg BW, 286 white crossbred gilts were penned individually and assigned to treatments: Ad lib, ad libitum intake from 13 to 25 wk of age; Control, ad libitum intake from 13 wk of age until 100 kg BW and then 90% of ad libitum intake until 25 wk of age; and Restricted, 74% of ad libitum intake from 13 wk to 25 wk of age. Feed was formulated to restrict energy intake. The study was replicated in three seasons. At 25 wk of age, gilts were moved by treatment to group pens, fed for ad libitum consumption, and estrus detection was initiated. Gilts were inseminated at first estrus, and those recycling were remated. Postmating gilts were fed 1.5x maintenance until 105 to 110 d of pregnancy. Gilts were moved either to the farrowing facility or the abattoir at 105 to 110 d of pregnancy. Those taken to the abattoir were slaughtered and number, weight, and condition of the fetuses were recorded. Gilts moved to the farrowing facility were allowed to farrow, and number, weight, and condition of the piglets were recorded. Daily feed intake during breeding was 3.4 kg/d by Restricted gilts, 2.9 by Control gilts, and 2.7 kg/d by Ad lib gilts. Increased feed intake by Restricted gilts during breeding resulted in compensatory gains that overcame the reduced reproductive performance that resulted from the reduced BW and backfat these gilts carried at the start of breeding. Days to first estrus and pregnancy were not influenced by development period treatment (P < 0.13). Percentage of Ad lib, Control, and Restricted gilts that successfully completed their pregnancies were 61, 74, and 66, respectively (P > 0.19). Total feed fed from 13 wk of age to end of the first pregnancy per gilt assigned did not differ among Ad lib (506 kg) and Control (498 kg) gilts but was less (P < 0.01) in Restricted gilts (451 kg). Number of piglets born per gilt assigned (P > 0.09) and piglets produced per kilogram of feed fed from 13 wk of age to term (P > 0.29) were 6.47 and 0.0134 in Ad lib gilts, 7.26 and 0.0150 in Control gilts, and 6.38 and 0.0149 in Restricted gilts, respectively. Moderate feed restriction, 74% of ad libitum intake, reduced feed consumed from 13 wk of age to end of the first pregnancy with no significant impact on efficiency of piglet production.  相似文献   

14.
Transfer of porcine embryos after 3 days of in vitro culture   总被引：1，自引：0，他引：1  
Two experiments were conducted to determine the viability of porcine embryos transferred after long-term in vitro culture. In Exp. 1, four-cell embryos were kept in culture for 120 h. Embryos that were exposed to fresh culture medium every 12 h survived better than embryos kept in the same medium throughout the culture period. In Exp. 2, four- and eight-cell embryos were cultured in vitro for 72 h before transfer to estrus-induced recipient gilts. Each gilt received, on average, 19 embryos. If recipients were synchronous with donors 3/32 (9%) recipients remained pregnant with an average of 4.0 +/- .6 viable young. If the sexual cycle of the recipients was 24 h behind that of the donors the pregnancy rate was 18/34 (53%) with 4.4 +/- .5 viable young. Average embryo survival rate for the two groups was 1.8 and 12.5%, respectively. A 24-hourly medium replacement during the in vitro culture period had no significant effect on transfer results. When transferring freshly collected blastocysts, pregnancy rate, number of viable young and survival rate of embryos were 6/10 (60%), 7.8 +/- 1.4, and 23.9% for synchronous recipients and 7/10 (70%), 9.3 +/- 1.8, and 32.9% for asynchronous recipients, respectively. Recipients with very high plasma progesterone levels or numerous follicular cysts at the time of transfer were less likely to remain pregnant than others.  相似文献   

15.
The purpose of this study was to assess the effects of two currently available commercial European-type modified-live virus (MLV) vaccines against porcine reproductive and respiratory syndrome in a reproductive pig model. Sixteen 90-day pregnant gilts were divided into four groups and allocated to one of the following intranasal treatments: group A gilts served as negative controls; group B gilts were exposed to a virulent European field strain; group C gilts were exposed to vaccine strain VP046 Bis and group D gilts to vaccine strain All-183. The results indicated that MLV strains can replicate in breeding animals and have the ability to cross the placenta. In particular, viraemia was detected in all gilts in group C and 2/4 gilts in group D, at least at one time point. In addition, transplacental infection was demonstrated in 3/4 gilts in group C and 2/4 gilts in group D. However, congenital and early postnatal infection did not have a marked detrimental effect on piglet performance when compared to negative controls, and no statistically significant differences were observed in most cases. Conversely, the reproductive performance of gilts in group B was significantly worse than that of the other groups. Specifically, the number of born-alive piglets, the survival rate of piglets during lactation and the mean weight of weaned pigs were significantly lower. It was concluded that the two commercial European-type MLV vaccines tested had no marked detrimental effects in pregnant gilts, although the MLV strains can cross the placenta leading to the birth of congenitally infected piglets.  相似文献   

16.
Chitosan oligosaccharides (COS) are the hydrolyzed product of chitosan and have multifunctional health benefits. The objective of this study was to elucidate the effect of COS as a dietary supplement to gilts on their productivity and health and that of their litters. Gilts were randomly assigned to either a treatment (n = 30) or control group (n = 30). The treatment gilts were fed a standard dry sow ration supplemented with COS at 0.12 and 0.24 g/gilt per d during gestation and lactation, respectively, and the control group was fed the standard dry sow ration only. The body weight, reproductive performance, milk production and litter size for each gilt and body weight of corresponding litters were recorded. The serum immunoglobulins (IgA, IgG, IgM) and secretory immunoglobulin A (sIgA) concentrations of gilts and piglets and fecal sIgA concertation of gilts were measured by Enzyme-linked immunosorbent assay (ELISA). Our study showed that maternal COS supplementation 1) significantly increased gilt body weight in late pregnancy (P < 0.05), 2) significantly increased milk production of gilts at different stages (d 1, 3, 7 and 19) of lactation (P < 0.05), 3) significantly increased body weight gain of piglets at weaning (P < 0.05), 4) significantly increased the serum concentrations of IgM and sIgA in piglets, and sIgA in fecal sample of gilts (P < 0.05), and 5) tended to increase the pregnancy success rate (P > 0.05) in the treatment group compared to the control group. These results suggest that maternal COS intervention in gilts can improve gilt milk production, piglet pre-weaning growth and immunity parameters in both gilts and piglets.  相似文献   

17.
In commercial pigs, the greatest susceptibility for pre-weaning mortality occurs in low birth-weight piglets. Despite their overall decreased birth weight, Meishan (MS) piglets have decreased pre-weaning mortality rates compared with contemporary Western breeds. The objective of the current study was to determine the contributions of the maternal uterine environment, piglet genotype, and their interaction on the development of neonatal piglets pertaining to pre-weaning survivability using reciprocal embryo transfer between MS and White crossbred (WC) pigs. Twenty-five successful pregnancies were produced from 2 farrowing seasons, generating litters of maternal uterine environment (MUE) by piglet genotype (PigG) combinations; MS × MS (n = 4 litters), MS × WC (n = 7 litters), WC × MS (n = 7 litters), and WC × WC (n = 7 litters). At approximately 24 h of age (Day 1), piglets (n = 173) were weighed and a blood sample was taken. Hematocrit, hemoglobin, glucose, plasma urea nitrogen, albumin, NEFA, lactate, and cortisol were measured in all blood samples. Representative piglets (n = 46) from each litter were harvested and body measurements (i.e., organ weights, tissue glycogen content, and body composition) were determined. Piglet data were analyzed by ANOVA using MIXED model procedures. Both MUE (P < 0.001) and PigG (P < 0.01) affected piglet BW, illustrating that piglets gestated in WC gilts were heavier than piglets gestated in MS gilts, and WC piglets were heavier than MS piglets. Serum albumin concentrations were increased (P < 0.05) in MS piglets compared with WC piglets, indicating greater liver maturity. Significant MUE × PigG interactions were observed for hematocrit and hemoglobin, in which the greatest concentrations were observed in MS piglets gestated in MS and WC gilts, and the lowest concentrations were observed in WC piglets gestated in WC gilts, demonstrating increased oxygen-carrying capability. The percentage of fat and nitrogen, as well as the GE of the body, were greater (P < 0.05) in MS piglets, indicating greater energy stores. Liver, bicep femoris, and LM glycogen concentrations were greater (P < 0.01) in WC piglets compared with MS piglets, demonstrating increased glycogen catabolism in MS piglets. This study demonstrated limited interactions between the maternal uterine environment and piglet genotype on weaning survivability potential, suggesting that the MS piglet is a viable model for pre-weaning survivability.  相似文献   

18.
试验通过使用人工授精后绵羊作为受体进行胚胎移植,以寻找一种更加有效的方法提高绵羊胚胎移植的经济效益。试验中使用FSH对10只无角道赛特绵羊进行超数排卵处理,同时对60只受体小尾寒羊进行同期发情。供体羊在发情配种后4.5～5.0d从子宫角收集胚胎。同时,将胚胎移植到同期发情并进行人工授精的受体羊子宫内。总共有57枚可用胚移植给44只受体小尾寒羊,32只怀孕到分娩,共产下羔羊51只(无角道赛特羔28只,道赛特与小尾寒羊杂种羔23只)。此外,经人工授精但未进行手术移植的7只小尾寒羊产下15只杂种羔羊。移胚植受体妊娠率72.7%(32/44),移胚受体繁殖率118%(51/44),受体利用率88.3%(53/60)。移胚受体总妊娠率和受体利用率均显著高于常规ET组(P<0.01)。与常规胚胎移植相比,受体羊人工授精后移植胚胎不仅提高了无角道赛特母羊的繁殖率,而且提高了受体羊的利用率。  相似文献   

19.
Contents
The reproductive performance of gilts transported for long distances from three high-health breeding farms to six commercial farms was tested after the use of a Parapox-ovis-virus-based immunomodulator, Baypamun N (Bayer AG, Germany). Sixty (60) gilts were injected with Baypamun N, three times (2 days before departure, 2 h before departure and 2 days after their arrival at the commercial farms), while the remaining 60 gilts were injected with placebo at the same times. The results indicated that: (i) no adverse reactions or adverse effects were noticed related to the treatment with Baypamun N, (ii) treatment with Baypamun N improved the reproductive performance of gilts; the proportion of gilts farrowed/total gilts examined, the total number of piglets born, the number of piglets born alive and the body-weight of piglets at farrowing were significantly increased (p < 0.05), and (iii) treatment with Baypamun N reduced (p < 0.05) the cost of medication per gilt examined and per served gilt.  相似文献   

20.
This study aimed to evaluate the effect of recipient-donor estrous cycle synchrony on recipient reproductive performance after nonsurgical deep-uterine (NsDU) embryo transfer (ET). The transfers (N=132) were conducted in recipients sows that started estrus 24 h before (–24 h; N=9) or 0 h (synchronous; N=31), 24 h (+24 h; N=74) or 48 h (+48 h; N=18) after the donors. A total of 30 day 5 morulae or day 6 blastocysts (day 0=onset of estrus) were transferred per recipient. The highest farrowing rates (FRs) were achieved when estrus appeared in recipients 24 h later than that in the donors (81.1%), regardless of the embryonic stage used for the transfers. The FR notably decreased (P<0.05) when recipients were –24 h asynchronous (0%), synchronous (61.3%) or +48 h asynchronous (50%) relative to the donors. No differences in litter size (LS) and piglet birth weights were observed among the synchronous and +24 h or +48 h asynchronous groups. While a +24 h asynchronous recipient was suitable for transfers performed with either morulae (FR, 74.3%; LS, 9.2 ± 0.6 piglets) or blastocysts (FR, 84.6%; LS, 9.8 ± 0.6 piglets), a + 48 h asynchronous recipient was adequate for blastocysts (FR, 87.5%; LS, 10.4 ± 0.7 piglets) but not for morulae (FR, 30.0%; LS, 7.3 ± 2.3 piglets). In conclusion, this study confirms the effectiveness of the NsDU-ET technology and shows that porcine embryos tolerate better a less advanced uterine environment if they are nonsurgically transferred deep into the uterine horn.  相似文献   

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