Growth, development and composition of the ovine conceptus and mammary gland during pregnancy   总被引：5，自引：0，他引：5  

P V Rattray  W N Garrett  N E East  N Hinman 《Journal of animal science》1974,38(3):613-626

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Efficiency of utilization of metabolizable energy during pregnancy and the energy requirements for pregnancy in sheep   总被引：1，自引：0，他引：1  

P V Rattray  W N Garrett  N E East  N Hinman 《Journal of animal science》1974,38(2):383-393

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Principles of Siphons     

Roger E.  Garrett 《Journal of the World Aquaculture Society》1991,22(1):1-9

A simple siphon raises water over a crest and discharges it at a lower level. As water flows through a siphon, energy due to pressure and elevation is either lost to pipe friction or converted to velocity energy. For most practical siphons, between 50 and 75% of the elevation energy available to drive flow will be converted to velocity energy. A standpipe covered with a dome will begin to siphon when the standpipe flows full. During siphoning, the flow rate may be several times higher than the flow through an uncovered standpipe of the same size. Furthermore, the covered standpipe can be designed to lower the water level to a point below the top of the standpipe before siphoning is allowed to stop. Flow into the covered standpipe can be drawn from the bottom of the reservoir by extending the skirt of the dome. A vent tube allows easy adjustment of the elevation at which air enters the dome and siphoning stops. Flow rate and water level required to start the siphon depend on the pipe diameter. Some flow through the standpipe will occur before siphoning begins. Flow into the reservoir must be greater than the flow required to start siphoning. Maximum flow through the standpipe during siphoning depends on pipe diameter and the elevation energy driving the flow. Adding a trap to the outlet of the covered standpipe eliminates the leakage flow prior to the start of siphoning. When air bubbles out the trap at the end of the standpipe, pressure inside the dome is released suddenly allowing the water level to jump above the critical level needed to start siphoning. For reliable operation, the crest height of the trap should be about equal to one diameter of the standpipe. The vent tube opening must be below the top of the standpipe to prevent premature overflow of the standpipe. Because a trapped outlet siphon has no minimum flow limit, the standpipe can be sized to carry any maximum flow. While the trapped outlet siphon eliminates low rate leakage flow prior to the onset of siphoning, the height differential between the start and stop of siphoning cannot be as small or as easily adjusted as with a covered standpipe without a trap. The simple siphon is convenient for some applications, but it does not lend itself to automatic cycling operation. The choice depends on the needs of the situation.  相似文献   

An update on Reproductive Technologies with Potential Short-Term Application in Pig Production     

EA Martinez  JM Vazquez  J Roca  C Cuello  MA Gil  I Parrilla  JL Vazquez 《Reproduction in domestic animals》2005,40(4):300-309

Over the past decade, there has been an increase in the development and/or in the improvement of emerging reproductive technologies in pigs. Among emerging reproductive technologies with potential short-term application in pig production are: artificial insemination with low number of spermatozoa, cryopreservation of spermatozoa and embryos, sperm sexing, and non-surgical embryo transfer. The following review will give emphasis to recent advancements in these reproductive technologies that are starting to show possibilities of serious applications under field conditions.  相似文献   

Three minimum tile paths from bacterial artificial chromosome libraries of the soybean (Glycine max cv. 'Forrest'): tools for structural and functional genomics     

JL Shultz  C Yesudas  S Yaegashi  AJ Afzal  S Kazi  DA Lightfoot 《Plant methods》2006,2(1):9-10

Background  

The creation of minimally redundant tile paths (hereafter MTP) from contiguous sets of overlapping clones (hereafter contigs) in physical maps is a critical step for structural and functional genomics. Build 4 of the physical map of soybean (Glycine max L. Merr. cv. 'Forrest') showed the 1 Gbp haploid genome was composed of 0.7 Gbp diploid, 0.1 Gbp tetraploid and 0.2 Gbp octoploid regions. Therefore, the size of the unique genome was about 0.8 Gbp. The aim here was to create MTP sub-libraries from the soybean cv. Forrest physical map builds 2 to 4.  相似文献   

仔猪梭菌性肠炎的防治经验     

黄建亮 《中国兽药杂志》2006,40(3):56-57

某场饲养的64头仔猪，于10d内发生梭菌性肠炎，采用疫苗免疫和中药治疗进行防治取得了很好的效果，其中中药治疗32例，治愈25例。  相似文献   

Gene Expression and Developmental Competence of Bovine Embryos Produced In Vitro with Different Serum Concentrations     

ATD de  Oliveira  RFF Lopes  JL Rodrigues 《Reproduction in domestic animals》2006,41(2):129-136

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Low-Dose Insemination in Pigs: Problems and Possibilities     

JM Vazquez  J Roca  MA Gil  C Cuello  I Parrilla  I Caballero  JL Vazquez  EA Martínez 《Reproduction in domestic animals》2008,43(S2):347-354

Low-dose AI procedures are required by the pig industry to efficiently utilize emerging sperm technologies, such as cryopreservation and sex-sorting. Currently, several different procedures for inseminating with a low or very low number of spermatozoa have been described. Deep intrauterine insemination allows the deposition of the spermatozoa in the depth of the uterine horn, allowing a significant reduction in the number of spermatozoa inseminated with maintenance of optimal reproductive performance. Intra-oviductal laparoscopic insemination has been recently applied in pigs. This technique has proved to be applicable with diluted and sex-sorted spermatozoa. This review discusses several problems encountered during the development of deep intrauterine insemination and intra-oviductal laparoscopic insemination of pigs and provides potential solutions for the practical application of both the technologies.  相似文献   

Uterine serpin (SERPINA 14) correlates negatively with cytokine production at the foetal–maternal interface but not in the corpus luteum in pregnant dairy heifers experimentally infected with Neospora caninum          下载免费PDF全文

B Serrano‐Pérez  S Almería  R Mur‐Novales  I López‐Helguera  I Garcia‐Ispierto  JL Alabart  L Darwich  F López‐Gatius 《Reproduction in domestic animals》2018,53(2):556-558

This study examines gene expression patterns in dairy heifers experimentally infected with N. caninum during on Day 110 of pregnancy with live foetuses at euthanasia, 42 days later. The study population was constituted of four non‐infected controls and three infected dams. Gene expression was determined on gamma interferon (IFNγ), (Th1 pro‐inflammatory cytokine), interleukin‐4 (IL4) (Th2 pro‐gestation cytokine) or interleukin‐10 (IL10) (T regulatory cytokine) and the serine peptidase inhibitor SERPINA14 in intercaruncular, placental, uterine lymph node (UTLN) and luteal tissue samples. Intercaruncular SERPINA14 expression was negatively correlated with IFNγ expression in cotyledon samples and with IL4 expression in UTLN. No relationships were detected between cytokine gene expression at the foetal–maternal interface and SERPINA14 expression in the luteal samples. Our findings suggest that gene expression of the uterine serpin SERPINA14 correlates negatively with the expression of Th1 and Th2 cytokines at the foetal–maternal interface but not in the corpus luteum.  相似文献   

Monitoring changes in back fat thickness and its effect on the restoration of ovarian activity and fertility in Bos indicus cows          下载免费PDF全文

BR Díaz  CS Galina  I Rubio  M Corro  JL Pablos  A Orihuela 《Reproduction in domestic animals》2018,53(2):495-501

With the objective of testing the hypothesis if animals with a stable layer of body fat (FAT) during the peripartum have a better chance of becoming pregnant after calving, fifty‐nine multiparous Brahman cows in their last trimester of pregnancy were used. Animals averaged four parturitions and were stocked at a rate of 1.25 animal units per hectare and divided into two groups depending on the time postpartum (dpp) that the intravaginal releasing device CIDR was inserted; Group 1 (<30 dpp; n = 30) received the implant at 25.2 ± 4.21 and withdrawn 9 days later. Group 2 (≥30 dpp; n = 29) received the CIDR at 38.41 ± 5.8. Animals were AI at detected oestrus until 170 dpp and calculated as pregnant at first service or requiring more than one service (1s and >1s), not pregnant but cycling (not pregnant) and those not cycling at all (anestrus). The FAT measurements were taken twice each month from the last trimester of gestation until 96 dpp. The onset of ovarian activity was monitored through blood levels of progesterone (P4) at days 14 and 9 prior to CIDR insertion and days 10, 13, 30 and 33 after CIDR withdrawal. Animals pregnant did not have any major changes in their fat thickness. In contrast, cows pregnant in the group ≥30 dpp had changes in their FAT homoeostasis, and pregnant animals in the 1s and >1s groups did not show differences in dorsal back fat in the last trimester of pregnancy and early postpartum. In contrast, animals not pregnant and in anestrus FAT values decreased considerably after parturition. Overall, fertility was 49%, but 18% of all the animals remained anestrus losing FAT. Thus, animals with adequate metabolic conditions will have a better chance of pregnancy regardless of the time postpartum when the reproductive programme starts.  相似文献