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111.
The future of beef cattle production in tropical regions is uncertain because of land tenure concerns, threatening the survival of extensive management programmes in these areas of the world. The need to intensify production systems will inevitably lead to changes in the management of replacement animals in existing herds. The present review underlines the main constraints, which in the past could be resolved by the sheer numbers of animals present in beef cattle operations, with replacements reliant only on finding enough heifers to substitute the adult females destined for culling. This scenario is rapidly changing as beef cattle units in tropical regions subdivide to share out the land between as many farmers as possible. Consequently, issues such as the efforts needed to manage the pregnant cow, particularly her nutritional status and its effect on the new‐born calf, the future replacement heifer growing in the presence of the dam, weaning management and procedures required before a heifer can be introduced into a breeding programme, need to be adequately and efficiently addressed by farmers in tropical regions. 相似文献
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Influence of Cysteamine on In Vitro Maturation, In Vitro and In Vivo Fertilization of Equine Oocytes
S Deleuze CS Dubois M Caillaud B Bruneau G Goudet G Duchamp 《Reproduction in domestic animals》2010,45(1):1-7
The effect of cysteamine on in vitro nuclear and cytoplasmic maturation of equine oocytes collected by transvaginal ultrasound guided follicular aspiration was assessed. Oocytes were matured in vitro with (cysteamine group) or without (control group) cysteamine. The nuclear stage after DNA Hoechst staining, penetration rates after two different in vitro fertilization (IVF) techniques (IVF media with ionophore and Hepes buffer with heparin) and the embryo yield following oocyte intra-oviductal transfer were used as a criterion for assessing nuclear and cytoplasmic maturation, respectively. Contrary to the data described in other domestic species, there was no effect of cysteamine on in vitro nuclear maturation, IVF or in vivo embryonic development under our conditions. Ovum pick up yields (52%) and maturation rates (control group: 47% and cysteamine group: 55%) were similar to those previously reported. From 57 oocytes transferred to the oviduct in each group, the number of embryos collected was 10 (17%) in the control group and five in the cysteamine group (9%). Those two percentages were not statistically different (p > 0.05). No effect of IVF technique was seen on the success rate (6%) in each group. 相似文献
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Identification of lactoferrin and glutamate receptor‐interacting protein 1 in bovine cervical mucus: A putative marker for oestrous detection 下载免费PDF全文
WY Lee MH Park KW Kim H Song KB Kim CS Lee NK Kim JK Park BC Yang KB Oh GS Im HJ Chung 《Reproduction in domestic animals》2017,52(1):16-23
Accurate detection of oestrus is important for artificial insemination. The aim of this study was to identify oestrous‐specific bovine cervical mucus proteins that could be used to determine the optimal time for artificial insemination. Non‐oestrous and controlled internal drug release (CIDR)‐induced oestrous‐stage mucus proteins were purified and subjected to surface‐enhanced laser desorption/ionization time‐of‐flight mass spectrometry, sodium dodecyl sulphate polyacrylamide gel electrophoresis and MALDI‐TOF/TOF. Among differentially expressed proteins, lactoferrin (LF) and glutamate receptor‐interacting protein 1 (GRIP1) showed a twofold increase during the CIDR‐induced oestrous stage compared to the levels in non‐oestrous stage in bovine cervical mucus. The RT‐PCR, Western blotting and immunohistochemistry results showed that LF and GRIP1 expression was significantly increased during the oestrous stage in the uterus. This study demonstrated that bovine LF and GRIP1 exist during the oestrous stage, but not during the non‐oestrous stage, suggesting that cervical mucus LF and GRIP1 are useful oestrous detection markers in cattle. 相似文献
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Andrea Ladinig Wilhelm Gerner Armin Saalmüller Joan K Lunney Carolyn Ashley John CS Harding 《Veterinary research》2014,45(1)
In spite of more than two decades of extensive research, the understanding of porcine reproductive and respiratory syndrome virus (PRRSv) immunity is still incomplete. A PRRSv infection of the late term pregnant female can result in abortions, early farrowings, fetal death, and the birth of weak, congenitally infected piglets. The objectives of the present study were to investigate changes in peripheral blood mononuclear cell populations in third trimester pregnant females infected with type 2 PRRSv (NVSL 97–7895) and to analyze potential relationships with viral load and fetal mortality rate. PRRSv infection caused a massive, acute drop in total leukocyte counts affecting all PBMC populations by two days post infection. Except for B cells, cell counts started to rebound by day six post infection. Our data also show a greater decrease of naïve B cells, T-helper cells and cytolytic T cells than their respective effector or memory counterparts. Absolute numbers of T cells and γδ T cells were negatively associated with PRRSv RNA concentration in gilt serum over time. Additionally, absolute numbers of T helper cells may be predictive of fetal mortality rate. The preceding three leukocyte populations may therefore be predictive of PRRSv-related pathological outcomes in pregnant gilts. Although many questions regarding the immune responses remain unanswered, these findings provide insight and clues that may help reduce the impact of PRRSv in pregnant gilts. 相似文献
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Jean‐Luc Solandt Stephen K. Pikesley Colin Trundle Matthew J. Witt 《水产资源保护:海洋与淡水生态系统》2020,30(9):1829-1835
- Case studies of Marine Protected Area (MPA) upscaling were solicited from participants of a workshop at the International Marine Protected Areas Conference held in Autumn 2013 in Marseille.
- One such case study was Solandt, Jones, Duval‐Diop, Kleiven, and Frangoudes (2014; Governance challenges in scaling up from individual MPAs to MPA networks. Aquatic Conservation: Marine and Freshwater Ecosystems, 24, 145–152) which illustrated the role of science, non‐governmental organizations, government and local regulators in applying systemic management measures for local MPAs based on risk, highlighting the importance of balancing top‐down and bottom‐up drivers.
- Here we follow up on the UK example, illustrating the incentives and actors involved in developing centralized and subsequent fisheries management measures in UK waters. Forty local laws were created to protect features in 143 inshore MPAs between 2013 and 2019.
- We illustrate best practice in delivering management, focusing on multiple practitioner involvement in a single MPA and the monitoring put in place after trawling and dredging were banned.
- We reflect on how the governance mechanisms in place in English inshore waters can be used as a template to allow for progressive MPA management in other coastal states.
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