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The objectives of the present study were to assess the reproductive performance and cumulative incidence risk of reproductive disorders and to compare the success of artificial insemination (AI) to natural service (by handmating; NS) in dairy cattle kept in smallholder herds under a zero-grazing system in a rural highland area of Tanzania. Data on occurrence of all normal and abnormal reproductive events were collected for 215 adult animals belonging to 74 households.

The median and range of the intervals: intercalving, calving to first service, and calving to pregnancy were 477 (335–860), 154 (38–486) and 206 (61–567) days, respectively. Breed and parity did not affect the reproductive parameters (P>0.05). However, cows in the milked group had a shorter median calving interval than those in the suckled group (P<0.001). The overall percentage pregnant and the percentage pregnant to first service were higher in the NS than in the AI group (49 vs. 32%; P=0.007) and (67 vs. 25%; P<0.001), respectively. The median numbers of services per pregnancy were not different between the AI (3) and NS (2) groups (P=0.17). The cumulative incidence risk of abortion, dystocia, prolapse, retained fetal membranes, mastitis, milk fever and cyclic non-breeders were 16.0, 1.7, 2.5, 4.2, 5.0, 1.7, and 6.1%, respectively. Hoof overgrowth (4.6%) and hoof deviation (4.6%) were the most-frequent digital problems. We concluded that reproductive parameters and cumulative incidence risk of abortion show suboptimal reproductive performance in rural-based, zero-grazed smallholder dairy herds in Tanzania particularly those using AI.  相似文献   

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The polypeptides of an Australian isolate of bovine herpesvirus 1 were analysed by polyacrylamide gel electrophoresis, and Western blotting was used to identify those polypeptides which reacted most strongly with sera from infected animals. Approximately 20 polypeptides ranging in molecular weight from 11,000 to 240,000 daltons (11-240K) were identified by 35S-methionine labelling of virus and approximately half of these classed as glycoproteins using 14C-mannose and 3H-glucosamine incorporation into infected cells. Convalescent sera from cattle all reacted strongly with glycoprotein bands at 85 and 70K, with most sera also recognizing another band at 140-150K. The intensity of bands on the Western blot analyses was found to correlate well with neutralization titres of individual serum samples, indicating the involvement of these proteins in virus neutralization. The importance of the 70K glycoprotein was supported by the finding that, of 12 monoclonal antibodies studied, those 3 with the strongest neutralizing activity, were those which recognized a band at 70K in Western blot experiments.  相似文献   
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A total of 8190 cattle from 42 well-managed herds in the Lake Victoria zone of Tanzania were tested for bovine tuberculosis by a single comparative intradermal test (SCITT) using avian and bovine purified protein derivative (PPD) antigens. The prevalence of bovine tuberculosis in this area was found to be 0.2%. There was significant variation (p<0.001) among the herds tested in the four regions in this zone (Kagera, Mara, Mwanza and Shinyanga). The highest prevalence (2.12%) was in a herd of 566 cattle which had recently arrived in Kagera region from Dar-es-Salaam. None of the 915 cattle tested in Shinyanga or of the 254 resident cattle in the Kagera region were positive by SCITT. This area, and particularly the Kagera region, has the highest human morbidity and mortality due to the acquired immunodeficiency syndrome in Tanzania. Therefore, the presence of bovine tuberculosis in cattle necessitates further investigations on the role of animal-derived tuberculos is in human health.  相似文献   
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Constraints and probable pathway towards increasing tree density and diversity within farmlands as a means of reducing human dependency on Mt. Marsabit forest for wood are addressed. The forest provides a carbon sink to counteract the risks and hazards associated with climate change. A structured questionnaire was administered to a sample of 205 respondents that were selected from a population of 3075 farming households using a systematic random sampling procedure. While majority of the farms (53%) had low tree density (1-10 trees), only 8% of the farms had high density (≥ 20 trees). About 50% and 15% farms had Grevelia robusta and Eucalyptus cammudelensis, which were grown for timber production, respectively. Broad leafed trees, like Croton megalocarpus and Moringa stenoptella had been established in 17% of the farmlands, respectively. With only 20% of the households having a fence around the crop fields, coupled by widely inter-household sharing of crop residues for grazing, tree browsing by livestock was a constraint to tree establishment. The challenges present an opportunity to establish governance structures and processes for communal responsibility and management of tree resources in the farms. A plausible approach entails the Adaptive Collaborative Management (ACM) as a process that facilitates to experiential learning and negotiation for probable actions and policies in management of natural resources.  相似文献   
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