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991.
J. Gordon ArbuckleJr. Corinne Valdivia Andrew Raedeke John Green J. Sanford Rikoon 《Agroforestry Systems》2009,75(1):73-82
Land tenure has long been considered a critical factor in determining the adoption and long-term maintenance of agroforestry
practices. Empirical evidence from non-US settings has consistently shown that secure land tenure is positively associated
with agroforestry adoption. In the US, over 40% of private agricultural land is farmed by someone other than the owner. Given
the importance of land tenure in agroforestry decisions in other countries and the magnitude of non-operator landownership
in the US, there has been surprisingly little focus on land tenure in the temperate agroforestry literature. Using data from
a 1999 survey in Missouri, this study explores factors associated with non-operator landowner interest in agroforestry. Results
suggest that differences in farming orientation are linked to interest in agroforestry. Closer ties to farming, stronger financial
motivations for landownership, and higher proportion of land planted to row crops were negatively related to interest in agroforestry
among non-operator landowners. Environmental or recreational motivations for landownership and contacts with natural resource
professionals were positively associated with interest in agroforestry. These results, consistent with earlier qualitative
research suggesting that farm operators who have a strong “conventional farming identity” were less interested in agroforestry,
point to a divide between landowners for whom environmental and recreational values play an important role in ownership motivation
and those for whom financial considerations take precedence. The findings imply that agroforestry development programs in
the US should take non-operator landowners and their farming and ownership orientations into account when designing research
and outreach efforts.
相似文献
J. Gordon Arbuckle Jr.Email: |
992.
苯达松敏感基因在杂交水稻制种技术上的应用研究(英文) 总被引:1,自引:0,他引:1
WANG Shi-mei ZHU Qi-sheng WANG Wan-lin ZHANG De-wen YANG Qian-jin WANG Yun-sheng .Green Food Project Research Institute Anhui Academy of Agricultural Sciences Hefei .Anhui Agricultural University Hefei 《(《农业科学与技术》)编辑部》2008,(1)
The seed production of male and female parent of 'Hunzhi 1' contained bentazon susceptible gene was studied.The result showed that spraying 3.375 L/hm2 48% bentazon aqua could control the self-pollinated fertilization rate below 1.0% and survival plant rate was 0.The spray of bentazon would not influence MC526 pollen vitality.Seed setting rate of female parent was not obvious different from that of control group with spraying bentazon aqua more than 3.375 L/hm2 from the sprouting appearing period to full heading stage.This demonstrated that bentazon aqua had no influence on seed setting rate during florescence of female parent.The weight ratio between male parent seeds and female parent seeds was 1 to 5,then seeds from parents with that weight ratio would be mixedly planted for seed production.With this weight ratio,relative proper structure of panicle and grain would be obtained,panicle ratio was 1 to 4.3,glumous flowers ratio was 1 to 3.5.Cross seed-setting rate of female parent was 72.6% and seed production per hm2 was 66 000 kg. 相似文献
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Martin J. Green Graham F. Medley Andrew J. Bradley William J. Browne 《Veterinary research》2010,41(2)
Knowledge of the efficacy of an intervention for disease control on an individual farm is essential to make good decisions on preventive healthcare, but the uncertainty in outcome associated with undertaking a specific control strategy has rarely been considered in veterinary medicine. The purpose of this research was to explore the uncertainty in change in disease incidence and financial benefit that could occur on different farms, when two effective farm management interventions are undertaken. Bovine mastitis was used as an example disease and the research was conducted using data from an intervention study as prior information within an integrated Bayesian simulation model. Predictions were made of the reduction in clinical mastitis within 30 days of calving on 52 farms, attributable to the application of two herd interventions previously reported as effective; rotation of dry cow pasture and differential dry cow therapy. Results indicated that there were important degrees of uncertainty in the predicted reduction in clinical mastitis for individual farms when either intervention was undertaken; the magnitude of the 95% credible intervals for reduced clinical mastitis incidence were substantial and of clinical relevance. The large uncertainty associated with the predicted reduction in clinical mastitis attributable to the interventions resulted in important variability in possible financial outcomes for each farm. The uncertainty in outcome associated with farm control measures illustrates the difficulty facing a veterinary clinician when making an on-farm decision and highlights the importance of iterative herd health procedures (continual evaluation, reassessment and adjusted interventions) to optimise health in an individual herd. 相似文献
998.
FM Monteiro MMG Ferreira JR Potiens BG Eberhardt LA Trinca CM Barros 《Reproduction in domestic animals》2010,45(5):860-864
There are indications in the literature that delaying the period between ovarian superestimulation and ovum pick up (OPU) would induce follicles to a condition of initial atresia, which could be beneficial to oocyte development. In this work, we compared three protocols for OPU and in vitro production (IVP) of embryos, in Nellore cattle. Nellore cows (n = 18) were randomly allocated in three groups: Group 1 (OPU), Group 2 [Follicle stimulating hormone (FSH) and OPU] and Group 3 (FSH deprivation and OPU). Three OPUs were performed, and the animals were switched to a different group each time (crossover), in such a way that at the end of the experiment all cows received the 3 protocols. At random stage of the oestrous cycle (D‐2), all follicles ≥ 6 mm were aspirated to induce a new follicular wave 2 days afterwards (D0). In Group 1, OPU was performed on D2 and oocytes were processed to IVP. In Group 2, starting on D0, cows were superstimulated (FSH, Folltropin®, 30 mg administered daily, i.m., during three consecutive days, total dose = 180 mg), and 6 h after the last FSH dose, they received exogenous luteinizing hormone (LH) (12.5 mg, i.m., Lutropin®, D3). The OPU was performed 6 h after LH administration, i.e. 12 h after the last dose of FSH. Animals in Group 3 received the same treatment as those in Group 2, except that LH was administered 42 h after the last dose of FSH, and OPU occurred 6 h later. Therefore, in this group, follicles were deprived of FSH at 48 h. Both cleavage and blastocyst rates were similar (p > 0.05, anova ) among oocytes from Groups 1, 2 and 3, respectively: 77.4% (144/185) and 42.70% (79/185); 75.54% (105/139) and 31.65% (44/139); 63.52% (101/159) and 33.33% (53/159). However, hatched blastocyst rate was higher (p < 0.01) in Group 1 (30.27%, 56/185) when compared with Group 2 (11.51%, 16/139) or 3 (15.72%, 25/159). It is concluded that, contrary to previous work on European breeds (Bos taurus), ovarian superstimulation associated with deprivation of FSH and OPU (Group 3) did not increase IVP of Nellore embryos (Bos indicus). On the contrary, the highest hatched blastocyst rates were observed in oocytes from non‐superstimulated cows. 相似文献
999.
Prostaglandin F2α and its analogues (PGF) are widely used in equine reproductive practice. The interval from PGF treatment to ovulation (ITO) varies greatly with a range from 2 to 16 days. Clinical observation suggests that mares mated and ovulated soon after PGF treatment may have poor fertility. Reproductive records of 329 cyclic Thoroughbred mares were analysed retrospectively. The following parameters were analysed: (i) use of cloprostenol; (ii) ITO and (iii) number of ovulations per cycle. According to these parameters, mares were classified into four groups. (i) mares with spontaneous ovulations, n = 57; (ii) mares induced with cloprostenol and ITO = 4–7 days, n = 77; (iii) ITO = 8–10 days, n = 89 and (iv) ITO = ≥11 days, n = 106. Differences in pregnancy (PR) and multiple ovulation (MO) rates among groups were tested using chi‐squared test. PR rates for groups 1–4 were: 73.7%, 46.7%, 64% and 71.7% respectively (p < 0.05). Groups 1 and 2 had lower (p < 0.05) MO rate (24.6% and 20.8%) than groups 3 and 4 (40.4% and 44.3%). It appears that ovulation soon after PGF‐induced luteolysis is detrimental to PR rates. It was found highly significant that in cloprostenol‐treated mares, the MO rate was enhanced without subsequent increase in multiple pregnancies. 相似文献
1000.
A 27‐year‐old Thoroughbred gelding was examined for a right nasal mass visible inside the right nares. Airflow through the right nostril was absent. Endoscopy and radiography revealed the mass to occupy the entire right nasal passage. Nasal biopsies were inconclusive, so en bloc resection was performed. A diagnosis of an incompletely resected osteoblastic osteosarcoma was made. Endoscopic biopsies performed 4 weeks post surgery revealed osteosarcoma cells present in the caudal right nasal cavity. Metastatic disease was not present in mandibular lymph node aspirates or on thoracic radiographs. The right nasal passage was irradiated with 12 treatments over the course of 4 weeks. Comfort and quality of life were excellent during treatment and no adverse side effects were noted. Endoscopy and follow‐up biopsies at 1, 2, 4, 12 and 14 months post radiation therapy have not found any evidence of regrowth of the osteosarcoma. 相似文献