首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   72篇
  免费   9篇
综合类   2篇
水产渔业   1篇
畜牧兽医   78篇
  2023年   1篇
  2020年   2篇
  2019年   2篇
  2018年   7篇
  2017年   3篇
  2016年   1篇
  2014年   2篇
  2013年   18篇
  2012年   1篇
  2011年   1篇
  2009年   4篇
  2008年   2篇
  2006年   1篇
  2003年   2篇
  2002年   2篇
  2001年   3篇
  1998年   5篇
  1997年   3篇
  1996年   2篇
  1995年   3篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   5篇
  1989年   6篇
  1988年   1篇
  1987年   1篇
排序方式: 共有81条查询结果,搜索用时 15 毫秒
21.
SUMMARY The prevalence of Mycobacterium bovis infection in populations of feral pigs from five areas in the Northern Territory was examined. In total 790 pigs were necropsied and positive cultures of M bovis were obtained from two pigs (0.25%) and a mycobacterial granuloma was found in one pig. The observed prevalence of M bovis infection in feral pigs is significantly less (x2= 139.8, df = 1, P < 0.001) than the results of a comparable survey conducted during the early 1970s before the implementation of the Brucellosis and Tuberculosis Eradication Campaign. The prevalence of all types of macroscopic lesions resembling tuberculosis was significantly (x2= 338.7, df = 1, P < 0.001) less than the earlier survey. The results are further support for the hypothesis that in the Northern Territory feral pigs are an end-host for M bovis infection, and that the previous high prevalence of M bovis recorded in feral pigs in the 1970s was caused by the close association between these animals and large populations of M bovis-infected buffalo and cattle.  相似文献   
22.
23.
AIMS: The aims of this study were (a) to evaluate the effect of xylazine and tolazoline, with and without lignocaine, on the cortisol response of calves following amputation dehorning and (b) to assess the effect of a non-steroidal anti-inflammatory drug (ketoprofen) and local anaesthesia on the cortisol response of calves to amputation dehorning.

METHODS: Plasma cortisol concentrations were measured in 100 dehorned or non-dehorned 3-month-old calves over an 8-h period following five different sedative/analgesic or control treatments. Sedative/analgesic treatments were: control (no anaesthesia); local anaesthesia and ketoprofen; local anaesthesia and xylazine; local anaesthesia, xylazine and tolazoline; and xylazine only. Within each sedative/analgesic treatment group, half the calves (n=10 per group) were amputation dehorned and half were not dehorned.

RESULTS: The change in plasma cortisol concentrations in calves dehorned after being given ketoprofen and local anaesthesia did not differ significantly from that of non-dehorned control calves for at least 8 h. In contrast, the cortisol response of dehorned calves not given analgesic drugs peaked 30 min after dehorning and lasted >4 h. Xylazine injected before dehorning significantly reduced but did not eliminate the peak of the cortisol response. When both xylazine and local anaesthesia were administered before dehorning the peak in the cortisol response was virtually eliminated. In the dehorned calves that received xylazine with or without local anaesthesia, cortisol concentration increased significantly 3 h after dehorning and did not return to baseline until at least 5 h later. When tolazoline was administered shortly after xylazine, it caused a marked cortisol response, higher than the response to any other treatment.

CONCLUSIONS: Combining ketoprofen and local anaesthesia minimised the cortisol response, and by inference the pain- induced distress, following amputation dehorning in calves. Xylazine reduced the initial cortisol response to dehorning but not as much as when local anaesthesia was also given. The increase in cortisol concentration from 3–8 h after dehorning in calves given xylazine alone or in combination with local anaesthesia suggests that calves experienced pain-induced distress during this time and that xylazine had no long-term analgesic effect. Tolazoline, used to reverse the sedative effects of xylazine, caused a marked cortisol response in calves via a mechanism which remains unclear.  相似文献   
24.
AIM: To determine the physiological status of calves at birth and the perinatal factors that might predispose newborn calves to debility and death, using criteria previously established for newborn lambs.

METHODS: Friesian mixed-aged cows and heifers on a dairy farm in New Zealand that were close to calving were separated from the main herd and observed 24 h a day until they calved. Cows in which labour did not progress for over 1 h or which were in distress were assisted. About 12–13 min after birth, rectal temperature was measured and a blood sample was taken from each calf. The packed cell volume (PCV) and plasma lactate, glucose and fructose concentrations were determined. The time to stand for each calf and the air temperature and weather conditions at birth were recorded.

RESULTS: The parameters measured were within normal ranges for newborns for the majority of calves. Calves sired by an Angus bull and born to heifers (AngusX) had significantly higher plasma lactate and fructose concentrations than Friesian calves born to cows, but there were no significant differences between the two breeds in any of the other parameters measured. Calves of both breeds born with assistance had significantly higher plasma lactate concentrations than those born without. Friesian calves that were assisted at birth had significantly lower PCvs and took significantly longer to stand than calves born without assistance. Assisted AngusX calves were significantly heavier than their unassisted counterparts. Calves born during windy and wet weather and when air temperatures were below 10°C had lower rectal temperatures, took longer to stand and had higher plasma glucose concentrations than those born in dry weather and when air temperatures were above 10°C.

CONCLUSIONS: Calves with physiological parameters outside the normal range had experienced difficult labour and/or intrapartum hypoxaemia. Placental insufficiency and maternal undernutrition during late pregnancy did not apparently contribute to neonatal problems in the present study.  相似文献   
25.
AIM: To determine the feeding ability of calves during the first 4 days after birth.

METHODS: The sucking behaviour of 171 dairy calves, fed from individual bottles during the first 4 days after birth, was evaluated by quantifying the volume of colostrum consumed, the duration of feeding, and speed of drinking. Calves had been separated from their mothers and brought into a rearing shed in the morning, when <24 h of age, and were offered 2 L colostrum from a bottle in the afternoon of the same day, and twice daily thereafter.

RESULTS: Newborn calves became efficient suckers from bottles within 24 h of removal from their dams (collection). On the day after birth, 95% of calves drank the 2 L of colostrum offered during the afternoon feed, and by Day 4 virtually all calves (99%) drank this amount. Calves that had inadequate colostrum from their dam were more likely to drink all 2 L offered after collection, but a small number of calves that had not had colostrum from their dams and drank <500 ml at the afternoon feed following collection were likely not to drink 2 L on the following days. However, calves that did not drink all 2 L on Day 1 were not disadvantaged in comparison to those that did, in that they were equally likely to drink 2 L on Day 4.

CONCLUSIONS: The majority of calves became efficient drinkers within 48 hours of birth, but a small number of slow feeders may need individual feeding at least up to 4 days after birth.  相似文献   
26.
AIM: To investigate the circumstances of dogs biting people in New Zealand.

METHODS: Veterinary science and veterinary nursing students enrolled at Massey University in 2003 completed a questionnaire detailing their lifetime experience of dog bites and their opinions of dog control legislation.

RESULTS: The response rate was 100%. There were 228 completed responses to the survey, and 87 (38%) respondents had been bitten by a dog. Most bites caused minor injury, but 17 (20%) required medical attention. Male respondents were more likely to have been bitten. The highest proportion of respondents (27; 31%) had been bitten while between 6 and 10 years of age, and the hand was the part of the body most often injured. Eighteen (21%) bites involved a stranger's dog, but most bites were by a dog known to the victim. Respondents from rural areas were three times more likely to have been bitten than city dwellers. The victim's home was the place where most (31; 36%) bites occurred. Male dogs were responsible for a larger proportion of bites (38; 44%) than females (24; 28%); respondents were unsure about the sex of the remainder of the dogs (25; 29%) that bit them. Protecting the home, play, accidents, rough handling and pain were identified as the common reasons for dogs to bite. Most (46; 52%) respondents did not believe legislation could have prevented their bite. Only four (5%) bites were reported to authorities.

CONCLUSION: Rural dwellers, people with more experience of dogs, children <11 years of age, and male respondents were bitten by dogs most often. Only legislation relating to the fencing of dog owners′ properties may have prevented a reasonable proportion (25; 29%) of the bites reported here.  相似文献   
27.
Atlantic salmon were fed one of four diets with increasing levels (11–58%of total fatty acids (FAs)) of n‐3 highly unsaturated FAs (HUFAs) in order to investigate the effect on muscle and mitochondrial membrane lipids and their susceptibility to oxidative stress. The high n‐3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) groups contained lower percentages of sphingomyelin and cardiolipin in total muscle than the intermediate n‐3 HUFA group. Cardiolipin and sphingomyelin are particularly susceptible to peroxidation, and a reduced percentage of these lipids showed that mitochondrial membranes had been damaged by oxidation. The intermediate n‐3 HUFA group had the highest level of mitochondrial integrity and tendencies of lower thiobarbituric acid reactive substances (TBARS) level than the other dietary groups. The high caspase‐3 activity, in addition to casp3a and bax gene expression levels, in the n‐3 DHA group also suggests that some degree of oxidative stress had occurred. Electron microscopy images showed a higher degree of myofibre–myofibre detachment in fish fed the high HUFA diets than in fish fed the intermediate n‐3 HUFA diet. Our findings show that intermediate levels of n‐3 HUFAs in salmon diets gave the best protection against oxidative damage of mitochondrial membranes and muscle structure.  相似文献   
28.
Following the routine use of tiabendazole at monthly intervals for several years, the trichostrongyle parasites of sheep and goats on a government research station in North-West Cameroon had become resistant to benzimidazole anthelmintics.  相似文献   
29.
30.
Reply     
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号