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1.
Three-year-old, non-lactating and non-pregnant Merino ewes, raised on pasture under a program of strategic treatment with anthelmintic and found to be extremely resistant to "trickle" infection with Haemonchus contortus, were given single-dose infections with either H. contortus or Trichostrongylus colubriformis or both species together. The purpose was to ascertain the intensity of protective immunity against the 2 parasites in sheep with immunity acquired from a presumably slight exposure to infection. To provide a criterion, some infected ewes were immunosuppressed with corticosteroid, dexamethasone. Untreated ewes were extremely resistant to challenge infection with either 15,000 or 150,000 H. contortus or 15,000 T. colubriformis. Surprisingly, when mixed infection was given, egg counts for H. contortus were significantly elevated compared with infection by that species alone. Antibody to antigens from infective larval and adult H. contortus was measured in serum by enzyme-linked-immunosorbent assay (ELISA) during the course of infection. Serum titres against larval antigens were significantly depressed when infections with either H. contortus or T. colubriformis were permitted by immunosuppression with dexamethasone, whereas those against adult antigen were depressed when infection with T. colubriformis was permitted.  相似文献   
2.
AIM: To investigate a possible interaction between lolitrem B and ergovaline by comparing the incidence and severity of ryegrass staggers in sheep grazing ryegrass (Lolium perenne) containing lolitrem B or ryegrass containing both lolitrem B and ergovaline.

METHODS: Ninety lambs, aged approximately 6 months, were grazed on plots of perennial ryegrass infected with either AR98 endophyte (containing lolitrem B), standard endophyte (containing lolitrem B and ergovaline) or no endophyte, for up to 42 days from 2 February 2010. Ten lambs were grazed on three replicate plots per cultivar. Herbage samples were collected for alkaloid analysis and lambs were scored for ryegrass staggers (scores from 0–5) weekly during the study. Any animal which was scored ≥4 was removed from the study.

RESULTS: Concentrations of lolitrem B did not differ between AR98 and standard endophyte-infected pastures during the study period (p=0.26), and ergovaline was present only in standard endophyte pastures. Ryegrass staggers was observed in sheep grazing both the AR98 and standard endophyte plots, with median scores increasing in the third week of the study. Prior to the end of the 42-day grazing period, 22 and 17 animals were removed from the standard endophyte and AR98 plots, respectively, because their staggers scores were ≥4. The cumulative probability of lambs having scores ≥4 did not differ between animals grazing the two pasture types (p=0.41).

CONCLUSIONS AND CLINICAL RELEVANCE: There was no evidence for ergovaline increasing the severity of ryegrass staggers induced by lolitrem B. In situations where the severity of ryegrass staggers appears to be greater than that predicted on the basis of concentrations of lolitrem B, the presence of other tremorgenic alkaloids should be investigated.  相似文献   

3.
The inbreeding coefficients are considered in breeding decisions, and the inverse numerator relationship matrix A ?1 is a prerequisite for breeding value estimation. Polyandry and haploid males are among the specifics of relationships between honey bees. Brascamp and Bijma (2014) averaged out the manifold possible relationships among honey bees that appear to have the same parents in a pedigree and assigned a single entry in A to animals that behave as a unit, for example, the workers of a hive. Their methods of calculation connected full‐sibs in the variance matrix of the Mendelian sampling terms D , via nonzero off‐diagonal elements. This impedes the inversion of A and the closely connected calculation of inbreeding coefficients, because efficient algorithms for this task take D to be a diagonal matrix. Memory limitations necessitate their use for large data sets. We adapted the quickest of them to the block diagonal matrix D , that is postulated for the honey bee. To our knowledge, the presented algorithm is the first one that facilitates the method of Brascamp and Bijma (2014) on large data sets.  相似文献   
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5.
以曲靖市兽药监察所最近十年的兽药质量监督抽检报告为基础材料进行统计分析,反映兽药质量监督抽检工作情况及兽药质量状况。  相似文献   
6.
论述了对兽药生产企业进行人员在岗培训的必要性,对实施在岗培训的基本程序和应注意的事项进行了总结,旨在为兽药企业进行GMP现场管理提供参考。  相似文献   
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8.
The ring‐tailed coati (Nasua nasua) is a procyonid whose population is in sharp decline. Therefore, studies are needed to better understand the reproduction of this animal. For this reason, this study aimed to evaluate the morphology, morphometry and sperm ultrastructure of ring‐tailed coati sperm. Four captive adult males were used for this study. Slides stained with Bengal Rose were used for the morphometric and morphologic analyses. The length and width of the head were measured, as well as the length of the midpiece and tail and the total length of the sperm. Scanning electron microscopy and transmission electron microscopy were used for the ultrastructural analyses. The most obvious morphological abnormalities observed were coiled tails (6.1 ± 8.7%) and the lack of acrosomes (5.4 ± 4.4%). Regarding the morphometry, the measurements of the head (length × width), midpiece (length) and tail (length) were (mean ± SD) 6.2 ± 0.4 × 8.1 ± 0.6 μm, 14.1 ± 0.5 and 63.9 ± 4.1 μm, respectively, and the total length of the sperm was 86.1 ± 4.3 μm. Through electron microscopy, the presence of electron‐lucent points in the nucleus and the presence of approximately 55 mitochondrial spirals in the midpiece were identified. The data obtained in this study provide detailed information on the sperm characteristics of coatis and may inform future research on germplasm conservation, both for this species and other threatened procyonids.  相似文献   
9.
Two groups of cows infected with the bovine leukosis virus (BLV) were kept on two different diets and the fat content of their milk was assayed. The results were compared with those obtained from two comparable groups of BLV-free cows. The cows in each group were of similar ages, those in the groups on the poorer diet being 1–4 months post partum, while those on the richer diet were 5–7 months post partum. The mean percentage of fat in the milk from uninfected cows on the poorer diet was 2.94 while that from the similar infected cattle was 3.06. Uninfected cows on the richer diet produced milk containing 3.39% fat, while those that were infected produced milk containing 3.30% fat. No statistical differences in milk fat production were observed between the BLV seropositive and seronegative cows.  相似文献   
10.
The fat in vegetable foods--tree nuts, peanuts, sunflower seeds, avocado, and olives--can be determined volumetrically by acid digestion of the material and separation of the fat. The assay can be performed conveniently by using the equipment developed for fat determination of milk (Gerber method). The results agree well with those obtained by Soxhlet extraction. The advantages of using the Gerber method for vegetable foods are simplicity, speed, low operation cost, and elimination of the use of inflammable solvents.  相似文献   
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