The combined effect of fenbendazole treatment and a move to aftermath 7 or 9 weeks after turnout on Dictyocaulus viviparus infections in calves     

M. Eysker  J. H. Boersema  F. N. J. Kooyman  T. J. G. M. Lam 《Veterinary parasitology》1995,60(3-4):339-348

A grazing study was performed with the main objective of examining the effect of fenbendazole (FBZ) in a ‘dose and move’ system on nematode infections in calves with special emphasis on Dictyocaulus viviparus.

Three groups of six calves were grazed from May to October 1993. One group (DM7) was treated with FBZ and moved to aftermath (pasture which had only been mown) 7 weeks after turnout. The second group (DM9) was similarly treated and moved 9 weeks after turnout and the third group served as untreated pasture control group (PC) and was moved to aftermath 9 weeks after turnout.

FBZ treatment removed adult lungworms from DM7 and DM9. Tracer calves grazed during the first 7 or the first 9 weeks after turnout acquired mean burdens of 18 and 125 lungworms, respectively. In PC faecal larval counts increased until the end of August. Most of the animals in this group were then suffering from lungworm disease and emergency treatment with ivermectin was given. In both FBZ-treated groups, larvae reappeared in the faeces of some of the calves 4–5 weeks after treatment. Subsequent reinfection resulted in higher mean faecal larval counts in both groups 2 months after treatment, although variation in faecal larval counts was high. In DM7 values tended to be higher than in DM9. These higher larval counts were associated with mild signs of parasitic bronchitis in some calves of DM7, whereas no signs were seen in DM9.

At the end of the experiment, all calves, and also a group of six permanently housed non-infected control calves (HC), were infected experimentally with 5000 D. viviparus larvae to evaluate development of immunity. The worm counts at necropsy showed that all calves on pasture had developed immunity.  相似文献   

Relationships between catch and effort in Fijian multispecies reef fisheries subject to different levels of exploitation   总被引：2，自引：0，他引：2  

S. JENNINGS  N.V.C. POLUNIN 《Fisheries Management and Ecology》1995,2(2):89-101

Abstract The catch-per-unit-effort (CPUE) and value-of-catch-per-unit-effort (VPUE) of reef-associated fish species from six Fijian native fishing grounds ( qoliqoli ) subject to different fishing intensities were determined using records of fishing activity from a voluntary logbook scheme. Line and spear fishing techniques were used for more than half the total fishing time (h person^-1 d^-1) in all qoliqoli , and yet the favoured technique in a given qoliqoli was frequently less efficient (lower CPUE) than other techniques. The popularity of relatively ineffective fishing methods implies that fishermen did not always attempt to maximize their catch rates. To compare fishing effort in different qoliqoli , all effort was rescaled on the basis of its recorded efficiency (measured as multispecies CPUE) and expressed as hours equivalent to boat-based spear fishing over coral by day to catch fish for sale. Total fishing intensity in the six qoliqoli ranged from 72 to 4310 h km^-2 reef year^-1. The relationship between catch and effort was linear at all fishing intensities, suggesting that the qoliqoli were all fished on a sustainable basis. Furthermore, whilst there was a significant difference in CPUE and VPUE between the one or two qoliqoli with lowest fishing intensity and all the others, there were no significant differences between these other qoliqoli in terms of the VPUE of the saleable multispecies boat catch or the CPUE of species from piscivorous and carnivorous genera ( Epinephelus, Lethrinus and Plectropomus ) which the fishermen prefer to catch.  相似文献   

Transforming genes: oncogenes, genes, and growth factors     

Ihle JN 《Science (New York, N.Y.)》1987,237(4818):1060-1061

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Behavioral ecology: ecological aspects of social evolution     

Austad SN 《Science (New York, N.Y.)》1987,236(4800):470

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Response of egg weight to the inclusion of various fats in layer diets     

R. H. Scragg  N. B. Logan  N. Geddes 《British poultry science》1987,28(1):15-21

1. Brown egg layers were fed diets differing in oil content, oil source and linoleic acid concentration and the effect on performance from 22 to 69 weeks of age was studied.

2. The birds responded with an increasing mean egg weight up to a linoleic acid intake of 2.75 g/bird d.

3. Increasing the intake of readily absorbable oil without increasing linoleic acid concentration did not increase mean egg weight.  相似文献   

Shapiro to leave michigan for princeton     

N C 《Science (New York, N.Y.)》1987,236(4802):665

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X chromosome mosaicism and infertility in a mare          下载免费PDF全文

Reid SW  Weatherston JF  Robinson BN 《The Canadian veterinary journal. La revue veterinaire canadienne》1987,28(8):533-534

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Interrelationships among Production and Clinical Disease in Dairy Cattle: A Review   总被引：1，自引：0，他引：1       下载免费PDF全文

Erb HN 《The Canadian veterinary journal. La revue veterinaire canadienne》1987,28(6):326-329

Epidemiological evidence is presented in order to answer two questions. The first question is: “Does high milk production put a cow at increased risk of disease?” The answer to this question seems to be “maybe” for milk fever, but “no” for most other common diseases (veterinary-assisted dystocia, retained placenta, metritis, cystic ovary, ketosis, left displaced abomasum, and mastitis). The second question is: “Is low milk production a consequence of disease?” For most diseases the answer is a cautious “yes”.  相似文献   

Response     

Ames BN  Gold LS 《Science (New York, N.Y.)》1991,251(4994):607-608

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The possible role of methionine in the detoxification of faba bean (Vicia faba L.) tannins in chick diets     

C. N. Wareham  J. Wiseman  D. J. A. Cole  J. Craigon 《British poultry science》1991,32(5):1017-1026

1. A metabolism trial was designed to investigate the role of methionine as a specific detoxifying agent of the condensed tannins present in faba beans (Vicia faba L.).

2. A 5 x 5 factorial approach was employed where 5 concentrations of dietary methionine were obtained (ranging from 3.9 to 12.15 g/kg diet dry matter) by the addition of DL‐methionine, and 5 concentrations of condensed tannins (ranging from 0.5 to 19.7 g/kg diet dry matter) by altering the ratio of tannin‐free and tannin‐containing faba bean hulls added to a basal diet.

3. The intake of condensed tannins had a significant, depressive effect on apparent available nitrogen (P< 0.001) and nitrogen corrected apparent metabolisable energy (AME_n ) (P< 0.001). There was no interaction between methionine and tannin (P>0.05). Thus the depressive effect of tannin was independent of methionine levels in the diet.

4. Methionine does not act as a specific detoxifier of faba bean condensed tannins.  相似文献