Milk antibodies against Ostertagia ostertagi: relationships with milk IgG and production parameters in lactating dairy cattle     

Sanchez J  Markham F  Dohoo I  Sheppard J  Keefe G  Leslie K 《Veterinary parasitology》2004,120(4):319-330

The present study was carried out to evaluate the relationship between milk optical density ratios (ODRs) from an indirect Ostertagia ostertagi ELISA, total milk IgG levels and milk production and then establish a correction factor to adjust ODR. Five hundred and sixty composite milk samples collected from 358 cows on four dairy herds in June and August 2002 were used in this analysis. The average ODR was 0.34. A positive correlation was found between ODR and IgG values in milk, days in milk, age and log transformed somatic cell counts (SCC). However, ODR was negatively correlated with milk production. The IgG levels and ODR values were constant from 30 to 200 days in milk. However, ODRs increased from 200 days until the end of the lactation. After controlling for age, season, herd and SCC, an increase in milk production of 13 kg/day was associated with a reduction in ODR values of 0.052. The results of the present study suggest that ODR values are not greatly influenced by production factors. ODR follow the same pattern as the IgG variation across lactation and could be adjusted in order to compare ODR values obtained from high producing cows with those obtained from low producing animals.  相似文献   

Comparative efficacy of enrofloxacin, oxytetracycline, and sulfadimethoxine for the control of morbidity and mortality caused by Escherichia coli in broiler chickens     

Glisson JR  Hofacre CL  Mathis GF 《Avian diseases》2004,48(3):658-662

The purpose of the present study was to compare the ability of enrofloxacin, oxytetracycline, and sulfadimethoxine to reduce morbidity and mortality caused by Escherichia coli (colibacillosis) in broiler chickens. The chickens were raised in 80 pens (20 birds per pen) with 20 pens representing each treatment group under simulated commercial conditions that produced a colibacillosis challenge scenario. Each group of 20 randomized pens (replicates) was given one of four water treatments. Chickens that received enrofloxacin had significantly less mortality (P < 0.01), lower average gross pathology (colibacillosis) scores (P < 0.01), and better feed-conversion ratios (P < 0.05) than did chickens that received either oxytetracycline or no medication. Chickens that received enrofloxacin had significantly less mortality and lower pathology scores than those that received sulfadimethoxine and numerically lower feed conversion than the sulfadimethoxine group. Results from the present study show that enrofloxacin is superior to oxytetracycline and sulfadimethoxine for the control of morbidity and mortality caused by E. coli in broiler chickens. Our findings will help veterinarians choose and prescribe the most efficacious antimicrobial when treating colibacillosis.  相似文献   

Tibial plateau leveling osteotomy--part I          下载免费PDF全文

Harasen G 《The Canadian veterinary journal. La revue veterinaire canadienne》2004,45(6):527-528

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Cognitive Neuroscience Society meeting. Probing the social brain     

Miller G 《Science (New York, N.Y.)》2006,312(5775):838-839

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Mental health in developing countries. China: healing the metaphorical heart     

Miller G 《Science (New York, N.Y.)》2006,311(5760):462-463

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Patellar luxation     

Harasen G 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(8):817-818

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Ruptures of the common calcaneal tendon     

Harasen G 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(12):1219-1220

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Postgraduate specialization: an alternative to undergraduate streaming and limited licensure     

Harasen GL 《The Canadian veterinary journal. La revue veterinaire canadienne》2006,47(10):953

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An enterprising approach to brain science     

Miller G 《Science (New York, N.Y.)》2006,314(5796):76-77

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Efficacy of using an internal teat sealer to prevent new intramammary infections in nonlactating dairy cattle     

Sanford CJ  Keefe GP  Dohoo IR  Leslie KE  Dingwell RT  DesCôteaux L  Barkema HW 《Journal of the American Veterinary Medical Association》2006,228(10):1565-1573

OBJECTIVE: To determine whether insertion of an internal teat sealer (ITS) at the end of lactation would prevent development of new intramammary infections (IMIs) during the nonlactating period. DESIGN: Controlled clinical trial. ANIMALS: 939 Holstein-Friesian dairy cows from 16 herds. PROCEDURES: Results of bacteriologic culture of milk samples collected 14 days prior to the end of lactation were used to assign cows to groups (group 1 = negative results for all quarters; group 2 = positive results for > or = 1 quarter). Quarters of cows in group 1 were treated with an ITS or a single intramammary dose of cloxacillin; quarters of cows in group 2 were treated with cloxacillin in conjunction with an ITS or with cloxacillin alone. Milk samples were collected at the end of lactation and within 8 days after calving. RESULTS: Regardless of whether the outcome of interest was new IMIs caused by any pathogens, major pathogens, environmental pathogens, or streptococci other than Streptococcus agalactiae, quarters in group 2 treated with both cloxacillin and an ITS were less likely to develop a new IMI than were quarters treated with cloxacillin alone. For cows in group 1, no significant difference in risk of new IMIs was found between treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that for dairy cattle with an IMI late in the lactation period, intramammary administration of cloxacillin at the end of lactation followed by insertion of an ITS enhanced protection against development of new IMIs, compared with use of cloxacillin alone.  相似文献