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Desoto Lakes, KS, United States

Ferguson J.D.,University of Pennsylvania | Skidmore A.,Merck Animal Health
Journal of Dairy Science | Year: 2013

Sixteen herds were selected from a pool of 64 herds nominated by consultants for participation in a national survey to demonstrate excellence in reproductive performance. For inclusion in the survey, herds had to have comprehensive records in a farm computer database or participate in a Dairy Herd Improvement Association record system and have superior reproductive performance as judged by the herd advisor. Herd managers were asked to fill out a questionnaire to describe their reproductive management practices and provide herd records for data analysis. Reproductive analysis was based on individual cow records for active and cull dairy cows that calved during the calendar year 2010. Breeding records by cow were used to calculate indices for insemination rate (IR), conception rate (CR), pregnancy rate (PR), and culling. Herds ranged in size from 262 to 6,126 lactating and dry cows, with a mean of 1,654 [standard deviation (SD) 1,494] cows. Mean days to first insemination (DFS) was 71.2. d (SD 4.7. d), and IR for first insemination was 86.9%. Mean days between inseminations were 33.4. d (SD 3.1. d), and 15.4% of insemination intervals were greater than 48. d (range: 7.2 to 21.5%). First-service conception rate was 44.4% (SD 4.8%) across all herds and ranged from 37.5 to 51.8%. Mean PR was 32.0% (SD 3.9%) with a range of 26.5 to 39.4%. Lactation cull rate was 32.2% (SD 12.4%) with a range from 13.6 to 58.1%. Compared with mean data and SD for herds in the Raleigh Dairy Herd Improvement Association system, mean indices for these herds ranked them in the 99th percentile for IR (using heat detection rate as comparison), 99th percentile for PR, the bottom 18.6 percentile for DFS, and around the 50th percentile for CR. This suggests that excellent herd reproductive performance was associated with reproductive management that resulted in high insemination rates combined with average CR. © 2013 American Dairy Science Association. Source

Walther F.M.,Merck Animal Health | Allan M.J.,MSD Animal Health Innovation GmbH | Roepke R.K.,MSD Animal Health Innovation GmbH
Parasites and Vectors | Year: 2015

Background: Fluralaner is a novel systemic ectoparasiticide for dogs providing immediate and persistent flea, tick and mite control after a single oral dose. Ivermectin has been used in dogs for heartworm prevention and at off label doses for mite and worm infestations. Ivermectin pharmacokinetics can be influenced by substances affecting the p-glycoprotein transporter, potentially increasing the risk of ivermectin neurotoxicity. This study investigated ivermectin blood plasma pharmacokinetics following concurrent administration with fluralaner. Findings: Ten Beagle dogs each received a single oral administration of either 56 mg fluralaner (Bravecto™), 0.3 mg ivermectin or 56 mg fluralaner plus 0.3 mg ivermectin/kg body weight. Blood plasma samples were collected at multiple post-treatment time points over a 12-week period for fluralaner and ivermectin plasma concentration analysis. Ivermectin blood plasma concentration profile and pharmacokinetic parameters Cmax, tmax, AUC∞ and t were similar in dogs administered ivermectin only and in dogs administered ivermectin concurrently with fluralaner, and the same was true for fluralaner pharmacokinetic parameters. Conclusions: Concurrent administration of fluralaner and ivermectin does not alter the pharmacokinetics of either compound. Based on the plasma pharmacokinetic profile and the clinical observations, there is no evident interaction between fluralaner and ivermectin, and co-administration does not increase the risk of ivermectin associated neurotoxicity. © 2015 Walther et al. Source

Soto E.,Ross University School of Medicine | Kidd S.,Ross University School of Medicine | Gaunt P.S.,Mississippi State University | Endris R.,Merck Animal Health
Journal of Fish Diseases | Year: 2013

Francisella noatunensis subsp. orientalis (Fno) (syn. F. asiatica) is an emergent Gram-negative facultative intracellular bacterium. Although it is considered one of the most pathogenic bacteria in fish, there are no commercially available treatments or vaccines. The objective of this project was to determine the most efficacious concentration of florfenicol (FFC) [10, 15 or 20 mg FFC kg-1 body weight (bw) per days for 10 days] administered in feed to control experimentally induced infections of Fno in Nile tilapia, Oreochromis niloticus (L.), reared in a recirculating aquaculture system. The cumulative mortality of fish that received 0, 10, 15 or 20 mg FFC kg-1 bw per day was 60, 37, 14 and 16%, respectively. Francisella noatunensis subsp. orientalis genome equivalents were detected in water from all challenged groups with slight reduction in the concentration in the florfenicol-treated groups 4 days after treatment. The mean LOG of CFU Fno mg-1 spleen was 3-5 and was present in all challenged groups at necropsy 11 days after treatment (21 days after challenge). Results show that florfenicol administered at doses of 15 and 20 mg FFC kg-1 bw per days for 10 days significantly reduced mortality associated with francisellosis in Nile tilapia. © 2012 Blackwell Publishing Ltd. Source

Lee J.K.,Mississippi State University | Smith W.C.,Mississippi State University | McIntosh C.,Mississippi State University | Ferrari F.G.,Merck Animal Health | And 2 more authors.
Ticks and Tick-borne Diseases | Year: 2014

Borrelia spp. are agents of Lyme disease and relapsing fever, diseases which use Ixodes hard ticks and Ornithodoros soft ticks, respectively, as primary vectors. Some relapsing fever spirochetes, such as B. miyamotoi, are also found in hard ticks. To date, no Borrelia sp. is known to use the hard tick, Amblyomma maculatum, as a vector. However, both B. burgdorferi and B. lonestari were recently detected in A. maculatum removed from hosts. In our study, DNA extracts from 306 questing adult A. maculatum collected in Mississippi in 2009 and 2010 were tested for Borrelia spp. DNA by PCR amplification of flaB and 16S rRNA gene targets. An additional 97 A. maculatum collected in 2013 were tested by amplification of 16S rRNA gene target. Two ticks, one collected in 2009 and the other in 2010, were positive by PCR of the flaB and 16S rRNA gene targets; both were collected from the same location in central Mississippi. Interestingly, 16S rRNA gene amplicons from these two tick extracts were 98% identical to twelve Borrelia spp. including the reptile-associated spirochete B. turcica and Borrelia sp. "tAG158M"; flaB amplicons from these two ticks shared closest identity (89%) to the reptile-associated spirochete, B. turcica. These results demonstrate a Borrelia sp. in unfed A. maculatum ticks that is unique from other species in the NCBI database and in a clade with reptile-associated Borrelia species. Detection of a previously unrecognized Borrelia in a hard tick species generates additional questions regarding the bacterial fauna in these arthropods and warrants further studies to better understand this fauna. © 2014 Elsevier GmbH. Source

Walther F.M.,Merck Animal Health | Allan M.J.,MSD Animal Health Innovation GmbH | Roepke R.K.A.,MSD Animal Health Innovation GmbH
Parasites and Vectors | Year: 2016

Background: Fluralaner is a novel systemic ectoparasiticide for cats providing immediate and persistent flea- and tick-control after a single topical dose. Emodepsid and praziquantel are routinely used to control intestinal worm infections in cats. The safety of concurrent use of fluralaner and a commercially available emodepsid-praziquantel combination topical solution was investigated using topical administrations at the maximum recommended dose rates. Findings: Few mild and transient clinical findings like erythema at the administration site and single incidences of salivation or vomiting were observed. All of which were consistent with the individual product leaflets. There were no findings suggesting an increased safety risk associated with the concurrent treatment of cats with fluralaner and emodepsid-praziquantel. Conclusions: Concurrent treatment with fluralaner, emodepsid and praziquantel is well tolerated in cats. © 2016 The Author(s). Source

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