Dynamics of Parasitaemia in Trypanosoma evansi Infection in Donkeys and the Efficacies of Buparvaquone and Isometamidium chloride Treatments
Garba UM,
Sackey AKB,
Lawal AI,
Esievo KAN
Issue:
Volume 4, Issue 3, May 2016
Pages:
32-38
Received:
27 May 2015
Accepted:
15 June 2015
Published:
23 May 2016
Abstract: The aim of this study was to evaluate the efficacies of Buparvaquone (an anti-theilerial drug) and Isometamidium chloride (a standard trypanocide) in the treatment of experimental Trypanosoma evansi infection in donkeys. Out of a total of 24 donkeys, 6 were assigned to each of the experimental groups A1, A2, A3 and B at random. About 2.0x106 T. evansi parasite in 2 mL inoculum was used to infect each of the donkeys in groups A1, A2 and A3 through jugular vein while group B remained as Un-infected control. On day 28 post-infection, animals in groups A2 and A3 were treated with Isometamidium chloride and Buparvaquone respectively. Parasitaemia levels were evaluated post-infection and post-treatment using Haematocrit Centrifugation Technique and supported with mice inoculation tests to ascertain effectiveness of treatments. Group means of parasitaemia were presented on graphs. Result showed that parasites were first detectable from peripheral blood of the infected animals from day 3 and by day 4 post-infection all animals were parasitaemic and the levels fluctuated in subsequent days. The infected-untreated group of animals was aparasitaemic on day 100 post-infection onward using haematocrit centrifugation technique test but mice inoculation test detected relapse with death of all mice used due to heavy parasitemia. Similarly, the buparvaquone-treated group was aparasitemic on day 49 post-treatment (corresponding to day 77 post-infection) but mice inoculation test detected relapse of parasitaemia in the group and all mice used also died. Isometamidium-treated animals were negative for parasitaemia for 50 days on mice inoculation test but later on day 100 post-treatment, showed 60% relapse with parasiaemia level of 1+ in the mice used and they did not die within 48 days of observation. In conclusion, experimental Trypanosoma evansi infection in donkeys have pre-patent period of 3-4 days, parasitaemia pattern is undulating and infected-untreated animals became subclinical carriers from day 100 post-infection. The parasites in untreated, carrier animals maintained their virulence and pathogenicity. Buparvaquone on the other hand, depressed parasitaemia but the parasites were virulent and pathogenic to mice. Isometamidium chloride treatment resulted in incomplete clearance of parasitaemia due to Trypanosoma evansi and the relapsed parasites were avirulent and apathogenic. This is also the first report on the trial of buparvaquone for anti-Trypanosoma evansi effect in donkeys.
Abstract: The aim of this study was to evaluate the efficacies of Buparvaquone (an anti-theilerial drug) and Isometamidium chloride (a standard trypanocide) in the treatment of experimental Trypanosoma evansi infection in donkeys. Out of a total of 24 donkeys, 6 were assigned to each of the experimental groups A1, A2, A3 and B at random. About 2.0x106 T. eva...
Show More
Manipulation of Fertility in Crossbred Dairy Cattle Using Controlled Internal Drug Release Device Combined With Prostaglandin and Equine Chorionic Gonadotrophin
Alemselam Birhanu Mekonnin,
A. Forbes Howie,
Christopher R. Harlow,
Goitom Gidey,
Desalew Tadesse Tegegne,
Gidena Desta,
Tadesse Gugsa,
Berihu Gebrekidan,
Gebregiorgis Ashebir,
Simon C. Riley
Issue:
Volume 4, Issue 3, May 2016
Pages:
39-46
Received:
13 December 2015
Accepted:
27 April 2016
Published:
23 May 2016
Abstract: Simplifying and improving our understanding of the protocols for inducing or synchronizing estrus is important for improving management of dairy cattle. This study evaluated the estrus response and conception rate of crossbred (Holstein Friesian X Zebu) dairy cows (n=75) and heifers (n=47) assigned to a 10-day controlled internal drug release (CIDR) device – prostaglandin F2-alpha (PGF2α) – equine chorionic gonadotrophin (eCG) based estrus synchronization protocol. Animals were assigned to three groups (a) anestrus (n=62), (b) repeat-breeders (n=11) and (c) silent estrus (n=46), according to their reproductive history, per rectal palpation, and progesterone concentrations determined by On-Farm enzyme-linked immunosorbent assays (ELISA) in milk (lactating cows) or serum (dry cows and heifers). For each animal, a CIDR device (containing 1.38g progesterone) was inserted into the vagina and allowed to remain in-situ for 10 days. On Day 8 after device insertion, a dose of 500µg of PGF2α was administered intramuscularly (IM). On Day 10 (device removal), 500 IU of eCG was given IM. Animals were inseminated or mated 48 and 72 hrs post device removal. Pregnancy was assessed 20-24 days post insemination by measurement of progesterone in milk/serum and pregnancy was confirmed by per rectal palpation and/or ultrasonography 44-90 days post insemination. Overall estrus response and conception rates were 97.5% and 78.3%, respectively, with no significant differences in parity, pre-treatment reproductive status and farming system (smallholder vs organized commercial farms). Conception rate after induced/synchronized estrus was 82.9% and 72.1% in cows and heifers, respectively, with an overall calving rate of 94.4%. In conclusion, the present study has shown high estrus response and conception rate in crossbred dairy cattle using this CIDR - PGF2α - eCG based estrus synchronization protocol. Application of this protocol is highly recommended to enhance fertility of dairy cattle in the study area, and this could readily be applied to other regions.
Abstract: Simplifying and improving our understanding of the protocols for inducing or synchronizing estrus is important for improving management of dairy cattle. This study evaluated the estrus response and conception rate of crossbred (Holstein Friesian X Zebu) dairy cows (n=75) and heifers (n=47) assigned to a 10-day controlled internal drug release (CIDR...
Show More
