Prevalence and molecular diagnosis of <Emphasis Type="Italic">Trypanosoma evansi</Emphasis> in Nili-Ravi buffalo (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>) in different districts of Punjab (Pakistan)

The prevalence of Trypanosoma evansi was investigated in 1,250 Nili-Ravi buffaloes of mixed age and sex by polymerase chain reaction (PCR) for the first time in Pakistan. DNA of the trypanosomes was isolated with TRIREAGENT®. The assay was employed using primers ESAG 6/7, specific for a 237-bp fragment from T. evansi genomic DNA. The samples were screened for the presence of T. evansi also by stained thin smear. Forty-four (3.5%) samples were positive by microscopy, while 97 (7.7%) samples were identified by PCR, indicating the high sensitivity of PCR for surveying the disease in epidemiological studies.     

Ultrasonography of spontaneous lesions of the genital system of three rams, and their influence on semen quality

Three young Suffolk ram lambs had lesions which rendered them reproductively unsound. One had a unilateral scrotal hernia, detected by palpation, and two had sperm granulomas which were detected by trans-scrotal ultrasonography at 18 to 20 weeks of age, before they could be detected by palpation. Changes in the lesions were monitored ultrasonographically at two-week intervals with a 7.5 MHz linear array transducer. On the day of each examination, semen was collected from the rams with sperm granulomas by using an artificial vagina, and their libido was assessed. Semen could rarely be collected from the third ram. Comparisons were made with similar data obtained from two normal rams. When the rams were 20 to 21 months of age, they were vasectomised on the normal side, so that the influence of the lesions on semen composition and libido could be assessed, and semen was collected and evaluated until they were euthanised at approximately 24 months of age, when the genital system was examined for gross lesions. The sperm granulomas changed in size (one of them increased in size by about 30 times) and echotexture over the 19-month period of the study, whereas the scrotal hernia, which contained omental fat, remained fairly constant. The libido of the two rams with sperm granulomas was comparable with the two normal controls. The total mean (sem) number of sperm in the ejaculates were 1.11 (0.10) x 10(9) and 2.03 (0.17) x 10(9) sperm/ml in the affected rams and 4.11 x 10(9) sperm/ml in the normal rams over the same period; the differences were significant (P<0.05). After unilateral vasectomy, the ejaculates from these two rams contained small numbers of dead spermatozoa, mostly with degenerate heads. Postmortem examination confirmed the gross lesions identified ultrasonographically.     

Note: Toxicity of some insecticides onBracon hebetor under laboratory conditions

Insecticides which were environmentally friendly and the least toxic, were screened against a laboratory strain ofBracon hebetor (Say) (Hymenoptera: Braconidae) for their suitability for release in IPM of cotton. Concentrations ranging from 1 to 1000 ppm of the formulated insecticides in acetone were applied in glass vials and also by a leaf method, whereby cotton leaves were dipped in aqueous solutions of the same concentrations of insecticides. Adult parasitoids were exposed in both methods. According to the LC₅₀ at 24 h exposure, Λ-cyhalothrin and spinosad were the most (7 and 5 ppm) and least (263 and 225 ppm) toxic in the vial and the leaf method, respectively, toB. hebetor. The possible use of the parasitoid for IPM of cotton is discussed. http://www.phytoparasitica.org posting July 20, 2006.     

The infrequency of transmission of herpesviruses between humans and animals; postulation of an unrecognised protective host mechanism

The infrequency of natural transmission of herpesviruses between humans and animals is surprising as there is extensive contact between humans and non-human species with unequivocal evidence that host cells from non-susceptible species will support replication of herpesviruses which do not seem to naturally infect that species. This review examines natural cross-infections between human and other species and suggests that, firstly, it is possible that humans and animals do become asymptomatically or symptomatically cross-infected from other species, but the infection is not diagnosed or not diagnosable by conventional methods; secondly, an as yet unidentified novel mechanism(s) may operate to prevent infection using chemical, electrical or as yet unidentified pathways and may even be ‘switched on’ by exposure to the virus.     

Efficacy of macrocyclic lactones for the control of larvae of the Old World screw-worm fly (Chrysomya bezziana)

OBJECTIVE: To assess the efficacy of four macrocyclic lactones for the control of larvae of the Old World Screw-worm Fly (OWS), Chrysomya bezziana, and to examine the effects of excreted residues on the dung fauna. ANIMALS: 100 heifers were divided into five groups of 20 animals. One group remained untreated, whereas the other groups were treated respectively with pour-on formulations of moxidectin, eprinomectin or doramectin, or a sustained-release bolus of ivermectin. PROCEDURES: At intervals of 1 to 15 weeks after treatment, five cattle from each group were challenged with newly-laid eggs of OWS. The efficacy of each treatment was determined 48 h later by comparing the number of myiases in the treated and untreated groups. Abundance of fly larvae in naturally-voided dung pads and the survival of a species of dung beetle, Onthophagus sagittarius, were used to assess the effects of drug residues on the dung fauna. RESULTS AND CONCLUSIONS: Moxidectin showed no activity against larvae of OWS during the first 14 days after treatment. Eprinomectin provided protection for 3 days after dosing, but failed at days 7 and 14, whereas doramectin was effective at day 7, but not at days 14 or 21. In contrast, no myiases were established on bolus-treated cattle from 14 to 102 days after treatment. Faecal residues of moxidectin had no effect on the survival of larvae of dung-feeding flies, whereas those of eprinomectin and doramectin reduced survival for 1 to 2 weeks. Dung voided by bolus-treated cattle inhibited fly breeding and had adverse effects on the development and survival of O sagittarius for up to 15 weeks after treatment.     

Does the gradual increase in dietary zinc oxide supplementation can affect egg quality,serum indices,and productive performance of laying hens?

Tropical Animal Health and Production - This study was conducted to evaluate the influence of increased supplementation of zinc oxide (ZnO) on performance, quality of egg, blood chemistry, and...     

Review on small ruminant conservation status and prospects in India

Tropical Animal Health and Production - Small ruminants always play a major role in the agricultural economy of India. They provide livelihoods to numerous small and marginal farmers. The diversity...     

Dietary supplementation of milk thistle (Silybum marianum): growth performance,oxidative stress,and immune response in natural summer stressed broilers

Tropical Animal Health and Production - The aim of the study was to investigate the influence of dietary supplementation of various levels of milk thistle (MT) on growth performance, oxidative...