Application of DNA markers in parentage verification of Boran cattle in Kenya

Boran cattle provide livelihood to thousands of households in the arid and semiarid lands of Kenya. Due to their superior adaptive and productive traits in comparison to other breeds of cattle, they have also become a popular choice for breeders in Eastern and Southern Africa. Continued genetic improvement of the breed is important, and therefore accurate performance and pedigree records are required. One hundred seventy-eight pedigree records and blood samples of four Boran stud herds were evaluated for accuracy of parentage allocation using 11 microsatellite markers recommended by ISAG for parentage verification. The panel of the 11 microsatellite markers was found to be highly polymorphic (PIC of 0.6901) with a combined probability of exclusion of 0.9997. The dam misidentification was low ranging between 0% and 5% for the herds tested. The estimated rate of mispaternity however ranged between 4.3% and 80% among the four stud herds, and more than 50% of the offspring of some herds were misidentified. The high rate of mispaternity will have a negative impact on the response to selection. The use of DNA markers for parentage assignment will improve the accuracy of the pedigree records of Boran stud cattle in Kenya and contribute to more accurate selection of superior animals.     

Development of a multiplex assay for the detection of antibodies to Borrelia burgdorferi in horses and its validation using Bayesian and conventional statistical methods

Lyme disease is a zoonotic, vector-borne disease and occurs in mammals including horses. The disease is induced by infection with spirochetes of the Borrelia burgdorferi sensu lato group. Infection of mammalian hosts requires transmission of spirochetes by infected ticks during tick bites. Lyme disease diagnosis is based on clinical signs, possible exposure to infected ticks, and antibody testing which is traditionally performed by ELISA and Western blotting (WB). This report describes the development and validation of a new fluorescent bead-based multiplex assay for the detection of antibodies to B. burgdorferi outer surface protein A (OspA), OspC and OspF antigens in horse serum. Testing of 562 equine sera was performed blindly and in parallel by using WB and the new multiplex assay. Because a true gold standard is missing for Lyme antibody testing, we performed and compared different statistical approaches to validate the new Lyme multiplex assay. One approach was to use WB results as a 'relative gold standard' in ROC-curve and likelihood-ratio analyses of the new test. Cut-off values and interpretation ranges of the multiplex assay were established by the analysis. The second statistical approach used a Bayesian model for the calculation of diagnostic sensitivities and specificities of the multiplex assay. The Bayesian analysis takes into consideration that no true gold standard exists for detecting antibodies to B. burgdorferi and estimated sensitivities and specificities of both tests that were compared. Therefore, the Bayesian analysis also resulted in an evaluation of diagnostic sensitivity and specificity of WB. Overall, the new assay was characterized by low background values and a wide dynamic quantification range for the detection of antibodies to OspA, OspC and OspF antigens of B. burgdorferi. The diagnostic sensitivity and specificity for the OspA bead-based assay were calculated as 49% and 85%, respectively, and by a standard ROC curve analysis only because the Bayesian model could not be run on this parameter. The Bayesian-derived diagnostic sensitivities of the OspC and OspF assays were 80% and 86%, respectively. For comparison, the Bayesian-derived estimates for WB resulted in sensitivities of 72% for OspC and 80% for OspF. The Bayesian diagnostic specificities of the multiplex assay were 79% and 69% for OspC and OspF, respectively. WB analysis had specificities of 92% for OspC and 77% for OspF. Although the analysis of a new assay in the absence of a true gold standard remains challenging, the approach used here can help to address this problem when new technologies and traditionally used test standards differ significantly in their analytical sensitivities, which consequently causes problems in the calculation of diagnostic sensitivity and sensitivity values for the new assay. In summary, the new multiplex assay for the detection of antibodies to B. burgdorferi OspA, OspC and OspF antigens in horse serum has improved analytical and diagnostic sensitivities compared to WB analysis. Multiplex analysis is a valuable quantitative tool that simultaneously detects antibodies indicative for natural infection with and/or vaccination against the Lyme pathogen.     

Thromboelastographic Clot Characteristics of Autologous Equine Blood Products After Activation by Autologous Thrombin,Bovine Thrombin,or Calcium Chloride

Objective

To compare clotting efficiency of platelet‐rich plasma (PRP) and concentrated platelet‐poor plasma (cPPP) to citrated whole blood after activation by autologous thrombin, bovine thrombin, or calcium chloride (CaCl₂).

Study Design

Experimental study.

Animals

Healthy adult horses (n = 6).

Methods

PRP and cPPP were prepared by commercial devices. Using thromboelastography, clotting variables were compared after activation of citrated autologous blood, PRP, and cPPP by autologous thrombin, bovine thrombin, or CaCl₂, respectively.

Results

PRP had the greatest clot strength and quickest clot rate, whereas cPPP had the weakest clot strength, slowest clot rate, and longest clot initiation time. Bovine thrombin resulted in the shortest clot initiation time, quickest clot rate, and was similar to CaCl₂ for greatest clot strength. CaCl₂ also resulted in the longest clot initiation time and time to reach maximum clot strength. Autologous thrombin resulted in the lowest clot strength.

Conclusion

When combined with either bovine thrombin or CaCl₂, PRP provided the best combinations for clinical use. Autologous thrombin was suboptimal, but could be an autologous alternative for clinical application. As prepared here, cPPP had inefficient clotting, but may be sufficient for plasma spray indications.     

Comparison of efficacy and safety of paste formulations of firocoxib and phenylbutazone in horses with naturally occurring osteoarthritis

OBJECTIVE: To compare efficacy and safety of paste formulations of firocoxib and phenylbutazone in horses with naturally occurring osteoarthritis. DESIGN: Randomized controlled clinical trial. ANIMALS: 253 client-owned horses with naturally occurring osteoarthritis. PROCEDURES: Horses were treated with firocoxib (0.1 mg/kg [0.045 mg/lb], PO, q 24 h) or phenylbutazone (4.4 mg/kg [2 mg/lb], PO, q 24 h) for 14 days. Physical examinations and lameness evaluations were performed prior to treatment and after 7 and 14 days. Clinical improvement was defined as a reduction of at least 1 lameness grade or a combined reduction of at least 3 points in scores for pain during manipulation or palpation, joint swelling, joint circumference, and range of motion. RESULTS: Proportion of horses clinically improved on day 14 for the firocoxib group (104/123 [84.6%]) was not significantly different from the proportion for the phenylbutazone group (103/119 [86.6%]). Proportion of horses that were improved on day 14 was significantly greater for horses treated with firocoxib than for horses treated with phenylbutazone with regard to score for pain on manipulation or palpation (P = 0.028), joint circumference score (P = 0.026), and range of motion score (P = 0.012), but not for overall lameness score or joint swelling score. No direct treatment-related adverse effects were detected during the study. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that overall clinical efficacy of a paste formulation of firocoxib in horses with naturally occurring osteoarthritis was comparable to efficacy of a paste formulation of phenylbutazone.     

Sex chromosomes behavior and G‐banding treatment of male meiosis in nuptial gift‐giving spiders of the family Trechaleidae

Preliminary genetic studies in Trechaleidae spider family show high variation in sex chromosomes and high heterocigocity, suggesting high chromatin plasticity. The trechaleids Paratrechalea ornata, Trechalea bucculenta and Trechaleoides biocellata are present in Uruguay. Males offering nuptial gifts during courtship have been reported in P. ornata and T. bucculenta but not in T. biocellata. Nuptial gifts are an inherited trait probably highly affected by environmental factors, which play an important role in gene expression. We hypothesize that this trait could be associated with tissue‐specific genes existing in G‐bands. We investigate the male meiosis in these 3 species, their sex chromosome system and the effects of G‐banding on their chromosomes, and elucidate genetic differences among them. Meiotic stages of the 3 species were submitted to Giemsa‐staining and G‐banding treatments. We observed a haploid number of n= 11 in P. ornata and n= 13 in both T. bucculenta and T. biocellata. Males from the 3 species presented an X₁X₂0 sex chromosome system, which is suggested as ancestral in Araneae. In P. ornata and T. bucculenta, both sex chromosomes were together and aligned in parallel until the segregation during anaphase I. In contrast to these species, sex chromosomes of T. biocellata usually remained distant from each other until diakinesis when they were observed associated in parallel disposition. Interstitial G‐bands were similar in P. ornata and T. bucculenta, and they both differed from those in T. biocellata. The special behavior of sex chromosomes in T. biocellata as well as the different G‐banding pattern of this species suggests the existence of novel modifications in this species.     

Distribution of Crenosoma vulpis and Eucoleus aerophilus in the lung of free-ranging red foxes (Vulpes vulpes).

Crenosoma vulpis and Eucoleus aerophilus are nematode parasites that can cause verminous pneumonia in wild carnivores. There is a paucity of information regarding the distribution of parasites in the lungs and the relationship between histopathological and parasitological diagnoses in naturally infected foxes. The objectives of this study were: first, to study the lobar and airway distribution of C. vulpis and E. aerophilus in wild red foxes and second, to investigate the relationship between fecal and histopathological diagnoses. Samples from 6 sites of the lung and fecal contents were obtained from 51 wild foxes in Prince Edward Island. By fecal examination, 78.4% of wild foxes tested positive for C. vulpis and 68.6% for E. aerophilus. In contrast, 66.6% and 49% of foxes had histopathological evidence of C. vulpis and E. aerophilus in the lungs, respectively. Anatomically, C. vulpis was observed in the small bronchi and bronchioles of all pulmonary lobes whereas E. aerophilus was restricted to the large bronchi and the caudal lobes. Affected airways exhibited severe epithelial glandular hyperplasia and bronchiolar mucous metaplasia. It was concluded that C. vulpis is widely distributed in airways of all pulmonary lobes, whereas E. aerophilus is mainly restricted to the bronchi of caudal lobes. Also, this study showed that histological examination of lung underestimates the infection with E. aerophilus.     

Gross, histologic, and gene expression characteristics of osteoarthritic articular cartilage of the metacarpal condyle of horses

OBJECTIVE: To identify patterns and correlations of gross, histologic, and gene expression characteristics of articular cartilage from horses with osteoarthritis. ANIMALS: 10 clinically normal horses and 11 horses with osteoarthritis of the metacarpal condyles. PROCEDURES: Metacarpophalangeal joints were opened and digitally photographed, and gross lesions were scored and quantified. Representative cartilage specimens were stained for histologic scoring. Total RNA from dorsal and palmar articular surfaces was processed on an equine gene expression microarray. RESULTS: Histologic scores were greater in both regions of osteoarthritic joints, compared with corresponding regions in control joints. Cartilage from the palmar aspect of diseased joints had the highest histologic scores of osteoarthritic sites or of either region in control joints. A different set of genes for dorsal and palmar osteoarthritis was identified for high and low gene expression. Articular cartilage from the dorsal region had surface fraying and greater expression of genes coding for collagen matrix components and proteins with anti-apoptotic function, compared with control specimens. Articular cartilage from the palmar region had greater fraying, deep fissures, and less expression of genes coding for glycosaminoglycan matrix formation and proteins with anti-apoptotic function, compared with cartilage from disease-free joints and the dorsal aspect of affected joints. CONCLUSIONS AND CLINICAL RELEVANCE: Metacarpal condyles of horses with naturally occurring osteoarthritis had an identifiable and regional gene expression signature with typical morphologic features.