Theses and Dissertations Collection

Permanent URI for this collectionhttp://10.10.97.169:4000/handle/123456789/118

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Cryopreservation of dog semen as an alternative method to improved fertility in bitches: A review article
(Tanzania Veterinary Association, 2018-02-01) Bunyaga, A. S.; Kashoma, I. P.
Cryopreservation of dog semen facilitates the exchange of genes between populations and makes it possible to preserve genes from valuable males for an extended time. Although AI in dogs can help avert sexually transmitted diseases and reducing the chances of inbreeding, the technique is not routinely practised in most developing countries including Tanzania. Among the reasons are problems associated with cryopreservation. Cryopreservation of semen has a number of problems limiting its success and thus, affecting fertility in dogs as a whole. The common assisted reproductive technologies like AI in dogs are constrained by challenges in semen cryopreservation which partly is caused by freezing temperature, cryoprotectants and lifespan of spermatozoa. The purpose of this review is to study the possible ways which can improve cryopreservation of semen in dogs. Improving semen cryopreservation is not a one process; it involves a combination of factors with the ultimate goal of improving the outcome of semen cryopreservation in terms of conception rates in bitches, and thus, fertility in general. Cryopreservation parameters to improve include: type of ejaculate, insemination technique, storage, post thawing procedures, extenders, cryoprotectants, collection method and antioxidants. Several approaches have been recommended, including cryopreservation protocols, for instance freezing rates should be slow enough to allow the cells to minimize chemical potential and osmolality gradients across the plasma membrane, but fast enough to dehydrate the cell without exposing it to lethal salt concentrations. Moreover, the first ejaculates and the ejaculates from old dogs are to be discouraged if we need to improve fertility output under cryopreservation method. Thawing temperature of 70°C and above within a few seconds, have shown promising results. Possibly, this temperature is helpful to reduce the toxic nature of cryoprotectants. However, this review suggests the use of intrauterine method, and possibly innovation of new modification and training expertise would help to improve fertility in bitches. Nevertheless, more work is needed to accurately predict fertility of cryopreserved canine semen.
Cytotoxic T-lymphocyte antigen-2 alpha participates in axial skeletogenesis during mouse embryo development
(Tanzania Veterinary Journal, 2015-02-12) Luziga, C. D.; Bui, T. N.; Kashoma, I. P.; Aligawesa, E.; Yamamoto, Y.
Cytotoxic T-lymphocyte antigen-2 alpha (CTLA-2α) has been discovered and expressed in mouse activated T-cells and mast cells. Structurally, it is homologous to the proregion of mouse cathepsin L, a lysosomal cystein proteinase. Expressed recombinant CTLA-2α is shown to exhibit selective inhibition to cathepsin L and is localized in the uterus during pregnancy where it is implicated in embryo plantation and development. CTLA-2α has also been demonstrated in the maternal side of the placenta in the deciduas basalis, metrial gland and myometrium layers in mouse but its vivo targets in the embryo are yet to be identified. We carried out studies to investigate the specific cell types synthesizing CTLA-2α protein in mouse embryo and examine its cellular localization. Immunofluorescence labeling showed intense localization of CTLA-2α in the cranium, vertebrae of cervical and thoracic region and the sternabrae. In the visceral organs, staining level was strong in the pancreas. Moderate staining was visible within the brain and remnants of the notochord. The rest of the organs including the spleen, small intestine and lungs were delineated by CTLA-2α. These findings suggest that CTLA-2α participates in an important role from the potential commitment of mesenchymal cells lineages to the ossification of axial skeleton early in embryogenesis.
Foetal wastage and incidence of ovarian disorders in goats slaughtered at Dodoma municipal abattoir, Tanzania
(Tanzania Veterinary Association, 2017-04-01) Kashoma, I. P.; Melkiory, G. U.
Livestock husbandry and slaughter have become millenary traditions in every part of the world. In request for meat, numerous viable embryos and foetuses are wasted due to lack of effective pregnancy detection system and thus pregnant animals are not spared in the slaughtering process. In Tanzania, limited data are available on the level of foetal wastage in small ruminants slaughtered daily. This study was carried out to establish the level of foetal wastage and prevalence of ovarian disorders in does slaughtered at Dodoma municipal abattoir for a period of seven days (September 14 – 20, 2015). Foetal age was estimated using Crown Rump Length (CRL) method. Gross ovarian lesions were observed and sampled for histopathology. The total number of goats slaughtered during the study period were 2869 representing 72.3% males and 27.7% females. Up to 412 out of 795 (51.8%) of slaughtered does were pregnant including 34.7% carrying singletons and 17.1% having twins (p < 0.05). Of the recovered foetuses, 60% (n= 247) were males whereas 40% (n=165) were females. Gestation length estimated from CRL ranged from 37 to 103 days (CRL 5-35cm). Majority (80%) of foetuses were in second trimester, 12.8% first trimester and minority (7.2%) being in third trimester. The net economic value (NEV) daily forgone as a result of loss of potential offsprings at Dodoma abattoir was estimated to be between 8,610 and 14,350 US $. The incidence of ovarian disorders was recorded in 9.6% (37/383) of non-pregnant does. Follicular and luteal cysts were seen in 7.8% (n= 30) and 1.8% (n=7), respectively. Most of follicular cysts (65%) occurred as multiples, of which 52.9% (n=16) were on the right ovary and 47.1% (n=14) were on the left ovary. Luteal cysts were observed singly in either of the ovaries. Based on these findings, foetal wastage due to slaughtering of pregnant does is quite alarming at Dodoma municipal abattoir. Effective pregnancy screening before slaughter is recommended to avert the economic loss and human nutrient wastage.
Prevalence and antimicrobial resistance in Campylobacter from different stages of the chicken meat supply chain in Morogoro, Tanzania
(Tanzania Veterinary Journal, 2015-01-12) Kashoma, I. P.; Mkomba, F. D.; Bunyaga, A. S.
Poultry are recognized as a main reservoir of Campylobacter spp. However, longitudinal studies investigating the persistence of Campylobacter on broilers and retail chciekn meat in Tanzania are rare. The aim of the current work was to evaluate the prevalence and antimicrobial susceptibility of Campylobacter spp. isolated from broiler farms and retail chicken meat. Eight hundred samples were collected from broilers aged 1 week to slaughter and retail chicken carcasses, consisting of 600 fecal droppings and 200 carcass rinses. The overall Campylobacter prevalence was 43.3% (381/880). The isolation rate of Campylobacter from chicken faeces was 41.5%, from carcasses at the farm was 51.0% and from carcasses from retail stores was 37.5%. Biochemical testing by hippurate hydrolysis identified 72.4% of all isolates as C. jejuni, 20.5% as C. coli, and 7.1% as other Campylobacter spp. Multiplex polymerase chain reaction confirmed 75.1% of all isolates as C. jejuni, 17.8% as C. coli, 4.2% as both, and 2.9% as other Campylobacter spp. Antimicrobial susceptibility testing using disk diffusion assay and broth micro-dilution method revealed resistance to: ampicillin (41% and 44%, respectively), ciprofloxacin (56 and 59%), erythromycin (17 and 18%), gentamicin (6% and 12%), streptomycin (20 and 23%), and tetracycline (62 and 63%). Resistance to azithromycin (9%), chloramphenicol (7%) and nalidixic acid (72%) was determined using the disk diffusion assay only. Up to 5% and 4% of all isolate tested were pan-susceptible, while, 67% and 40% showed multidrug resistance using the disk diffusion assay and the broth microdilution method, respectively. These results reinforce the need of efficient strategy implementation to control and reduce Campylobacter in chickens at production and slaughter levels, and the necessity to reduce the use of antimicrobials in poultry sector.
Productive and reproductive performance of Friesian cows at Kitulo livestock multiplication unit, Tanzania
(Tanzania Veterinary Journal, 2015-02-12) Kashoma, I. P.; Mwingira, S. M.; Werema, C. W.; Kessy, B. M.
Retrospective data were collected to assess reproductive and productive performance of Friesian dairy cows reared at Kitulo Livestock Multiplication Unit, Tanzania. Records of 314 cows within consecutive five productive periods; 2009 - 2014 were analyzed using Statistical Package for SocialScience (SPSS). The overall mean age at first calving (AFC), calving interval (CI), days open (DO), number of services per conception (NSPC), lactation length (LL) and total lactation milk yield (TLMY) were 1151.72±9.63 days, 404.57±1.54 days, 121.82±1.24 days,1.83±0.24, 306.54±5.53 days and 5,042.12±23.73 kg, respectively. CI differed significantly (P < 0.05) as it decreased with increasing parity but did not affect the TLMY. Number of services per conception positively correlated with DO and CI but negatively correlated with parity. Total lactation milk yield was significantly (P < 0.05) influenced by parity and lactation length, but TLMY had no significant (P > 0.05) effect on the average number of services per conception. It is concluded that reproductive and productive performance of Friesian dairy cows in the present study were low to moderate so it is required to improve management practices at the farm for better reproductive and productive performance.
Reproductive and productive performance of crossbred dairy cows kept in different production systems in Morogoro municipality, Tanzania
(Tanzania Veterinary Journal, 2015-08-25) Ngou, A. A.; Kashoma, I. P.
Crossbred cows are the main type of cattle used for milk production on smallholder and medium farms in urban and peri-urban areas of Morogoro Municipality. A study was undertaken on four medium-scale and forty five smallholder farms to investigate the reproductive and productive performance of crossbred maintained under farmer’s management. Retrospective data on age at first calving (AFC), calving interval (CI), days open (DO), number of service per conception (NSC), lactation length (LL) and total lactation milk yield (TLMY) obtained from 311 cows for lactations (1-6) during seven years (2009-2015) were analyzed. Overall mean of AFC, CI, NSC, DO, LL and TLMY were 30.9 ± 0.8 months, 405±15.4 days, 2.5 ± 0.6 numbers, 119 ± 15.9 days, 333 ± 26.7 days and 4026 ± 1158 liters, respectively. The results of all traits showed variation between the two production systems (medium-scale versus smallholder farms). However, AFC, CI and TLMY parameters only differed among the medium-scale farms. It is concluded that reproductive and productive performance of crossbred cows in the present study were low to moderate so, it is required to improve management practices atall the farms under the study for better reproductive and productive performance.
Surgical sterilization of the African Giant Pouched Rats
(Tanzania Veterinary Journal, 2015-08-25) Werema, C. W.; Samson, R.; Ndossi, D. G.; Kashoma, I. P.; Mwakijungu, E.
Surgical sterilization of rodents is increasing as a result of increased biomedical research centers which employ rodents. In order for them to perform their duties effectively, the rodents have to be sterile to avoid interference from estrus, pregnancy and lactation. Other reasons include control of breeding, treatment of diseases or conditions such as tumors cysts, pyometra, pyometritis, and endometritis. In this study three surgical procedures were performed to African Giant Pouched Rats; 6 females were ovariectomized, 6 females were ovariohysterectomized, and 6 males were Orchidectomized. All eighteen (18) animals in the study recovered well and have returned to APOPO to continue with the training on smelling and detecting landmines and tuberculosis in human sputum samples without any difficulties. Complications from these surgical procedures are rare but comprise anesthetic overdose, dehydration, hypothermia, pulmonary hypostatic congestion, hemorrhage, eviscerations, wound dehiscence, and infections. However, many of these complications can be prevented by careful physical examination and selection of health animals fit for the intended surgical procedure, as well as adherence to all principles of surgery. This study has demonstrated the three surgical procedures for African Giant pouched rats as being useful to veterinarians in public/private practice and/or in biomedical research facilities.

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