Department of Animal Science

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    Development of the Bottom and Perihytic Invertebrate Fauna into the Volta Man-Made Lake during the First Years
    (University of Ghana, 1970-07) Tomislav, P.
    Development of the Bottom and Perihytic Invertebrate Fauna into the Volta Man-Made Lake during the First Years
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    Single Nucleotide Polymorphisms in Insulin-Like Growth Factor (IGF) Genes and their Associations with Growth in Local Guinea FOWLS (NUMIDA MELEAGRIS) of Ghana
    (University Of Ghana, 2018-07) Ahiagbe, K.M.J.
    Due to the pivotal role of Insulin-like Growth Factor 1 (IGF1) and Insulin-like Growth Factor 2 (IGF2) in growth regulation of poultry, the IGF1 gene (gIGF1) and IGF2 gene (gIGF2) in guinea fowl were examined as candidate genes for early growth in helmeted guinea fowls (Numida meleagris) from three populations of Northern Ghana (TPNG). Keets hatched from eggs collected from 32 sample locations comprising 11 subpopulations across three main populations located in Upper East Region, Upper West Region, Northern Region, North East Region, Savannah Region and an experimental flock maintained at Animal Research Institute (ARI) were raised and appraised for body weight and growth rate traits up to 11 weeks. Protein coding exons of gIGF1 and selected targets of gIGF2 were sequenced, aligned for discovery of novel Single Nucleotide Polymorphisms (SNPs) and genotyping. Effect of the genotypes at each SNP and gIGF1 haplogroups were estimated using linear models. Birds from the TPNG did not vary in body weights and weekly growth rates among the populations and with that of ARI flock from the fourth week (p > 0.05). However, birds from subpopulations within the three main populations varied significantly (p < 0.05) in weekly body weights and growth rates from the second week, with between subpopulation variations becoming pronounced after the sixth week. Although ARI flock did not vary with other three populations in terms of body weight and growth rate, they demonstrated remarkably high survivability. In total six novel SNPs were identified within gIGF1 including two SNPs within 5’ Untranslated Region (UTR), one SNP in the second protein coding exon and three SNPs within 3’UTR. These SNPs were distributed among seven haplotypes and eight haplogroups among local guinea fowls from Northern Ghana. SNPs within the 5’UTR and 3’UTR had significant effects on body weights and weekly growth rates from the second and fourth week, respectively, indicating possible roles for these polymorphisms influencing IGF1 synthesis at the translation level, and need to be further investigated to decipher the underlying molecular mechanisms. The only synonymous SNP located at the second protein coding region in gIGF1 and both SNPs identified in gIGF2 did not influence early growth in local guinea fowls from TPNG. The study provides baseline information on novel SNPs in gIGF1 and their associations with body weight traits and early growth rates in local guinea fowls from Northern Ghana. It is recommended that the effect of the SNPs residing within 5’UTR and 3’UTR in gIGF1 should be further investigated up to slaughter stage in structured breeding programmes aimed at developing fast growing guinea fowl breeds with pedigree data to facilitate their use in Marker Assisted Selection.
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    Effect of Maturity on Dry Matter Accumulation and Quality of Forage from Natural Grassland and Three Introduced Grasses in the Accra Plains, Ghana
    (University of Ghana, 1977-12) Fianu, F.K.; Winch, J.E.; University of Ghana,College of Basic and Applied Sciences School of Agriculture Department of Animal Science.
    EFFECT OF MATURITY ON DRY MATTER ACCUMULATION AND QUALITY OF FORAGE FROM NATURAL GRASSLAND AND THREE INTRODUCED GRASSES IN THE ACCRA PLAINS, GHANA Francis Kwasivie Fianu, Supervisor: University of Guelph, 1977 Dr. J.E. Winch Two studies were conducted in Legon, Ghana, in 1974 and- 1975 to characterize the dry matter accumulation and quality of a natural grassland sward (dominated by Sporobolus and Heteropogon) and of introduced giant star grass (Cynodon plectostachyus (k . Schum) Pilger), buffel grass (Cenchrus ciliaris L. cv. biloela) and pangola grass (Digitaria decumbens Stent.). The natural grassland study was a split plot experiment with pretreatment slashing, grazing and burning in the main plots and.ten harvest dates during the major rainy season in the subplots. Each of the ten subplots was subdivided into three parts and harvested sequentially at the end of the rainy season, mid-dry season and at the end of the dry season. Pretreatments did not affect the botanical composition, dry matter accumulation during the growing season or regrowth during the ensuing dry period. Sporobolus p.yramidalis Beauv. grew faster than Heteropogon contortus (L.) Beauv. at the early stages, dominated the sward and flowered at 3-6 weeks. Heteropogon initially grew slowly and flowered from week 6. By week 7 Heteropogon became the dominant species of the sward. Cenchrus sp., Bothriochloa sp. and Setaria sp. flowered within 4-fc weeks but gamba grass (Andropogon gayanus Kunth.) did notflower during the study. Dry matter accumulation in the natural grassland sward and its dominant species continued after flowering until the end of the rainy season. Leaf production, and the In Vitro digestibility as well as nitrogen content of Sporobolus and Heteropogon were not affected by pretreatment. While Sporobolus maintained a high percentage of leaf throughout the growing season, leaf proportions dropped in Heteropogon at the mature stages. Leaves were more digestible and contained more nitrogen than stems in both species. Heteropogon tended to be more digestible than Sporobolus. The two species were similar in leaf and whole plant nitrogen, but Sporobolus stems contained more nitrogen than those of Heteropogon. In the study on introduced grasses, giant star and buffel were harvested at ten dates during the minor rainy season of 1974 (September 16 - December 3l)j during the major rainy season of 1975≫ pangola grass was included in the experiment. Pangola was sensitive to moisture stress during early growth and failed to grow during the minor rainy season of 1974* Buffel, on the other hand, was drought tolerant and grew even under light showers. Buffel flowered from week 3 in both seasons while giant star flowered only during the minor rainy season at week 6 , and pangola flowered in week 6 during the major rainy season. Growth continued in all three grasses after flowering. In buffel, senescent leaves were retained on the plant whereas in the stoloniferous grasses, they were stripped off by rainfall. During the minor rainy season, giant star and buffel produced similar dry matter yields. In the major rainy season, however, buffel was superior in yield to the prostrate grasses which showed np consistent differences. Leaf dry matter yield increased until week 8-9* Buffel and giant star produced more leaf dry matter than pangola grass. Leaf proportions in the plant declined steeply with maturity in buffel grass but slowly in the prostrate grasses. During the minor rainy season, whole plant In Vitro digestibility and nitrogen were similar in giant star and buffel during the minor rainy season, but buffel had the highest whole plant digestibility followed by pangola and giant star was the least digestible. The leaves were more digestible than stems, this difference being most striking in mature buffel grass. Leaf nitrogen levels were higher than stem nitrogen levels in all the grasses but species differences in nitrogen content were not consistent. The nitrogen content of whole plants would probably be adequate for the maintenance requirements of a steer until week 7 during the minor rainy season and week 11 in the major rainy season. In Vitro digestibility was highly correlated with nitrogen content of leaves, stems and whole plants of all species except giant star stem. It would appear that buffel grass should be harvested at 5 weeks and giant star at 7 weeks during the minor rainy season. In the major rainy season buffel would be harvested at 9 weeks and giant star and pangola at 8 weeks for optimum combination of nutrient yield during the rainy season and regrowth during the ensuing dry period. The natural grassland species and the introduced grasses were similar in digestibility at the early stages but the erect grasses -natural and introduced - declined more rapidly than the prostrate introduced ones. For high animal performance both the natural and the introduced species would have to be supplemented with concentrates.
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    Development of Monoclonal Antibody-Based Assays For Detection and Differentiation of Trypanosome Species In The Tsetse Fly (Glossina Spp.)
    (University of Ghana, 1993-03) Bosompem, K. M.; Assoku, R. K. G.; Nanlulya V. M.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Animal Science
    Diagnosis of trypanosome infections in tsetse (Glossina spp.) is currently based on dissection and microscopic examination of different organs of the vector for the presence of infecting trypanosomes. This procedure is slow and labour intensive, and it is not accurate. The work reported in this thesis was conducted with the objective of developing a field applicable, monoclonal antibody (MoAb)-based assay for the detection of, and differentiation between trypanosome species in infected Glossina species. The development of a more accurate alternative technique to the dissection method would provide a useful tool for estimation of the trypanosomiasis risk in various localities. MoAbs had been previously generated against invariant antigens of various trypanosome subgenera, including the Trypanozoon, Nannomonas and Duttonella, and the T. congolense species. Some of these MoAbs were selected and used in the studies described in this thesis. It was, however, necessary to produce additional trypanosome species-specific MoAbs for several reasons: Firstly, there was no T. simiae specific MoAb. Secondly, the selected T. vivax specific MoAbs were less sensitive compared with some of the T. congolense and Nannomonas species-specific MoAbs, in terms of the minimum number of procyclics or epimastigotes that they could detect. Thirdly, some of the selected MoAbs could not be used in the Western immunoblot assay to identify the antigens involved. The additional trypanosome species-specific MoAbs produced included three Trypanozoon subgenus-specific MoAbs (KT39a/18.17, KT43/33.32 and KT43/27.32), two Duttonella subgenus-specific MoAbs (KD32/48.17 and KD37/19.3), two Nannomonas subgenus-specific MoAbs (KN4/13.9 and KN5/6.15) and one T. simiae specific MoAb KNS7/14.X. Characterization of the specific antigens, using the indirect immunofluorescent antibody test (IFAT), Western immunoblot analysis, proteinase-K digestion and periodate oxidation, showed that some of the new MoAbs detected trypanosome species or subgenus-specific antigens that previously had not been identified. These new antigens included a T, brucei species-specific antigen which localized in the cytoplasm of T. brucei procyclics and differed from previously identified antigens which were located at the cell membrane. Employing the nitrocellulose membrane (NC)-based dot-enzyme-linked immunosorbent assay (dot-ELISA), it was found that the selected MoAbs could identify and differentiate between in vitro propagated trypanosome species. The dot-ELISA detected in vitro propagated T. brucei, T. congolense and T. simiae procyclics, and T. vivax epimastigotes, in both single and artificially mixed preparations. The assay had a specificity more than 99.9% and a sensitivity as good as 10 trypanosomes per dot for some T. brucei, T. congolense and Nannomonas specific MoAbs. The integrity of trypanosome antigens applied onto NC membrane remained unaffected for up to 60 days of storage at 4°C under desiccated conditions or under similar conditions at room temperature (17-26°C). Each of the derived MoAbs was able to detect isolates of the respective trypanosome species obtained from different geographical areas, and none cross-reacted with T. grayi. Furthermore, each of the T. congolense specific MoAbs reacted with all three types of this parasite species (savannah, Kilifi and riverine-forest types) that were tested. The dot-ELISA developed, however, could not be applied directly to the diagnosis of trypanosome infections in tsetse because of non-specific staining of NC membrane by samples prepared from tsetse gut, due to the presence of pigments and undigested blood meals. This non-specific staining was eliminated by prior decoloration of tsetse gut samples on NC membrane, using 5% hydrogen peroxide (H2O2 ). This finding enabled successful detection and differentiation of T. brucei, T. congolense and T. simiae parasites in the gut of experimentally infected Glossina, using a modified dot- ELISA. The sensitivity of the assays was; 90.5% in detecting T. brucei infections, 85.4% in detecting T. congolense infections and 94.4% in detecting T. simiae infections. The sample from the gut of each tsetse fly could be replicated in 15 dots onto NC membrane for testing. When stored on NC membrane at room temperature (19-26°C) under desiccated conditions, the samples did not show any loss in activity over a period of 90 days. The dot-ELISA technique was also used successfully to detect T. brucei parasites in the salivary glands of experimentally infected Glossina. This application of the technique was, however, achieved following the substitution of Na2 EDTA buffer for PBS or PSG which were used in detecting T. brucei in infected tsetse gut. The assay was more than 99.9% specific and 90% sensitive in detecting T. brucei in infected tsetse salivary glands. Trypanosoma congolense and T. vivax infections were successfully detected in the mouthparts of experimentally infected tsetse flies using dot- ELISA. However, it was not possible to replicate tsetse proboscide samples for testing with different MoAbs due to the very low parasite numbers in this organ. The recommended strategy, therefore, was to randomly sort all tsetse flies suspected to be infected with T. congolense, T. simiae or T. vivax into three separate groups and test them with different MoAbs. In a limited field evaluation of the dot-ELISA, 2 out of 104 G. pallidipes flies identified by dissection and microscopy to carry midgut infections, were also positive by dot-ELISA. Using the dissection technique, such infections would have been diagnosed as immature T. brucei and/or T. congolense and/or T. simiae. However, by the dot-ELISA, it was possible to determine with certainty that the two flies were infected with T. congolense parasites. Furthermore, the dot-ELISA detected T. congolense antigens in the midguts of an additional 6(5.8%) of the 104 G. pallidipes and 17(4.4%) of 390 G. longipennis that were negative by the dissection method, suggesting that the dot-ELISA may be more sensitive than the dissection method. This ability of the dot-ELISA to detect more infections than the dissection method, suggests that the MoAb-based dot-ELISA is not only a more precise tool for identification and differentiation of trypanosome species in the vector, but that it may also be more sensitive than the dissection method
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    Breeding for Drought Tolerance in Cowpea [Vigna Unguiculata (L.) Walp.] Using Marker Assisted Backcrossing
    (University of Ghana, 2014-12) Batieno, T. B. J.; Danquah, E.Y.; Ofori, K.; Yeboah, M.; Drabo, I.; University of Ghana, College of Basic and Applied Sciences , School of Agriculture , Department of Crop Science
    The potential of cowpea to address food security in Burkina Faso in particular is well established. However, there is limited information on drought tolerance and diversity in the germplasm in Burkina Faso and farmers’ perceptions on the effects of drought and their varietal preferences are not known. The present study was, therefore, conducted to: (1) identify farmers’ perceptions on the impact of drought on cowpea production and identify their preferences regarding cultivars and traits, (2) identify drought tolerant varieties in cowpea germplasm, (3) determine single nucleotide polymorphisms (SNPs) based genetic diversity in the cowpea germplasm, and (4) implement marker-assisted backcrossing to transfer yield and stay-green QTLs into Moussa local, a farmer preferred landrace. A participatory rural appraisal (PRA) was conducted to identify farmers’ perceptions on the impact of drought on cowpea production. This study established that farmers have a deep knowledge about cowpea production constraints. Limited access to seed of improved variety was ranked as the most important constraint in all the areas where the study was conducted. Drought was classified among the four most important constraints to cowpea production in the three districts where the PRA was conducted. The preferred grain traits for all regions were white colour, large seeds with a rough texture for food and market purposes, except for the northern region where brown grain colour was preferred for food. The identification of drought-tolerant varieties in cowpea germplasm through field screening of fifty genotypes and the use of selection indices revealed wide genotypic variability among the tested germplasm. Biplot displays indicated that the genotypes could be grouped into four categories according to their drought tolerance and yielding ability as indicated below: high yielding-drought tolerant (group A), high yielding-drought susceptible (group B), low yielding-drought tolerant (group C), and low yielding-drought susceptible (group D). Genotypes like Djouroum local, KVx404-8-1, IT98K-1111-1, Gorom local, CB27, IT93K-693-2, Mouride, and KVx61-1 were clustered in group A, that is they were high yielding and drought tolerant. The stress tolerance index was the best criterion for assessing genotypes for variability to drought tolerance because it enabled the identification of high yielding and drought tolerant genotypes. Genetic diversity was assessed using 181 SNP markers on 50 cowpea lines. The phylogenetic pattern of this germplam revealed seven clusters. The lines were almost grouped based on their geographical origin, and the breeding background. Thus, materials which originated from Burkina Faso were clustered in the same group while those from IITA/Nigeria were also almost all clustered in the same group. The genetic distance was low (≤0.29) suggesting a narrow genetic base in the cowpea germplasm used in this study. SNPs were efficient in the study of the diversity and a core collection of 20 lines was generated for further use in the breeding program. Marker-assisted backcrossing (MABC) was used to transfer QTLs for yield under drought and stay-green into Moussa local, a farmer preferred landrace. Two backcrosses assisted by SNP markers in foreground and background selections were sufficient to select for QTLs presence and to recover the background of Moussa local, the recurrent parent. The BC3F1s were selfed and six BC3F2s were evaluated for preliminary yield under drought stress and non-stress conditions. Out of the six, three MABC selected lines were promising and yielded better than the check and the parents. From these recombinant lines, several high yielding lines are likely to be developed for release in the near future. Most of them could be used in intercropping which will make great impact on cowpea production in Burkina Faso. In general, potential parents for genetic improvement for yield and drought tolerance were identified. However, further studies for assessing yield stability of cowpea genotypes are necessary and could be achieved by including more seasons and sites to get a better understanding of the genotype × environment interaction and yield stability of cowpea in Burkina Faso for all the materials identified including the MABC lines. Key words: Burkina Faso, farmers, drought tolerance, cowpea, genotypes, genetic distance, SNPs, marker-assisted backcrossing, Participatory Rural Appraisal.
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    Studies on the Immune Response to Amblyomma Variegatum in Cattle and the Effects of Haemoparasitism on The Acquisition of Tick Resistance
    (University of Ghana, 1995-06) Dossa, S.C.; Kaaya, G.; Essuman, S.; Assoku, R.K.G.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Animal Science
    Acaricides in tick control, had been thought to be in Africa the panacea for over a century. Environmental and economic constraints, development of acaricide-resistant strains due to acaricide misuse, have brought about the need for an alternative tick control strategy. The use of tick resistant cattle has then been advocated and echoed in the USA and Australia where it got its full expansion. In Africa, few works have been undertaken on tick resistance despite the fact that many tick species are found on the continent. Studies on acquisition of immunity to tick and especially to A. variegatum in Africa are very scarce so several questions need to be answered before the use of such a method. Therefore, an attempt was made to shed some lights on the tick-cattle interactions and on some of the factors which could influence the acquisition of resistance. We have chosen the Boran cattle-A variegatum model. That model was compared to those of A. variegatum-Ayrshire cattle and A. variegatum-crossbred Friesian x Boran. The resistance was artificially induced by applying simultaneously at one month interval, 100 nymphs on one ear and 20 males and 20 females on the other ear. At the beginning of the experiment the average age of the 20 animals was one year. For the first time, the status of acquired resistance was assessed with a multivariate analysis method. The principal component analysis (PCA) and fastclus procedure (SAS/STAT) were performed on the variables with high loads. It was noticed after the first infestation that, all the biological parameters favoured tick survival. The percentage engorged (PENGD), the percentage dead (PDEAD), the feeding period (FPR), the engorgement weight (ENGWT), the percentage that moulted (PMLTD) and the percentage that engorged above critical weight (PEACWT), with loads > 0.45 proved to be the indicators for the resistance to nymphs and adults. Three groups (high, moderate, low) of resistance have been defined using the fastclus procedure. Each group has been subdivided into three lots with two individuals each. The resistance dynamic was assessed using the ANOVA procedure. It was observed with the Boran cattle that resistance to the nymphs was already induced from the third infestation. Resistance to adults did not show a defined trend. A decline in the immunity level to nymphal and adult stage was observed from the 4th and 5th infestation. In order to assess the effects of trypanosomosis or babesiosis on the acquired immunity, the tick-immune animals from the above lots were infected separately with either 1 ml of 107 blood stream T. congolense or with 150 ml of infective blood from an immunosuppressed donor calf bearing 10% B. bigemina parasites. The same number of ticks was applied, in the same manner at the height of parasitaemia. There was a significant decrease in the PENGD, ENGWT, PMLTD, PEACWT, and a significant increase in the PDEAD and the FPR which indicated an increase in the resistance status. Acquired resistance to A. variegatum could also be demonstrated in the purebred Bos taurus Ayrshire as well as in the crossbred Bos indicus (Boran) x Bos taurus (Friesian) cattle, after four to five successive infestations though some individual variations could also be noticed. acquired by crossbred Friesian x Boran and Ayrshire revealed that, the crossbred acquired significantly higher immunity than the other two breeds after the first two infestations. Although relatively lower, the resistance acquired by the Ayrshire was not significantly different from that of the Boran. The profile of gel filtration chromatography of the tick-immune serum obtained from the Boran cattle showed 3 peaks corresponding to IgM, IgGs, and albumins. The IgGs run through affinity chromatography using protein ASepharose 4BR, showed two peaks corresponding to the lgG1 and lgG2 fractions. The silver-stained profile revealed the heavy and light chains respectively around 54kDs and 29kDs while the IgM fraction showed three different bands of 77kDs, 69kDs and 29kDs. SDS-PAGE gels of saliva and salivary gland homogenates, sequentially prepared from the ticks, showed that different molecules were injected into the host during attachment and feeding. Several molecules were recognized by the whole tick-immune serum as well as by the lgG1 and lgG2 obtained after fractionation and purification through gel filtration chromatography and gel affinity chromatography and the immunoblotting procedure. Quantification of the antibodies implicated in the acquired immunity by indirect and direct ELISA showed that lgG1 was present and correlated with some of the parameters used to assess the acquisition of resistance. A higher host antibody concentration was observed after the sixth infestation when ticks were fed on the haemoprotozoan-infected animals. The IgM concentration remained unchanged during the infestations denoting its passive role in the mechanism of acquired immunity.