A total of 54 lactating dairy cows from 20 farms in Hai District were monitored to assess production performance and methane (CH4) emission under different feeding practices and altitude zones. Of the selected farms 8 were in the highland zone and 12 in the lowland zone. In the lowland, cows were managed under zero grazing (FP1), grazing with supplementation (FP2) and extensive grazing (FP3), while all highland cows were managed under FP1. Measurements included body weight, nutrients intake, milk yield and composition and CH4 emission. Feedstuffs were also analysed for their nutritive values. The results showed that, daily dry matter intake (DMI), crude protein intake (CPI) and metabolisable energy intake (MEI) were higher (P<0.05) in cows under FP1 (11.1 kg, 1.2 kg and 117 MJ, respectively) than those in FP2 (9.8 kg, 938 g and 90 MJ) and FP3 (7.5 kg, 539 g and 45.3 MJ). Similarly, cows in the highland zone had higher (P<0.05) DMI, CPI, and MEI (11.7 kg, 1.3 kg, and 121.9 MJ) than those in the lowland zone (11.1 kg, 1.18 kg, and 117.1 MJ). Weight gain was highest (P<0.05) in FP1 (0.35 kg/d), followed by FP2 (0.21 kg/d), and lowest in FP3 (0.11 kg/d). Cows in the highland zone had significantly higher weight gain 0.46 kg/d) compared to those in the lowland zone 0.35 kg/d). Daily mean milk yield followed a similar trend, with cows under FP1 producing the highest (9.0 kg), followed by FP2 (6.8 kg) and FP3 (4.7 kg). Across zones, milk yield was significantly higher (P<0.05) in the highland (11.2 kg) than in the lowland (9.0 kg). Milk from cows under FP3 had slightly higher (P<0.05) lactose content (4.4%) than those under FP1 and FP2, while cows under FP1 produced milk with higher solids-non-fat (SNF) content (8.5%). Milk from lowland cows contained more (P<0.05) fat (4.0%), protein (3.6%), total solids (12.0%) and solids-non-fat (8.5%) than milk from highland cows. Mean gross methane emission did not differ significantly among feeding practices but was higher (P<0.05) in the highland zone (265 g/d) than the lowland zone (149.9 g/d). Methane intensity was similar (P>0.05) across feeding practices and zones. It was concluded that cows under FP1 achieved higher production performance by producing higher milk yield per unit of methane emitted compared to other feeding practices. Further research is recommended to evaluate the effects of different supplementation levels on production performance and methane emission.

A survey study was conducted to assess the influence of altitude and socioeconomic characteristics of smallholder dairy farmers in adaptation to feeding practices (FPs) and their ultimate effect on the nutrition of dairy cattle and milk production. One hundred and twenty dairy farmers from highland (60) and lowland (60) zones of Hai district, Tanzania were interviewed. Feed samples were collected for evaluation of proximate and Van Soest composition, in vitro dry matter (INVDMD) and organic matter (INVOMD) digestibility for three FPs, namely zero grazing (FP1), grazing with supplementation (FP2) and extensive grazing (FP3). Data on milk yield was obtained from the farmer record books and database of African Asian Dairy Genetic Gain program. Most respondents from both highland (88%) and lowland (53%) zones were practicing zero grazing (FP1) than grazing plus supplementation. High level of education, farming experience of >10 years, and dairying plus other sources of livelihood showed positive likelihood of influencing adaptation of zero grazing practice (FP1). Forage diets offered to cows under FP1 had lower mean values of crude protein (6.9%, CP) and metabolisable energy (5.01 MJ ME/kgDM) compared to other practices. Concentrate diets used in FP1 practice had higher CP (13.7%) compared to those in FP2 (10.9%). There was higher average milk yield from cows under FP1 in the highland (11.6 kg) compared to their counterparts. Cows under FP1 on the lowland had similar (P>0.05) average milk yield (8.7 kg) to those under FP2 in the highland zone (9.47 kg). Cows under FP3 in the lowland produced the lowest (P<0.05) milk yield of 4.61 kg. The study concluded that differences in socioeconomic characteristics of farmers and altitude zones have influence on the adaptation and domination of a specific feeding practice, which ultimately determines the level of performance of the dairy cattle. It is recommended that more studies are required to assess the influence of feeding and other management practices of dairy cows on the environmental effects.

This study was carried to investigate the levels and types of microbial contamination in raw milk from selected nodes of the dairy value chain in Mbulu District, northeastern, Tanzania. A total of 185 raw milk samples were collected from dairy farmers, vendors, and restaurants across four wards namely Endagikot, Imboru, Hydom, and Dongobesh. The target bacteria were Escherichia (E.) coli, Staphylococcus spp., Klebsiella (K.) pneumoniae, and Enterococcus (E.) faecalis. A total of 185 milk samples were collected from dairy farms, vendors and restaurants across four wards. Total viable bacteria count and bacterial isolates were analysed using culture, biochemical test and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS. Contamination increased up the chain with the lowest mean bacterial load (7.78 × 10³cfu/ml) in milk samples collected directly from udder and the highest (2.09 × 10⁴cfu/ml) in farmers bulking containers. E. coli and Staphylococcus spp. were the most prevalent bacteria detected at rates of 32.1 and 17 percent respectively of total samples from the vendors as well as 18.9 and 17 percent of total samples collected directly from udder. The E. faecalis and K. pneumoniae were detected at much lower rates (3.77 and 1.89 percent respectively). The bacteria levels determined in the present study are sufficiently high to contribute to milk-borne illnesses among consumers. The findings highlight public health risks associated with poor hygiene practices, inadequate milk handling, and environmental contamination. Enhanced training for milk handlers, improved hygiene protocols and regular surveillance are recommended to ensure milk quality and safety.

Animal production is negatively impacted by global warming and is subject to serious consequences for livestock production systems. In order to understand how PBMCs of Indian Zebu-Jersey crossbreds respond to various levels and durations of thermal assault and heat shock, in this chapter we will discuss techniques involving in vitro thermal stress stimulation (TSS) to stimulate bovine peripheral blood mononuclear cells (PBMCs) under various thermal assault conditions (TACs), including normal to extreme temperatures and varying durations of thermal exposure (DTEs). The consequences of thermal stress on bovine species can be lessened and managed with an understanding of how PBMCs as a cellular system respond to in vitro heat shock and thermal assault. To learn more about how Indian Zebu-Jersey crossbreds respond to in vitro thermal conditions, it may also be possible to explore the relationship between the decrease in PBMCs count during in vitro TSS and the expression of the heat shock protein genes (HSPs) such as HSPs 70 and 90 genes. This will be exploited to discover how Indian Zebu-Jersey crossbreds respond in vivo to diverse environmental thermal conditions and will further enable in vivo understanding of the potential for thermotolerance in bovine species for better adaptability, survival, and production performance.

In the semi-arid areas of Africa many pastorallsts move their livestock to find better grazing when forage is scarce during the dry season. However, the practice of forage cultivation can sustain fodder supply for effective livestock feeding during these times. This study was undertaken to (1) assess grazing land management, and perception among Maasai pastoralists, and 2) evaluate Cenchrus ciliaris L. (Buffel grass) establishment and biomass yield under four levels of fertilisation and three seedbeds in a semi-arid area of eastern Tanzania. The seedbeds were not tilled (NT), tilled flat (TF) and tilled sunken (SN) with manure applied at rates of 0, 5, 10 and 15 t ha(-1). The 2m x 3m subplots were replicated three times per seedbed-manure treatment. Communal grazing land was perceived to be in poor condition by pastoralists due to the long time spent by their livestock in search of forage. Private forage reserves for dry-season feeding were present and could be used for forage cultivation. The TF, manure at 10 and 15 t ha(-1) treatments had significantly higher (p < 0.001) C. ciliaris establishment rates (97%) and biomass than other treatments. The TF10 and TF15 t ha(-1) treatments had biomass values of 9.8 and 10.1t OM ha(-1), respectively, by Week 10. Pastoralists preferred the TF method because of its high forage yield and low cost. Cultivation of C. ciliaris is important for livestock production and it can be established on privately owned forage reserves.

Rotavirus group A genomic characterization is critical for understanding the mechanisms of rotavirus diversity, such as reassortment events and possible interspecies transmission. However, little is known about the genetic diversity and genomic relationship of the rotavirus group A strains circulating in Tanzania. The genetic and genomic relationship of RVA genotypes was investigated in children under the age of five. A total of 169 Fecal samples were collected from under-five with diarrhea in Mbeya, Iringa and Morogoro regions of Tanzania. The RVA were screened in children under five with diarrhea using reverse transcription PCR for VP7 and VP4, and the G and P genotypes were determined using Sanger dideoxynucleotide cycle sequencing. Whole-genome sequencing was performed on selected genotypes. The overall RVA rate was 4.7% (8/169). The G genotypes were G3 (7/8) and G6 (1/8) among the 8 RVA positives, while the P genotypes were P[6] (4/8) and P[8] (2), and the other two were untypeable. G3P[6] and G3P[8] were the identified genotype combinations. The genomic analysis reveals that the circulating G3P[8] and G3P[6] isolates from children under the age of five with diarrhea had a DS-1-like genome configuration (I2-R2-C2-M2-axe-N2-T2-E2-H2). The phylogenic analysis revealed that all 11 segments of G3P[6] were closely related to human G3P[6] identified in neighboring countries such as Uganda, Kenya, and other African countries, implying that G3P[6] strains descended from a common ancestor. Whereas, G3P[8] were closely related to previously identified equine-like G3P[P8] from Kenya, Japan, Thailand, Brazil, and Taiwan, implying that this strain was introduced rather than reassortment events. We discovered amino acid differences at antigenic epitopes and N-linked glycosylation sites between the wild type G3 and P[8] compared to vaccine strains, implying that further research into the impact of these differences on vaccine effectiveness is warranted. The phylogenic analysis of VP7 also identified a bovine-like G6. For the first time in Tanzania, we report the emergence of novel equine-like G3 and bovine-like G6 RVA strains, highlighting the importance of rotavirus genotype monitoring and genomic analysis of representative genotypes.

Cenchrus ciliaris (African foxtail grass) is one of the perennial grass species with high drought and grazing tolerance, biomass yields and nutritional values. These factors emphasize its potential to improve livestock production in drylands. The study was conducted to investigate effects of seedbed types and manure levels on C. ciliaris herbage characteristics and nutritional values in a semi-arid area of eastern Tanzania. C. ciliaris was cultivated for 12 weeks on three seedbed types, namely not tilled (NT), tilled flat (TF) and sunken (SN), with cattle manure applied at 0, 5, 10 and 15 t/ha rates. Forages were evaluated for biomass yield, grass cover, seed production potential, and nutritional values. Forage biomass yield and grass cover were affected by seedbed type and manure level. The combination of TF seedbed and 10 or 15 t/ha cattle manure had the highest forage biomass yields of 12.4 and 12.6 t/ha, respectively. Similarly, TF seedbed with manure 10 and 15 t/ha had highest vegetative covers of 76.0% and 78.2%, respectively. Inflorescence density did not vary among seedbeds and manure levels. Forage energy and protein contents were not affected by seedbed. Energy intake was affected by manure level whereby it was higher in manure 10 and 15 t/ha for all seedbeds. It was concluded that TF and 10 t/ha are the best seedbed and manure level to establish C. ciliaris for sustainable livestock feeding in semi-arid areas of eastern Tanzania and similar environment.

The success or failure of artificial insemination (AI) depends on the quality of semen used. This study was conducted to investigate the effect of breed, age, collection period, and ejaculate number on semen quality collected from 15 breeding bulls available at the centre with different ages (4 Friesian, 4 Ayrshire, 3 Jersey, 2 Simmental and 2 Boran breeds) maintained at National Artificial Insemination Center (NAIC), Arusha, Tanzania. A total of 600 ejaculates were collected for four weeks per month consecutively from January to May 2022, weekly per bull and twice a day; morning (6.00 - 9.00 AM) and evening (3.00 - 6.00 PM) sessions). The ejaculates were first examined visually for volume, color, foreign bodies, and consistency whereas sperm concentration (SPC), progressive motility (PM) and total motility (TM) were assessed using Computer Assisted Semen Analysis System (CASA). Viability/vitality (SPVI) and morphology (SPNR) of sperms were analyzed microscopically after staining with Eosin-Nigrosin. Data were subjected to SAS program and results showed that ejaculate volume, progressive motility, total motility, sperm viability, and morphology were significantly (P<0.05) affected by age and collection period. Simmental, Friesian, and Ayrshire bulls produced more voluminous semen than Jersey and Boran bulls. Jersey bulls had higher (P<0.05) sperm concentrations and live spermatozoa as compared to other bulls. Boran and Jersey's bulls exhibited higher PM and TM than the other bulls. The period of semen collection (morning versus evening) negatively affected semen volume, total motility, and semen viability in which morning harvests performed better than evening collections. Middle aged bulls (3-5 years) produced semen of higher quality compared to other groups (< 3 years and > 5 years old bulls). In conclusion, age, breed, period of semen production and ejaculate number revealed significant effect on bovine semen characteristics.

Several factors are said to influence semen quality in breeding bulls. This research was carried out to investigate the effect of season and cold value chains on semen quality parameters. A total of 1652 semen production records from 2018 to 2021 from 10 dairy bulls preserved at the National Artificial Insemination Centre (NAIC), USA River, Arusha, Tanzania, and 540 cryopreserved semen examined were analyzed using Analysis of Variance (ANOVA) and the results were expressed as mean ± standard error of the mean using statistical analysis system (SAS, 2004), to determine whether there were significant differences among variables tested. All semen traits (VOL, SPC, PM, TM, PM, TM, VER, MP, and HP) were significantly (P <0.05) affected by season and cold value chain. During the cold season, the highest values of SPC, PM, TM, PM, TM, VER, MP, and HP were observed as compared to that of the warm season. Furthermore, semen quality decreased gradually from pre-state (before freezing) to post-state (after freezing for 48 hours) with minor affection for semen motility. There was a higher decrease (P <0.05) in quality from cryo-stored semen straw to those of the same batch retrieved back from the field. The semen quality parameters were satisfactory in the first three stages when compared to the semen straw from the field which was observed to have poor motility which could be due to poor handling, leakage of storage and transportation containers, and sometimes the delay of refilling the LN2. Finally, during the cold season and in all stages of semen production the semen is qualitatively and quantitatively good.

Rotavirus group A (RVA) causes neonatal calves diarrhoea, causing massive economic losses in many countries due to deaths, treatment costs, and stunted growth. However, little is known about Tanzanian cattle's RVA burden and genotypes. The prevalence and genetic diversity of rotaviruses circulating in cattle in Southern and Eastern Tanzania regions were investigated. A total of 272 faecal samples collected from calves (102 from Mbeya, 89 from Iringa, and 81 from Morogoro) were tested for RVA. 30 (11.03%) of the 272 samples tested positive for RVA, 7 (6.8%) of the 30 RVA positive samples were from Mbeya, 23 (28.39%) from Morogoro, and no positive samples were found in the Iringa region. Using RT-PCR, 20 samples were identified as G10 genotypes, while the remaining 10 samples were untypeable with the primers used, whereas all P genotypes were untypeable. To confirm the RT-PCR results, representative samples were chosen and sequenced in the ABI 3130XL using a Big-dye Terminator kit with Sanger dideoxy sequencing method. Phylogenetic analysis and nucleotide comparison revealed that G10 was closely related to and clustered with human G10 strains from neighboring Kenya, implying that circulating G10 strains may have the potential for zoonotic transmission. When circulating G10 amino acid alignment was compared to bovine vaccine strain B223, our G10 samples had various nucleotide substitutions at antigenic epitopes, which resulted in the acquisition of glycosylation sites suggesting that G10 has the potential to evade neutralization antibodies induced by a vaccine. Our study provided preliminary data on RVA in cattle in Tanzania, paving the way for further research into the rotavirus epidemiology and risk factors associated with RVA in cattle in Tanzania. Key words: Cattle, rotavirus groups A, G10 genotype, Tanzania.

This study was designed to evaluate various genetic parameters for growth characteristics, genetic progression, and to find out the genetic constitution of a population of Mecheri sheep, a tropical breed native to Tamil Nadu, southern India. Data for this study were various records from 2768 lambs, which were a result of mating of 110 sires and 748 dams during a period of 10 years, between 2010 and 2019. Among the evaluated traits included body weights at various stages of growth such as birth weight (BWT), as well as weight at weaning (WWT), at 6-months (6WT), at 9-months (9WT), and at one-year-old (12WT). Estimated genetic parameters included additive direct and maternal heritabilities and genetic correlations, genetic changes, inbreeding, and generation interval. Among the software required for various analyses were the ENDOG (version 4.8) and Restricted Maximum Likelihood (REML). Mean ( +/- SE) values of weight at birth and at 12 months were 2.37 +/- 0.02 and 21.34 +/- 0.34 kg respectively. Direct heritability values estimated at birth, six months, as well as 12 months were respectively 0.14 +/- 0.05, 0.07 +/- 0.03, and 0.08 +/- 0.03. Maternal heritability value for BWT was 0.28 and whereas low and varied values between 0.03 and 0.05 were obtained for both weaning and post-weaning traits. Overall, genetic improvement was low at birth (-0.0025 kg) and highest (0.1314 kg) around weaning age. Average inbreeding coefficient value was 0.16 % and the effective population size of founders was 100.35, while mean generation interval (+/- SE) was 3.44 +/- 1.15 years. Effective number of founders was 18.01 % and indicates that Mecheri sheep have their origin from a moderate genetic base. The observed f(e)/f(a) ratio was 1.00 and is linked to presence of sufficient founding ancestors, less bottlenecks, and possibly implementation of rotational mating scheme at the farms. In summary, our study revealed that there are high correlations between WWT and post-weaning weights. Based on heritability values, the WWT could be used as an important trait which can facilitate improvement in body weight of Mecheri lambs. Further, the present genetic parameter values for different variables advocates that the genetic progress for body weight at various stages of growth is feasible in Mecheri sheep thorough genetic selection strategies. We conclude that sufficient genetic diversity is maintained within Mecheri sheep.

Background and Aim: Global warming has grave consequences on livestock production systems and profound negative effects on animal production. This study aimed to carry out an in vitro thermal stress stimulation (TSS) of bovine peripheral blood mononuclear cells (PBMCs) using different thermal assault conditions (TACs), including normal to extreme temperatures and varying durations of thermal exposure (DTE) to understand how PBMCs of Indian Zebu–Jersey crossbreds respond to various levels and durations of heat shock. Materials and Methods: Ten milliliters of blood were collected from 70 Indian Zebu–Jersey crossbreds under aseptic conditions and were sampled for isolating PBMCs. Peripheral blood mononuclear cells were divided into seven groups, each comprising 10 PBMC samples isolated from 10 different animals. Aliquots of 500 μL of PBMCs were stressed by exposure to different TACs (37, 40, and 45°C) for DTEs of 3 or 6 h. Subsequently, the cells were harvested. The control unstressed samples (500 μL aliquots of PBMCs) were exposed to no TAC (0°C) and zero DTE (0 h). Total RNA from all the treatment groups of PBMCs were isolated and quantitated. Results: We found a very strong association between TACs and RNA levels. In addition, PBMCs viability was negatively affected by heat shock. This led to an exponential reduction in PBMC count as TACs toughened. Only 3.59 × 105 ± 0.34 cells/mL were viable after exposure to 45°C for a 6 h DTE. This cell viability was lower than that measured in controls subjected to no stress and zero time DTE (2.56 × 107 ± 0.22 cells/mL). We also observed a reduction in the concentration of RNA isolated from thermally stressed PBMCs. Conclusion: In vitro TSS of PBMCs provided biological information on the response of cellular systems to heat shock after exposure to TACs. This will help to mitigate and manage the effects of thermal stress in bovine species. The association between the reduction in PBMC count after in vitro TSS and the expression of heat shock protein 70 gene will be investigated in the future to further understand how Indian Zebu–Jersey crossbreds respond to in vitro thermal conditions. This will be used to determine the in vivo response of Indian Jersey crossbreds to different environmental thermal conditions and will further enable the in vivo understanding of thermotolerance potentials of bovine species for better adaptation, survival, and production performance.

Animals have been identified as the potential reservoirs of rotavirus group A (RVA) for human infection. However, very little is known regarding the genotype and genomic profiles of circulating RVA in Tanzanian piglets. The rotavirus genetic diversity and genome analysis was assessed among piglets from Southern highlands and Eastern Tanzania. A total of 241 faecal samples were collected from piglets in the regions of Mbeya, Iringa, and Morogoro. RVA was detected and genotyped using reverse transcription polymerase chain reaction (RT-PCR). Sanger dideoxynucleotide cycle sequencing of the viral protein (VP) 4 and VP7 genes was afterwards performed to confirm the RT-PCR results. Selected genotypes were subjected to whole genome sequencing. The overall prevalence of RVA was 35.26% (85/241) in piglets (30.58% in Mbeya, 43.75% in Iringa and 31.16% in Morogoro). Upon genotyping, the G genotypes were G4 (26), G9 (10), G3 (6), G5 (3) and the remaining 40 were untypeable, while the P genotype, were P[6] (35), P[13] (3) and the remaining 47 were untypeable. The G4P[6] were the predominant genotype followed by G3P[6], G3P[13], G4P[13] and G5P[13] were most common genotypes combinations. On phylogenetic analysis, G4 was grouped to lineage V, sublineages VIIa and VIIc, G9 to lineage I, G5 to lineage II, G3 to lineage IV, P[6] to lineage V and sublineage Ic and the P[13] to lineage IV. We revealed amino acid differences between the circulating G4 and the G4 in the ProSystems RCE vaccine used in pigs. The whole genome reveals genomic constellation of G4-P[6]-I1-R1-C1-M1-A8-N1-T1-E1-H1, G5-P[x]-I5-R1-C1-M1-A8-N1-Tx-E1-H1, G3/G4-P[13]/P[6]-Ix-R1-C1-M1-A8-N1-T1-E1-H1, G3-P[6]-Ix-R1-C1-M1-A8-N1-Tx-E1-H1 and G9-P[x]-Ix-R1-C1-M1-Ax-N1-Tx-E1-H1. The VP7 gene of G9, the VP4 gene of P[6] and NSP4 (E1) gene of some genotypes clustered together and closely related to humans origin or porcine-human reassortant strains with nucleotide similarities ranging from 97.90% to 99.74% from neighboring countries, implying possibility intragenogroup reassortment and interspecies transmission. The higher strain diversity observed within the gene segments highlight the importance of genomic analysis and continuous monitoring of RVA genotypes. Further research is needed to determine the risk factors associated with RVA infection in Tanzanian pigs in order to properly design a control program.

Aim: To investigate genetic diversity, gene flow and demographic history of frigate tuna (Auxis thazard) populations found in Tanzanian marine waters. Study Design: The study used a descriptive research design whereby fish samples were randomly collected from four locations and the genetic variation within and among the four populations analyzed using mitochondrial DNA (mtDNA) control region. Place and Duration of the Study: Fish samples were collected from landing sites in Tanga, Dar es Salaam, Mtwara and Zanzibar, Tanzania. The study was conducted between July 2020 and June 2021. Methodology: A total of 100 frigate tuna were randomly sampled from small-scale fishermen at the landing sites of Dar-es-Salaam (20), Tanga (30), Mtwara (30), and Zanzibar (20). For each fish, 50 g muscle tissue was obtained and put in a vial containing 95% ethanol. DNA was extracted from the muscle using a commercial DNA Kit (Quick-DNATM Miniprep Plus Kit, Zymo Research Corp.) according to the instructions of the manufacturer and a fragment of 432 bp of the mtDNA control region was amplified and sequenced using ABI PRISIM™ 3100 Genetic Analyzer (Applied Biosystems). Haplotype and nucleotide diversity, gene flow and historic demographic were estimated from 92 fish samples. Results: A total of 88 haplotypes were identified in all fish samples. The highest haplotype diversity was found in Zanzibar (1.000 ± 0.017) and Mtwara (1.000 ± 0.010) populations while the lowest was observed in Tanga population (0.992 ± 0.012). Tanga population had the highest nucleotide diversity (0.078 ± 0.018) while Dar es Salaam had the lowest (0.016 ± 0.009). The highest genetic differentiation (FST) was found between Tanga and Dar-es-Salaam (0.178) and the lowest was observed between Mtwara and Zanzibar (0.016). The genetic distances between pairs of populations were small. The phylogenetic tree revealed two main clusters. Cluster 1 which consisted of nine haplotypes was dominated by Tanga population with seven haplotypes while the remaining two haplotypes were from Mtwara and the reference sequences of Euthynnus affinis (Kawakawa tuna). Cluster II had 84 haplotypes of individuals from all four populations, with no population specific subcluster. The number of immigrants per generation was highest between Mtwara and Zanzibar (Nm=18.310) and lowest between Tanga and Dar-es-Salaam (Nm=1.180). The neutrality test indicated negative values, suggesting a recent population expansion. Conclusion: There is high genetic diversity within the populations, but there is no significant genetic differentiation among the four frigate tuna populations, suggesting that the four populations comprise a single panmictic population.

Most rangelands along the agro-pastoral villages of Tanzania are yearlong grazed and at various states of degradation. These rangelands contribute to over 60% of the meat and milk production in the country. An inventory was conducted to assess the status of grazing resources in a typical agro-pastoral village of Tanzania having communal rangelands. Systematic random sampling techniques were employed whereby line transects and quadrat frame were used following standard procedures to collect samples and undertake field measurements for both vegetation and soil parameters. The vegetation cover for desirable pasture species, undesirable pasture species and litter were 67.7%, 10.5% and 9.4%, respectively. The soil bare patches covered 12.3 % of the surveyed rangeland site. The most dominant grass species were Enteropogon macrostachyus, Bothriochloa insculpta and Heteropogon contortus. Forage dry matter (DM) yield was 806.8 kg DM/ha. Tree density was 1500 trees/ha and the total canopy cover was 63.49%. Combretum collinum was the most dominant tree species. Soil bulk density, pH, organic carbon, nitrogen, phosphorus and potassium were 1.4 g/cm3, 6.3%, 1.14%, 0.09%, 0.89 mg/kg and 0.33 g/kg, respectively. A total of 11 dicotyledonous species mainly forbs and 9 monocotyledonous species including two perennial grasses were revealed from the incubated soil samples. The findings of this study demonstrate that the communal grazing areas have low pasture productivity, poor soil seed-bank and high cover of woody plants mainly bushes. In order, to improve forage biomass at the study site and elsewhere with similar environments selective bush clearing and re-seeding should be considered.

Animals have been identified as the potential reservoir of rotavirus group A (RVA) for human infection. However, very little is known regarding the genotype circulating in Tanzanian piglets and its relationship to the global rotavirus genotype. The rotavirus genetic diversity was assessed among piglets from Southern highlands and Eastern Tanzania. A total of 241 faecal samples were collected from piglets in the regions of Mbeya, Iringa, and Morogoro. RVA was detected and genotyped using reverse transcription polymerase chain reaction (RT-PCR). Sanger dideoxynucleotide cycle sequencing of the VP7 and VP4 genes was then performed on a representative strain to confirm the RT-PCR results. The overall prevalence of RVA was 35.26% (85/241) in piglets (30.58% in Mbeya, 43.75% in Iringa and 31.16% in Morogoro). On genotyping, the G genotypes were G4 (26), G9 (10), G3 (6), G5 (3) and the remaining 40 were untypeable, while the P genotype, were P[6] (35), P[13] (3) and the remaining 47 were untypeable. The G4P[6], G3P[6], G3P[13], G4P[13] and G5P[13] were most common genotypes combinations. On phylogenetic analysis, G4 was grouped to lineage V, sublineages VIIa and VIIc, G9 to lineage I, G5 to lineage II, G3 to lineage IV, P[6] to lineage V and sublineage Ic and the P[13] to lineage IV. We discovered amino acid differences between the circulating G4 and the G4 in the ProSystems RCE vaccine used in pigs using amino acid alignment. The detected G9 and P[6] clustered together and were closely related to human G9 and P[6] by nucleotide similarities of 97.90% to 98.60% and 98.17% to 98.74% from neighboring, countries respectively. Rotavirus genotypes were genetically diverse and had a close relationship to human strains, implying the possibility of interspecies transmission. We therefore recommend further research on whole genome analysis to better understand the zoonotic potential of pig rotaviruses in Tanzania.

Abstract The dry seasons decline in milk production due to insufficient feed supply to dairy cattle poses a great challenge to sustainability of smallholder dairy production systems in Tanzania. Locally produced leguminous fodder tree leaf meals combined with maize bran provide a great potential for overcoming the dry season protein-energy deficit in the basal roughage feeds. This study evaluated the effects of dry season Calliandra calothyrsus (Calliandra) leaf-meal: maize-bran based protein-energy homemade supplementary ration (HSR) on milk production of lactating cross-bred dairy cows in the Western Usambara Highlands (WUHs), Tanzania. Complete randomized design was employed whereby four groups of 4 lactating dairy cows were subjected to four levels of HSR rationed at 0, 2, 4 and 6 kg/cow/day. The lactating cows which were not subjected to HSR supplementation (0 kg/cow/day) were left under farmers’ feeding practices as a control. HSR had significant effect on dry season milk yields (P < 0.001) whereby milk yields were 2.7, 4.5, 5.6 and 6.1 litres/cow/day for 0, 2, 4 and 6 kg HSR/cow/day, respectively. In addition, simulated year-round daily milk yields indicated that 4 and 6 kg HSR/cow/day would double the milk yields. Nevertheless, there was overall significant difference in the income to cost ratios (P = 0.02) whereby it was 0.50, 0.79, 1.06 and 1.09 for 0, 2, 4 and 6 kg HSR/cow/day, respectively. However, the income to cost ratios for 4 and 6 kg HSR/cow/day did not differ significantly (P < 0.05). In conclusion, if the dairy farmers in WUHs are to produce profitable milk amounts during the dry seasons the supplementation level of 4 kg HSR/cow/day to the basal diets is recommended.

There is a growing body of literature about cane rat species but most of the published work is patchy and current spatial distribution is unknown which limits its wide application in the utilization of the species for the broader commercial game industry and for improving wildlife conservation across Africa. We conducted a systematic review of 56 years (1964 - 2020) of cane rat research to understand existing research gaps, to analyze the spatiotemporal and thematic patterns, and investigated factors that influence the publication of the cane rat research in widely recognized journal outlets. We found 308 publications on the cane rat species from 14 countries authored by 39 nationalities globally. The publications increased significantly over the study period, with 97.7% of these biased geographically and thematically towards the west and central African region. Further, the published research mostly covered one species, the greater cane rat, and none had covered the biogeography, food biology, and conservation of any of the two cane rat species in situ. Also, the author's nationality had the strongest influence on publishing the research in journals with or without impact factor. These results suggest that the financial limitation and quality of the research influenced most cane rat research published in local national or regional journals which mostly had limited accessibility for widespread research use to improve applied conservation programs. Expanding coverage of the cane rat research in other species-range countries in the east and southern African regions will be necessary to tap the species as a priority commercial game to reducing exploitation pressure on the wild mammal populations particularly in the African savannas where illegal hunting for bushmeat consumption is a growing problem.

Genetic variants at heat shock protein 70 gene and their influence on heat stress (HS) tolerance were studied among selected Nigeria zebu, namely, 25 White Fulani (WF), 21 Sokoto Gudali (SG), 21 Red Bororo (RB), and 23 Ambala (AM). Detection of single nucleotide polymorphism (SNP) followed by determination of genotype and genotypic frequency was made among the selected breeds. The heat tolerance coefficient (HTC) was determined from thermo-related parameters including body temperature, rectal temperature, and respiratory rate. Thermo-Tolerance was evaluated through the SNP-thermo-parameter relationship. Statistical analyses were done using the GLM procedure in SAS. A quantitative real-time/high-resolution melting-based assay detected twelve genetic variants. Five of these were common and shared across all breeds of cattle. Of the remaining seven variants, three were specifically identified in AM, two in SG, and two in RB. Also, SNPs were evaluated and four unique SNPs (C151T, C146T, G90A, and C219A) were identified. Heterozygous animals had lower HTC suggesting their potential to withstand HS than homozygous counterparts. The WF and RB animals had significantly lower values for all parameters (BT, RT, RR, and HTC) compared to AM and SG breeds. Thermo-related parameters were significantly different (P < 0.001), and it is recommended that screening of SNPs in zebu is needed to enable selection for improved thermo-tolerance.

Milk from goats has uplifted the nutritional standards of many poor households in rural communities in developing countries. In Tanzania, consumption of milk in these communities has increased since introduction of dairy goats in 1960s. Nutritional composition including carbohydrate, protein, fat, minerals and associated quality attributes are important factors of milk for human consumption. Also, milk should be obtained from health animals in order to safeguard the health of consumers. These parameters are affected by many factors including management, production level, breed, parity and stage of lactation, as well as processing and handling conditions. We carried out this study to evaluate the composition of milk from dairy goats namely Norwegian Landrace (NL), mainly crosses with indigenous Small East African (SEA) goats which are bred and managed in Mgeta division, Morogoro region, Eastern Tanzania. We collected 75 milk samples considering various factors. These samples were analysed for somatic cell count (SCC), crude protein (CP), butterfat (BF), lactose, total solids (TS), solids-not-fat (SNF), Chloride (Cl) as well as milk density. We obtained averages of each parameter for each factor and made statistical based on analyses which were performed general linear model procedures of the statistical analysis system. Averages for milk yield (MY), SSC, CP, BF, lactose, Cl, TS, SNF and milk density were 1.32 litres/day, 1.48x105 cells/ml, 3.65, 4.34, 4.20, 0.15, 12.29, 7.95 and 27.98% respectively. Conclusively, values of parameters were within the recommended ranges and milk from NL goats is good for consumption.