Regional Livestock Research Articles

Evaluation of the Regional Livestock High Quality Development in China Based on Spatial–Temporal Heterogeneity

The livestock high-quality development (LHIQUD) is an important guarantee for promoting livestock modernization and sustainability. The scientific evaluation of LHIQUD and its regulations is significant to solving the key problems in livestock sustainability and promoting LHIQUD. This paper holds that LHIQUD is influenced by the cutting-edge view of economic development and ecological civilization construction, driven by innovation and the change in quality and efficiency. Its fundamental goal is to satisfy people’s growing demand for safe, high-quality agricultural products. Finally, it will realize the sharing of development achievements and enhance competitiveness of the livestock. Based on this, the study sets up an evaluation system for LHIQUD, including indicators of quality and efficiency improvement, coordination and sharing, green development, and innovative development. The entropy method, exploratory spatial data analysis, and kernel density estimation method are used to evaluate the regional LHIQUD of China from 2010 to 2019. The dynamic evolution and spatial auto-correlation analysis results show that (a) Regional LHIQUD in China has generally improved, and there is a decreasing trend from the East, Northeast, and central region to the West, with the characteristics of spatial non-equilibrium. (b) LHIQUD is positively correlated with the regional economic development. (c) The spatial auto-correlation of LHIQUD is not obvious, generally showing a weak agglomeration pattern. Provincial LHIQUD is interdependent in geographical space, with agglomeration characteristics. The findings of this study are invaluable for governments at all levels to accurately comprehend the true state of regional LHIQUD in China, thereby providing a solid foundation for formulating corresponding policies.

Heat Tolerance Differences Between Hu Sheep and Hu Crossbred Sheep in Microbial Community Structure and Metabolism.

The frequent occurrence of extreme temperature events causes significant economic losses to the livestock industry. Therefore, delving into the differences in the physiological and molecular mechanisms of heat stress across different sheep breeds is crucial for developing effective management and breeding strategies. This study explores the differences in heat tolerance mechanisms between Hu sheep and Xinggao sheep by comparing their growth performance under normal and heat stress conditions, as well as examining the differences in physiological, biochemical, and antioxidant indicators related to heat tolerance, serum metabolomics, and gut microbiomics in a heat stress environment. The results indicate that with changes in the temperature-humidity index (THI), Hu sheep exhibit superior stability in respiratory rate (RR) and rectal temperature (RT) fluctuations compared to Xinggao sheep. In terms of biochemical indicators and antioxidant capacity, the levels of creatinine (Cr) and superoxide dismutase (SOD) in Hu sheep serum are significantly higher than those in Xinggao sheep. In comparison, alkaline phosphatase (ALP) and malondialdehyde (MDA) levels are significantly lower. Metabolomic results showed that, compared to Hu sheep, Xinggao sheep exhibited higher cortisol (COR) and dopamine (DA) levels under heat stress conditions, a stronger lipid mobilization capacity, and elevated levels of tricarboxylic acid (TCA) cycle-related metabolites. Furthermore, gut microbiome analysis results indicate that Hu sheep demonstrate stronger cellulose degradation capabilities, as evidenced by significantly higher abundances of microorganisms such as Ruminococcus, Fibrobacter, and Bacteroidales_RF16_group, compared to Xinggao sheep. In summary, Hu sheep exhibit stronger heat tolerance compared to Xinggao sheep. These findings provide an important theoretical basis for the breeding and selection of heat-tolerant meat sheep varieties and offer strong support for the region's livestock industry in addressing the challenges posed by global warming.

Distinct amino acid substitutions in the EEV glycoprotein and DNA-dependent RNA polymerase of lumpy skin disease virus identified in wetland areas of Bangladesh.

The recent outbreak of lumpy skin disease virus (LSDV) in the wetland areas of Bangladesh presents a significant concern for both animal health and regional biosecurity. Epidemiological investigations into nine major outbreaks in the wetland areas revealed distinctive clinical symptoms in affected cattle, including elevated body temperature, excessive salivation, and the presence of skin nodules. Histopathological examination unveiled larger nodules compared to previous outbreaks, along with signs of secondary infection. Molecular analysis confirmed the presence of LSDV in all samples, with subsequent sequencing revealing genetic similarities with virus isolates of Bangladesh, India, China, Russia, Serbia and Greece. Most importantly amino acid variations in the viral EEV glycoprotein and DNA-dependent RNA polymerase were revealed that also altered the structures of the respective proteins significantly suggesting potential implications for viral pathogenesis. Additionally, successful isolation of LSDV in Vero cells demonstrated cytopathic effects, supporting the potential for vaccine development. In conclusion, this study provides comprehensive insights into the epidemiology, genomic characters with altered predicted structures of two major viral proteins and pathogenesis of LSDV outbreaks in Bangladesh. These findings emphasize the critical need for ongoing monitoring and adaptive control strategies, including the development of effective vaccines, to mitigate the impact of LSDV in affected regions and safeguard regional livestock health.

Research on Forage–Livestock Balance in the Three-River-Source Region Based on Improved CASA Model

As an important ecological barrier and a crucial base for animal husbandry in China, the forage–livestock balance in the Three-River-Source Region (TRSR) directly impacts both the degradation and recovery of grassland. This study examines the forage–livestock balance in the TRSR over the past 13 years (2010–2022) by calculating both the theoretical and actual livestock carrying capacity, thereby providing a scientific basis for regional animal husbandry policies. Firstly, the Carnegie–Ames–Stanford Approach (CASA) model was improved to fit the specific characteristics of alpine grassland ecosystem in the TRSR. This enhanced model was subsequently used to calculate the net primary productivity (NPP) of the grassland, from which the regional grassland yield and theoretical livestock carrying capacity were derived. Secondly, the actual livestock carrying capacity was calculated and spatialized based on the number of regional year-end livestock. Finally, the livestock carrying pressure index was determined using both the theoretical and actual livestock carrying capacity. The results revealed several key findings: (1) The average grassland NPP in the TRSR was 145.44 gC/m2, the average grassland yield was 922.7 kg/hm2, and the average theoretical livestock carrying capacity was 0.55 SU/hm2 from 2010 to 2022. Notably, all three metrics showed an increasing trend over the past 13 years, which indicates the rise in grassland vegetation activities. (2) The average actual livestock carrying capacity over the 13-year period was 0.46 SU/hm2, showing a decreasing trend on the whole. The spatial distribution displayed a pattern of higher capacity in the east and lower in the west. (3) Throughout the 13 years, the TRSR generally maintained a forage–livestock balance, with an average livestock carrying pressure index of 0.96 (insufficient). However, the trend of livestock carrying pressure is on the rise, with serious overloading observed in the western part of Qumalai County and the northern part of Tongde County. Slight overloading was also noted in Zhiduo, Maduo, and Zeku Counties. Notably, Tanggulashan Town, Zhiduo, Qumalai, and Maduo Counties showed significant increases in livestock carrying pressure, while Zaduo County and the eastern regions experienced significant decreases. In conclusion, this study not only provides feasible technical methods for assessing and managing the forage–livestock balance in the TRSR but also contributes significantly to the sustainable development of the region’s grassland ecosystem and animal husbandry industry.

Priority directions for increasing production volumes in the regional livestock industry

Abstract The efficiency of agricultural production is determined by one of key parameters, namely, the production volume, which directly affects the earning power and profitability of the agricultural sector. The current level of development of the agricultural sector, both in the country as a whole and in most regions, indicates two trends in the development of the livestock industry and production, namely, processes of an intensive and extensive nature, thanks to which production volumes are also growing. At the same time, their influence on the scale of production activity is multidirectional. With the further development of technical and technological modernization, the introduction of modern technologies, the digital transformation of the livestock industry, processes related to the intensification of agricultural production should become priority methods for stimulating the growth of volumes, which will significantly and rapidly increase production volumes, ensure a significant increase in labor productivity, increase the level of its intellectualization.

Climate change impacts on livestock in Brazil

Brazilian livestock provides a significant fraction of the food consumed globally, making the country one of the largest producers and exporters of meat, milk and eggs. However, current advances in the production of protein from Brazilian animal origin may be directly impacted by climate change and the resulting biophysical effects. Therefore, it is strategically consistent to develop measures to deal with the resulting environmental heat stress on domesticated animal species, especially the need in developing countries. This work aims to (1) evaluate the impacts of climate change on livestock (cattle-dairy, cattle-beef, goats, sheep, pigs, poultry-general) in different regions of Brazil and (2) discuss possible response strategies, associated with animal comfort and welfare. From our results, we can draw better strategies to mitigate the impacts of climate change on livestock production. The results presented show an increase of high heat stress in South and Southeast and an increase of extreme heat stress in North and Central-West areas of Brazil. The rise in extreme heat stress tends to occur mostly during spring and summer and tends to vary considering the different evaluated species. Within the evaluated species, the ones that seem to be more affected by climate changes are Poultry, pigs, cattle-beef and general (temperature-humidity index value). The differences between the results for the five geographic regions in Brazil suggests that different mitigation measures need to be considered to cope with future heat stress in livestock. To ensure the long-term success of Brazil's influence on the global market for proteins of animal origin, it must achieve sustainable production systems more intensively.

Genetic characterization and distinctiveness of forage cactus accessions in Northern Minas Gerais, Brazil

Forage cactus is a vital alternative food source for livestock in arid and semiarid regions. This study aimed to estimate the genetic dissimilarity among forage cactus genotypes grown in the semiarid region of northern Minas Gerais, Brazil. The study evaluated forage cactus accessions through morphological characteristics over different periods and molecular marker data. Key morphological traits assessed included cladode length, width, thickness, and the number of cladodes per plant. The experiments were conducted at the Agricultural Research Company of Minas Gerais (EPAMIG Norte) using a completely randomized experimental design with five replications in a split-plot arrangement. The design consisted of 21 forage cactus accessions in the plots and 7 evaluation times in the subplots. Morphological dissimilarities were compared individually (Scott-Knott test; p<0.05) and jointly (Euclidean distance). Molecular genotyping involved DNA extraction from young cladodes using inter-simple sequence repeat (ISSR) oligonucleotides. Dissimilarity based on molecular markers was estimated using the Jaccard index. Separate dendrograms were generated for each analysis (morphological and molecular) using the unweighted pair group method with arithmetic mean (UPGMA), and a tanglegram was created to illustrate the relationships between the two dendrograms. Significant differences were found in cladode length and width and in the fresh and dry weight of plants. The molecular analysis differentiated genotypes at the species and genus levels, even among those that appeared morphologically similar. Comparing morphological and molecular data revealed both divergences and similarities, providing valuable insights into the diversity and structure within the groups.

ECONOMIC-STATISTICAL ANALYSIS OF THE DEVELOPMENT OF THE FRUIT AND VEGETABLE SECTOR IN UZBEKISTAN

This article describes the current state and dynamics of the agricultural network of our republic, an economic and statistical analysis of the production of agricultural products in economic entities and promising directions. The activities of farms operating in our country were also carefully analyzed, and with the help of statistical methods, the role and importance of this industry in the development of the industry was revealed. Dynamic changes in statistical indicators of network development over the years are shown. KEY WORDS: agriculture, agricultural products, gross domestic product, gross regional product, agriculture, livestock breeding, structural changes, investments, regional economy, economic and statistical analysis, agrarian reforms, socio-economic processes .

Bovine leukemia virus transmission rates in persistent lymphocytotic infected dairy cows.

Bovine leukemia virus (BLV) establishes a lifelong persistent infection in dairy cattle. White blood cell count (WBC) is correlated with proviral load in the blood and milk of BLV-infected cattle, and testing WBC can be used to assess both BLV infectiousness levels and risk of BLV transmission from different types of infected animals. The objective of the study was to compare effective transmission rates (β) and the basic reproduction ratio (R o) among two types of BLV-infected dairy cows in Chile: those affected with persistent lymphocytosis (PL) vs. aleukemic (AL).The estimated (β) coefficient was higher in PL cattle [1.1; 95% Confidence interval (CI) (-1.6, 3.8)], compared to AL cattle (-3.1; 95% CI = -3.7, -2.5). In addition, the R o was higher in PL cattle (60.4; 95% CI = 3.5; 820.6), compared to AL cattle (1.5; 95% CI = 0.7, 3.1). The ratio between PL/AL expected rate of cases was 73.9. The estimated effective transmission rate and the Ro were higher in PL cattle compared to AL cattle. The WBC test is a convenient alternative that can be considered for risk identification and risk management of BLV infection in dairy herds; particularly in livestock regions where laboratory capacity is limited (e.g., use of PCR or gene sequencing techniques) and/or molecular tests are not cost-effective. Therefore, when prevalence of infection is high, the removal of PL cattle should be engaged to control BLV within-herds.

Voluntary optimisation of antimicrobial consumption in swine and poultry production in Thailand: a policy analysis.

Antimicrobial resistance (AMR) is a global health concern with significant implications on economies and health security, affecting humans, animals, food, and the environment. To tackle this issue, promoting responsible antimicrobial use in livestock production has emerged as a crucial intervention. In 2018, Thailand introduced the Voluntary Optimization of Antimicrobial Consumption (VOAC) programme, with the objective to encourage responsible antimicrobial use practises. This study aimed to analyse the context, content, process and actors of the VOAC programme. A qualitative method including document reviews and key informant interviews were applied. In-depth interviews were conducted with 18 key informants who are key stakeholders from public and private sectors involved in the policy formulation, design of policy contents and implementation of VOAC: policy makers or officers responsible for animal health (n = 12), animal producers (n = 2), animal product traders or retailers (n = 2), and farm veterinarians (n = 2). Interview transcripts were validated by informants for accuracy, and triangulated with document review findings. Deductive approach was applied for data analysis and interpretation based on Walt and Gilson's policy analysis framework. The VOAC farm certification comprises of Raised Without Antibiotics (RWA) and Reducing Antibiotic Use (RAU), both aiming to combat AMR in food animals. Global and national factors, including increased public awareness, policy commitments, export requirements from the European Union, and international organisation advocacies, influenced the development of the programme led by the Department of Livestock Development (DLD), under the Ministry of Agriculture and Cooperatives. Collaboration with the private sector facilitated policy clarity, with implementation primarily executed through regional, provincial, and district livestock officers. Integration of the programme with the pre-existing Good Agriculture Practise certification system enabled cost-effective implementation without additional resources. In 2022, DLD official data reported 214 RWA farms (112 pig and 102 broiler), and 230 RAU farms (83 pig and 147 broiler). Incentives for farms to participate in the programme include improving corporate image and demonstrating corporate responsibility addressing AMR in food products. Recommendations include optimising certification strategies, increasing consumer awareness of RWA and RAU products and strengthening monitoring and evaluation systems.

Improved serodiagnosis of Trypanosoma vivax infections in cattle reveals high infection rates in the livestock regions of Argentina.

Bovine trypanosomosis, caused by Trypanosoma vivax, currently affects cattle and has a significant economic impact in sub-Saharan Africa and South America. The development of new diagnostic antigens is essential to improve and refine existing methods. Our study evaluated the efficacy of two recombinant antigens in detecting specific antibodies in cattle. These antigens are derivatives of an invariant surface glycoprotein (ISG) from T. vivax. A fraction of a previously described antigen (TvY486_0045500), designated TvISGAf, from an African strain was evaluated, and a new ISG antigen from an American isolate, TvISGAm, was identified. The two antigens were expressed as fusion proteins in Escherichia coli: TvISGAf was fused to the MBP-His-tag, and TvISGAm was obtained as a His-tag fused protein. An ELISA evaluation was conducted using these antigens on 149 positive and 63 negative bovine samples. The diagnostic performance was enhanced by the use of a combination of both antigens (referred to as TvISG-based ELISA), achieving a sensitivity of 89.6% and specificity of 93.8%. Following the validation of the TvISG-based ELISA, the seroprevalence of T. vivax infection in 892 field samples from cattle in the central region of Argentina was determined. The mean seroprevalence of T. vivax was 53%, with variation ranging from 21% to 69% among the six departments studied. These results support the use of the TvISG ELISA as a valuable serological tool for the detection and monitoring of T. vivax infection in cattle. Furthermore, we report for the first time the seroprevalence of T. vivax in Argentina, which highlights the widespread endemic nature of the disease in the region. In order to effectively manage the increasing spread of T. vivax in the vast livestock production areas of South America, it is essential to implement consistent surveillance programs and to adopt preventive strategies.

A comparative plastome approach enhances the assessment of genetic variation in the Melilotus genus

BackgroundMelilotus, a member of the Fabaceae family, is a pivotal forage crop that is extensively cultivated in livestock regions globally due to its notable productivity and ability to withstand abiotic stress. However, the genetic attributes of the chloroplast genome and the evolutionary connections among different Melilotus species remain unresolved.ResultsIn this study, we compiled the chloroplast genomes of 18 Melilotus species and performed a comprehensive comparative analysis. Through the examination of protein-coding genes, we successfully established a robust phylogenetic tree for these species. This conclusion is further supported by the phylogeny derived from single-nucleotide polymorphisms (SNPs) across the entire chloroplast genome. Notably, our findings revealed that M. infestus, M. siculus, M. sulcatus, and M. speciosus formed a distinct subgroup within the phylogenetic tree. Additionally, the chloroplast genomes of these four species exhibit two shared inversions. Moreover, inverted repeats were observed to have reemerged in six species within the IRLC. The distribution patterns of single-nucleotide polymorphisms (SNPs) and insertions/deletions (InDels) within protein-coding genes indicated that ycf1 and ycf2 accumulated nonconservative alterations during evolutionary development. Furthermore, an examination of the evolutionary rate of protein-coding genes revealed that rps18, rps7, and rpl16 underwent positive selection specifically in Melilotus.ConclusionsWe present a comparative analysis of the complete chloroplast genomes of Melilotus species. This study represents the most thorough and detailed exploration of the evolution and variability within the genus Melilotus to date. Our study provides valuable chloroplast genomic information for improving phylogenetic reconstructions and making biogeographic inferences about Melilotus and other Papilionoideae species.

Climate Change Risks for the Mediterranean Agri-Food Sector: The Case of Greece

The study assesses the direct effects of climate change by 2060, including extreme events, on the productivity of regional crop farming and livestock in Greece, and the broader socio-economic effects on the agri-food and other sectors. Different approaches (i.e., agronomic models, statistical regression models, and equations linking thermal stress to livestock output) were combined to estimate the effects on productivity from changes in the average values of climatic parameters, and subsequently the direct economic effects from this long-term climate change. Recorded damages from extreme events together with climatic thresholds per event and crop were combined to estimate the direct economic effects of these extremes. The broader socio-economic effects were then estimated through input–output analysis. Under average levels of future extreme events, the total direct economic losses for Greek agriculture due to climate change will be significant, from EUR 437 million/year to EUR 1 billion/year. These losses approximately double when indirect effects on other sectors using agricultural products as inputs (e.g., food and beverage, hotels, and restaurants) are considered, and escalate further under a tenfold impact of extreme events. Losses in the GDP and employment are moderate at the national level, but significant in regions where the contribution of agriculture is high.

Choice heuristics and livestock farmers' preference heterogeneity for Rift Valley fever vaccines in Uganda

Rapid spread and erratic outbreaks of Rift Valley fever (RVF) disease across the African continent continues to pose serious threat to animal, public health, and regional livestock trade. Failure to institute timely control measures will have serious implications on food security and livelihoods. Among existing control options for the disease, vaccines are reported to be the most cost-effective. However, no RVF vaccines are currently registered for use in Uganda. Prior to approval, reservations exist concerning the uptake of vaccines by farmers as they have to weigh in several features and associated risks before acceptance. This study utilizes data from 444 livestock farming households in Uganda to elicit farmers’ preference heterogeneity and the influence of choice heuristics on their preferences for RVF vaccines. The empirical results reveal that two livestock farmer segments exist with respect to RVF vaccine preference. The single dose vaccine attribute is the most highly valued by farmers. Further, livestock farmers’ conditional perceptions and risk attitudes play a major role in vaccine choice decisions. The paper highlights the need for careful consideration of livestock farmers’ preference heterogeneities and intrinsic motivations such as risk attitudes and conditional perceptions when designing policy instruments for the promotion of RVF vaccination programmes.

Some Aspects of Animal Husbandry in Africa

It is emphasized that animal husbandry, which has existed since ancient times in many regions of Africa and is one of the most important areas of human activity, is an integral part of the socio-cultural code of the African population. To date, pastoralism plays an important role not only in the economic, but also in the social sphere of the inhabitants of vast regions of the continent; the size of herds is the main criterion for assessing the property and social status of its owner. Being the subject of trade and direct exchange, cattle bring a significant and stable income to their sellers, while at the same time performing the function of a bride price at the conclusion of marriages. The challenges of our time require a certain degree of flexibility and adaptability from the population of livestock regions, which is associated with inevitable changes in the centuries-old way of life and the system of socio-cultural ties. Attention is drawn to the fact that the tradition of husbandry is influenced by numerous factors of modern development: climate change and epizootics of recent decades have a negative imprint on livestock activities. High losses of livestock, a reduction in their per capita population over time, combined with demographic growth, have had a negative impact on the well-being of pastoralists, significantly increasing their poverty level. The governments of many African countries, in which husbandry plays a leading role, have an interest not only in maintaining existing positions, but also in improving them. In situations of epizootic danger, national livestock health surveillance systems in African countries are approached by international partners, including FAO, WHO, as well as one of the world’s leading organization whose functions include the formation of links in the field of veterinary medicine, ensuring the interaction of national and regional veterinary authorities – the International Epizootic Office (OIE). Continuous field research in livestock regions in a number of African countries provides significant assistance in the fight against livestock diseases. The use of modern information technologies in epizootiological diagnostics is increasingly becoming the basis of anti-epizootic and preventive measures.

Epidemiological investigation of Cryptosporidium in children with diarrhea in middle Inner Mongolia, China

Cryptosporidia (Cryptosporidium) is a protozoan that is widely parasitic in the intestinal cells of humans and animals, and it is also an important zoonotic parasite. However, there is no epidemiological investigation on Cryptosporidium spp. infection in infants with diarrhea of Inner Mongolia, the largest livestock region in China. To investigate the prevalence of Cryptosporidium, 2435 fresh fecal samples were collected from children with diarrhea in Inner Mongolia Maternal and Child Health Care Hospital. Molecular characterization of Cryptosporidium was carried out based on its 18S rRNA and gp60 gene sequences. The overall prevalence was 12.85% (313/2435), and in Hohhot (12.15%), it was lower than that in the surrounding city (14.87%) (P < 0.05). Moreover, Cryptosporidium was detected in different seasons and sexes. Concerning the age of children with diarrhea, the prevalence of those age groups between 0 and 1 was obviously lower than others, and there were significant differences in the prevalence at different ages (P < 0.001). Analysis of the 18S rRNA gene sequence revealed that all the positive samples were Cryptosporidium parvum, and there were 5 subtypes (IIdA23G3, IIdA24G3, IIdA24G4, IIdA25G3, and IIdA25G4). To the best of our knowledge, the above subtypes have not been reported. Our results provide a relevant basis for control and education on food safety and foodborne illness prevention.

What is the optimal timing to initiate strategic control of Rhipicephalus microplus in taurine cattle in a tropical region?

Cattle tick control poses a significant challenge for livestock in tropical and subtropical regions. The objective of this study was to determine the most suitable timing to initiate a strategic tick control program and to identify the ideal number of acaricide treatments for adult taurine cattle (Bos taurus taurus) in a tropical region throughout the year. Three groups with 10 bovines each were performed: T01 (strategic treatment in late autumn/winter/late spring, every 28 days), T02 (strategic treatment to act in the "first tick generation" - early spring/summer/early autumn, every 28 days) and T03 (control). Tick counts (females 4-8mm) were conducted every 14 days. If the tick burden in any group reached 30 or more during these counts, we applied an additional treatment. Over the course of a year, T02 required significantly fewer (p < 0.05) acaricide treatments than T01, with nine treatments for T02 and eleven for T01. Furthermore, during the tick counts, animals in T02 showed a lower tick burden compared to those in T01. Initiating the strategic tick control program in early spring, corresponding to the first tick generation, proved more effective than starting in autumn. This approach not only required fewer acaricide treatments but also resulted in a reduced tick burden. These benefits are particularly valuable in terms of animal welfare and managing acaricide resistance issues.

In Vitro Protection and Titer Duration of Anthrax-Specific Antibodies Following Subcutaneous Vaccination of White-tailed Deer (Odocoileus virginianus) with Bacillus anthracis Sterne 34F2 Strain Spores.

Outbreaks of anthrax, caused by the soilborne bacterium Bacillus anthracis, are a continuous threat to free-ranging livestock and wildlife in enzootic regions of the United States, sometimes causing mass mortalities. Injectable anthrax vaccines are commercially available for use in livestock, and although hand injection is not a cost- or time-effective long-term management plan for prevention in wildlife, it may provide a tool for managers to target selectively animals of high conservation or economic value. Vaccine-induced anthrax-specific antibody responses have been reported previously in white-tailed deer (Odocoileus virginianus), but the protective nature was not determined. In this study, five white-tailed deer were subcutaneously vaccinated with one dose (1 mL) of the Anthrax Spore Vaccine. Eight blood collections by jugular venipuncture were conducted over 146 d to measure the anthrax-specific antibody response in each deer's serum over time. Antibodies were first detected by ELISA and later with toxin neutralization assays to estimate in vitro protection. Average peak absorbance by ELISA occurred at 14 d postvaccination, whereas average peak in vitro protection occurred at 28 d postvaccination. Observed in vitro protection on average for white-tailed deer after this single-dose vaccination protocol lasted 42-56 d postvaccination, although three individuals still maintained lethal toxin-neutralizing serum antibody titers out to 112 d postvaccination. Vaccination responses were variable but effective to some degree in all white-tailed deer.

Experimental genetic crosses in tsetse flies of the livestock pathogen Trypanosoma congolense savannah

BackgroundIn tropical Africa animal trypanosomiasis is a disease that has severe impacts on the health and productivity of livestock in tsetse fly-infested regions. Trypanosoma congolense savannah (TCS) is one of the main causative agents and is widely distributed across the sub-Saharan tsetse belt. Population genetics analysis has shown that TCS is genetically heterogeneous and there is evidence for genetic exchange, but to date Trypanosoma brucei is the only tsetse-transmitted trypanosome with experimentally proven capability to undergo sexual reproduction, with meiosis and production of haploid gametes. In T. brucei sex occurs in the fly salivary glands, so by analogy, sex in TCS should occur in the proboscis, where the corresponding portion of the developmental cycle takes place. Here we test this prediction using genetically modified red and green fluorescent clones of TCS.MethodsThree fly-transmissible strains of TCS were transfected with genes for red or green fluorescent protein, linked to a gene for resistance to the antibiotic hygromycin, and experimental crosses were set up by co-transmitting red and green fluorescent lines in different combinations via tsetse flies, Glossina pallidipes. To test whether sex occurred in vitro, co-cultures of attached epimastigotes of one red and one green fluorescent TCS strain were set up and sampled at intervals for 28 days.ResultsAll interclonal crosses of genetically modified trypanosomes produced hybrids containing both red and green fluorescent proteins, but yellow fluorescent hybrids were only present among trypanosomes from the fly proboscis, not from the midgut or proventriculus. It was not possible to identify the precise life cycle stage that undergoes mating, but it is probably attached epimastigotes in the food canal of the proboscis. Yellow hybrids were seen as early as 14 days post-infection. One intraclonal cross in tsetse and in vitro co-cultures of epimastigotes also produced yellow hybrids in small numbers. The hybrid nature of the yellow fluorescent trypanosomes observed was not confirmed by genetic analysis.ConclusionsDespite absence of genetic characterisation of hybrid trypanosomes, the fact that these were produced only in the proboscis and in several independent crosses suggests that they are products of mating rather than cell fusion. The three-way strain compatibility observed is similar to that demonstrated previously for T. brucei, indicating that a simple two mating type system does not apply for either trypanosome species.Graphical

Dual‐purpose cowpea grain and fodder yield response to variety, nitrogen–phosphorus–potassium fertilizer, and environment

AbstractAddressing the challenges of food and nutrition insecurity in sub‐Saharan Africa will require innovative agriculture production systems that support multiple objectives. Dual‐purpose cowpea [Vigna unguiculata (L) Walp] varieties are expected to offer greater grain yields for human consumption and high‐quality fodder for livestock in semiarid regions of Senegal. However, limited information is available on the effects of varieties and fertilizer on dual‐purpose cowpea. The main objective of this research was to evaluate the grain and fodder yield of five newly released cowpea varieties (Kelle, Leona, Lizard, Sam, and Thieye) compared to traditional variety (Yacine) with fertilizer (nitrogen‐phosphorus‐potassium 6‐20‐10) and no‐fertilizer application. Genotype × environment × management experimentations were conducted across three cowpea production zones of Darou Mousty (400 mm per year), Bambey (500 mm per year), and Boulel (700 mm per year) over three growing seasons (2019–2021) to compare the growth and yield parameters of the cowpea varieties. Results of the study showed a 40% grain yield advantage from the greater yielding (Leona) variety in this study compared with the lower yielding (Lizard) variety. There was an additional 22% grain yield increase from the application of fertilizer compared with the unfertilized treatment. The variety (Leona) that produced the most grain also produced the most fodder yields. There was 67% fodder yield advantage from Leona compared with fodder yield from the older variety Yacine. Across varieties, application of fertilizer increased fodder yield by 15% compared to the unfertilized control. Average grain yield in high‐yielding environment (Boulel 2019, Darou Mousty 2019, and Bambey 2021) was 100% greater compared with average grain yield in low‐yielding environments (Boulel 2021, Darou Mousty 2021, and Bambey 2019). Compared to Yacine, dual‐purpose varieties increased net returns by 15%–58% or 13%–42% with early‐ and late‐season cowpea sales, respectively. However, fertilizer application was profitable only when cowpea grain and fodder were sold later in the season. In general, cowpea number of branches, pod number, and pod yield increased with fertilizer application. We concluded that producers can adopt dual‐purpose varieties and proper fertilizer management to increase grain yield, fodder availability, and profitability of cowpea production in Senegal.