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Abstract Background Neocortex development has been extensively studied in altricial rodents such as mouse and rat. Identification of alternative animal models along the “altricial-precocial” spectrum in order to better model and understand neocortex development is warranted. The Greater cane rat (GCR, Thyronomys swinderianus) is an indigenous precocial African rodent. Although basic aspects of brain development in the GCR have been documented, detailed information on neocortex development including the occurrence and abundance of the distinct types of neural progenitor cells (NPCs) in the GCR are lacking. Methods GCR embryos and fetuses were obtained from timed pregnant dams between gestation days 50–140 and their neocortex was analyzed by immunofluorescence staining using characteristic marker proteins for NPCs, neurons and glia cells. Data were compared with existing data on closely related precocial and altricial species, i.e. guinea pig and dwarf rabbit. Results The primary sequence of neuro- and gliogenesis, and neuronal maturation is preserved in the prenatal GCR neocortex. We show that the GCR exhibits a relatively long period of cortical neurogenesis of 70 days. The subventricular zone becomes the major NPC pool during mid-end stages of neurogenesis with Pax6 + NPCs constituting the major basal progenitor subtype in the GCR neocortex. Whereas dendrite formation in the GCR cortical plate appears to initiate immediately after the onset of neurogenesis, major aspects of axon formation and maturation, and astrogenesis do not begin until mid-neurogenesis. Similar to the guinea pig, the GCR neocortex exhibits a high maturation status, containing neurons with well-developed dendrites and myelinated axons and astrocytes at birth, thus providing further evidence for the notion that a great proportion of neocortex growth and maturation in precocial mammals occurs before birth. Conclusions Together, this work has deepened our understanding of neocortex development of the GCR, of the timing and the cellular differences that regulate brain growth and development within the altricial–precocial spectrum and its suitability as a research model for neurodevelopmental studies. The timelines of brain development provided by this study may serve as empirical reference data and foundation in future studies in order to model and better understand neurodevelopment and associated alterations.

Background: Neocortex development has been extensively studied in altricial rodents such as mouse and rat. Identification of alternative animal models along the "altricial-precocial" spectrum in order to better model and understand neocortex development is warranted. The Greater cane rat (GCR, Thyronomys swinderianus) is an indigenous precocial African rodent. Although basic aspects of brain development in the GCR have been documented, detailed information on neocortex development including the occurrence and abundance of the distinct types of neural progenitor cells (NPCs) in the GCR are lacking. Methods: GCR embryos and fetuses were obtained from timed pregnant dams between gestation days 50–140 and their neocortex was analyzed by immunofluorescence staining using characteristic marker proteins for NPCs, neurons and glia cells. Data were compared with existing data on closely related precocial and altricial species, i.e. guinea pig and dwarf rabbit. Results: The primary sequence of neuro- and gliogenesis, and neuronal maturation is preserved in the prenatal GCR neocortex. We show that the GCR exhibits a relatively long period of cortical neurogenesis of 70 days. The subventricular zone becomes the major NPC pool during mid-end stages of neurogenesis with Pax6 + NPCs constituting the major basal progenitor subtype in the GCR neocortex. Whereas dendrite formation in the GCR cortical plate appears to initiate immediately after the onset of neurogenesis, major aspects of axon formation and maturation, and astrogenesis do not begin until mid-neurogenesis. Similar to the guinea pig, the GCR neocortex exhibits a high maturation status, containing neurons with well-developed dendrites and myelinated axons and astrocytes at birth, thus providing further evidence for the notion that a great proportion of neocortex growth and maturation in precocial mammals occurs before birth. Conclusions: Together, this work has deepened our understanding of neocortex development of the GCR, of the timing and the cellular differences that regulate brain growth and development within the altricial–precocial spectrum and its suitability as a research model for neurodevelopmental studies. The timelines of brain development provided by this study may serve as empirical reference data and foundation in future studies in order to model and better understand neurodevelopment and associated alterations. [ABSTRACT FROM AUTHOR]

Grasscutters (GRCs) are hystricognath rodents that predominate West African countries where they are captured and bred in captivity as "microlivestock" and for research. Consequently, research priority has, of late, shifted to aspects of GRC biology particularly with regard to morphofunctional aspects of its body systems. The olfactory system plays critical roles in regulating social, sexual, maternal and feeding behaviors. This study examines, histologically and ultrastructurally, the pattern and magnitude of remodeling of the GRC olfactory mucosa (OM) and nasal respiratory mucosa (NRM) between suckling and adult ages and compares these with what is documented for other mammals. In adults, tubular-type Bowman's glands, olfactory receptor neuron (ORN) axon bundles and blood vessels were uniformly distributed in the OM lamina propria contrary to sucklings where acinar-type Bowman's glands lay superficially and the bundles relatively deeper. Apically in the adult NRM epithelium, ciliated and non-ciliated cells were uniformly distributed as opposed to the sucklings where linearly arranged ciliated cells separated large numbers of non-ciliated cells. Quantitatively between the suckling and adult ages, respective increment values (%) were 28.2, 23.0, 28.1 and 52.9 for OM epithelial thickness, axon bundle diameter, ORN packing density and cilia number/ORN dendritic knob. Age-related increment in volume density (%) was 53.9, 31.6, 19.4 and 46.3 for Bowman's glands, axon bundles, OM vessels and NRM glands, respectively. We conclude that microstructural refinement of the OM and NRM varies in qualitative and quantitative detail depending on age and species and that phenotypic plasticity in these structures suggests environmentally driven morphology. [ABSTRACT FROM AUTHOR]

Introduction: The African grasscutter (Thryonomys swinderianus) is a nocturnal rodent of the family thryonomidae and suborder hystricomorpha. It has gained attention in West Africa as an alternative source of meat and income. Method: Twelve apparently healthy grasscutters between the ages of three and seven months old were divided into three groups according to their ages. Euthanization was achieved via chloroform inhalation. An incision was made at the neck region and the thymuses were located and identified by their prominent bilateral nature. Extracted thymuses from each animal were immediately weighed, grossly described and fixed in Bouin's fluid for 48 hours. The tissues were then prepared using standard methods. Haematoxylin and Eosin was used for routine histology while Rhodamine B aniline methylene blue was used for studying the architecture of the elastic and reticular fibres of the thymus. Results: Grossly, the thymi of the grasscutters were brightly red in colour and elongated in shape, found at the cervical region bounded externally by the maxilla. The organs were bilateral in nature with each lobe located on either side of the thoracic midline. The organ size decreased consistently as the animals advanced in age. Mean ± SEM values for thymic weights were 1.23 ± 0.048g, 0.53 ± 0.019g and 0.30 ± 0.042g at three, five and seven months of age respectively. Histologically, the thymus had two distinct zones, the cortex and medulla, the presence of eosinophilic structures known as the Hassal's corpuscles were scattered around the medulla. Significant: The findings obtained in this research would be used for disseminations of anatomical knowledge and for clinical application where necessary. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the preference for grasscutter offal among consumers in the Greater Accra and Ashanti regions of Ghana. The stratified three-stage random sampling was adopted for the selection of respondents. A total of 140 respondents (120 consumers; 20 operators) were used in this study. In the Ashanti region, 93 consumers and 13 chop bar operators were considered. Within the Greater Accra region, only one market was selected (Agbogbloshie market), where 27 consumers and seven chop bar operators were considered. Relevant information was collected through the administration of well-structured questionnaires. Results obtained showed a relatively higher offal preference by consumers in the Ashanti region (91.4%) as compared to the Greater Accra region (81.5%). Most consumers preferred the intestines and intestinal contents in both represented areas 60% from the Ashanti region and 45.6% from the Greater Accra region. 90.6% and 81.8% of the consumers from the Ashanti and Greater Accra regions, respectively preferred cooked offal to either smoked or roasted. These regional differences were not statistically significant. The rate of offal consumption was higher in the Ashanti region (i.e., on a weekly basis) as compared to the Greater Accra region (i.e., occasionally), represented by 63.5% and 68.2%, respectively. This difference was statistically significant (p<0.05). The taste was considered the most significant, relevant and important factor affecting consumer preference for grasscutter offal consumption in both regions. It is concluded in this study that the grasscutter offal has relatively high patronage by the respondents in this study. Further studies should be focused on the possible health implication of offal consumption on consumers as the intestines, and their contents might contain some parasites and other bacteria which can be harmful to humans. Further studies should be carried out to obtain a nationwide view of grasscutter offal consumption. [ABSTRACT FROM AUTHOR]

Spraying of pesticides and cutting the grass is an important task in the agricultural sector to protect the crops from insects for obtaining high yield. In this study, a solar-powered sprayer cum grasscutter was introduced. The total fabrication cost of the solar powered sprayer cum grasscutter was 12550 Tk.. The application rate of the sprayer was 281.25 lit/ha with spray coverage of 46.7%. The theoretical field capacity and the effective field capacity of sprayer cum grasscutter were 0.08ha/hr and 0.06ha/hr respectively. The field efficiency of solar-powered sprayer cum grasscutter was found 75%, for an average of 2.1 km/hr operating speed. This research observed that cutting efficiency was 79%. The operating cost of the machine was 903.17 Tk/ha. The solar-powered sprayer cum grasscutter is free from pollution because no fuel is needed. The price of the machine is low as compared to others, which are available in the market. [Fundam Appl Agric 2021; 6(1.000): 35-42]

Abstract The greater cane rat, as it is commonly known, is often called grasscutter (in Ghana, Nigeria and other regions of West Africa). Even though is highly patronized as a delicacy by a majority of Ghanaians (akrantie—Twi language) mostly in the rural areas, the persistent reports on people being poisoned as a result of eating food prepared with grasscutter which has been captured/killed by the use of poison are deterring people from consuming the grasscutter meat despite its high protein content. The objective of this study was, therefore, to investigate the actual ingredients that are used in the formulation of poison to capture grasscutter for human consumption. Questionnaires were administered to participants (farmers) who are involved in grasscutter hunting to solicit the ingredient they formulate to poison the grasscutter in their hunting. To prove the activeness of these ingredients, the main ingredient used in formulating the poison to capture the grasscutters were tested on two male grasscutters and these were yellow oleander root (Cascabela thevetia; syn: Thevetia peruviana) powder and carbofuran. The findings of the experimental trial revealed that the grasscutter that was fed with yellow oleander root powder did not die but showed some signs of intoxication and staggered each time it tried to move. However, the grasscutter fed with carbofuran died within 10 hr of being poisoned. Majority of the participants attested to the fact that the use of poison increases their chance of capturing the grasscutter, especially in the dry season since the poison is not washed away by the rainwater. However, consuming grasscutter poisoned with either yellow oleander root power or carbofuran could be detrimental to human health.

Abstract Background The greater cane rat (GCR), reputed to be African's second largest rodent, is a precocial hystricomorph with an uncommon phenotype and life history. Scientific and socio‐economic interests in the GCR have led to heightened research efforts targeted towards a better understanding of its biology and exploration of its economic and translational usefulness. Methods Records of all online scientific publications on the GCR from Google, Google Scholar, PubMed, science.gov, Ebscohost and Worldwide science, with the exception of research theses, proceedings, unpublished projects and abstracts, were collated and analyzed using descriptive statistics. Results A total of 146 published scholarly articles spanning about six decades were retrieved, with 98% of the GCR publications originating from African countries. Nigeria boasts the highest number of publications (58.22%) followed by Ghana (21.23%) and South Africa (5.48%) while Senegal contributed the least (0.69%). Publications were sorted into ten field categories. The field with the highest number of articles (41.78%) was animal breeding and management recording, closely followed by anatomy (37.67%). Lesser contributions were made by parasitology (5.48%), biochemistry/hematology (4.8%), pharmacology/toxicology (4.11%), pathology (2.06%), and surgery/anesthesia and physiology (1.37% apiece). The fields with fewest contributions were microbiology and developmental biology (0.69% each). Conclusion This study chronicles the spectrum of knowledge available on the GCR, highlighting the knowledge gap that still exists in various fields in order to provide advocacy for new frontiers in research efforts on this rodent. We suggest the need for a clearly defined and well integrated national/regional policy aimed at establishing Africa's foremost micro‐livestock rodent, the greater cane rat, on the world's scientific radar.

This study investigated factors determining the willingness to adopt grasscutter domestication technology in South west, Nigeria. Multi-stage sampling procedure was used to select 160 respondents from 9 urban towns in Oyo, Ogun and Osun States. Well-structured questionnaire was used for data collection. Data was analysed using descriptive analysis, correlational analysis and t-test. Results showed that the majority (69.4%) of the respondents were male and married. Coefficient correlation (r value) at (p< 0.05), shows that there is a significant association between respondents' educational status, religion, household size, primary as well as secondary education with respondents' willingness to adopt the technology. There was also found significant relationship between, perceived health status of those who are into the grasscutter technology, perceived nutritional value and economic value of the grasscutter domestication technology with the willingness to adopt the grasscutter domestication technology. The result if the T-test revealed that there is significant relationship between perceived ease of practice and willingness to adopt the technology. The majority of the respondents are willing to rear grasscutter if variables like space, fund, availability of ready-made buyer and feed, breeding stock and training are put into place. However, issues relating to having enough plots of land, funding, ready-made buyer of grasscutter, and training facilities are most germane. It is therefore recommended that funding and training on the adoption of the grasscutter domestication technology should be made available to individuals. [ABSTRACT FROM AUTHOR]

This research aims to evaluate the physicochemical and energetic quantity of succulent and sweet taste forage grasses, Panicum maximum and Pennisetum purpureum (Poaceae) incorporated in the feed of grasscutters growing (GG), fattening (FG) and maintenance (MG). This study is set to determine the chemical and energetic composition of three levels of green fodder (50, 75 and 85%) incorporated into the diets of grasscutters and compare it to nutrient intake and energy consumption of feed resources used normally in the ration by farmers. The three experimental diets were: 75% fodder and 25% of food complement (diet T25); 50% of fodder and 50% of food complement (diet T50); 85% of fodder and 15% of food complement (diet T15). The results showed that the green fodder used contains important sources of proteins, lipids, carbohydrates and minerals. Dry matter content of Panicum maximum (13.4 to 22.9%) and Pennisetum purpureum (10.9 to 18.6%) provide energy needs as calories needed of grasscutters. Food ingredients consisting of minerals and organic matter provide the energy potential in the form of calories for maintenance and production feed needs of grasscutters. A positive and highly significant effect (p

The feed of grasscutters is particularly rich in organic matter (proteins), vitamins, minerals and energy. This study aims is to evaluate the effect of the incorporation of three levels of dietary supplements in the diet on some reproductive parameters in raised grasscutter (Thryonomys swinderianus) in a farm in Grand-Lahou on Côte d’Ivoire. The experimental design consists of a randomized complete block with three treatments and three repetitions. Dietary treatments were of three levels: 15, 25 and 50 % of additional food ingredients corresponding respectively to 85, 75 and 50 % of green fodder. The following three food rations were tested: 75 % forage and 25 % of food supplements (diet T25); 50 % forage and 50 % of food supplements (diet T50); 85 % forage and 15 % of food supplements (diet T15). Forty-five breeding grasscutters of which thirty-six are female and nines males were used, with the presence of feed and a water source for nutrition and watering the animals and a secure reproductive building. The results showed a positive effect of diet T15 in grasscutter husbandry that helps enhance flock reproduction. The best reproductive performances that were statistically significant (p

The greater cane rat, as it is commonly known, is often called grasscutter (in Ghana, Nigeria and other regions of West Africa). Even though is highly patronized as a delicacy by a majority of Ghanaians (akrantie—Twi language) mostly in the rural areas, the persistent reports on people being poisoned as a result of eating food prepared with grasscutter which has been captured/killed by the use of poison are deterring people from consuming the grasscutter meat despite its high protein content. The objective of this study was, therefore, to investigate the actual ingredients that are used in the formulation of poison to capture grasscutter for human consumption. Questionnaires were administered to participants (farmers) who are involved in grasscutter hunting to solicit the ingredient they formulate to poison the grasscutter in their hunting. To prove the activeness of these ingredients, the main ingredient used in formulating the poison to capture the grasscutters were tested on two male grasscutters and these were yellow oleander root (Cascabela thevetia; syn: Thevetia peruviana) powder and carbofuran. The findings of the experimental trial revealed that the grasscutter that was fed with yellow oleander root powder did not die but showed some signs of intoxication and staggered each time it tried to move. However, the grasscutter fed with carbofuran died within 10 hr of being poisoned. Majority of the participants attested to the fact that the use of poison increases their chance of capturing the grasscutter, especially in the dry season since the poison is not washed away by the rainwater. However, consuming grasscutter poisoned with either yellow oleander root power or carbofuran could be detrimental to human health. [ABSTRACT FROM AUTHOR]

The objective of this study is to make the economic evaluation of farmed grasscutters fattened with three levels of food supplements in the production of the kilogram of meat Grand-Lahou, Côte d'Ivoire. The experimental setup consisted of a simple random block with three treatments, three repetitions rations composed of three batches of five to ten grasscutters each. Lots of grasscutters tested were divided into 2 groups of 3 lots each according to their physiological stages (growing, feeding and maintenance). The three levels of substitution of green fodder by a supplementary ration energy in the feed of grasscutters breeding composed of: rations 75 % forage and 25 % of food supplements (diet T25), 50 % forage and 50% food supplements (diet T50) and 85 % forage and 15 % of food supplements (diet T15). The technical-economic is made with 60 grasscutters in growth analysis (GG) aged 28 days, 60 grasscutters fattening (GF) aged 140 days and 45 breeding grasscutters maintenance (GM) older than 224 days including 36 grasscutter does ( females) and nine grasscutter bucks (males). The best breeding performances statistically significant (P<0.05) were obtained with individuals under T15 and were as followed: an interval of 151.58 days between parturitions; a fertility rate of 16.67 %; a prolificacy rate of 5.71 offspring; a survival rate of 88.77 %. The economic optimum, stable and efficient food rations based on 15 % of feed concentrates revealed a better economic cost of F CFA 437.32. The profit for the production of 1 kg of farmed grasscutter meat is 9 853.70 F CFA. In sum, the substitution of green fodder by a T15 supplementary ration energy in the breeding of grasscutters feed with 85 % forage confirms the rate of at least 70 % basic diet recommended by research and already popularized in grasscutter husbandry.textile confection, achieving a sustainable sheep farming in Ite. [ABSTRACT FROM AUTHOR]

The grasscutter (also known as the greater cane rat; Thryonomys swinderianus) is a large rodent native to West Africa that is currently under domestication process for meat production. However, little is known about the physiology of this species. In the present study, aiming to provide information about gut microbiota of the grasscutter and better understand its physiology, we investigated the intestinal microbiota of grasscutters and compared it with that of other livestock (cattle, goat, rabbit, and sheep) using 16S rRNA metagenomics analysis. Similar to the other herbivorous animals, bacteria classified as Bacteroidales, Clostridiales, Ruminococcaceae, and Lachnospiraceae were abundant in the microbiome of grasscutters. However, Prevotella and Treponema bacteria, which have fiber fermentation ability, were especially abundant in grasscutters, where the relative abundance of these genera was higher than that in the other animals. The presence of these genera might confer grasscutters the ability to easily breakdown dietary fibers. Diets for grasscutters should be made from ingredients not consumed by humans to avoid competition for resources and the ability to digest fibers may allow the use of fiber-rich feed materials not used by humans. Our findings serve as reference and support future studies on changes in the gut microbiota of the grasscutter as domestication progresses in order to establish appropriate feeding methods and captivity conditions.

Summary: The hindlimb of the grasscutter (Thryonomys swinderianus, Temminck‐1827) was studied using 12 adult (≥6 months) rats of either sex with the mean weights of 1.42 ± 0.20 kg and 0.82 ± 0.13 kg for buck (n = 6) and doe (n = 6), respectively (p < .05). Characteristics of the bones were studied by gross observation after their preparation. Measurements of different segments of the hindlimb were also taken, giving a total average length of 31.80 cm. Correlation coefficients between length of bone and weight of rats were positive (p < .05) in bucks for all bone segments, except the pes (p > .05), whereas those in does were all non‐significant (p > .05), with significant sexual dimorphism in the relationships. The average total number of bones in the hindlimb was 92, with no apparent sexual dimorphism. The bones of the hindlimb revealed important differences and similarities in morphology with those of other rodents. The Os coxae presented a relatively large obturator foramen, formed by the ramus of the ischium and shaft of the pubis. The femur had a body and two extremities with a prominent head, well‐defined neck and trochanter. The fibula, a slender bone with triangular‐shaped proximal extremity, ran down the length of tibia with proximal attachment (via cartilage) and distal fusion, leaving an extensive interosseus space. The pes revealed eight tarsals and four metatarsals; each of the metatarsals showed three phalanges. [ABSTRACT FROM AUTHOR]

This study investigated the effect of energy level on the growth of grasscutters and also nutrient retention of grasscutters. A total of 36 grasscutters were used for the study. The experimental animals were allowed two weeks of stabilization period and feeding trials lasted for eight weeks. Three diets having energy levels of 2800 (control), 2600 and 3000 kcal/kg respectively were used for the experiment. The results of the study showed significant differences (P<0.05) among the treatment in average daily weight gain, average daily feed intake, although there was no significant effect (P>0.05) on the feed conversion ratio. The effect of dietary treatment on feed intake were significantly different (P<0.05) in favour of grasscutters fed 3000ME. Also, other growth performance parameters - daily weight gain and final body weight were better (P<0.05) and higher for grasscutters fed 3000ME. The effect of dietary treatments also had a significant effect on the parameters for nutrient retention, the level of protein retained increased with increase in dietary energy levels, and other nutrients retained were all statistically significant (P<0.05). The cost of producing feed increased with increase in the energy level, although in terms of the cost of producing 1kg of body weight, it was lesser i.e. more economical in grasscutters fed 3000ME. [ABSTRACT FROM AUTHOR]

Introduction: Sexual dimorphisms in biological structures such as brain and behaviour have been widely recognized in animals and humans. The purpose of this study was to examine whether there are sex differences in the size of the cerebellum with other body traits, such as the head, tail and brain.Methods:Twelve grasscutters comprising of 6 males and 6 females were used in this study. Each brain was extracted from the skull by standard procedures and the mean values of the weights, dimensions and volumes of the brain, cerebellum, head and tail were compared in male and female using quantitative analytical statistical method.Results:The results showed that the absolute mean brain weight and volume obtained in the male was slightly higher than that of the female, while the cerebellar mean weight was slightly higher in the female; although these values were not statistically significant (P> 0.05). The mean cerebellar lengths and widths did not differ between the two sexes (> 0.05), but the mean cerebellar circumference in the male was statistically higher than in the female (P< 0.05). The female cerebellar length was positively correlated with the length of the brain, head, body and tail.Discussion:In conclusion, the brain weight was slightly higher in the male than female, while the cerebellar weight was higher in the female than male. The significantly higher value of the cerebellar circumference in the male may partly be responsible for the big round head seen in the live male grasscutter.

This study was carried out to investigate the effect of whole cassava root and yam tubers on performance of grass cutter. Twenty-seven young male grass cutter (Thyrononysswindarianus), 5-7 months old with an average body weight of 679.00±1.95g were used in a completely randomized design experiment lasted for 12 weeks. Animals were grouped to three groups with nine animals per group, balanced for body weight (680.20.20± 1.80g, 678.50± 2.15g and 679.00± 1.90g) and designated as Gl, G2, and G3 groups respectively. Grass cutter in Gl was fed 200g/h/d of pelleted growers mash, G2 was offered 100g/h/d of pelleted growers mash and 200g/h/d of cassava tuber while G3 was served 100g/h/d of pelleted growers mash and 200g/h/d of fresh yam tuber. Fresh water was provided without restriction during the time of the trial. The results showed that crude protein and ash contents of the diet Gl, and G3 diets decreased compared to Gl diet. Dry matter and ether extract decrease in diet G2 to G3 compared to G1, while crude fibre and nitrogen free extract increased in G2 group compared to G1 and G3 groups and oxalate increased in G3 compared to G1 and G2 while Tanin % increase in G2 compared to G1 and G3 respectively. Dry matter intake, feed conversion ratio, weight gain and growth rate were higher (P<0.05) in G2 animals compared to G3 and G1 respectively. These results suggested that whole cassava roots and yam tubers can be included in grass cutter diet without any adverse effects on animals. However, cassava rooted-based diet improved performance of grass cutter held in captivity. [ABSTRACT FROM AUTHOR]

During pregnancy, maternal metabolism changes to support the gravid uterus and the timing of these changes are a function of both gestational length and fetal number. In order to predict the nutrient requirements throughout pregnancy, it is necessary to know the changes which occur in both the reproductive and maternal tissues. Fifty-seven (57) wild grasscutters were used to investigate the increased nutrient requirement of fetal growth on reproductive and maternal tissues in the grasscutter. The animals were categorized into non-pregnant, early pregnancy (d 1 - 50), mid pregnancy (d 51 - 100), and late pregnancy (> d 100) status. Maternal organ weights were reported as fresh weight (g), scaled to empty body weight (EBW; g/g), and maternal body weight (MBW; g/g). Carcass weight declined with advancing pregnancy (P = 0.029), as were the lungs, small and large intestines whilst the weights of the kidneys, liver and remaining viscera increased. The total internal organ mass, due mainly to the significant increases in the 'remaining viscera' mass, which is made up of mainly adipose tissues, also increased with advancing pregnancy. From mid pregnancy to late pregnancy, uterine weight increased by 675.3% (52.33±6.525 v. 353.37±26.580). This suggests that pregnancy imposes a huge metabolic demand on the grasscutter, but the animals appear to mobilize maternal nutrient stores, as well as slow down metabolic rate (as indicated by the increases in the fat component of the remaining viscera mass) to meet requirements of the growing fetus and developing mammary glands. [ABSTRACT FROM AUTHOR]

The grasscutter ( Thryonomys swinderianus) is a hystricomorph rodent that inhabits mainly Sub-Saharan Africa and its meat is highly relished by most people in this region. The animal is hunted in the wild using techniques that are sometimes detrimental to the environment. It is therefore being domesticated to make the meat readily available to forestall the negative consequences of hunting. There are currently no genetic markers available and we report here, 33 novel microsatellite markers developed using next-generation sequencing technology. The number of alleles ranged from 3 to 11 (mean 6.4) while the observed and expected heterozygosities ranged from 0.188 to 1.000 (mean 0.591) and 0.322-0.873 (mean 0.713), respectively. Cumulative probability of identity (PI) for all loci was very low (PI = 3.1 × 10), indicating that these markers can be used for individual identification in the domestic setting. They will also be useful to study the genetic diversity of the grasscutter in the wild for population monitoring and conservation. [ABSTRACT FROM AUTHOR]

Introduction: Sexual dimorphisms in biological structures such as brain and behaviour have been widely recognized in animals and humans. The purpose of this study was to examine whether there are sex differences in the size of the cerebellum with other body traits, such as the head, tail and brain. Methods: Twelve grasscutters comprising of 6 males and 6 females were used in this study. Each brain was extracted from the skull by standard procedures and the mean values of the weights, dimensions and volumes of the brain, cerebellum, head and tail were compared in male and female using quantitative analytical statistical method. Results: The results showed that the absolute mean brain weight and volume obtained in the male was slightly higher than that of the female, while the cerebellar mean weight was slightly higher in the female; although these values were not statistically significant (P> 0.05). The mean cerebellar lengths and widths did not differ between the two sexes (> 0.05), but the mean cerebellar circumference in the male was statistically higher than in the female (P< 0.05). The female cerebellar length was positively correlated with the length of the brain, head, body and tail. Discussion: In conclusion, the brain weight was slightly higher in the male than female, while the cerebellar weight was higher in the female than male. The significantly higher value of the cerebellar circumference in the male may partly be responsible for the big round head seen in the live male grasscutter. [ABSTRACT FROM AUTHOR]

The metabolic fecal nitrogen and digestibility estimates in the grasscutter were determined using 12 captive-bred adult animals fed with four experimental diets differing primarily in crude protein content using nitrogen balance trial approach. Grasscutters required 343.5 mg N kg d of nitrogen to meet maintenance requirements, which were met on diets containing 7.4% crude protein. The true digestibility of nitrogen was moderate (52%) but within the range for eutherians. Dry matter intake increased with decreasing dietary nitrogen content, suggesting that animals on nitrogen-deficient diets displayed appreciable compensatory intake. Metabolic fecal nitrogen was 3.5 g N kg dry matter intake, and endogenous urinary nitrogen was 257.5 mg N kg d. The low value of metabolic fecal nitrogen found for grasscutters affected the dry matter intake required for nitrogen balance, and it may allow grasscutters to exploit nitrogen poor diets. [ABSTRACT FROM AUTHOR]

Abstract: This study was conducted using 210 whole uteri collected from hunters’ kills from July 2006 to March 2007 at Esiam and Sokode in the Ekumfi and Ho Districts respectively; and data on 148 dams from eight farms in the Greater Accra Region of Ghana from January to December 2007. The objective of the study was to investigate the effects of embryonic resorption, litter size and parity on sex ratio in the grasscutter. Embryonic resorption rate, which occurred at all stages of pregnancy, ranged between 41.3% and 47.2%, and was not biased towards male or female offspring. The rate of resorption also had no effect on sex ratio (r =−0.011, P =0.396). The study also showed that litter size in the grasscutter could be improved if embryo resorption is controlled. Primiparous dams had offspring with a sex ratio of 0.43±0.020 which was not significantly different from dams of parities 3 (0.47±0.040) and ≥4 (0.53±0.053). Parity 2 dams, however, had a significantly higher proportion of males (0.54±0.024). There was a tendency towards a decreasing proportion of males as litter size increased but the overall sex ratio observed in the farmed grasscutter (0.48) did not deviate significantly from the theoretical sex ratio of 0.50. [Copyright &y& Elsevier]

The gastrointestinal parasites of the grasscutter were investigated between 1996 and 2006 using 180 grasscutters from the Accra Plains. The aim of the study was to develop strategies for the control of the parasites under captive management. The gastrointestinal tracts of the animals were examined for the presence of both helminth and protozoan parasites with the aid of a hand lens, the direct smear and Willis Flotation techniques. In all, fourteen species of helminths were found including twelve nematodes and two cestodes. Trichuris muris was the most common nematode encountered, whilst Hepatocola hepatica was the least commonly encountered nematode. Three genera of protozoans, viz, Trichomonas spp, Giardia spp and Eimeria spp were also encountered, with Giardia spp and Trichomonas spp being reported for the first time in the grasscutter. Eimeria spp were the most prevalent protozoa. The widespread occurrence of protozoal and helminthic parasites in the grasscutter suggests that routine treatment of grasscutters with coccidiostats, anti-flagellates and anthelminthics such as dimetridazole and albendazole may contribute significantly to improve productivity of animals and reduce the pressure on wild populations. [ABSTRACT FROM AUTHOR]

This study was carried out to record the morphometric parameters of the brain of male and female grasscutters. Ten healthy grasscutters (5 males and 5 females) were used in this study. The mean brain weights were 9.80 + 0.50 g and 10.27 + 0.45 g for males and females respectively. The olfactory bulb mean weight was 0.57 + 0.05 g for males and 0.43 + 0.10 g for females. The cerebral and cerebellar mean lengths of 3.14 + 0.04 cm and 1.34 + 0.04 cm for males, 6.26 + 0.10 cm and 3.80 + 0.32 cm for females were observed. The cerebrum, cerebellum and olfactory bulb account for 70 %, 12 % and 6 % of the total brain weight in males and 64 %, 13 % and 4 % in the females respectively. The mean brain lengths were 5.63 + 0.07 cm and 6.26 + 0.1 cm for males and females respectively. There were significant differences in the body and olfactory bulb weights and also, in the whole brain and cerebral lengths between the males and females. In our present research, the ratios of 0.01 for males and 0.006 for females were observed. This suggests a relatively low brain weight in the ruminants. The olfactory bulb in the male is larger than that in the females. Females in turn have longer brain dimension than the males. Cerebellum has no sex variation both in weight and in length. [ABSTRACT FROM AUTHOR]

The structure of the efferent ducts of animals is known to vary from one species to another, it even varies between segments of the ducts in the same species. In the grasscutter or greater cane rat (Thryonomys swinderianus), there are three segments of the efferent duct, based on their content of non-ciliated or principal cell types. Type I non-ciliated cell is present exclusively in the long proximal part of the duct, and exhibits a well-developed subapical endocytic apparatus as well as numerous oval or pleomorphic dense bodies. The type II non-ciliated cell predominates in the middle part of the duct, displays a poorly developed subapical endocytic apparatus but contains large, numerous vacuoles and dense bodies, all of which fill about two-thirds of the cell height. The type III non-ciliated cell, found in the epithelium of the terminal part of the duct, is poorly endowed with a subapical endocytic apparatus and contains no conspicuous endocytic vesicles or vacuoles. Only a few, small, dense bodies are present, if at all. The efferent duct of the cane rat is thus similar to that of man, the bull, goat and dog, in containing three varieties or types of non-ciliated cells. This report is the first to describe multiple non-ciliated cells in the epithelium of the efferent ducts of a rodent and, indeed, of a mammal smaller than the dog. [ABSTRACT FROM AUTHOR]

• Ticks found on grasscutters were identified as Ixodes aulacodi and Rhipicephalus sp. • Ixodes aulacodi were positive for Anaplasma, Babesia and Ehrlichia infections. • The presence of Candidatus M. mitochondrii endosymbiont was observed in 85.5% of Ixodes aulacodi. Ticks and tick-borne pathogens constitute a great threat to livestock production and are a potential health hazard to humans. Grasscutters (Thryonomys swinderianus) are widely hunted for meat in Ghana and many other West and Central African countries. However, tick-borne zoonotic risks posed by wild grasscutters have not been assessed. The objective of this study was to investigate bacterial and protozoan pathogens in ticks infecting wild grasscutters. A total of 81 ticks were collected from three hunted grasscutters purchased from Kantamanto, the central bushmeat market in Accra. Ticks were identified as Ixodes aulacodi and Rhipicephalus sp. based on morphological keys, which were further confirmed by sequencing mitochondrial 16S ribosomal DNA (rDNA) and cytochrome oxidase I (COI) genes of specimens. Protozoan infections were tested by PCR amplifying 18S rDNA of Babesia / Theileria / Hepatozoon , while bacterial infections were evaluated by PCRs or real-time PCRs targeting Anaplasmataceae, Borrelia , spotted fever group rickettsiae, chlamydiae and Candidatus Midichloria mitochondrii. The results of PCR screening showed that 35.5% (27 out of 76) of I. aulacodi were positive for parasite infections. Sequencing analysis of the amplified products gave one identical sequence showing similarity with Babesia spp. reported from Africa. The Ca. M. mitochondrii endosymbiont was present in 85.5% (65 out of 76) of I. aulacodi but not in the five Rhipicephalus ticks. Two Anaplasmataceae bacteria genetically related to Ehrlichia muris and Anaplasma phagocytophilum were also detected in two I. aulacodi. None of the ticks were positive for Borrelia spp., spotted fever group rickettsiae and chlamydiae. Since I. aulacodi on wild grasscutters are potential carriers of tick-borne pathogens, some of which could be of zoonotic potential, rigorous tick control and pathogen analyses should be instituted especially when wild caught grasscutters are being used as foundation stock for breeding. [ABSTRACT FROM AUTHOR]

The grasscutter (also known as the greater cane rat; Thryonomys swinderianus) is a large rodent native to West Africa that is currently under domestication process for meat production. However, little is known about the physiology of this species. In the present study, aiming to provide information about gut microbiota of the grasscutter and better understand its physiology, we investigated the intestinal microbiota of grasscutters and compared it with that of other livestock (cattle, goat, rabbit, and sheep) using 16S rRNA metagenomics analysis. Similar to the other herbivorous animals, bacteria classified as Bacteroidales, Clostridiales, Ruminococcaceae, and Lachnospiraceae were abundant in the microbiome of grasscutters. However, Prevotella and Treponema bacteria, which have fiber fermentation ability, were especially abundant in grasscutters, where the relative abundance of these genera was higher than that in the other animals. The presence of these genera might confer grasscutters the ability to easily breakdown dietary fibers. Diets for grasscutters should be made from ingredients not consumed by humans to avoid competition for resources and the ability to digest fibers may allow the use of fiber-rich feed materials not used by humans. Our findings serve as reference and support future studies on changes in the gut microbiota of the grasscutter as domestication progresses in order to establish appropriate feeding methods and captivity conditions. [ABSTRACT FROM AUTHOR]

Background: The greater cane rat (GCR), reputed to be African's second largest rodent, is a precocial hystricomorph with an uncommon phenotype and life history. Scientific and socio-economic interests in the GCR have led to heightened research efforts targeted towards a better understanding of its biology and exploration of its economic and translational usefulness., Methods: Records of all online scientific publications on the GCR from Google, Google Scholar, PubMed, science.gov, Ebscohost and Worldwide science, with the exception of research theses, proceedings, unpublished projects and abstracts, were collated and analyzed using descriptive statistics., Results: A total of 146 published scholarly articles spanning about six decades were retrieved, with 98% of the GCR publications originating from African countries. Nigeria boasts the highest number of publications (58.22%) followed by Ghana (21.23%) and South Africa (5.48%) while Senegal contributed the least (0.69%). Publications were sorted into ten field categories. The field with the highest number of articles (41.78%) was animal breeding and management recording, closely followed by anatomy (37.67%). Lesser contributions were made by parasitology (5.48%), biochemistry/hematology (4.8%), pharmacology/toxicology (4.11%), pathology (2.06%), and surgery/anesthesia and physiology (1.37% apiece). The fields with fewest contributions were microbiology and developmental biology (0.69% each)., Conclusion: This study chronicles the spectrum of knowledge available on the GCR, highlighting the knowledge gap that still exists in various fields in order to provide advocacy for new frontiers in research efforts on this rodent. We suggest the need for a clearly defined and well integrated national/regional policy aimed at establishing Africa's foremost micro-livestock rodent, the greater cane rat, on the world's scientific radar., Competing Interests: None., (© 2020 The Authors. Animal Models and Experimental Medicine published by John Wiley & Sons Australia, Ltd on behalf of The Chinese Association for Laboratory Animal Sciences.)