Comparison of equilibration times when freezing epididymal sperm from African buffalo (Syncerus caffer) using Triladyl or AndroMed

Because of risks of disease transmission, it is not possible to move African buffalo (Syncerus caffer) within South Africa. Therefore, new ways must be found to enable exchange of genetic material and to increase genetic diversity. In this study epididymal sperm from 11 African buffaloes was exposed to 8 different pre-freezing equilibration times, using 2 different semen extenders. To test the influence of equilibration time and to find a practical way of freezing sperm in the field equilibration times between 2 and 9 h were compared. The extenders used were Triladyl and the totally defined extender AndroMed (both Minitüb, Tiefenbach, Germany). Post-thaw motility, longevity and acrosomal integrity were compared. Different equilibration times did not result in different post-thaw qualities. The use of Triladyl resulted almost always in higher post-thaw motilities and in better acrosomal integrity. Individual bulls had a significant influence on measured parameters. Results indicate that sperm flushed in the field can be stored in freezing medium for up to 9 h before being further processed and that Triladyl is superior to AndroMed when freezing epididymal African buffalo sperm. This knowledge is important to plan fieldwork, since working conditions are usually far from the ideal of a laboratory.     

Age determination of the West African buffalo Syncerus caffer brachyceros and the constancy of tooth wear

Maxillae of 34 West African buffalo Syncerus caffer brachyceros were collected from three sites in Burkina Faso, West Africa, and age determined from tooth appearance and the enamel height of M1 according to the criteria of Grimsdell (1973) for Ugandan buffalo Syncerus caffer caffer. Good agreement between the two methods was found. Ground and decalcified sections were prepared from M1 and the interradicular cementum lines counted. Although this gave inconsistent results in terms of assumed age compared with the other two methods, it is concluded that agreement was sufficiently close to suggest that the rate of attrition with age was similar in both populations.     

Thelazia rhodesii in the African buffalo, Syncerus caffer, in Zambia

We report 2 cases of Thelazia rhodesii infection in the African buffaloes, Syncerus caffer, in Zambia. African buffalo calves were captured from the livestock and wildlife interface area of the Kafue basin in the dry season of August 2005 for the purpose to translocate to game ranches. At capture, calves (n=48) were examined for the presence of eye infections by gently manipulating the orbital membranes to check for eye-worms in the conjunctival sacs and corneal surfaces. Two (4.3%) were infected and the mean infection burden per infected eye was 5.3 worms (n=3). The mean length of the worms was 16.4 mm (95% CI; 14.7-18.2 mm) and the diameter 0.41 mm (95% CI; 0.38-0.45 mm). The surface cuticle was made of transverse striations which gave the worms a characteristic serrated appearance. Although the calves showed signs of kerato-conjunctivitis, the major pathological change observed was corneal opacity. The calves were kept in quarantine and were examined thrice at 30 days interval. At each interval, they were treated with 200 μg/kg ivermectin, and then translocated to game ranches. Given that the disease has been reported in cattle and Kafue lechwe (Kobus lechwe kafuensis) in the area, there is a need for a comprehensive study which aims at determining the disease dynamics and transmission patterns of thelaziasis between wildlife and livestock in the Kafue basin.     

Habitat preferences of the secretive forest buffalo (Syncerus caffer nanus) in Central Africa

The forest buffalo Syncerus caffer nanus is one of the three subspecies of African buffalo inhabiting the rainforests of Western and Central Africa. Because of its secretive behaviour and main habitat (dense rainforests), there is little quantitative information on the habitat preferences of this buffalo. We present here the first data on the frequencies of this species along a habitat gradient ranging from clearings and rivers to forests, as well as the characteristics of the buffalo's resting places. We recorded information from a buffalo herd during the period January 2002–January 2004 in the Bai-Hokou area (Dzanga-Ndoki National Park, Central African Republic). Resting places were firstly compared with available habitat (i.e. resting vs. random sites) and, successively, comparisons were made between diurnal versus nocturnal and wet versus dry season resting places. Forest buffalos were found to be highly dependent on clearings, as well as on the more open forest stands, characterized by large trees and open canopy. Such preferences could be due to the tendency of the buffalos to rest all together; open patches are likely to facilitate social interactions between the members of the herd.     

Epididymal sperm from the African buffalo (Syncerus caffer) can be frozen successfully with AndroMed and with Triladyl but the addition of bovine seminal plasma is detrimental

Numerous diseases are carried and can be transmitted from the African buffalo (Syncerus caffer) to livestock. Buffaloes free of specific diseases (BFSD) are thus in demand amongst game farmers. Current BFSD derive from a small genetic pool and hence there is a special interest in bringing new genetic material into such herds. In this study epididymal sperm from 16 mature African buffalo bulls was frozen with Triladyl and AndroMed extender (Minitüb, Tiefenbach, Germany) with and without addition of bovine seminal plasma. Post-thaw motility, longevity and acrosomal integrity were compared. In all but one animal, post-thaw motility was higher, although not always significant, if sperm was frozen with Triladyl than with AndroMed. Seminal plasma was detrimental to the post-thaw motility. Neither semen extender nor seminal plasma had an influence on post-thaw acrosomal integrity. It can be concluded that bovine seminal plasma at a concentration of 10% is detrimental rather than beneficial for the post-thaw motility of African buffalo sperm. Even though being inferior AndroMed does, however, have the advantage that it is a defined semen extender and therefore clearly has a lower risk of contamination.     

Microsatellite analysis of genetic diversity in African buffalo (Syncerus caffer) populations throughout Africa

Genetic diversity in nine African buffalo (Syncerus caffer) populations throughout Africa was analysed with 14 microsatellites to study the effects of rinderpest epidemics and habitat fragmentation during the 20th century. A gradient of declining expected heterozygosity was observed among populations in Save Valley Conservancy (Zimbabwe), and northern and southern Kruger National Park (South Africa). This was explained by a high mortality in northern Kruger National Park during the rinderpest pandemic at the end of the 19th century followed by recolonization from neighbouring populations, resulting in intermediate heterozygosity levels in northern Kruger National Park. In other populations expected heterozygosity was very high, indicating that rinderpest and recent habitat fragmentation had a limited effect on genetic diversity. From expected heterozygosity, estimates of long-term effective population size were derived. Migration rates among populations in eastern and southern Africa were very high, as shown by a weak isolation by distance and significant correlation in allele frequencies between populations. However, there were indications that dry habitats could limit migration. Genetic distances within buffalo in central Africa were relatively large, supporting their status as distinct subspecies. Finally, it was observed that the higher polymorphic microsatellites were less sensitive at detecting isolation by distance and differences in Ne, which may be a result of the high mutation pressure at these loci.     

Necropsy and parasitic findings from an adult forest buffalo (Syncerus caffer nanus) found dead in the Republic of Congo

A field necropsy was performed on a recently dead adult forest buffalo, Syncerus caffer nanus, found in the Nouabalé-Ndoki National Park, Republic of Congo. Based on the gross and histological lesions, the cause of death was determined to be conspecific fighting. Ectoparasites collected from this forest buffalo were Amblyomma sp. (larvae) and Rhipicephalus ziemanni Neumann. Endoparasites collected included a paramphistomid trematode, Carmyerius gregarius, and oocysts of Eimeria spp., paramphistomid eggs (presumably from C. gregarius), metastrongylid lungworm larvae, and strongylid eggs. Parasitic findings from this forest buffalo were compared to previous reports from savanna and forest buffalo.     

Variation of group size among African buffalo herds in a forest-savanna mosaic landscape

Documenting within species group size variation is important to completely understand social organization within species and to interpret variation among species. Here, I investigated group size of African buffalo Syncerus caffer over 2 years in a heterogeneous landscape. African buffalo use closed continuous forest and vast open savannas, and anecdotal observations suggest that habitat type influences their social structure. While the Cape buffalo Syncerus caffer caffer is well studied, few data exist for the forest-dwelling Syncerus caffer nanus . I observed forest buffalo at Lopé National Park, Gabon, and examined variation of group size. Eighteen forest buffalo herds used the study area with an estimated population of 342 individuals (∼5 buffalo km⁻²). The mean group size for the 18 herds was 12 ± 2 (range of means=3–24), considerably smaller than Cape buffalo herds. For eight radiocollared forest buffalo, the mean group size was stable, varying little with time of day, across seasons, or between savanna and marsh habitat. However, herd size varied widely across herds, from fewer than 10 individuals in the smallest herds to more than 20 buffalo in the largest. Large herd size is associated with home ranges that contain substantial areas of open habitat, and thus more food resources than forested habitats.     

Influence of habitat fragmentation on the genetic structure of large mammals: evidence for increased structuring of African buffalo (Syncerus caffer) within the Serengeti ecosystem

Wildlife species exposed to habitat fragmentation are often in need of a conservation effort. The African buffalo (Syncerus caffer) is one of the key species in the Serengeti ecosystem as they form a large part of the herbivore biomass, providing ecotourism and valuable trophies. The ecosystem is a part of Tanzanias protected areas and is administrated under different management practices. Among these, we have analysed the genetic structure of buffalo (n = 68) from the Serengeti National Park (SNP), the Ngorongoro conservation area (NCA) and the Maswa game reserve (MGR). Both the sequence variation in a 493 base pair fragment of the mitochondrial D-loop and the allele frequency-distribution in 15 microsatellites suggest genetic structuring of the buffalo populations within the ecosystem. Both the allele frequency-distribution and the amount of genetic variation were high and similar in SNP and MGR, suggesting a high degree of gene flow between these locations. By comparison, the NCA buffaloes had significantly lower genetic variation and were genetically differentiated from SNP and MGR. Approximate Bayesian computation estimates suggest that the observed genetic structure is of a recent origin, indicating that the recent increases in developmental activity in the region may have influenced the genetic structure of the buffalo within the Serengeti ecosystem.     

Population structure and ecology of the African buffalo (Syncerus caffer Sparrman, 1779) in Chebera Churchura National Park,Ethiopia

An investigation of population structure and ecology of the African buffalo (Syncerus caffer Sparrman, 1779) was carried out in the Chebera Churchura National Park, Ethiopia during the wet and dry seasons of 2005–2006. Sample counts of African buffaloes were carried out in an area of 1,215 km². The estimated population of buffalo was 2,617 individuals. Males comprised 35.0%, while females 52.8% of the population. The remaining 12% of the population was young of both sexes and of all ages of unknown sex. It was difficult to categorize the young into male and female in the field, as their primary sexual characteristics were not easily visible. Male to female sex ratio was 1.00 : 1.51. Age structure was dominated by adults, which constituted 72.06% of the total population. Subadults comprised 22.02%, and young accounted for 5.9% of the population. Larger herds of up to 27 individuals were observed during the wet season and smaller herds of eight individuals during the dry season. The mean herd size during wet and dry seasons was 24.81 and 7.77, respectively. The African buffaloes were distributed in four habitat types such as grasslands, woodlands, montane forests and riverine habitat in the study area. They were observed more in the riverine vegetation types during the dry season. Relative abundance of food resources, green vegetation cover and water availability in the area were the major factors governing their distribution in the present study area. They spent a greater proportion of the time in feeding and resting/ruminating activities. On the average, 49.7% of the daytime was spent in feeding, and 38.75% of the day on resting (lying down and standing). Morning and the late afternoon activity peaks were more pronounced during the dry season than the wet season.     

Potential effects of prescribed savannah burning on the diet selection of forest buffalo (Syncerus caffer nanus) in Lopé National Park,Gabon

Seasonality and management are factors that may affect the diet selection of the forest buffalo (Syncerus caffer nanus). Fire is considered a major driving force in savannah systems and prescribed burning is a commonly applied conservation tool in protected areas such as Lopé National Park, Gabon. Prescribed annual fires contribute to the maintenance of open areas and provide high‐quality forage for forest buffalo, a major herbivore in the park. We used microhistological faecal analysis to determine the diet selection of forest buffalo and measured the extent of variation between a dry season, preburn and a wet season, postburn sampling period. The buffalo diet comprised mainly of monocotyledons, primarily grasses (Poaceae) and sedges (Cyperaceae). Intake of open‐area‐associated plant species was higher in the wet season, postburn treatment sampling period (97%) than the dry season, preburn sampling period (87%), which corresponded conversely to a reduction in forest‐associated Marantaceae plants (10% versus 1%). High proportions of grasses and sedges in the diet signify the importance of open areas for forest buffalo. Controlled burning as tool for maintenance of open areas may play a key role in the meta‐population management of the forest buffalo.     

Behaviour-Related Scalar Habitat Use by Cape Buffalo (Syncerus caffer caffer)

Studies of habitat use by animals must consider behavioural resource requirements at different scales, which could influence the functional value of different sites. Using Cape buffalo (Syncerus caffer caffer) in the Okavango Delta, Botswana, we tested the hypotheses that behaviour affected use between and within habitats, hereafter referred to as macro- and microhabitats, respectively. We fitted GPS-enabled collars to fifteen buffalo and used the distances and turning angles between consecutive fixes to cluster the resulting data into resting, grazing, walking and relocating behaviours. Distance to water and six vegetation characteristic variables were recorded in sites used for each behaviour, except for relocating, which occurred too infrequently. We used multilevel binomial and multinomial logistic regressions to identify variables that characterised seasonally-preferred macrohabitats and microhabitats used for different behaviours. Our results showed that macrohabitat use was linked to behaviour, although this was least apparent during the rainy season, when resources were most abundant. Behaviour-related microhabitat use was less significant, but variation in forage characteristics could predict some behaviour within all macrohabitats. The variables predicting behaviour were not consistent, but resting and grazing sites were more readily identifiable than walking sites. These results highlight the significance of resting, as well as foraging, site availability in buffalo spatial processes. Our results emphasise the importance of considering several behaviours and scales in studies of habitat use to understand the links between environmental resources and animal behavioural and spatial ecology.     

Demographics and parasites of African buffalo (Syncerus caffer Sparrman, 1779) in Ruaha National Park,Tanzania

The number of African buffaloes (Syncerus caffer Sparrman, 1779) inhabiting Ruaha National Park, Tanzania, is thought to be declining, but little data exist to determine whether the population is actually in decline. As an initial phase of collecting population data, we conducted demographic surveys, faecal egg counts and gastrointestinal parasite identification in Ruaha's buffalo herds in September 2011 and 2013. Most herds encountered in the two surveys appeared to be in good health, but with fewer calves in 2013 compared with 2011. The herd‐level body condition score was positively associated with the number of calves per 100 cows after adjusting for year, and the lower number of offspring in 2013 could possibly be associated with a below average rainfall in the 2012–2013 rainy season. Mean herd‐level egg counts ranged from 83 to 140 and from 28 to 113 eggs per g faeces in 2011 and 2013, respectively. Haemonchus, Nematodirus, Cooperia and Oesophagostomum spp., as well as coccidian oocysts, were detected in the population. Monitoring herd demographics and baseline health parameters over time will provide insight into population performance, increase the understanding of population stressors and contribute to buffalo conservation within Ruaha National Park and other protected areas of Africa.     

Seasonal variation in forages utilized by the African buffalo (Syncerus caffer) in the succulent thicket of South Africa

The succulent thicket of the Eastern Cape, South Africa, is characterized by densely wooded vegetation that is dominated by succulents with little understory of ephemeral and weakly perennial grasses and forbs. Studies have developed around the question: how do bulk grazers such as the African buffalo (Syncerus caffer) survive in the succulent thicket? In this study, the diet of the African buffalo at the Great Fish River Reserve (GFRR) was studied in two seasons (wet and dry). The diet profile was assessed from faecal matter, using the micro‐histological analysis method. During the wet season, grass species contributed 72% to the diet while 28% was contributed by browse species. In the dry season there was a significant increase in the intake of browse by 5% (χ² = 19.94, df = 11, P < 0.05). There were species that were neglected in the wet season but became principal dietary items in the dry season, these included Setaria neglecta, Cymbopogon plurinodis, Capparis sepiaria and Portulacaria afra. Diet quality, as estimated from faecal samples, suggested that the buffalo were nutritionally stable; however, the presence of sarcoptic mange in the buffalo suggests nutritional stress.     

Ecological cues, gestation length, and birth timing in African buffalo (Syncerus caffer)

We examined annual variation in the timing of conception andparturition in the African buffalo (Syncerus caffer) and thesynchrony of birth timing with resource cues, using 8 yearsof monthly birth, rainfall, and vegetation data, measured asNormalized Difference Vegetation Index (NDVI). Monthly birthshad the strongest significant correlations with NDVI and rainfalllevels 12 and 13 months in the past, respectively. In addition,the synchrony of current year births corresponds most stronglyto the synchrony of the previous year's NDVI distribution. Becausethe gestation period of buffalo has been estimated to be around11 months, these findings suggest that improved protein levels,occurring approximately a month after the first green flushof the wet season, are either a trigger for conception or conceptionhas evolved to be synchronous with correlated environmentalcues that ensure females enter a period of peak body conditionaround the time of conception and/or parturition. With a gestationperiod of approximately 340 days, parturition occurs to takeadvantage of the period when forage has its highest proteincontent. A comparative analysis of gestation periods withinthe subfamily Bovinae indicates that African buffalo have aprotracted gestation for their body size, which we suggest isan adaptation to their seasonal environment. We also found thatinterannual variation in the birth distribution suggests a degreeof plasticity in the date of conception, and variation in thenumber of calves born each year suggest further synchrony ata timescale longer than a single year.     

Immobilization of African buffaloes (Syncerus caffer coffer) in large numbers for veterinary research

Four hundred and eleven African buffaloes were immobilized with etorphine hydrochloride (M99, Reckitts) and sampled under difficult conditions in North Western Botswana. The buffaloes were darted from a helicopter in 36 days. 584 darts were fired giving a success rate of 70-5%. Various age groups in three separate buffalo populations were included. The technique and difficulties encountered when working from a helicopter are described. Mechanical failure of the darting equipment was negligible. A breakdown of the costs involved is given and a comparison made with similar work carried out solely from land vehicles.     

Applicability of bovine microsatellite markers for population genetic studies on African buffalo (Syncerus caffer)

The applicability of bovine autosomal microsatellite markers for population genetic studies on African buffalo was investigated. A total of 168 microsatellite markers were tested for PCR amplification on a test panel of seven African buffalo. Amplification was observed for 139 markers (83%), and 101 markers were studied further with 91 (90%) being polymorphic. The mean number of alleles per marker was 5.0 (SE = 0.2) and the mean heterozygosity per marker was 0.61 (SE = 0.03). Considering the overall high level of polymorphism, it was concluded that most bovine microsatellite markers are applicable in African buffalo.     

Antibodies to Brucella spp. among blue wildebeest and African buffalo in Kenya

A serologic survey of blue wildebeest (Connochaetes taurinus Burchell) and African buffalo (Syncerus caffer Sparrman) in the Masai Mara area was conducted. Antibodies to Brucella spp. were found in 18% of the blue wildebeest and 30% of the African buffalo examined. There were titers in all age groups and in both sexes. Hygromata were seen in both species. The increase in numbers of blue wildebeest and African buffalo which share grazing and watering areas with cattle of the Masai people, makes the presence of infections by Brucella spp. in wildlife an important consideration in any program for control of brucellosis.     

Age determination of the African buffalo, Syncerus caffer Sparrman

Age criteria for the African buffalo are described. These are based on the tooth eruption sequence and on wear of the first molar. Assignment of absolute ages to the tooth eruption and wear classes has been made by reference to known-age animals and to numbers of cementum lines in tooth sections. For ageing animals to the nearest year, the normal degree of accuracy of the methods is assumed to be about ± 1/2year (1–5 years of age); about ± 1 year (5–15 years of age); and about ±2 years (15-20years of age). A field method of age determination is presented based on horn characteristics and relative body size.     

In vitro production of cattle × buffalo hybrid embryos using cattle oocytes and African buffalo (Syncerus caffer caffer) epididymal sperm

Interspecies hybridization of bovids occurs between domestic cattle and at least three other species; American bison (Bison bison), yak (Bos grunniens) and banteng (Bos banteng). Birth of a cattle × buffalo (Bubalus bubalis) hybrid has reportedly occurred in Russia and in China, but these reports were not authenticated. Such hybrids could be important in improving livestock production and management of diseases that impede production in tropical Africa. This study investigated hybridization between cattle and its closest African wild bovid relative, the African buffalo (Syncerus caffer caffer). In an attempt to produce cattle × buffalo hybrid embryos in vitro, matured cattle oocytes were subjected to a standard in vitro fertilization (IVF) procedure with either homologous cattle (n = 1166 oocytes) or heterologous African buffalo (n = 1202 oocytes) frozen-thawed epididymal sperm. After IVF, 67.2% of the oocytes inseminated with the homologous cattle sperm cleaved. In contrast, fertilization with buffalo sperm resulted in only a 4.6% cleavage rate. The cleavage intervals were also slower in hybrid embryos than in the IVF-derived cattle embryos. Of the cleaved homologous cattle embryos 52.2% progressed to the morula stage compared with 12.7% for the buffalo hybrid embryos. No hybrid embryos developed beyond the early morula stage, while 40.1% of the cleaved cattle × cattle embryos developed to the blastocyst stage. Transfer of buffalo hybrid IVF embryos to domestic cattle surrogates resulted in no pregnancies at 60 days post-transfer. This study indicates that interspecies fertilization of cattle oocytes with African buffalo epididymal sperm can occur in vitro, and that a barrier to hybridization occurs in the early stages of embryonic development. Chromosomal disparity is likely the cause of the fertilization abnormalities, abnormal development and subsequent arrest impairing the formation of hybrid embryos beyond the early morula stage. Transfer of the buffalo hybrid embryos did not rescue the embryos from development arrest.