A comparison of the uterine proteome of mares in oestrus and dioestrus

Proteomic analysis of mare uterine flush fluid provides a minimally invasive technique for studying protein changes associated with the oestrous cycle. The aim of this study was to identify differentially abundant proteins in the uterine flush fluid of mares in oestrus and dioestrus. In this study, uterine flush fluid samples were collected from eight reproductively healthy mares in either oestrus (n = 5) or dioestrus (n = 3). Proteomic analysis was performed using liquid chromatography‐tandem mass spectrometry. Of 172 proteins identified, six proteins (immunoglobulin lambda‐like polypeptide 1, haemoglobin subunit alpha, alpha‐1B‐glycoprotein, serotransferrin, apolipoprotein A‐1, and haemoglobin subunit beta) were significantly more abundant in oestrus. These proteins may contribute to the endometrial defence system through roles in inflammation, immunity or antimicrobial activity. In other species, some of these proteins have been described as immunoglobulins, negative acute phase proteins or defence agents against micro‐organisms. During dioestrus, immunoglobulin alpha‐1 chain C region‐related, complement factor I, CD 109 antigen and uterocalin, were significantly more abundant. Research in other species suggests that these four proteins contribute to the immune response through proposed immunoregulatory characteristics, complement system involvement or roles in B cell–T cell interactions. In conclusion, ten differentially abundant proteins were identified in the uterine flush fluid of mares in oestrus and dioestrus. Targeted studies on these proteins could elucidate their role in uterine defence mechanisms during the oestrous cycle in the mare.     

Different drivers create spatial vegetation cover and vertical structure in semi-arid African savannas

Important drivers of woody cover in African savannas are rainfall, soil and nutrients, and disturbance factors, such as fire and herbivory. However, very little is known about how these drivers influence woody cover at specific height classes. The main aim of this study was to identify which of these drivers are the best predictors of woody cover at three height classes: shrub (0.75–2.5 m), brush (2.5–5.5 m) and tree (>5.5 m). Percent woody cover estimates were collected using a rapid monitoring technique over 1 700 sites in Kruger National Park, South Africa. Geology (basalt and granite), mean annual rainfall, fire frequency and elephant density were analysed as potential drivers of woody cover. Results indicate that mean annual rainfall was negatively associated with shrub cover, fire frequency was negatively associated with brush cover, and elephant density was negatively associated with tree cover. Patterns of woody cover show that while geology influences the spatial distribution of horizontal woody cover, variation in vertical vegetation structure is created and maintained by top-down disturbance. This provides the first documentation of drivers associated with structurally differentiated woody cover at regional scales. Future studies on woody cover in disturbance-driven environments should not ignore vegetation structure.     

INFLUENCE OF NORMOVOLEMIC ANEMIA ON DOPPLER-DERIVED BLOOD VELOCITY RATIOS OF ABDOMINAL SPLANCHNIC VESSELS IN CLINICALLY NORMAL DOGS

Doppler spectra of the abdominal aorta (AAo), cranial mesenteric artery (CMA), celiac artery (CA), and left renal artery (LRA) were obtained from 11 fasted, clinically healthy, conscious Beagles before and after inducing severe acute normovolemic anemia (mean±standard deviation hematocrit 16.0±0.77%). Peak systolic, end diastolic, and time-averaged mean velocities were measured. The different vessels were compared with each other. Peak systolic velocity ratio and time-averaged mean velocity ratio of splanchnic vessels to corresponding variables of the AAo were computed and compared between and within vessels during physiologic and anemic states. There was no difference between LRA and AAo, CMA or CA regarding time-averaged mean velocity, time-averaged mean velocity ratio, or end diastolic velocity during the physiological state. During the anemic state, LRA mean time-averaged mean velocity ( P ≤0.008) and mean end diastolic velocity ( P ≤0.041) were significantly lower than those of AAo, CMA, and CA. Mean time-averaged mean velocity ratio of the LRA was also significantly ( P ≤0.004) lower than the CMA and CA ratios, and significantly ( P =0.014) lower during anemic state than physiologic state of the same vessel. End diastolic and time-averaged mean velocities of the AAo, CMA, and CA increased proportionally during anemia, but there was a relatively less increase in the same variables of the LRA, suggesting less increase in blood flow. Doppler ratios allowed a noninvasive comparison between splanchnic and aortic hemodynamics. Velocity ratios might be useful for clinical detection of relative hemodynamic changes between different vessels.     

Genetic variability and relationships in nine South African cattle breeds using microsatellite markers

Tropical Animal Health and Production - Genetic variability within and between breeds allows adaptation to a changing environment and consequently prepares producers for the future. Eleven...     

Effects of cattle treatment with a fluazuron pour-on on survival and reproduction of the dung beetle species Onthophagus gazella (Fabricius)

While resistance against many other classes of acaricides has been described, products containing benzoylphenyl urea are currently still successfully used against the pesticide-resistant blue tick (Boophilus decoloratus) in South Africa. In order to assess any adverse impact of these tickicides on the important dung beetle (Coleoptera: Scarabaeidae) fauna, a bioassay was undertaken on the ecotoxicological effects of a fluazuron (benzoylphenyl urea) pour-on formulation (Acatak) on the survival and reproduction of the African dung beetles species Onthophagus gazella (Fabricius). The experiment yielded no significant differences in adult or larval survival, egg production, fecundity and fertility between the control and treatment group following three beetle generations over. These results suggested that treatment of cattle with the fluazuron pour-on formulation Acatak was not detrimental to the selected dung beetle species in any notable way.     

Woody Plant Encroachment Mitigated Differentially by Fire and Herbicide

Woodland expansion is a global phenomenon that, despite receiving substantial attention in recent years, remains poorly understood. Landscape change of this magnitude has several impacts perceived as negative on landscape processes, such as influencing fire regimes, habitat for wildlife, and hydrological processes. In southern Great Plains, Juniperus virginiana has been identified as a major contributor to woodland expansion. Adding to the perplexity of this phenomenon is its evidence on numerous landscape types on several continents, documented under varying climates. Our study aimed to quantify a direct treatment to reduce or slow down woodland expansion in an experimental rangeland in central Oklahoma, United States under three treatments: 1) herbicide, 2) fire with herbicide, and 3) control (no fire, no herbicide) within areas classified as “open grassland” in 1979. Thereafter, we identified these same areas in 2010 with remotely sensed imagery (Light Detection And Ranging) to quantify 1) total encroachment and 2) total encroachment by three size classes: a) small 1 ? 2.5 m, b) intermediate 2.5 ? 4.5 m and c) tall > 4.5 m. Overall, of the total area classified as grassland in 1979 (277.64 ha), 31% had been encroached by 2010. Encroachment was greatest in the control treatments, followed by herbicide-only treatment application and lowest in the fire and herbicide treatment with minor differences in mean plant height (4.11 m ± 0.28). Encroached areas were mostly dominated by tall individuals (45 ± 3.5%), followed by the intermediate-height class (31.53 ± 1.10%) and the least recorded in the smallest-height class (23.46 ± 2.29%), suggesting expansion occurred during the initial phases of treatment application. The costly practice of herbicide application did not provide a feasible solution to control further woodland expansion. However, when using herbicide with fire, woodland expansion was reduced, highlighting the effectiveness of early intervention by fire in reducing encroachment. This further supports landscape-scale studies highlighting the effect of fire to reduce woodland expansion.     

Factors influencing reproductive performance of cows from different Nguni ecotypes in southern Mozambique

The objective of this study was to assess the reproductive performance of two Nguni ecotypes (Nguni and Landim) raised in a subtropical environment to enhance strategies for livestock development and restocking programmes within the southern African region. Reproduction data collected between 1996 and 2009 from 365 cows of the Landim and Nguni ecotypes were analysed. From the results, ecotype, place of birth, year and season of birth/calving had significant effects on age at first calving (AFC) and calving interval (CI). Overall means for AFC and CI were 1,071 ± 166 days and 432 ± 85 days, respectively, while average calving rate was 88.0 ± 4.7%. Heifers born in the dry season had lower AFC than heifers born in the wet season. Heifers born at Impaputo Breeding Center were the youngest at first calving, followed by the South African born ones. Heifers of the Landim ecotype also calved younger than heifers of the Nguni ecotype. CI was shorter in wet seasons (main breeding seasons) than in dry seasons. Interaction between ecotype and year–season (p < 0.005) showed that, in wet and dry seasons, Nguni cows had shorter CI than the Landim. This study demonstrates for the first time a possible genotype-by-environment interaction between Nguni ecotypes. This might aid future cattle development and restocking programmes in southern Africa taking into consideration the adaptation of indigenous genotypes and climate change.     

Climate change and the genus Rhipicephalus (Acari: Ixodidae) in Africa

The suitability of present and future climates for 30 Rhipicephalus species in Africa are predicted using a simple climate envelope model as well as a Division of Atmospheric Research Limited-Area Model (DARLAM). DARLAM's predictions are compared with the mean outcome from two global circulation models. East Africa and South Africa are considered the most vulnerable regions on the continent to climate-induced changes in tick distributions and tick-borne diseases. More than 50% of the species examined show potential range expansion and more than 70% of this range expansion is found in economically important tick species. More than 20% of the species experienced range shifts of between 50 and 100%. There is also an increase in tick species richness in the south-western regions of the sub-continent. Actual range alterations due to climate change may be even greater since factors like land degradation and human population increase have not been included in this modelling process. However, these predictions are also subject to the effect that climate change may have on the hosts of the ticks, particularly those that favour a restricted range of hosts. Where possible, the anticipated biological implications of the predicted changes are explored.