Comparative Study on Five Different Commercial Extenders for Boar Semen

Increasing interest in a longer preservation of diluted boar sperm raises questions in the field concerning the choice of the extender. The aim of this study was to evaluate the longevity of boar sperm extended in currently used commercial semen extenders. Three long-term extenders and two short-term extenders were compared for different semen quality parameters that can be assessed under routine laboratory conditions. Sperm morphology, motility, pH and bacteriological contamination were investigated during a 7-day period. The number of dead spermatozoa did not differ significantly among the extenders (p > 0.05). Sperm motility was not only related with storage period but most of all with pH, especially in long-term extenders. Differences between the different extenders were prominent (p < 0.05); the sperm preserved in only one long-term extender showed good motility during the whole test period. In all cases, the pH of the extended semen increased by 0.3-0.5 in the first days of storage and was significantly correlated with a decrease in motility. Bacteriological quality had no significant influence on motility or pH of the semen. In conclusion, we can state that in both short-term extenders and in only one long-term extender, sperm longevity, as evaluated by the parameters used in this study, was sufficient during the preservation period. To preserve the quality of diluted boar semen during long-term storage, the choice of the long-term extender is important. In addition, the monitoring of the pH of extended boar semen in our study emphasizes the importance of the buffering capacity of semen extenders.     

Tomato brown rugose fruit disease: current distribution,knowledge and future prospects

Tomato is the most economically important fruit/vegetable crop grown worldwide. However, viral diseases remain an important factor limiting its productivity, with estimated quantitative and qualitative yield losses in tomato crops often reaching up to 100%. Many viruses infecting tomato have been reported, while new viral diseases have also emerged. The climatic changes the world is experiencing can be a contributing factor to the successful spread of newly emerging viruses, as well as the establishment of disease in areas that were previously either unfavourable or where the disease was absent. Because antiviral products are not available, strategies to mitigate viral diseases rely on genetic resistance/tolerance to infection, control of vectors, improvement in crop hygiene, roguing of infected plants and seed certification. Tomato brown rugose fruit virus (ToBRFV) is an emerging viral threat to tomato productivity and is currently spreading into new areas, which is of great concern to the growing global production in the absence of mitigation measures. This review presents the current knowledge about ToBRFV and future prospects for an improved understanding of the virus, which will be needed to support effective control and mitigation of the impact it is likely to cause.     

Comparison of Computer-assisted Sperm Motility Analysis Parameters in Semen from Belgian Blue and Holstein–Friesian Bulls

Subjective microscopic sperm motility results have recently been demonstrated to differ between Holstein-Friesian (HF) and Belgian Blue (BB) bulls. However, such assessments are rather imprecise. In the present study, sperm motility was assessed objectively by means of the Hamilton Thorne CEROS version 12.2c computer-assisted sperm motility analyser (CASA), and differences between the BB and HF breed could also be demonstrated. Higher percentages of both totally (p < 0.0001) and progressively (p < 0.0001) motile spermatozoa were encountered in the HF breed compared with the BB breed. Furthermore, a lower kinetic efficiency of the BB spermatozoa, evidenced by a lower beat cross-frequency (p = 0.0007) combined with a higher lateral head displacement (p = 0.0015), was the basis for the lower velocity of BB sperm cells. Additionally, BB spermatozoa move less straight forward, resulting in a lower straightness (p < 0.0001). No sperm motility differences were observed between age groups within the BB breed. The breed differences were observed in the examined bull populations residing at AI centres, in Belgium for the BB bulls and in the Netherlands for the HF bulls. However, these bull populations are selected for fertility. A similar pattern was observed in an unselected bull population of both breeds, although these differences were mostly non-significant for the different CASA parameters. Nevertheless, these data suggest that a genetic component might be responsible for the observed sperm motility breed differences.     

Behavioral and physiological evaluation of sows raised in outdoors systems in the Brazilian semiarid region

Tropical Animal Health and Production - The objective of this study was to evaluate the biochemical, behavioral, and physiological parameters in pregnant sows of native and improved crossbreeds...     

Contrasting edge and pasture matrix effects on ant diversity from fragmented landscapes across multiple spatial scales

Landscape Ecology - Harmful effects of habitat loss and fragmentation can be detected across multiple spatial scales, yet most studies that aim to characterize these effects take place at a single...     

Leaf litter decomposition of dominant tree species of Namdapha National Park,Arunachal Pradesh,northeast India

Rates of weight loss and nutrient (N and P) release patterns were studied in the leaf litter of the dominant tree species (Ailanthus grandis, Altingia excelsa, Castanopsis indica, Duabanga sonneriatioides, Dysoxylum binectariferum, Mesua ferrea, Shorea assamica, Taluma hodgsonii, Terminalia myriocarpa and Vatica lancefolia) of a tropical wet evergreen forest of northeast India. Nitrogen and phosphorus mineralization rate and decay pattern varied significantly from species to species. In general, the decay pattern, characterized by using a composite polynomial regression equation, exhibited three distinct phases of decay during litter decomposition—an initial slow decay phase (0.063% weight loss day⁻¹), followed by a rapid decay phase (0.494% weight loss day⁻¹) and a final slow decay phase (0.136% weight loss day⁻¹). The initial chemical composition of the litter affected decomposition rates and patterns. Species like D. sonneriatoides, D. binectariferum, and T. hodgsonii with higher N and P content, lower carbon and lignin content, and lower C:N ratio and lignin:N ratio exhibited relatively faster decomposition rates than the other species, for example M. ferrea, C. indica and A. grandis. A slow decay rate was recorded for species such as M. ferrea, C. indica, and A. grandis. The initial N and P content of litter showed significant positive correlations with decay rates. Carbon and lignin content, lignin:N, and C:N showed significant negative correlations with decay rates. Soil total N and P, and rainfall, soil temperature, and soil moisture had positive correlations with decay rates. The rapid decomposition rates observed in comparison with other different forest litter decay rates confirm that tropical wet evergreen forest species are characterized by faster decomposition rates, indicating a faster rate of organic matter turnover and rapid nutrient cycling.     

Population status and regeneration of a tropical clumping bamboo <Emphasis Type="Italic">Schizostachyum dullooa</Emphasis> under two management regimes

Schizostachyum dullooa (Gamble) Majumder ‘dolu bamboo’ is a thin walled sympodial moderate sized to large tufted bamboo, dominant in the successional fallows of northeast India. The impact of resource management on productivity and sustainability of the species was evaluated by investigating the population status and regeneration in Cachar tropical semi evergreen forest under private property resource management (PPRM) and common property resource management (CPRM) regimes. Population status revealed current-year, one-year, two-year and three-year-old culms contribute 54%, 24%, 16% and 6% of the total culms per clump, respectively, under PPRM. Three-year-old culms were absent in CPRM and population status was thus represented by current year (83%), one-year (16%) and two-year (1%) old culms. Net change, rate of change and % gain in population for different age classes showed the prevalence of management practices under CPRM was unscientific. Efficiency of new culm production per clump used as an index of regeneration was 69.7% in PPRM and 59.88% in CPRM. New culms produced under CPRM were small and thin. We conclude that CPRM is inappropriate for a long term economic and ecological sustainability of the species and alternative management protocols are needed for conservation of the species.     

Scientific analysis of indigenous techniques for guggal （Commiphora wightii） tapping in India

Guggal, a threatened species that is endemic to western India, is tapped to extract medicinally important oleo–gum–resin(guggul). However, the plant dies after gum exudation. The indigenous tapping techniques used by local people were examined in Gujarat, India to discover the scientific basis behind these techniques: selection of gum inducer, season of tapping, and plant parts to be tapped. First, the presence of Xanthomonas axonopodis pv. commiphorae(Xac) in the gum suspension used for tapping was established. This bacterium induces gum oozing from the tapped plants and later, causes them to die off. The population of Xac in gum was found to decrease with the age of the gum. With that, fresh gum increased the tapping success. Second, local people preferred tapping during the warm season, which we validated by determining that Xac growth was best at 30 °C. Tapping during September(mean temperature 25.7–30.0 °C) clearly favoured growth of the pathogen and yielded maximum guggul. Multiple tapping on a mature tree ensured maximum gum extraction before its death. Finally, application of indigenous technology under natural plant stands by the local people ensured availability of this important raw drug for consumption. Our study established that the age–old traditional methods have a strong scientific basis. However, it is imperative to formulate strategies based on contemporary scientific understanding to protect this natural resource before it becomes extinct.     

Enhanced anther culture efficiency of indica rice (Oryza sativa L.) through modification of the culture media

The production of microspore-derived green plants from anther culture of indica rice is generally very low compared with japonica cultivars. A modified anther culture medium, consisting of a higher KNO₃ content (31 mm ) and casein hydrolysate (CH, 500 mg/1) but without ammonium salts, was tested in comparison with a medium consisting of the widely-used N6 medium nitrogen background, using four indica × indica F₁ hybrids as test materials. Green plant regeneration frequency was at least three-fold higher in the microspore-calli derived from the former medium than in those derived from the modified N6 medium. More than 700 microspore-derived plants were raised in the field. Another study was carried out using indica × japonica and indica × javanica F₁ hybrids. The results indicated that a medium with higher (3.5 mm ) ammonium sulphate may induce a higher frequency of anthers with microspore-calli but not necessarily lead to a larger number of green-plant regenerating calli. Subsequently, using the indica cv. ‘IR-43’ as the test material, use of a lower level (1.75 mm ) of (NH₄)₂SO₄, in addition to KNO₃ (31 mm ), was found to be better than CH (500 mg/l) for anther-response as well as green plant regenerability of the derived microspore-calli. Nitrate-nitrogen or ammonium-nitrogen alone elicited poor response. Twenty-five media involving combinations of KNO₃ (20–34 mm ) and (NH₄)₂SO₄ (1–3 mm ) were tested for their effects on anther response. Combinations involving KNO₃ (31–34 mM) and (NH₄)₂SO₄ (2.0–2.5 mm ) were found superior not only for achieving greater anther response but also, for subsequent green-plant regeneration. This contrasts with the 28 mm of KNO₃ and 3.5 mm of (NH₄)₂SO₄ in the widely-used N6 medium developed for japonica rice. Other than potassium nitrate and ammonium sulphate, and potassium phosphate to some extent, the levels of other inorganic salts tested did not make any significant difference to the process of anther response. Based on these results, modified media with three levels of ammonium sulphate were tested for anther culture efficiency of indica × japonica and indica × javanica derivatives (F₃s). Microspore-calli derived from a medium of a lower (1.75 mm ) level of (NH₄)₂SO₄ showed a higher regeneration potential overall than those derived from a higher (3.5 mm ) level. A revised medium has been suggested, on the basis of these results, for the realization of improved anther culture efficiency and, consequently, improved feasibility of using doubled haploids in genetic and breeding research with indica rice.