Effects of exogenous amylase on the in vitro digestion kinetics of whole-crop maize silages made from flint or dent grain type at different phenological stages grown in tropical condition

The effect of exogenous amylase on the in vitro rumen digestion kinetics of whole-crop maize silage made from dent (RB9004) or flint grain type (RB9308) was evaluated at different phenological stages: soft dough (SOD), early dent (EAD), ½ milkline (½M) and ¾ milkline (¾M). Forage was harvested from 70 to 110 days after sowing. Two rumen-cannulated cows receiving or not exogenous amylase (0.7 g/kg dry matter—DM, provided to achieve 396 kilo Novo units of amylase activity/kg of TMR DM) were used as donor of ruminal fluid. The in vitro gas production kinetics was evaluated according to a dual-pool logistic model. The chemical composition and gas production kinetics were affected by the hybrid and phenological stages. The flint hybrid had lower range for chemical analysis among physiological stages. Harvesting at ½M and ¾M improved DM content, bromatological composition and silage quality parameters compared to dent or flint types. Amylase (i) increased methane (CH₄) production and in vitro dry matter digestibility (IVDMD) in ½M stage, (ii) improved digestion kinetics by reducing lag time and increasing total gas production and fermentation rates of non-fibrous carbohydrates (NFC) and fibrous carbohydrates (FC), and (iii) increased extent and fermentation rate of NFC and increased fermentation rate of FC fraction in whole-crop maize silages produced from dent or flint types in all phenological stages. Harvesting between ½M and ¾M is the best phenological stage to improve chemical composition and silage quality parameters. Exogenous amylase showed improvements on fibre digestion of silages at ½M and ¾M phenological stages in both grain types of corn.     

Effect of site and storage conditions on quality of industrial fresh pepper

The commercial expansion of roasted pepper as a high market value product have made that the period of time in which canning industries process the fresh pepper fruits needs to be extended. Fresh sweet pepper (Capsicum annuum L.) destined for industry grown in different sites was cold stored in order to analyse the effect of different sites and storage conditions on the quality of the product at harvest and during storage. Storage during 10 days at 8 °C was the best storage condition to improve quality of pepper destined for industry, because colour was improved, weight loss (1–1.6%) was lower than maximum permissible and decay incidence was only between 0% and 2.3%. Harvest should be delayed until pepper reaches the red state in order to increase the quality of the fruit. However, these results suggest that pepper growers should assure a high content of Ca (>0.6 g kg⁻¹) in the soil to avoid a high incidence of decay during storage when a late harvest is needed to guarantee the enhancement of colour in pepper fruit destined for industry. These storage conditions are in accordance with those found to improve the sensory quality of roasted pepper.     

In vitro generation of mature neutrophils from canine Lin- bone marrow cells

The major goal of this work was to describe the in vitro generation of mature functional neutrophils derived from a canine enriched haematopoietic progenitor cell population. We have utilised lineage depletion by immunomagnetic selection to isolate a canine haematopoietic progenitor cell population. The physical, immunological, metabolical and morphological methodologies employed in this study have permitted us to isolate and define a cell population enriched in Rh-123low and CD34+ cells. Irradiated pre-established long-term bone marrow cultures (LTBMC) were utilised to determine the self-renewal ability of lineage negative (Lin-) cells, as well as their capacity to differentiate into mature functional neutrophils. The authors demonstrate for the first time that canine neutrophils derived from Lin- cells are able to produce oxyradicals, express a specific neutrophil surface antigen, and contain gelatinase granules. These characteristics enable them to migrate through basement membranes to act as a first line defence mechanism. The fact that these cells are able to differentiate into functional mature cells, and give rise to long-term culture-initiating cells (LTC-IC) after 35 days of culture, allows the authors to assure that the isolated canine enriched haematopoietic cell population exhibit functional characteristics, associated with primitive haematopoietic cells.     

Role of wild ruminants in the epidemiology of bluetongue virus serotypes 1, 4 and 8 in Spain

ABSTRACT: Although the importance of wild ruminants as potential reservoirs of bluetongue virus (BTV) has been suggested, the role played by these species in the epidemiology of BT in Europe is still unclear. We carried out a serologic and virologic survey to assess the role of wild ruminants in the transmission and maintenance of BTV in Andalusia (southern Spain) between 2006 and 2010.A total of 473 out of 1339 (35.3%) wild ruminants analyzed showed antibodies against BTV by both ELISA and serum neutralization test (SNT). The presence of neutralizing antibodies to BTV-1 and BTV-4 were detected in the four species analyzed (red deer, roe deer, fallow deer and mouflon), while seropositivity against BTV-8 was found in red deer, fallow deer and mouflon but not in roe deer. Statistically significant differences were found among species, ages and sampling regions. BTV RNA was detected in twenty-one out of 1013 wild ruminants (2.1%) tested. BTV-1 and BTV-4 RNA were confirmed in red deer and mouflon by specific rRT-PCR.BTV-1 and BTV-4 seropositive and RNA positive wild ruminants, including juveniles and sub-adults, were detected years after the last outbreak was reported in livestock. In addition, between the 2008/2009 and the 2010/2011 hunting seasons, the seroprevalence against BTV-1, BTV-4 and BTV-8 increased in the majority of provinces, and these serotypes were detected in many areas where BTV outbreaks were not reported in domestic ruminants. The results indicate that wild ruminants seem to be implicated in the dissemination and persistence of BTV in Spain.     

The use of Verticillium dahliae and Diplodia scrobiculata to induce resistance in Pinus halepensis against Diplodia pinea infection

The pathogenic fungi Verticillium alboatrum and Diplodia scrobiculata were assayed for biological control of Diplodia pinea on Aleppo pine (Pinus halepensis) in Catalonia (north-eastern Spain). Young shoots were pre-treated with inoculations of either V. dahliae or D. scrobiculata, by placing colonized agar plugs on wounds made by removing a single needle fascicle. An inoculation with D. pinea was performed 15 days later. Two months after the shoot inoculations, the canker length on the stems was measured and the percentage of shoot dieback calculated. Verticillium dahliae and D. scrobiculata were found to significantly reduce the canker length of D. pinea (P < 0.05) when compared with positive controls. Diplodia pinea was slightly more sensitive to V. dahliae than to D. scrobiculata, but no significant differences (P > 0.05) were observed in the mean canker length between the two treatments. Trees pre-inoculated with V. dahliae resulted in 31.12% shoot dieback, while those pre-inoculated with D. scrobiculata resulted in 32.18% shoot dieback, compared with positive controls (42.85%).     

Adrenomedullin (AM) and adrenomedullin binding protein (AM-BP) in the bovine mammary gland and milk: Effects of stage of lactation and experimental intramammary E. coli infection

Adrenomedullin (AM) has been characterized as an endogenous tissue survival factor and modulator of many inflammatory processes. Because of the increased susceptibility of the mammary gland to infection during the time surrounding parturition in the cow, we investigated how milk and tissue content of AM and its binding protein (AM-BP) might be affected by the stage of lactation and the udder health status. Milk and mammary biopsy samples were obtained from Holstein cows 21 days prior to and at various times after calving to represent the dry period and early and mid-stages of lactation. Additional cows received an intramammary challenge with Escherichia coli for immunohistochemical characterization of AM and AM-BP. Milk AM concentrations were relatively constant across the stages of lactation while AM-BP increased two-fold (P<0.04) between early and mid-lactation. Milk AM (P<0.04) and AM-BP (P<0.03) increased as somatic cell counts (SCCs) increased within a given stage of lactation. Tissue content of both (AM and AM-BP) were significantly affected by stage of lactation, lowest in the dry period and progressively increasing to peak at mid-lactation as well as increasing in association with higher levels of SCCs. Following E. coli challenge, AM increased in epithelial cells surrounding mammary alveoli presenting high levels of SCCs. The data suggest that AM and AM-BP are cooperatively regulated in the mammary gland during lactation; changes in localized tissue AM and AM-BP content reflect a dynamic regulation of these tissue factors in the bovine mammary gland consistent with their protective effects within inflamed tissue.     

Detection of antibodies and risk factors for infection with bovine respiratory syncytial virus and parainfluenza virus 3 in dual-purpose farms in Colima, Mexico

A cross-sectional study was carried out, from November 2007 to March 2008, to estimate the prevalence of and to determine risk factors associated with bovine syncytial respiratory virus (BRSV) and parainfluenza 3 virus (PIV3) in dual-purpose herds in Colima, México. One hundred and seventy-six sera from 33 herds for PIV3 and 232 sera from 44 herds for BRSV were used. Sera were analyzed by indirect ELISA for the detection of antibodies against BRSV and PIV3 in cattle herds to determine the seroprevalence of respiratory diseases. The apparent and true prevalences for PIV3 were 60.8% and 54.4% and for BRSV 52.2% and 50.8%, respectively. The percentage of herds showing at least one positive animal was 78.7% for PIV3, and 93.2% for BRSV. Age (≤12, 13-48, and >48?months old) and respiratory signs (no, yes) showed significant association (P?相似文献