Experimental infection of alpine goats with a Moroccan strain of peste des petits ruminants virus (PPRV)

Peste des petits ruminants virus (PPRV) recently caused a serious outbreak of disease in Moroccan sheep and goats. Alpine goats were highly susceptible to PPRV with mortality rates approaching 100%, as opposed to local breeds of sheep which were less susceptible to the disease. The relative susceptibility of alpine goats was investigated through an experimental infection study with the Moroccan strain of PPRV. Severe clinical signs were observed in the alpine goats with virus being excreted through ocular, nasal and oral routes. No difference in the severity of the disease in goats was observed with different inoculation routes and transmission of the virus by direct contact was confirmed. This study confirmed the susceptibility of the alpine goat to PPRV infection and describes a challenge protocol that effectively and consistently reproduced severe clinical signs of PPR in experimentally infected goats.     

Effect of egg parasitoid density on the population suppression of Sunn Pest, Eurygaster integriceps (Hemiptera: Scutelleridae), and its resulting impact on bread wheat grain quality

The impact of the density of Sunn Pest egg parasitoids, Trissolcus grandis Thomson (Hymenoptera: Scelionidae), at three levels of Sunn Pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), infestation was assessed on bread wheat variety Cham 6 in screened cages in the field for percentage of egg parasitism and grain quality. Percent parasitism ranged from 60.1 to 83.9%. No statistically significant differences were detected at parasitoid densities of 1, 2, or 3 insects per square meter at Sunn Pest densities of 2 or 4 insects per square meter. The quality of grain collected from all Sunn Pest infested cages without egg parasitoids was unacceptable for baking purposes and was significantly lower than grain from both non-infested plots and plots where either two or three egg parasitoids were present. The abundance of egg parasitoids in Al Hassakeh province in Syria was also determined. Egg parasitism was observed 1 week after the initiation of Sunn Pest oviposition and ranged between 22 and 59% in non-insecticide treated fields, while no parasitoids were recovered from insecticide treated areas within the same region. The impact of feeding by Sunn Pest on different wheat stages indicated that only feeding prior to the spike stage does not affect the bread-making quality of the grain.     

Effect of dietary inclusion of fermented pigeon pea (Cajanus cajan) meal on growth, apparent nutrient digestibility and blood parameters of cockerel chicks

The effect of dietary inclusion of fermented pigeon pea meal (FPPM) on growth response, apparent nutrient digestibility, haematological indices and serum biochemistry of cockerel chicks was studied using 240-day-old cockerel chicks allotted to four dietary treatments consisting of 60 birds each. Four experimental diets were formulated to include FPPM at 0, 50, 100 and 150?g/kg inclusion levels, respectively. Each of the diets was fed to 60 birds replicated six times with ten birds per replicate. The feeding trial lasted for 56?days. Results indicated that final live weight (linear (L). quadratic (Q): P??0.05) by the inclusion of FPPM. Haemoglobin and serum uric acid concentrations were also reduced (P?相似文献   

Saccharomyces cerevisiae decreases inflammatory responses induced by F4+ enterotoxigenic Escherichia coli in porcine intestinal epithelial cells

Probiotic yeasts may provide protection against intestinal inflammation induced by enteric pathogens. In piglets, infection with F4+ enterotoxigenic Escherichia coli (ETEC) leads to inflammation, diarrhea and intestinal damage. In this study, we investigated whether the yeast strains Saccharomyces cerevisiae (Sc, strain CNCM I-3856) and S. cerevisiae variety boulardii (Sb, strain CNCM I-3799) decreased the expression of pro-inflammatory cytokines and chemokines in intestinal epithelial IPI-2I cells cultured with F4+ ETEC. Results showed that viable Sc inhibited the ETEC-induced TNF-α gene expression whereas Sb did not. In contrast, killed Sc failed to inhibit the expression of pro-inflammatory genes. This inhibition was dependent on secreted soluble factors. Sc culture supernatant decreased the TNF-α, IL-1α, IL-6, IL-8, CXCL2 and CCL20 ETEC-induced mRNA. Furthermore, Sc culture supernatant filtrated fraction < 10 kDa displayed the same effects excepted for TNF-α. Thus, our results extended to Sc (strain CNCM I-3856) the inhibitory effects of some probiotic yeast strains onto inflammation.     

Functional relationships between leaf structure and photosynthetic traits as modulated by irradiance and nutrient availability in a sclerophyllous and a non-sclerophyllous mediterranean oak species

Plasticity of structural and physiological leaf traits elicited by irradiance and soil nutrients was investigated in two sympatric mediterranean oaks: a sclerophyllous (Quercus suber L.) and a non-sclerophyllous species (Q. canariensis Willd.). Seedlings were grown for 2 years in pots in a 2-way crossed factors design. Leaf mass-to-area ratio (LMA) and nitrogen were recorded, and photosynthetic capacity (i.e. the apparent maximal carboxylation rate by rubisco, V _cmax) was derived from response curves of net CO₂ assimilation (A) versus intercellular CO₂ mol fraction (C _i). Structural equation modelling was applied to the data for disentangling the complex correlation structure between variables. The two species differed significantly in photosynthetic nitrogen use efficiency (PNUE). They displayed the expected responses to irradiance, with large increases in LMA, V _cmax and nitrogen per unit leaf area and decreases in mass-based nitrogen content. Nutrient availability modulated severely leaf N content (mass- and area-based) and mass-based maximal carboxylation rate, but not the plastic response of all these parameters to irradiance. Irradiance primarily modulated leaf structure (LMA), and secondarily nitrogen content, while nutrient availability modulated directly nitrogen content. Nitrogen content in turn had a severe impact on mass-based photosynthetic capacity. It is concluded that in young trees solely leaf structure displayed irradiance-elicited plasticity. This plasticity was not modulated by nutrient availability and was similar in a sclerophyllous and a non-sclerophyllous species.     

Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance,hydrocyanide intake and haematological parameters of broiler chicks

The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2?×?2?+?1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P?P?P?P?P?P?P?P?P?P?P?P?P?P?相似文献   

Effect of Pregnancy on Some Biochemical Parameters in Sahel Goats in Semi-arid Zones

The effects of pregnancy on some biochemical parameters were studied using 20 sexually mature, cycling goats with weight range 20-25 kg. They were randomly separated into two groups of 10 animals each. In one group, oestrus was detected while going round with a buck in the morning and evening; a single buck on detection of oestrus mated the does and the does were tagged as pregnant after confirmation of non-return of oestrus. The other group was kept cycling and tagged as non-pregnant. The mean serum glucose concentration in pregnant does was 63.35 +/- 7.70 mg/dl, significantly lower than 71.59 +/- 1.14 mg/dl for non-pregnant does (p < 0.05); the mean serum cholesterol concentrations were 79.48 +/- 14.93 for pregnant and 67.29 +/- 1.10 for non-pregnant does, with significant difference (p < 0.05). Protein (g/dl), urea (mg/dl), creatinine (mg/dl) and free fatty acid (microequiv/L) remained unchanged between the two groups (p > 0.05), as did the liver enzymes (ALT, AST). Therefore this study showed that low serum glucose and high cholesterol levels are features of mid to late pregnancy in Sahel goats.     

Water relations and drought-induced embolism in olive (Olea europaea) varieties 'Meski' and 'Chemlali' during severe drought

We examined the effects of drought on the water relations, osmotic adjustment and xylem vulnerability to embolism of olive (Olea europaea L.) varieties, 'Meski' and 'Chemlali'. Two-year-old self-rooted cuttings growing in sand-filled pots in a greenhouse were subjected to water stress by withholding water for 60 days. Water relations and gas exchange measurements showed that 'Chemlali' was more drought resistant than 'Meski' and had a greater capacity for osmotic adjustment through solute accumulation. However, when water stress was acute, the effect of osmoregulation on leaf cell turgor was largely counteracted by xylem cavitation. Cavitation vulnerability curves showed that both varieties were highly resistant to embolism formation. The xylem water potential inducing 50% loss of stem conductivity approached -7 MPa in 'Meski' and only slightly less in 'Chemlali'. Although the difference between varieties in susceptibility to xylem embolism was small, it appears to account in large part for the difference between them in the ability to tolerate severe drought.     

Phosphorus Adsorption Isotherm: A Key Aspect for Effective Use and Environmentally Friendly Management of Phosphorus Fertilizers in Calcareous Soils

Crop response to the phosphorus (P) application is often erratic in most soil types in the world. In Algeria, there is no information on the P behavior in calcareous soils. The purposes of this work were to investigate the degree of P fixing capacity and to predict P fertilizer requirements of crops according to calcareous levels in the soil. Soil samples (at 0–30 cm depth) were collected and spiked with 0, 25 and 50% of lime (CaCO₃). Phosphate sorption curves were well fitted to the Freundlich equation. Results indicated that the calcareous level was predominantly controlled the P sorption indices [sorption capacity (a), and P sorption energy (n)] to affect the estimation of external d P requirement (EPR_0.2) and P fertilizer rates. The understanding of P sorption and desorption by soils and extrapolating the developed relationship between soil calcareous contents and P fertilizer rates would be quite promising and accurate approach for the economic and effective use of P fertilizers in calcareous soils of Algeria.     

Innate humoral immune parameters in Tilapia zillii under acute stress by low temperature and crowding

Redbelly tilapia (Tilapia zillii; Gervais, 1848) is one of the most valuable freshwater species in North Africa representing an important part of the continental production, especially in brackish lakes. In Algeria, T. zillii is distributed in several lakes and tributaries of some rivers in the south. Though some attempts are in progress to culture this species, many investigations covering its biology and farm management are still needed. In this sense, this is the first study attempting to evaluate some of the T. zillii immune parameters and valuable data to assess their health and well-being status. Thus, we have determined the levels of serum peroxidases as well as the alternative complement, antiprotease and bactericidal activities. Furthermore, we have also evaluated the potential impact of two acute stress factors, commonly found in fish farms, in these parameters. Although it was assessed that fish exposed to low temperatures or crowding were stressed, as indicated by their increased serum levels of cortisol and glucose, both acute stressors failed to significantly affect serum peroxidases as well as antiprotease and complement activities. However, the bactericidal activity was reduced in general but only in those exposed to crowding reached statistical significance. Further studies are needed to characterise the immune response in T. zillii as well as the effects that farming stresses may produce.