Serological Diagnosis of Lentivirus Infection in Goats Raised in Algeria.

INTRODUCTION: Infection of goats with caprine arthritis encephalitis virus (CAEV) has been detected in variable proportions in many countries all over the world. Here, we investigated the seroprevalence of CAEV in goats raised in Algeria. MATERIAL AND METHODS: A serological survey was performed on serum samples from 1,313 goats, including the local breeds (Arabia and Dwarf of Kabylia) and imported European breeds (Alpine and Saanen). Blood samples were taken from goats on 38 farms distributed across four different geographical regions of Algeria. Serum samples were tested for CAEV antibodies using a commercial ELISA. RESULTS: A total of 390 serum samples were found to be positive for CAEV, giving an overall seropositivity rate of 29.7% in individual animals and 97.37% (37/38) at the goat farm level. CONCLUSION: These results provide the first large-scale serological evidence for the presence of CAEV infection in both the local and imported breeds of goats raised in Algeria, indicating that the virus infection is widespread.

A vaccination trial with a precocious line of Eimeria magna in Algerian local rabbits Oryctolagus cuniculus.

Coccidiosis is a major health problem in rabbits. A vaccine using Eimeria with perfect safety and effectiveness seems to be necessary to face this parasitosis. To assess the safety and the efficacy of a vaccine based on the Algerian precocious line of Eimeria magna against rabbit coccidiosis, twenty eight young rabbits from six litters of Coccidia free females were used to monitor oocystal excretion and body weights, they were distributed into four groups (vaccinated-challenged group, double challenged non vaccinated group, simple challenged non vaccinated group and control group). Three other Coccidia free rabbits served for the necropsy in order to compare the effect of the wild and the precocious strains of Eimeria magna at the histological level. Following the challenge inoculation, a statistically significant decrease of about 97% in the oocyst excretion was noticed in the vaccinated rabbits as a sign of a good immune response acquired by the vaccination associated to a good growth rate. Moreover, a statistically significant increase in oocyst output following the challenge in both double challenged non vaccinated group and simple challenged non vaccinated one was noticed: (1.2 × 108 and 1.5 × 108vs 4.6 × 106 oocysts/rabbit respectively). Taking the control group showing a steady growth as a reference, the vaccinated rabbits showed a good growth during the experiment (p < 0.05). Globally the challenged groups showed a normal growth compared with the control group except for a temporary decrease in weights. No case of diarrhea was recorded in the vaccinated - challenged group and the control one (neither vaccinated nor challenged) whereas more than 50% of the young rabbits from both simple and double challenged - non vaccinated groups presented diarrhea. Consequently, the Algerian precocious strain of Eimeria magna constitute a good candidate for anticoccidian vaccine in the future.

Reproduction performance and blood biochemical parameters in dairy cows: Relationship with oxidative stress status.

BACKGROUND AND AIM: During the last decades, reproduction performances declined dramatically worldwide, but little is known concerning the involvement of oxidative stress as a causative factor. Oxidative stress may act at different levels, with negative impacts on cell membrane integrity and other active molecules with potential subsequent effects on reproduction. The aim of the current study was to investigate the oxidative stress status in cows according to their reproductive performances. MATERIALS AND METHODS: Peripheral blood concentration of two oxidative stress biomarkers, glutathione S-transferase (GST) and malondialdehyde (MDA), and other biochemical parameters (glucose, total lipids, cholesterol, triglycerides, albumin, total proteins, calcium, urea, creatinine, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase) were determined in 40 healthy cows. Body condition score (BCS), calving to first service interval (FSI), calving to conception interval (CCI), and the number of service per conception (SPC) were simultaneously recorded for each cow. RESULTS: Concerning FSI, three groups were established: Group 1 (from 44 to 60 days), Group 2 (from 60 to 70 days), and Group 3 (from 70 to 80 days). For CCI, two groups were considered: Group 1 (<110 days) and Group 2 (>110 days). MDA showed significant high values only in cows with the lowest BCS (1.5) compared to cows with BCS note of 2.5 and 3.5. No significant difference was observed in cows oxidative stress status (MDA and GST) according to reproductive performances (FSI, CCI, and SPC) in all studied groups. CONCLUSION: The results revealed relatively altered oxidative stress status in cows with abnormal reproductive performances; however, no significant difference was recorded whatever the considered reproductive parameter.

The effects of early age thermal conditioning and vinegar supplementation of drinking water on physiological responses of female and male broiler chickens reared under summer Mediterranean temperatures.

The effects of early age thermal conditioning (ETC), vinegar supplementation (VS) of drinking water, broilers' gender, and their interactions on respiratory rate, body temperature, and blood parameters (biochemical, hematological, and thyroid hormones) of broiler chickens reared under high ambient temperatures were determined. A total of 1100 1-day-old chicks were divided into four treatments: the "control" which were non-conditioned and non-supplemented; "heat-conditioned" which were exposed to 38 ± 1 °C for 24 h at 5 days of age; "vinegar supplemented" which were given drinking water supplemented with 0.2% of commercial vinegar from 28 to 49 days of age; and "combined" which were both heat conditioned and vinegar supplemented. All groups were exposed to the natural fluctuations of summer ambient temperature (average diurnal ambient temperature of about 30 ± 1 °C and average relative humidity of 58 ± 5%). ETC and broiler gender did not affect the respiratory rate or body temperature of chronic heat-exposed chickens. VS changed the body temperature across time (d35, d42, d49) (linear and quadratic effects, P < 0.05) without changing respiratory rate. Heat-conditioned chickens exhibited lower levels of glycemia (P < 0.0001) and higher hematocrit and red blood cell counts (P < 0.05). Furthermore, the greatest effects of VS, alone or associated with ETC, were the lowering of cholesterol and triglyceride blood concentrations. A significant (P < 0.05) effect of ETC, gender, and ETC×gender on T3:T4 ratio was observed. Finally, some beneficial physiological responses induced by ETC and VS, separately or in association, on chronically heat-stressed chickens were observed. However, the expected cumulative positive responses when the two treatments were combined were not evident.

Infectious bursal disease virus in Algeria: Detection of highly pathogenic reassortant viruses.

Infectious bursal disease (IBD) is an immunosuppressive viral disease, present worldwide, which causes mortality and immunosuppression in young chickens. The causative agent, the Avibirnavirus IBDV, is a non-enveloped virus whose genome consists of two segments (A and B) of double-stranded RNA. Different pathotypes of IBDV exist, ranging from attenuated vaccine strains to very virulent viruses (vvIBDV). In Algeria, despite the prophylactic measures implemented, cases of IBD are still often diagnosed clinically and the current molecular epidemiology of IBDV remains unknown. The presence of the virus and especially of strains genetically close to vvIBDV was confirmed in 2000 by an unpublished OIE report. In this study, nineteen IBDV isolates were collected in Algeria between September 2014 and September 2015 during clinical outbreaks. These isolates were analyzed at the genetic, antigenic and pathogenic levels. Our results reveal a broad genetic and phenotypic diversity of pathogenic IBDV strains in Algeria, with, i) the circulation of viruses with both genome segments related to European vvIBDV, which proved as pathogenic for specific pathogen-free chickens as vvIBDV reference strain, ii) the circulation of viruses closely related - yet with a specific segment B - to European vvIBDV, their pathogenicity being lower than reference vvIBDV, iii) the detection of reassortant viruses whose segment A was related to vvIBDV whereas their segment B did not appear closely related to any reference sequence. Interestingly, the pathogenicity of these potentially reassortant strains was comparable to that of reference vvIBDV. All strains characterized in this study exhibited an antigenicity similar to the cognate reference IBDV strains. These data reveal the continuous genetic evolution of IBDV strains in Algerian poultry through reassortment and acquisition of genetic material of unidentified origin. Continuous surveillance of the situation as well as good vaccination practice associated with appropriate biosecurity measures are necessary for disease control.

Acute cold- and chronic heat-exposure upregulate hepatic leptin and muscle uncoupling protein (UCP) gene expression in broiler chickens.

Emerging evidence showed that variations in environmental temperature affect both leptin and uncoupling protein (UCP) gene expression in mammals, whereas a little is known about such interactions in birds. Thus, we conducted the present study to investigate the influence of acute (2 hours) cold (4 degrees C) and chronic (10 days) heat (32 degrees C) exposure on hepatic leptin and muscle UCP gene expression in 5-wk-old broiler chickens. Both cold- and heat-exposure significantly (P < 0.05 to P < 0.001) upregulated hepatic leptin (by 35 and 46%, respectively) and muscle UCP mRNA levels (by 71 and 71%, respectively) compared to the thermoneutrality (22 degrees C). This result suggests that leptin and UCP may be involved in the thermoregulation response of chickens to extreme climate (cold and hot temperatures). The upregulation of hepatic leptin gene expression was accompanied by an increase in plasma leptin levels, indicating that leptin may be regulated at transcriptional level. The increase of leptin and UCP mRNA abundance, and leptinemia we report here were not related to plasma glucose or insulin levels. In conclusion, the exposure of broiler chickens to extreme ambient temperatures (cold and heat) increases hepatic leptin and muscle UCP gene expression.