Antibiotic residues in milk are a major health threat for the consumer and a hazard to the dairy industry, causing significant economic losses. This study aims to assess the presence of antibiotic residues in raw milk comparatively by a rapid screening test (BetaStar^® Combo) and Liquid Chromatography coupled with Tandem Mass Spectrometry (LC-MS/MS). A total of 445 samples were collected from 3 dairy companies of north-central Algeria (Algiers, Blida, Boumerdes), and they were rapidly screened for β-lactams and tetracyclines; 52 samples, comprising 34 positive tanker-truck milk and 18 negative bulk-tank milk were tested by LC-MS/MS, which revealed 90.4% were contaminated (n = 47) and 55.3% exceeded the Maximum Residue Limit (MRL). The β-lactams as parent compounds and their metabolites were the most frequently detected with maximum value for cloxacillin (1231 µg/kg) and penicillin G (2062 µg/kg). Under field condition, the false-positive results, particularly for tetracyclines, seems to be related to milk samples displaying extreme acidity values (≥19°D) or fat-level fluctuations (2.7 g/100 mL and 5.6–6.2 g/100 mL). Despite a relatively low prevalence (7.64%) of residues using the rapid test, the detection by LC-MS/MS of flumequine (52 µg/kg), cefaclor (maximum 220 µg/kg) and metabolites of β-lactams at high levels should lead to reflections on the control of their human and environmental toxicological effects.

To characterize and compare the protein quality of ten durum wheat genotypes grown under three cropping modalities in Algeria (subhumid in Algiers, subhumid-semiarid in Constantine, and semiarid in Sétif), the protein profile of their kernels was performed by High-Performance Liquid Chromatography (SE-HPLC and RP-HPLC). The “variety” factor has a major impact, mainly on the insoluble fraction (Fi), on the gliadin/glutenin ratio, on the large and small glutenin aggregates (F1 and F2, respectively), and on ω-gliadins and high molecular weight albumins (F3). Conversely, the total protein content and the albumin-globulin fraction (F5) depend mainly on the environment. The α- β- and γ-gliadins (F4) are equally dependent on variety and environment. The subhumid-semiarid agroecological conditions of Constantine (SH-SA) favored an important accumulation of proteins (14.1%), particularly by an increased synthesis of omega gliadins and high-molecular-weight glutenin subunits (HMW-GS), compared to those of Algiers (SH) and Sétif (SA). For these latter environments, metabolic-type proteins are predominant, reflected in a higher F5 fraction (p < 0.05) (albumin and globulin), and significantly more alpha-beta and gamma gliadins. The use of chromatographic analyses to characterize wheat genotypes remains a reliable tool for breeding and variety promotion programs and can provide a better understanding of the ecophysiology of cereal crops.

Bovine red offal is one of the main sources of animal proteins. The monitoring of the sanitary status of these foods is mandatory to protect human and animal health against transmitted diseases. The aim of this study was to establish an epidemiological situation of these diseases in the El Oued region. To do so, the registries of red offal seizures from three successive years (2018–2020) of 14,478 slaughtered cattle were retrospectively analyzed. The results showed a continuous evolution of the number of red offal seizures cases mainly in the liver and the lungs. The annual average prevalence of lung lesions increased progressively from 3.45% in 2018 to 10.50% in 2020 while a decrease of about 1% in pulmonary and hepatic hydatid cysts prevalence was observed. For liver diseases, the frequency of seizures increased, also predominately fasciolosis which reached 2.8% in 2020. Concerning tuberculosis, the prevalence did not show significant variations. These findings confirm the value of hygienic control along the entire red offal production chain and the need to strengthen zoonotic diseases prevention to reduce economic losses and to safeguard public health in this arid developing region.

This study aimed to evaluate the efficacy of oregano essential oil (OEO) in improving the production performance, health, and welfare of late-phase laying hens raised under commercial farm conditions by analyzing its effect on performance metrics and metabolic and endocrine profiles. Daily performance data for approximately 7884 Hy-Line Brown layers divided into two commercial flocks, one consisting of 96-week-old hens (n = 3849) and the other of 79-week-old hens (n = 4035), were recorded before (Pre-OEO Tx), during (OEO Tx-Week) and one week (Post-OEO Tx Week) following the week of water supplementation with commercial oregano essential oil (5%) of Origanum heracleoticum containing carvacrol (79.75%) as the main component (300 mL of product/1000 L of water). The results show a significant improvement in hen-day egg production (HDEP) during treatment (p < 0.05), a significant decrease in daily mortality one week after the cessation of treatment, mainly in the youngest hens (p < 0.05), and a reduction in feed conversion rate (p < 0.05). The general model (GLM) analysis of data from blood samples collected before and after OEO addition showed a significant decrease in plasma levels of procalcitonin (PCT), calcium, albumin (p < 0.05), and aspartate aminotransferase (AST) (p < 0.01). In contrast, a significant increase in estradiol, total protein globulin (p < 0.01), and phosphorus levels (p < 0.05) was recorded. The changes in endocrine profiles were significantly related to a restoration of calcium–phosphorus balance and a decrease in hepatic activity of AST and gamma glutamyl transferase (GGT). These results reveal the investigative value of PCT, in conjunction with metabolic profiling and reproductive hormones, for evaluating the effectiveness of phytogenic additives. Further studies are suggested to determine whether essential oil components can improve health and production performances of laying hens by a potential concurrent modulation of their metabolism, inflammatory response, and reproductive axis function.

The control of mastitis is a crucial step in the preparation of the next lactation in dairy cows. In order to assess the practices and attitudes surrounding the use of antimicrobials at dry-off, a survey was conducted among veterinary practitioners in fifteen provinces of Northern Algeria. The results revealed that 45.95% of the farms followed by the respondents were rather small in size comprising about ten cows per farm and that a large majority of the farmers practised gradual drying off (72.97%) without adjusting the feed ration (70.27%) to this stage. Antibiotic dry cow therapy (DCT) was a common practice and selectively performed in 86.49% of cases regardless of udder health status. Cefalexin was the most infused intra-mammary (IMM) antibiotic (40.54%), while tylosin was the one favoured for parenteral administration (48.15%). Analysis of factors influencing the antibiotic DCT efficacy showed that a frequent (13.51%) occurrence of new intramammary infections (IMIs) was related to farmers’ attitudes (self-medication) and the policy of blanket DCT. Although the use of a teat sealant was uncommon (71.43%) in the farming traditions, the substitution of antibiotics seems to be a plausible prospect, since the majority of participants (89.19%) agreed with the implementation of aromatherapy concept at dry-off, mainly as a complement to antibiotics. This survey gives an overview of risk practices regarding mastitis management in northern Algeria. Hence, further zootechnical, veterinary and organizational efforts need to be made to promote animal production and welfare as well as public health through improved udder health.

Retained placenta (RP) is a common complication of bovine parturition. It is a multifactorial reproductive disorder that predisposes to infection and hence, to infertility. The impact of body condition changes during the transition period on the risk of RP appearance was evaluated in 12 Holstein dairy cows calving from October to January in north-eastern Algeria. The animals were body condition scored (BCS) 3 weeks antepartum and two weeks postpartum to assess the peripartum body fat loss (BCS loss). The statistical analysis involving variables related to BCS and parity was performed using the principal component analysis (PCA). An RP critical occurrence of 41.66% exceeding significantly the threshold prevalence of 10% (p<0.05) was recorded. This could be related to the BCS loss that exceeded one unit over the transition period (r=0.84, p<0.01), expressing the high body fat mobilisation in response to stressor factors such as negative energy balance, feed availability and climatic condition. Scoring the body condition, particularly around the peripartum, may serve as a tool to monitor the risk factors related to the energetic status of dairy cows.