Inhibition of aflatoxin production in Aspergillus flavus by pyrazolines and pyrazoles

A new series of 1,3,5-triarylpyrazolines, obtained from 3, 4-dichloroacetophenone, were readily dehydrogenated by tetrachloro-o-benzoquinone at room temperature to the pyrazoles. The spectra and fluorescence of the compounds are discussed. The pyrazolines and pyrazoles did not significantly affect the mycelial growth of 19 fungal isolates, but at low concentrations, they inhibited aflatoxin production by Aspergillus flavus.     

Participatory rural appraisal in smallholder dairy systems in Tunisia

Participatory Rural Appraisal (PRA) was carried out by a multidisciplinary team on a total of 60 smallholder dairy farms in three different geographical areas of Tunisia. Farms with less than three cows were excluded. Those participating had between three and 10 cows. Average milk production ranged between 8 and 32 litres per cow per day. 70% or over of milk produced was sold off the farms. Average inter-calving intervals — measured from month of calving only — ranged from 12.9 months to 19. Age at first calving varied from two to nearly three years. Most work was done by the families. PRA revealed that the farmers in all three regions perceived unbalanced nutrition, which included availability of forages, to be the most important constraint, followed by poor reproductive efficiency. Reseeding with new species was instituted for grazing and hay. Farmers from the different regions were taken on exchange visits to see how these approaches worked. Training in reproductive management and milking hygiene was introduced. Seasonal ration formulation depending on local forage analysis was instituted. Two farms are participating in a programme of evaluation of olive oil extraction by-product as a ruminant feed. Partial budget analysis of these interventions will be carried out.     

Induction of proinflammatory cytokines and caspase-1 by leptin in monocyte/macrophages from holstein cows

The proliferation of peripheral blood mononuclear cells (PBMC) containing both monocyte/macrophages and T lymphocytes increased after treatment with T-cell mitogen (concanavalin A: Con A). PBMC treated with either leptin alone or combination of leptin and ConA showed enhanced proliferative activity by 10-40%, compared with those treated with ConA alone. In contrast, isolated T lymphocytes treated with leptin and ConA showed lowered proliferative activity than the ConA-treated alone, indicating that leptin induced production of some cytokines from monocyte/macrophages, that subsequently resulted in enhancement of T lymphocytes proliferation in PBMC. Among the cytokines examined, monocyte/monocytes constitutively expressed interleukin (IL)-1beta, IL-12p35, IL-18 mRNA, and faintly expressed tumor necrosis factor (TNF)-alpha and IL-12p40 mRNA. Leptin treatment augmented the monocyte/macrophages mRNA expression of only TNF-alpha and IL-12p40 to comparable levels of cells treated with lipopolysaccharide (LPS). However, leptin treatment increased monocyte/macrophages production of IL-1beta as well as TNF-alpha, and induced the mRNA expression of caspase-1, which is shown to mediate the conversion of latent pro-IL-1beta and pro-IL-18 to active forms. These results suggest that leptin directly acts on monocyte/macrophages to produce factors that induce T lymphocytes proliferation such as IL-12p35/p40 complex through IL-12p40 induction and IL-1beta/IL-18 production through caspase-1 induction.     

Differential growth of the brown mussel,Perna perna (Linnaeus, 1758), in longline and pole cultures in Dakhla Bay (SW Morocco,Atlantic Ocean)

There is a great interest in establishing mussel farming in Dakhla bay. Selection of suitable sites is more meaningful only if a reliable culture method at proposed site is included. We compared two different culture methods, longline and pole, over 1 year (June 2016 to June 2017). Growth indicators for Perna perna (size and weight growth rates, frequency distributions and estimating growth curves) were analysed from seeding to harvest. The results highlighted the influence of culture method on growth rates of mussels (p < 0.05). At harvest, individuals reared on longline presented higher growth rates and consequently reached greater weight and length values than those reared on pole. Mussels reared at the longline grew 73.2 mm and gained 53.5 g W_L (live weight) and 3.3 g W_t (tissue dry weight) after 12 months of cultivation. However, mussels cultured at the pole gained only 52.3 mm, 26.7 g W_L and 1.6 g W_t. Aerial exposure of mussels at low tides could explain this reduced performance on pole compared with longline. Size frequency distributions at harvest fitted bimodal distribution in both cultures due to an asymmetric competition among individuals. Effect of density started in both treatments after 7 months of culture when mussels reached 60–70 mm, implying an increment of their food and space requirements. To prevent overcrowding, the initial density should have been reduced through “thinning‐out.” The longline method exhibited high‐performance growth and hence is highly recommended for cultivation of P. perna in Dakhla bay.     

Insulin‐independent actions of glucagon‐like peptide‐1 in wethers

Insulin‐independent actions of glucagon‐like peptide‐1 (GLP‐1) are not yet clear in ruminants. Four Suffolk mature wethers (60.0 ± 6.7 kg body weight (BW)) were intravenously infused with insulin (0.5 mU/kg BW/min; from 0 to 90 min) and GLP‐1 (0.5 μg/kg BW/min; from 60 to 150 min) with both hormones co‐administered from 60 to 90 min, in a repeated‐measure design under euglycemic clamp for 150 min, to investigate whether GLP‐1 has insulin‐independent actions. Jugular blood samples were taken at 15‐min intervals for plasma hormones and metabolites analysis. Compared to baseline concentrations (at 0 min), insulin infusion decreased (P < 0.05) plasma concentrations of glucagon, non‐esterified fatty acids (NEFA), lactate, nonessential amino acids (NEAA), branched‐chain amino acids (BCAA), total amino acids (TAA) and urea nitrogen (UN). Insulin plus GLP‐1 infusion induced a greater increase (P < 0.05) in plasma concentrations of insulin and triglyceride (TG), but decreased (P < 0.05) glucagon, total cholesterol (T‐Cho), NEAA and UN plasma concentrations. GLP‐1 infusion increased (P < 0.05) NEFA, β‐hydroxybutyrate and TG, but decreased (P < 0.05) glucagon, T‐Cho, NEAA, BCAA and UN plasma concentrations. In conclusion, GLP‐1 exerts extrapancreatic roles in ruminants not only insulin‐independent but probably, in contrast to non‐ruminants, antagonistic to insulin effects.     

The effect of dietary ratios of corn silage and alfalfa hay on carbohydrate digestion and retention time of feed particles in the gastrointestinal tract of steers

Four Holstein steers fitted with duodenal cannula were used in a 4 × 4 Latin square design to investigate the effect of the combination of corn silage (CS) and alfalfa hay (AH) in different ratios on the ruminal and intestinal digestion of carbohydrates and feed particle passage rate. Steers were fed mixed diets containing both CS and AH in ratios of 80:20, 60:40, 40:60 and 20:80 on a dry matter basis at 95% of ad libitum feed intake. The increase of AH proportion in diets increased dry matter intake and ruminal digestion of dry matter, non-fiber carbohydrate, neutral and acid detergent fiber linearly. Ruminal digestibility of neutral detergent fiber showed a quadratic response, and total digestibility increased linearly with increasing AH proportion. Digestibility of acid detergent fiber in the rumen was not affected by the dietary treatments, but the total tract digestibility increased as the AH proportion increased. Mean retention time of feed particles in total compartment increased when the AH proportion increased from 20% to 60%, but decreased with further increase of the AH proportion. These results indicate that moderate combinations of CS and AH have an associative effect on ruminal fiber digestion, modifying particle movement in the rumen.     

Flowering and fruiting phenology,and physico-chemical characteristics of 2-year-old plants of six species of Opuntia from eight regions of Morocco

SUMMARY

We have described the flowering and fruiting phenology of 14 accessions of six Opuntia species grown in Morocco: O. ficus-indica, O. robusta, O. aequatorialis, O. dillenii, O. leucotricha, and O. stricta. We also determined the physicochemical characteristics of their cladodes. For each accession, we used four-to-20 plants. Two systems were used to measure phenology: the extended Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH)-scale and the National Phenology Monitoring System. Five principal stages were described: the development of vegetatively-propagated organs (vegetative buds), the development of flower buds, flowering, fruit development, and fruit maturity. The number of vegetative buds varied significantly among the 14 accessions, while only four accessions produced flower buds. After reaching their final size, fruit lengths varied from 3.40–6.40 cm, while fruit diameters varied from 1.93–3.90 cm. The average cladode number differed significantly among genotypes and varied from 1.75–7.75. There were also significant differences in cladode length (13.75–30.63 cm), width (6.25–17.33 cm), thickness (0.65–1.38 cm), fresh weight (FW; 67.50–766.00 g), and dry weight (DW; 8.75–67.15 g) between species. Water content and ash content, as well as total protein and total sugar concentrations, showed significant differences and were within the ranges of 86.67–92.04% (w/w), 12.97–22.08g 100 g^?1 DW, 4.64–11.56g 100 g^?1 DW, and 3.22–12.51 g 100 g^?1 DW, respectively. Our results will help in the development of agronomic management practices and improve the characterisation, valorisation, and use of cactus pear species grown in Morocco.     

Nanoparticles of Arthrospira platensis improves growth,antioxidative and immunological responses of Nile tilapia (Oreochromis niloticus) and its resistance to Aeromonas hydrophila

Several studies investigated the usage of spirulina (Arthrospira platensis) in aquaculture as a functional dietary additive or plant proteins replacers; however, more efforts still needed to test its nano form inclusion in aquafeed. In this study, Nile tilapia (Oreochromis niloticus) fed dietary spirulina (A. platensis) nanoparticles (SNP) at 0 (control), 0.1, 1 and 10 g/kg diet while the fifth diet was mixed with 10 g/kg of the normal form of A. platensis as a positive control. The final weight (FW), weight gain (WG) and feed conversion ratio of fish fed SNP at 10 g/kg displayed improved values comparing with the other groups (p < 0.05). Further, fish fed 1 g SNP had higher FW and WG than the control and 0.1 g SNP and 10 g normal A. platensis. The incorporation of SNP at 1 and 10 g/kg in Nile tilapia diets significantly (p < 0.05) enhanced total protein, albumin, globulin, lowered the values of serum glucose and activities of ALT and AST compared with control and spirulina groups. The SOD, CAT, GPx, lysozyme and respiratory burst activities were meaningfully promoted (p < 0.05) in fish received 1 and 10 g/kg diet concerning the control and spirulina groups. Nile tilapia challenged with Aeromonas hydrophila showed congestion of the kidney, liver and spleen tissues while SNP alleviated the inflammation induced by A. hydrophila. Different levels of SNP-incorporated group showed lower cumulative mortality than the other groups. In conclusion, the obtained results illustrated that spirulina in nano form is recommended to enhance Nile tilapia well-being.