Performance of desert black goat under extensive production systems in North Sinai in Egypt

A production system approach was used to study the performance of desert black goat under semi-aird conditions in North Sinai. A random sample of 19 goat breeders was taken. Least squares analysis of variance was performed using fixed effects linear models for all productive traits to develop the technical coefficients used in the study. Biological criteria were kg of kids weaned per doe joined and kg of kids marketed per doe joined. Gross margin per head of goat and output/input ration were used as criteria of the economic efficiency of the existing production system. The technical coefficients for the studied area were 80.5%, 1.5, 11.0%, 12.2 and 15.9 for conception rate, twining rate, weaning mortality up to 4 months, kg of goat was LE 62.4 and output/input ratio was 1.85. These result indicated that with improvements in management, it is feasible to substantially improve the level of performance of goats

The role of detoxifying enzymes in the resistance of the cowpea aphid (Aphis craccivora Koch) to thiamethoxam

The cowpea aphid (Aphis craccivora Koch) is considered a serious insect pest attacking several crops. We carried out biochemical studies to elucidate the role of the metabolising enzymes in conferring resistance to thiamethoxam, in two strains (resistant and susceptible) of the cowpea aphid. Bioassay experiments showed that the thiamethoxam selected strain developed a 48 fold resistance after consecutive selection with thiamethoxam for 12 generations. This resistant strain also exhibited cross-resistance to the tested carbamates; pirimicarb and carbosulfan, organophosphorus (malathion, fenitrothion, and chlorpyrifos-methyl), and the neonicotinoid (acetamiprid). Synergism studies have indicated that S,S,S-tributyl phosphorotrithioate (DEF), a known inhibitor for esterases, increased thiamethoxam toxicity 5.58 times in the resistant strain compared with the susceptible strain. Moreover, the biochemical determination revealed that carboxylestersae activity was 30 times greater in the resistant strain than in the susceptible strain. In addition, the enzyme activity of glutathione S-transferase (GST) and mixed function oxidases (mfo) increased only in the resistant strain 3.7 and 2.7 times, respectively, in relation to the susceptible (the control). Generally, our results suggest that the higher activity of the detoxifying enzymes, particularly carboxylesterase, in the resistant strain of the cowpea aphid, apparently have a significant role in endowing resistance to thiamethoxam, although additional mechanisms may contribute

Evaluation of crude larval protein and recombinant somatic protein 26/23 (rHcp26/23) immunization against Haemonchus contortus in sheep

© Kandil, et al. Aim: The aim of this study was to evaluate the potential possibility of crude larval and recombinant (rHcp26/23) antigens of Haemonchus contortus for immunization to control sheep hemonchosis. Materials and Methods: A total of 21 lambs were divided into five groups. Lambs were immunized with larval and recombinant (rHcp26/23) proteins at day 0 and day 14 and after that challenged with 5000 infective larvae of H. contortus on day 42. An unvaccinated positive control group was challenged with L3 in the meantime. An unvaccinated negative control group was not challenged. Results: Fecal egg count reduction taking after challenge for rHcp26/23 and larval antigens was 92.2% and 38.2%, respectively, compared with the positive control group. Vaccine incited protection in rHcp26/23 and larval immunization was reflected in significant (p\u3c0.05) decreases in worm burden; 59.9% and 40.1%, respectively. Conclusion: Recombinant rHcp26/23 vaccine induced a partial immune response and had immune-protective effect against sheep hemonchosis