Thymus satureioides and Origanum majorana essential oils improve the quality of Beni Arouss buck semen during storage at 4°C

This study aims to investigate the effects of essential oils (EOs), extracted from Thymus satureioides (TS) and Origanum majorana (OM), on Beni Arouss buck semen quality stored in skimmed milk at 4°C. EOs were extracted by hydro-distillation, and the chemical compounds were determined. Ejaculates were collected from six Beni Arouss bucks, once a week for 10 weeks, and they were pooled, divided into five equal aliquots and diluted to 400 × 10⁶ sperm/ml with skimmed milk supplemented with 0.01% of OM EO, 0.01% of TS EO, 0.05% of OM EO and 0.05% of TS EO. Non-supplemented skimmed milk was considered as a control. Semen motility, kinematic parameters, viability, abnormality, membrane integrity and lipid peroxidation were evaluated at 0, 4, 8, 24, 28, 32 and 48 hr of liquid storage at 4°C. The main EO components were carvacrol (31.7%), thymol (28.0%) and borneol (14.4%) for TS, and terpinene-4-ol (31.2%), γ-terpinene (17.4%) and α-terpinene (12.7%) for OM. The results highlighted a dose-dependent effect of TS and OM EOs on all semen quality parameters. 0.01% of both EOs had a beneficial effect on the sperm preservation stored at 4°C compared with control (p < .05) excepted for the straight-line velocity. The 0.05% EO addition had harmful effects during storage particularly for TS EO. In conclusion, 0.01% of TS and OM EOs are recommended to improve the Beni Arouss buck semen preservation at 4°C.     

Characterization of an S-locus receptor protein kinase-like gene from peach

A receptor-like protein kinase gene (Ppsrkl1) was isolated from a peach (Prunus persica (L.) Batsch.) bark cDNA library prepared with RNAs isolated from bark collected in December (cold acclimated). Sequence analysis indicated that this gene is related to the S-locus family of receptor protein kinases (SRKs) and that it shares greatest homology with ZMPK1 from maize and At4g32300 from Arabidopsis, both of which are intron-less genes. In bark tissues, Ppsrkl1 is induced by water deficit treatment, repressed by short-day photoperiods and showed no response to cold treatment. The Ppsrkl1 mRNA also increased in roots in response to water deficit. In fruit, Ppsrkl1 shows no response up to 6 h after wounding, but at 12 and 24 h after wounding, Ppsrkl1 mRNA shows an abrupt decline. This decline was prevented by the addition of salicylic acid to the wound site. The Ppsrkl1 mRNA rapidly decreased in fruit after 10-min exposure to UV-C radiation, followed by a return to normal levels within 1.5 h. Taken together, these experiments indicate that Ppsrkl1 is negatively regulated by light and positively influenced by salicylic acid treatment in fruit and water stress in bark and roots.     

Production Economics of Nile Tilapia (Oreochromis niloticus) Pond Culture in El-Fayum Governorate,Egypt

Econometric techniques were used to estimate a production function for tilapia pond culture in El-Fayum Governorate, Egypt, utilizing cross-sectional field data. Explanatory variables were feed, initial stocking weight, and pond size. The function was used to examine returns to scale, estimate the productivity of feed and initial stocking weight, and estimate the profit maximizing demand equations for feed and fingerlings. Diminishing returns to scale seem to exist for tilapia pond culture. Optimal economic stocking and feeding rates, yield, and profits for the whole sample were estimated at prevailing prices. Results indicated that producers were using stocking rates greater than the optimal by 36% to 115% and using insufficient feed by 8% to 22%. Investigation of the effects of changes in tilapia selling price and feed price on optimal stocking and feeding rates, yield, and profits showed that a change in tilapia selling price has greater effect on profits, yield, stocking, and feeding rates than a proportional change in feed price. Profits, feeding, and stocking rates are more sensitive than yield to changes in selling price, while feeding rate is more sensitive than stocking rate, yield, and profits to changes in feed price.