seasonal changes of spermatogenic activity in khouzestan arabian rams

Seasonal Changes in the Testicular Size of Grazing Rams

Studies over 3 years showed that testicular volume falls during summer and autumn when forage quality and availability decline and when rams are mating. Loss in testicular size may also occur in summer in the absence of mating activity and at a greater rate than loss in live weight. The results suggest that mating and nutrition may override the influence of photoperiod on testicular size and th...

Seasonal Changes I N T H E Semen of Rams

E ACH year in the central valley of California, about 10% of the breeding ewes fail to lamb. In certain years the percentage of "dry ewes" in individual flocks may be higher. Available information indicates that the problem may be environmental in nature, because a high percentage of the nonlambing ewes produce lambs in subsequent years. Because ram fertility may influence breeding efficiency u...

Seasonal changes in sexual activity and serum levels of LH and testosterone in Finnish Landrace and Suffolk rams.

comparison of catalytic activity of heteropoly compounds in the synthesis of bis(indolyl)alkanes.

heteropoly acids (hpa) and their salts have advantages as catalysts which make them both economically and environmentally attractive, strong br?nsted acidity, exhibiting fast reversible multi-electron redox transformations under rather mild conditions, very high solubility in polar solvents, fairly high thermal stability in the solid states, and efficient oxidizing ability, so that they are imp...

Apoptosis during the seasonal spermatogenic cycle of Rana catesbeiana.

In the bullfrog Rana catesbeiana, testicular weight is constant throughout the year, but the volume densities of germinative and interstitial compartments undergo inverse changes from winter (non-breeding) to summer (breeding). The occurrence of apoptosis in the seminiferous lobules of bullfrogs was investigated in these two periods using sections stained with haematoxylin and eosin (H&E), the ...

Seasonal variations in the liver and muscle fatty acid composition of Barbus luteus from Karkhe river (khouzestan , Iran)

from Karkhe river  (khouzestan , Iran) were determined. 84 sample were collected in the middle month of each season and Total fatty acid compositions were investigated by a gas chromatographic method. . The most abundant fatty acids in the (SFAs) of the liver and muscle were at the highest in the autumn and spring, respectively. The total monounsaturated fatty acids (MUFAs) were at the highest ...