فهرست مطالب hamid reza ansari renani

In order to survey slow release mineral-vitamin boluses effects on reproductive performance, wool and follicle structure characteristics of Farahani sheep, 60 head ewes were divided into two control and treatment groups. Control group didnt receive any mineral - vitamin supplement. The treatment group received slow release mineral-vitamin boluses 15 days before mating. The reproductive performance includes pregnancy rate, lambing rate, abortion rate, weaned rate and means values of fleece weight, staple length, fiber diameter and tenacity of two groups of ewes and secondary to primary follicle ratio(S/P) in treating ewes and their lambs in relation to the control group were evaluated and statistical differences between them were estimated. The result indicated that the slow release mineral-vitamin boluse hadnt significant effect (p

Wool growth is influenced by photoperiodic period of different seasons; under similar nutritional conditions, more wool is produced in longer photoperiodic season. In this study, the effects of photoperiod on fiber and skin follicle characteristics of three sheep breeds were studied. Forty non-pregnant and non-milking ewes (Chios, ArkhaMerino × Moghani and Suffolk × Moghani breeds) with a similar age were selected. Equal numbers from each breed were divided into two groups (20 ewes/group), and the two groups were treated with a natural photoperiod (open natural environment: 12 hours light - 12 hours dark) and an artificial photoperiod (8 hours light and 16 hours dark) for 50 days. All animals were fed ad libitum with a similar diet including alfalfa, straw and barley at maintenance level. At the end of the treatment period, 50 g of wool was collected from the left mid side area (about 20 cm from the spinal column on the third rib) by a laboratory wool clipper, and a skin biopsy was taken from the right mid side area using a 1 cm diameter trephine. The following fiber characteristics were measured: staple length, fiber diameter, percentage of medullated and non-medullated fibers, wool efficiency. Analyzed follicle characteristics included follicle type ratio, follicle density, and follicle activity. A randomized design analysis of the data and comparison of means were performed with Duncan's new multiple range test. Results indicated that the primary follicle density in sheep under a natural photoperiod were significantly (p<0.01) lower than under an artificial photoperiod. The secondary to primary follicle ratio in sheep under a natural photoperiod were significantly (p<0.01) higher than in sheep under the artificial photoperiod. The percentage of inactive secondary follicles in sheep under the natural photoperiod were significantly (p< 0.05) lower than in sheep treated with the artificial photoperiod. Both natural and artificial photoperiod had no effect on fiber characteristics