a. towhidi

Supplementing the semen extender with various antioxidants can increase the quality of semen.

The aim of the present study was to investigate the addition of pyridoxine (vitamin B6), a phenolic compound with antioxidant properties, to soybean lecithin extender on motility and quality indices of goat sperm after freezing-thawing process.

Semen was collected at weekly intervals from four Mahabadi goats, mixed, and was divided into 7 subsamples. They were then diluted with the basal extender supplemented with 0, 2, 4, 6, 8, 10, and 12 mM pyridoxine. Following freeze-thawing process, quality parameters such as sperm motility characteristics, viability, plasma membrane integrity, and malondialdehyde content were determined.

The results showed that pyridoxine at the level of 6 mM caused the highest total motility rate (P<0.05). Progressive sperm motility was highest at the 4, 6, and 8 mM pyridoxine (P<0.05). Although the control group showed the least progressive motility, it was not statistically significantly different from the 12 mM level. Among the pyridoxine levels, the 6 mM level recorded the best performance in term of plasma membrane integrity, sperm viability, and decreasing malondialdehyde concentration compared to the control group (P<0.05).

The findings indicated that soybean lecithin extender supplemented with 6 mM pyridoxine can improve motility and quality parameters such as viability, plasma membrane integrity, and reduce oxidative stress of goat sperm after thawing.

The current study evaluated the effects of cryopreservation medium supplementation with folic acid as an antioxidant on post-thawed semen quality in bulk. Semen samples were collected from four proved Iranian Mahabadi bulls and diluted in extender containing 1.5% soybean lecithin. The diluted semen was assigned into six parts and supplemented with different doses of folic acid as follows: FA0 (extender without folic acid), FA0.05, FA0.1, FA0.2, FA0.4, and FA0.8 (extenders containing 0.05, 0.1, 0.2, 0.4, and 0.8 mM folic acid, respectively). Then, the semen samples were cryopreserved in liquid nitrogen. Sperm motility and velocity parameters, membrane integrity, abnormal morphology, viability, and lipid peroxidation were evaluated after thawing. In the results, FA0.05 presented higher (p≤0.05) total motility, progressive motility, membrane integrity, and viability and lower lipid peroxidation compared to other groups. Abnormal morphology was not affected (p>0.05) by treatments. In conclusion, supplementation of cryopreservation medium with 0.05 mM folic acid is a helpful method to conserve the quality of post-thawed semen in bulk.

The aim of this study was to determine the effect of low levels of glutathione on post-thawed buck sperm quality. In this experiment، different concentrations of glutathione [0 (LG-0)، 0. 5 (LG-0. 5)، 1 (LG-1)، 1. 5 (LG-1. 5)، and 2 (LG-2) mM] were added in a soybean lecithin-based extender. A total of 16 ejaculates from four bucks were collected and pooled. Each pooled sample was divided into five equal parts and each part was diluted by one of the above mentioned groups. After freeze-thawing process، motility and velocity، plasma membrane integrity and functionality، and apoptosis features of spermatozoa were evaluated. The results of this experiment showed that total motility (50. 75 ± 2. 33)، plasma membrane integrity (55. 75 ± 3. 01) and functionality (46. 75 ± 2. 79) were higher in LG-1 extender compared to other extenders (P<0. 05). The percentage of live spermatozoa (53. 23 ± 3. 26) was higher in LG-1 extender compared to other extenders، with the exception of LG-1. 5 extender (P<0. 05). Also، the percentage of late apoptotic spermatozoa (21. 33 ± 1. 63) was lower in LG-1 extender compared to other extenders (P<0. 05). In conclusion، our results showed that GL-1 extender resulted in higher post-thawed buck sperm quality compared to other extenders.

Zilpaterol (ZH) is a ß-adrenergic agonist which has been shown to improve feedlot performance in rumiunant. The aim of this study was to investigate the effects of alternative consume of dietary ZH on growth performance in Ross broiler chicks. Eighty 25 d-old Ross female broiler chicks were used in a 20 day feeding (four pens per treatment in a completely randomized design) Chicks were fed a corn and soybean meal based finishing diet and received ZH at level 0, 0.2, 0.25, 0.3 mg/kg of live body weight in a skip 2 days manner. Each bird was individually weighed on d 25, 48 of the experiment. On d 48, chickens were slaughtered and carcass data were collected. Data were analyzed using Proc GLM in SAS program. Supplemental ZH significantly improved feed efficiency compared with control group (P<0.05) and treatment that contained 0.25 ZH had best result (P<0.05). ZH increased final LBW of broiler chicken. But the effect of ZH on carcass weight and carcass yield was not significant. Consumption of Zilpaterol hydrochloride increase glucose plasma (P<0.05). Also Zilpaterol hydrochloride induced an increase in tissue protein (P<0.05). The result suggested that Zilpaterol hydrochloride as a ß-agonist improved growth performance in broiler chicken.