Oxidative stress is an important factor for development of male infertility because of very high rate of cell division and mitochondrial oxygen consumption in testicular tissue as well as comparably higher levels of unsaturated fatty acids in this tissue than in other tissues. Moreover, the level of oxygen pressure is low due to the weakness of testicular artery; therefore, there is a severe cell competition for oxygen. Therefore, the testicular tissue and male reproductive system are particularly susceptible to oxidative stress. On the other hand, exposure to X-ray, toxins and chemicals found in the environment as well as specific physical conditions such as varicocele can exacerbate the oxidative stress and induce apoptosis of germ cells and subsequently spermatogenesis. However, under normal conditions, the body's capacity to produce antioxidants for inhibiting adverse effects of oxidative stress is affected by metabolic process and genetic structure. Besides that, environmental factors such as diet, pollutants, and chemicals can affect this capacity. Thus, the body's antioxidant system alone is not able to neutralize all free radicals and prevent harmful complications of oxidative stress. Therefore, use of antioxidants and development of antioxidant therapy can break down the oxidative chain reaction and play a very significant role in increasing the body's capacity to fight free radical-induced oxidative stress, and therefore improve the process of spermatogenesis.

No abstract

Ghrelin can improve the capacity of antioxidant enzymes to reduce the oxidative stress caused by varicocele and reduce spermatogenesis cycle. Therefore, special attention should be paid to ghrelin in studies evaluating antioxidant compounds in varicocele.

This study was conducted to determine the effects of dietary supplementation of peppermint (Mentha piperita L.) on the performance of broiler chicks. 500 Ross broiler chicks were divided into 5 treatment groups of 4 replications in a completely randomized design format. The diets were ISO-caloric and ISO-nitrogenous ones and contained 1.5, 3, 4.5, and 6 g/kg of peppermint powder. At start, growing, and end periods, the effects of peppermint powder on average daily weight gain, feed conversation ratio, and mortality rate were studied. The results of the present study showed that over a production period of 42 days peppermint had a significant effect on average daily weight gain and feed conversation ratio when compared with the control group (P < .05). The level of 4.5 g/kg had the highest average daily weight gain (52.78 g), and control treatment with 46.98 g had the least average daily weight gain among different levels of peppermint. The level of 4.5 g/kg and 6 g/kg of peppermint had the least mortality compared to control treatment during training period (P < .05). From this experiment, we can conclude that treatment with 4.5 g/kg peppermint powder has better performance and carcass characteristics in broilers.

No abstract

Calpastatin is a natural occurring inhibitor of calpastatin (CAST) and consequently the balance of calpain-calpastatin activity in muscles is believed to dictate the rate of tenderization in post-mortem meat. Genomic DNA was extracted from 100 sheep blood sample. Polymerase chain reaction was performed to amplify a 622 bp fragment of this gene. Restriction reaction of polymerase chain reaction (PCR) products was done using MspI enzyme. The MspI digestion of the PCR products produced digestion fragments of 336 and 286 bp. The results show that in the population, genotypes AA, AB and BB, respectively, had frequencies 32.2, 63.2 and 4.6, and that this locus was not at Hardy -Weinberg equilibrium in the lori sheep strain (P<0.05).