BACKGROUND: Nowadays, infertility is one of the major problems of human societies. OBJECTIVES: To study oral administration of bulk milk and milk of late pregnant cows on spermatogenesis of male rats. METHODS: The first group of rats from day 1 of pregnancy until the end of lactation and then their male pups to maturity were treated with late pregnant cow’s milk. The second group from day 12 of pregnancy up to 15 days after delivery was treated with late pregnant cow’s milk. The third group of rats from day 1 of pregnancy until the end of lactation and then their male pups to maturity were treated with bulk milk. The fourth group from day 12 of pregnancy up to 15 days after delivery was treated with bulk milk. Rats in the control group during the study period were only fed with special food of rats and at the end viability, types of movement (progressive and in-place movement, immobility), number of sperms and also the serum testosterone level were elevated. RESULTS: Administration of both types of milk had no effect on in-place movement and also viability of sperms of experimental groups but they could cause a significant increase in sperm  immobility and a significant decrease in number of sperms of experimental groups. Also,the level of serum testosterone of experimental groups was significantly reduced in comparison with control group (p<0.05). CONCLUSIONS: Overall, it was determined consumption of late pregnant cow’s milk and bulk milk when it contains high estrogen can cause changes in some sperm species that are involved in male reproduction.

BACKGROUND: Subclinical mastitis plays an important role in the economic losses of dairy cattle farms. Staphylococcus aureus is one of the most important causes of this disease. Treatment of this disease with synthetic antibiotics has complications like antibiotic resistance. Using herbal antibiotics can be an excellent way to reduce these side effects.OBJECTIVES: This study aimed to determine the minimum inhibitory concentration of alcoholic extract of olive leaf on Staphylococcus aureus isolated from milk of cows with subclinical mastitis to achieve herbal treatment.METHODS: This study was conducted on 175 Holstein female cattle. The milk samples of 60 cows were obtained with the sterilized method, and Subclinical mastitis-positive cases were determined using the California mastitis test. Staphylococcus aureus bacteria were isolated from positive samples by culture method, and the minimum inhibitory concentration of olive (Olea europaea L.) leaves alcoholic extract on isolated bacteria was determined by microdilution method.RESULTS: From 175 cows under study, 60 cows had a positive California mastitis test, and Staphylococcus aureus separated from milk samples of 14 cows. The minimum inhibitory concentration of olive (Olea europaea L.) leaves extract on this bacterium was 12000 ppm.CONCLUSIONS: Alcoholic extract of olive (Olea europaea L.) leaves has an antimicrobial effect on Staphylococcus aureus as a cause of mastitis. The minimum concentration required for this effect was 12000 ppm. Further studies on the impact of this plant on other bacterial causes of subclinical mammary inflammation in cows and investigation of the effective substances in the extract are needed.

BACKGROUND: Over the recent years, Neospora caninum has been one of the most important causes of abortion in dairy cattle. OBJECTIVES: We conducted the present study in order to investigate the seroprevalence of N. caninum in dairy cattle in Semnan province and its effect on abortion. METHODS: 237 blood samples were obtained from various Semnan dairy farms and 104 bulk dairy samples from four milk collection centers in Semnan, Garmsar, Damghan, and Shahrood were tested for sera and milk utilizing ELISA (Svanova Biotech AB) test kits. RESULTS: The results revealed that 87.27 % of bovine serum was positive. The percentage of opacity density (OD) of positive sample (PP) ranged from 72.17 to 137.3 (114.21±24.65). In addition, the average rate of milk seroprevalence to the parasite was 95.23 % in Semnan province. CONCLUSIONS: The frequency of Neospora caninum infection in blood and milk was high in Semnan, yet no significant relationships were observed with abortion (p < /em>>0.05).