Pathogens in Processed Ram Semen and Approaches for Their Elimination

Semen quality and total microbial load: An association study in important Indian Goat breeds during different seasons

The invasion of the male urogenital tract by microorganisms, and its subsequent effects on sperm fertilising ability, has not been well discussed in bucks. The present study was conducted to assess the bacterial load in fresh semen of the 2-6 years old bucks. For conducting the experiment, semen ejaculates from 18 bucks (6 from each breed namely Jakhrana, Jamunapari and Barbari) were used. We collected 5 ejaculates from each buck in each season (Summer-April to June, Rainy-July to Sept and Winter-November to January). Semen was collected with the artificial vagina (AV) method, and separate AV was used for each buck every time. The semen collection frequency was once in a week. Immediately after initial evaluation, collected semen samples were transferred to the microbiology laboratory of the institute. Thereafter, the semen samples were subjected to bacteriological examination to assess the microbial load. The results of the current study indicate that the microbial load in the semen was significantly (p < 0.05) higher in the Jamunapari bucks and in aged bucks. Bacteriospermia in different seasons was not significantly varied; however, nonsignificant increase in microbial load during the rainy season was observed. Overall, the average bacterial load in the semen of Jamunapari, Barbari and Jakhrana bucks was found 540.50 ± 55.88 CFU/ml, 391.81 ± 46.33CFU/ml and 388.93 ± 44.71 CFU/ml respectively. No significant difference in bacterial counts in the subsequent ejaculates among bucks was observed. Moreover, correlation analysis revealed that the proportions of motility, viability, plasma membrane integrity and acrosomal integrity were negatively influenced by the increased bacterial contamination of buck semen.

Bacteriospermia and Sperm Quality of Cryopreserved Bull Semen Used in Artificial Insemination of Cows in South Wollo Zone, Ethiopia

The objectives of this trial were to estimate prevalence of bacteriospermia, to determine the bacterial load, and to isolate the types of bacteria as well as to assess the association between bacterial load and sperm quality traits in cryopreserved bull semen in field conditions in the South Wollo Zone. A total of 309 cryopreserved straws of semen from the Holstein Friesian (HF)-cross bull (n = 180 straws) and pure Jersey bull (n = 129 straws) were investigated. Bacteriological assessments of the presence of aerobic bacteria, estimation of bacterial count and bacterial isolation, as well as semen quality were performed. Aerobic bacterial contamination was prevalent in 38.8% of the semen straws. No significant difference in the prevalence of bacteriospermia was observed among bulls although the HF-cross bull had a higher prevalence (40.0%). But, significant difference in prevalence of bacteriospermia was found among semen ejaculates of the same bull. The risk of bacteriospermia in the HF-cross bull was higher (Odds ratio = 1.86, 95% CI = 0.168–20.26) compared to Jersey although not significant. Overall average bacterial load of 50.38 ± 16.29 colony-forming units (CFU)/ml (from nil to 1318.20 CFU/ml) was found. No significant difference in bacterial count among bulls and their ejaculates was observed. Moreover, correlation analysis revealed that the proportions of motility, live, and normal morphology were negatively influenced by an increase in the bacterial contamination of semen. In this study, three isolates of coagualse-negative Staphylococcus species and one isolate of Corynebacterium species were found. Average percentages of sperm motility (48.35 ± 1.23), live (66.08 ± 1.0), and normal morphology (80.62 ± 1.24) were observed. It was concluded that cryopreservation does not guarantee the quality of semen from bacterial contamination. Hence, meticulous care should be adopted to prevent contamination of semen by bacteria during collection, transportation, processing, and storage times.

Toxoplasma gondii infection and toxoplasmosis in farm animals: Risk factors and economic impact

The protozoan parasite Toxoplasma gondii is a zoonotic parasite that can be transmitted from animals to humans. Felids, including domestic cats, are definitive hosts that can shed oocysts with their feces. In addition to infections that occur by accidental oral uptake of food or water contaminated with oocysts, it is assumed that a large proportion of affected humans may have become infected by consuming meat or other animal products that contained infective parasitic stages of T. gondii. Since farm animals represent a direct source of infection for humans, but also a possible reservoir for the parasite, it is important to control T. gondii infections in livestock. Moreover, T. gondii may also be pathogenic to livestock where it could be responsible for considerable economic losses in some regions and particular farming systems, e.g. in areas where the small ruminant industry is relevant. This review aims to summarize actual knowledge on the prevalence and effects of infections with T. gondii in the most important livestock species and on the effects of toxoplasmosis on livestock. It also provides an overview on potential risk factors favoring infections of livestock with T. gondii. Knowledge on potential risk factors is prerequisite to implement effective biosecurity measures on farms to prevent T. gondii infections. Risk factors identified by many studies are cat-related, but also those associated with a potential contamination of fodder or water, and with access to a potentially contaminated environment. Published information on the costs T. gondii infections cause in livestock production, is scarce. The most recent peer reviewed reports from Great Britain and Uruguay suggest annual cost of about 5-15 million US $ per country. Since these estimates are outdated, future studies are needed to estimate the present costs due to toxoplasmosis in livestock. Further, the fact that T. gondii infections in livestock may affect human health needs to be considered and the respective costs should also be estimated, but this is beyond the scope of this article.