Today, there are some 200 different breeds. Goats have been used by the U.S. Fish and Wildlife Service, the Bureau of Reclamation, the Bureau of Land Management, and the U.S. Forest Service. State, county and city contractors (such as the city of Seattle) have also used goats for weed and invasive species control.
Recent data has redefined the way that urologists look at PSA, and what is considered a normal PSA. Age-adjusted PSA values take into account that a 40-year-old should not have the same PSA as an 80-year-old. Accepted age-adjusted PSA rates are below 2.4 ng/ml for men under the age of 50 and 6.5 ng/ml for patients in their 70s. Other limits have been defined for varying age ranges, but there is not universal agreement about the accuracy of the age-adjusted levels.
Between these two groups is the diagnostic gray zone of the PSA value, 4.0 to 10.0 ng/mL, for which a positive biopsy of cancer is problematic. In this range, nearly 25% of men will have prostate cancer, and 75% will have benign prostatic enlargement.irst, age-specific reference ranges could improve the sensitivity of PSA by detecting curable, organ-confined tumors in younger men when the threshold of 4.0 ng/mL is lowered. Second, age-specific reference ranges could improve the specificity of the PSA test by raising the PSA threshold for normal among older men.