BST use leveling off in Wisconsin


MADISON, Wis. – Use of bovine somatotropin on Wisconsin farms may have hit a plateau, with about one-sixth of state dairy farms currently using the technology.

This adoption level is well below what was expected of this controversial technology in the debate that preceded its commercial release in 1994.

BST use statistics. According to a study by researchers at the University of Wisconsin-Madison, BST adoption grew from use on 7 percent of Wisconsin’s dairy farms in 1995 to 15 percent in 1999.

Survey results in 2001 show that adoption has only inched up since 1999, with 16 percent of farmers currently using BST.

Between 1995 and 1999, new users of BST accounted for about two-thirds of the increase, and the disproportionate exit of farmers not using BST accounted for the rest of the apparent increase, according to researchers with the Program on Agricultural Technology Studies at the UW-Madison’s College of Agricultural and Life Sciences.

Use has fallen. Between 1999 and 2001, the estimated number of BST users in the state actually fell, meaning that the slight increase in adoption was accounted for almost entirely by the exit of farmers not using BST.

In a statewide mail survey of dairy producers in 1999, researchers found that just 5 percent of farms with less than 50 cows were using BST, compared with 75 percent of farms with more than 200 cows.

This gap in BST use between smaller and larger herds has widened since 1995. The median herd size for farms using BST was 85 cows, compared with 50 cows for non-users. Rolling herd average for BST users was 22,947 pounds of milk, compared with 19,129 pounds for non-users.

Three categories. For this study, the researchers also grouped Wisconsin’s dairy farms into three categories: high-end confinement farms, traditional semi-confinement farms, and low-input/grazing operations.

Compared with the other two groups, high-end farms are much more likely to use BST, the survey showed. The high-end farms are also much more likely to keep production records for individual cows, balance rations, and feed total mixed rations.

“It appears as if use of BST is strongly associated with a bundle of technologies and management practices that are most likely to be used by farmers of larger scale,” said study author Brad Barham.

BST probably accounts for a 2-percent increase in Wisconsin milk supplies, assuming treatment rates of 50 percent on adopting farms and a 10-percent increase in milk from treated cows.

While significant, this increase must be considered along with continuing improvements in dairy cattle genetics and other factors.

Dairy productivity rises. “Even without BST, dairy herd productivity in Wisconsin and the United States has tended to grow at relatively high rates – more than 2 percent per year.

“Thus, this one-time production boost created by the use of BST seems relatively minor when compared with the secular trend of ongoing productivity growth in the industry,” said Barham.

“In terms of milk prices, then, BST has also fallen short of the impact that many analysts foresaw during the heat of the controversy.”

The survey also examined the attitudes of Wisconsin dairy farmers. About 90 percent of the respondents, whether high-end, traditional, or low-input, believed that a system of family operated farms was essential to the future of rural Wisconsin.

High-end and low-input farmers were more likely than traditional farmers to encourage their kids to take up farming, but fewer than half the respondents in any group wanted their children to become farmers.

Among the high-end farmers, 41 percent said that large California-style farms with thousands of cows were inevitable in Wisconsin, compared with about 23 percent of traditional and low-input farmers.

See for yourself. For a copy of the full report, “Use and Implications of Bovine Somatotropin for the Wisconsin Dairy Sector in the 1990s,” contact Nancy Carlisle at 608-265-2908.


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