The short answer is yes. Minnesota loses a small number of cows each year, but mostly cows move from one farm to another.
    Examining the United States Department of Agriculture’s recent dairy census versus 2012 and 2017 data shows this. The current dairy census uses data from 2017.
        In Figure 1, the first 10 counties, from Stearns to Swift, were the top 10 counties, by number of cows, from top to bottom, in the most recent census. The last three counties all were listed at least once in the top 10 counties in 2007 or 2012 but were not in the top 10 in 2017. The most recent census did not list cow numbers for Stevens County; however, the table shows the 2012 data for that county. Total Minnesota cow numbers are at the top of the list. The 10 year percentage change column is the total change for the 10 years from 2007 to 2017.
Minnesota lost 1,951 cows, or 0.4%, in the 10 year period, but Otter Tail County lost 6,971 cows or almost 33%. Swift County gained 8,104 cows or 179%. Winona County lost 5,337 cows, or 18.2%, while Kandiyohi County gained 7,751 cows or 118%. Counties with significant gains now have much larger herd sizes than counties that have lost cows.
    Figure 2 shows the average dairy herd size by county in Minnesota for each of the three dairy census years and the percentage change over 10 years.
    Overall, in Minnesota, herd size grew by 41% over 10 years, but Kandiyohi, Swift and Nicollet herd sizes grew by 225%, 300% and 162%, respectively. It is clear that growth in county cow numbers and average herd sizes is largely because of a few very large farms in some counties. Thus, the answer is yes, cows are moving around within the state, and that is changing the Minnesota dairy landscape.
 
Figure 1: Top Minnesota counties by number of cows    
        5 year         5 year         10 year
    2007    change    2012    change    2017    change
Minnesota    459,752    0.8%    463,312    -1.2%    457,801    -0.4%    
Stearns    68,677    2.5%    70,407    -5.5%    66,524    -3.1%    
Morrison    24,657    14.3%    28,173    -1.3%    27,805    12.8%    
Winona    29,369    -2.9%    28,515    -15.7%    24,032    -18.2%    
Stevens    17,925    19.5%    21,428    0%    21,428*    18.5%    
Wabasha    20,110    2.5%    20,614    -1.7%    20,257    0.7%    
Goodhue    19,320    -9.7%    17,450    5.3%    18,382    -4.9%    
Todd    16,300    -1.4%    16,521    -12.2%    14,498    -11.1%    
Ottertail    21,312    -21.7%    16,689    -14%    14,341    -32.7%    
Kandiyohi    6,581    0.4%    6,606    117%    14,332    117.8%    
Swift    4,474    -34.4%    2,935    325.5%    12,488    179.1%    
Fillmore    10,837    14%    12,359    -11.3%    10,963    1.2%    
Nicollet    6,961    62.1%    11,281    2.5%    11,566    66.2%    
Benton    12,593    -11%    11,204    -7.1%    10,404    -17.4%    
Figure 2: Top Minnesota counties cows per farm
            2007    2012    2017    10 year change
Minnesota    89    98    126    41%
Stearns        83    88    107    28%
Morrison    85    90    130    53%
Winona        117    139    150    28%
Stevens        1,494    2,679    2,125    42%
Wabasha    103    131    152    48%
Goodhue    102    114    136    33%
Todd        63    53    65    4%
Ottertail        72    65    74    3%
Kandiyohi    80    82    261    225%
Swift        136    95    543    300%
Fillmore    76    85    88    16%
Nicollet        116    251    304    162%
Benton        84    86    121    44%

    Bennett is one of four dairy veterinarians at Northern Valley Dairy Production Medicine Center in Plainview, Minn. He also consults on dairy farms in other states. He and his wife, Pam, have four children. Jim can be reached at bennettnvac@gmail.com with comments or questions.