Comparison of low-moisture blocks and salt for manipulating grazing patterns of beef cows

¹ Department of Animal and Range Sciences, New Mexico State University, P.O. Box 30003, MSC 3-I, Las Cruces, NM, 88003, USA
² Northern Agricultural Research Center, Montana State University 3848 Fort Circle, Havre, MT, 59501, USA

^* To whom correspondence should be addressed. E-mail: dwbailey{at}nmsu.edu.

	Abstract

A study was conducted to compare the effects of strategically placed salt and low-moisture blocks (LMB) and salt on grazing distribution and diurnal behavior patterns of individual cows grazing foothill rangeland in northern Montana during autumn. The study was divided into two sets each containing two consecutive 10-d periods. Cows (n = 32) were tracked with global positioning system (GPS) collars for one set of two periods. Salt and LMB were available for one period and only salt was available for the other period. During these two periods, all supplements were placed in roughly the same location (within a 5 ha area) on ridges away from water and that historically received little use. When LMB was available, cows used higher elevations (1182 ± 2 m) and were farther horizontally from water (531 ± 7 m) than when only salt (1171 ± 2 m and 486 ± 7 m, respectively) was provided (P < 0.001). Cows traveled 4.35 ± 0.09 km/d when supplemented with LMB and 3.94 ± 0.09 km/d with salt (P < 0.001). Observed differences between treatments for time spent near supplements were most apparent (P < 0.001) in the higher terrain between 10 to 100 m from placement sites. Cows were more active (not resting) when LMB was available than when only salt was available (P < 0.001), but much of the difference in activity between treatments appeared to be consumption of LMB at night. Over a 24-hour period, 47 of the 73 min that cows spent within 10 m of LMB (a visit) occurred at night. Results from this study support previous research suggesting that LMB is an effective attractant that can be used to lure cattle to graze high elevations away from water.

Key Words: cattle, distribution, grazing behavior, rangeland, supplement