O R N I A Kenneth LWegnon CALIFORNIA AGRICULTURAL EXPERIMENT STATION BULLETIN 838 was Digitized by the Internet Archive in 2012 with funding from University of California, Davis Libraries http://www.archive.org/details/useofdifferentcl0838wagn USE OF DIFFERENT CLASSES OF RANGE LAND BY CATTLE This bulletin reports a study of the utilization by cattle of ten different classes of rangeland in the Sierra Nevada foothills, adjacent to the San Joaquin Valley. It also discusses the effects on cattle utilization from seasonal variations in the forage crop through the year, differences in rates of utilization, variations in annual rainfall, and convenience of salt licks. MARCH, 1968 THE AUTHOR: Kenneth A. Wagnon is Specialist in the Agricultural Experiment Station, Department of Animal Science, Davis. USE OF DIFFERENT CLASSES OF RANGE LAND BY CATTLE 1 Otudies of the annual-type range in the Sierra Nevada' foothills and its utilization by cattle revealed several different land types that varied in extent from place to place. It was noted that the forage on these land types varied somewhat in the amount produced per acre, time of growth, and species composition (Hutchi- son and Kotok, 1942; Bentley and Talbot, 1951; and Wagnon et al, 1959). Bentley and Talbot (1951), in evaluat- ing the grazing capacity of their experi- mental pastures, found that the range could be separated into six readily identi- fiable land classes, four of which could be further divided into north and south ex- posures. The relative average annual herbage yields per grazable acre of these land classes were determined. By meas- uring the extent of each land class within a pasture it was possible to calculate its average forage productivity. Wagnon (1963), studying the grazing behavior of cows in these pastures, noted variability in their use of the different land classes apparently affected by differ- ences in forage productivity due to season of year, growth stage of certain forage species, and composition of the annual forage crop. In addition, other factors such as range fertilization (Green et al., 1959), range fires, and heel fly activity have been observed to influence cattle to use certain areas more than others at times. Moorefield and Hopkins (1951) in a Kansas study of the grazing habits of cattle in a mixed-prairie pasture com- posed of 9.3 per cent lowlands, 64.5 per cent hillsides and 26.2 per cent uplands (each land class supporting a different type forage) found that the cattle favored the lowlands 49.2 per cent, the hillsides 22.0 per cent and the uplands 28.8 per cent of the time. Furthermore, there was a monthly variation in the percentagewise distribution of the cattle among these three areas. This study investigates the frequency with which feeding cows use the various land classes of the California annual-type foothill range as affected by such factors as annual variability in herbage produc- tion, seasonal variability in plant growth, variation in degrees of utilization of the forage crop, and location of the salt lick. EXPERIMENTAL PROCEDURE This study was conducted on seven pas- tures (I to VI, and XIV, figures 1A and IB, see pocket in the back of the bulletin) i at the San Joaquin Experimental Range 2 which has been previously described (Hutchison and Kotok, 1942; Bentley and Talbot, 1951). Basic maps of the experi- mental area showing the extent of 10 dif- ferent classes of range land within each pasture were prepared by the Pacific Southwest Forest and Range Experiment Station, USDA (fig. 1). The percentage of each land class within each experimental pasture was calculated from these maps. Data used on the relative average yield 1 Submitted for publication September 14, 1967. 2 Maintained by the Forest Service, USDA. of herbage per surface acre for each land class, on estimated total annual produc- tion of air-dry herbage per grazable acre, on the degree of utilization in pastures I through VI and the description of the dif- ferent land classes are from Bentley and Talbot (1951). Land classes 2, 4, 6 and 8 are on northern exposures and classes 3, 5, 7 and 9 are on southern exposures. De- scription of the land classes are as follows: Class 1. Swale. The swale soil (drain- age bottom) is typically a dark gray, sandy loam with a fairly good water-holding capacity, as contrasted to the shallow, brownish, sandy loams of low 3] water-holding capacity that are found on the slopes. The swales receive a considerable amount of seepage water; in wet winters some portions re- main saturated for several months. Swales consist of a heavy, poorly drained phase, or wet swale, and a lighter, better-drained phase, or dry swale, that usually borders the wet swale. Classes 2 and 3. Gentle slope. Located just above the swale, the fine sandy loams of gentle slopes represent the transition from transported soil in the drain- ages to soil developed in place on the slopes. Gradient is be- low 10 per cent. Classes 4 and 5. Open, rolling slope. These sites, with a gradient of 10 to 25 per cent, have an open cover of trees and shrubs and only scattered rock outcrops. Most of the sandy loams are about 24 inches deep. Classes 6 and 7. Rocky, brushy, rolling slope. The average gradient of these sites is greater than for the open, rolling slope but the range in gradient, 10 to 25 per cent, is about the same. In general, the soils are shallower and coarser and more of the surface is covered by rocks, shrubs, and trees. Such lands comprise more acreage than any other site class within the area of gra- nitic soils. Classes 8 and 9. Rocky, brushy, steep slope. These sites have a gra- dient of 25 per cent or greater and numerous outcrops or many shrubs and trees. The steep areas are not common in the lower foothills; they differ considerably from place to place, including some pro- ductive soils as well as thin, sandy soils. Class 10. Steep, rocky bluffs. These localized areas are small in size and practically unused by cattle. To obtain data on the frequency of use of the various land classes, the experi- mental pastures (figure 1) were checked by horseback and the location of each cow found was plotted on a tracing-paper overlay on a topographical map. For a short period at the start, the bull in each pasture was also included. Symbols were used to indicate whether the cow was feeding or engaged in other activities. Later the tracing-paper overlay was placed over a map snowing the extent of the various land classes within each pas- ture and the data on all feeding cows summarized according to the land class on which they had been plotted. In order that the cows in pastures I through VI would be checked during the different daylight hours we alternated the rotation in which the pastures were checked, and also varied the starting time. Pasture XIV was not checked during the earlier morn- ing or later afternoon hours. Cows were not plotted after dark or during rain. Data were collected over six annual periods (1941-1946) in pastures I-VI and for three annual periods (1943-44 to 1945-46) in pasture XIV. In pastures I-VI grazing was initiated each year be- o tween January 9 and March 7, and ter- minated between July 12 and August 13. Each pasture contained 15 cows, their calves until weaned about July 1, and a bull until May 1. In pasture XIV grazing was initiated between July 20 and August 8, and terminated between January 9 and March 7. Stocking rate varied from 43 to 47 cows annually, calving commenced about October 1, and a bull was added about December 28. Supplements were not fed in any of the pastures. Each pasture was provided with a salt lick that contained block salt during the rainy months and coarse-ground salt dur- ing the dry months. During the first year in pastures I-VI, the licks were located in what were considered convenient loca- tions. Thereafter, and alternating each year with half the pastures, the lick was placed in convenient or inconvenient lo- | 4] cations. In pasture XIV the lick was each year in a different place, one of which was conveniently located. Convenient lo- cation implies that the lick was located in an area or near a trail frequently used, whereas inconvenient location implies an area less frequently visited. Locating a lick near a water source does not neces- sarily mean that it is conveniently located unless that is the only source of water within the pasture. The extent of land class 10 in the pas- tures, and data on its use by cattle were not used in the analysis of results, but are included in table 1. RESULTS AND DISCUSSION Annual average pounds of herbage pro- duced per acre differed markedly among most years of the six-year study period. The first two years were near a 13-year average for the station, the third and fifth years was above average, and the fourth and sixth years below average (figure 2). From figure 1 it is evident that the extent of each of the 10 different land classes within each pasture is quite vari- able. Data in table 1 show the percentage of each land class, in relation to pasture size, as well as the average percentage of estimated total forage produced by that land class in each pasture. The estimated average total production of air-dry herb- age per pasture (figure 3) show marked differences in total forage production be- tween paired pastures (pastures I and III, II and V, and IV and VI). -o c => o Q- >^ -a U < on LU CL Q _J LU >- 2.400 2,000 1,600 1.200 800 400 pi HP sstffi *m m m m p m rSB?5 w mm r.liiri *mii m IP ■§i3? is P : 3 mm sip w if $&% m0 mi < :X)IT Mil*;* w IP 3$ Fig. 2 Estimated total pro- duction of air-dry herbage per grazable acre during the plant-growing sea- son — September to time of plant maturity. (Adapted from Bentley and Talbot, 1951.) 1940-41 41-42 42-43 43-44 44-45 45-46 PLANT GROWING SEASON [5] 600,000 500,000 100,000 - J PASTURE The total number of daily observations made in each pasture with the total num- ber of feeding cows recorded in each is given in table 2. As expected, a greater percentage of the cows were accounted for in those pastures containing greater areas of gentle and open slopes, (Pastures I, II, III). Of the total number of cows found in each pasture the number of feed- ing cows varied from 47.6 to 61.0 per cent. The large numbers of nonfeeding cows are explained by the fact that ob- servations were made through the morn- ing and afternoon resting periods as well as at times the cows were moving about their pastures. Some of the early-morning observations began when cows were still at their night beds and the last observa- tions in the day were made when the cows were moving towards their night feeding and bedding areas (Wagnon, 1963). Fig. 3. Estimated average total production of air-dry herbage per pasture. (Calculated from data in Bentley and Talbot, 1951.) LAND CLASS USE Variability in the use of the different land classes by the cows is evident in table 1. A summation by percentages of cow distribution for each land class, of each land class in the entire study area, and the estimated forage production per acre of each land class is given in table 3. From these data we find a definite rela- tionship between forage productivity per acre and frequency of cow distribution, in descending order, from the highest pro- ducing land class 1 to the lowest produc- ing land class 8. The only exception was land class 9 which had the same ratio as land classes 6 and 7. Bentley and Talbot (1951) calculated the relative herbage production of each land class from yield measurements made in pastures I, II and III during the period 1943-45. Steep slopes were not well rep- resented within the sampling areas, but the estimated yields for these land classes (8 and 9) were considered indicative of the average production of such areas. The 1944 and 1945 forage years were the low- est and highest, respectively, in forage production during this six-year period of study, while 1943 was a better than aver- age forage year (figure 2). Evidence that the percentage of cow distribution is highly correlated with the forage production of the different land classes, and not with the percentage of area in each land class, is shown by the data given in table 4. The correlation co- efficients between forage production and cow distribtuion were high for all pas- tures while those between area and cow distribution were variable and extremely low in some pastures. For the entire study area the correlation coefficient was 0.92 between percentage of forage produced and percentage of cow distribution for each land class, as compared with a cor- relation coefficient of 0.61 between per- centage of area and percentage of cow distribution for each land class. Even though the percentage of the dif- ferent land classes varied markedly be- tween pastures, as well as in degree of [6] o p < Q o p Q O Pin o < o « S 00 3 d PL, > 3 ra 0) w o3 >o 00 3 "5 "3 O s 6-^3 ^"3.0 5 OO^H^HirSCNr^OiCOOO CO CO •^COCOOCM-HCNOO 00 >— 'OUi^riOCOl^OO "* CO 03 £ n 6 d «' ei n * CO I-H > 00 £ V sS CO CO 00 3 X 3 ►■AJ -3^ NCOfNONNrftOCO 00-H»OcNt~-CO^H-^ ao 0) « a CM oo 3 rfCOOO^f'OOOINMiO CO"— i © -h -h OO OS i— I — c t-1 i-h -h CM CO hi fe -3 ■f CM © »0 CO t— ^f00©-h-hiO CO ■* > 00 !~ U 03 as o CO g 3 09 cS V T3 O £ CXI 3 T)Jo lO©Ot^CN©©-H©"5 t^ -h © io i— i <* r» * » o ^h i-c CM CM 45 -ri co©©cNcMt~t~»-H©o — i CM hji 03 £ «3«H*ii^N0100 •— > © © —< — 1 a h n uj u) i-H CO CO g OS a to % 3 0) «0 o O o|| 30.3 2.5 1.2 0.7 0.6 19.3 29.3 4.9 11.2 5a8 2£« o a ^ HNOOOONO!Ni|i* ^NONHNOntOO CM i-H CO rt 33 < ONfOON^llONOO l>. i— lOi-Hi— 1 CO Oi 00 CO © CM OO — a 00 ou CJ a3 o CO CM 0) oo 3 ^1 ail "3-D 37.9 9.2 5.5 10.0 10.4 12.2 9.7 0.9 4.2 o a s P=» -3 tnOl^OOlOOCOOtOH r^©cocNCMcoos©co© £ i-Hioco ^t 1 CO CO t"- i-H CNOOOCNhhcxiOOO CO h ^h CN rt -h 03 0) O CO O CM f i-H TflOt^OCOCMCOOOO i-H i-H CM CM CM ~S oo o3i2 HNC0*i0!0N00*O Table 2 NUMBER OBSERVATIONS OF FEED- ING COWS IN EACH PASTURE Pasture Total daily observations Total possible observations individual cows Total number cows feeding I 304 4,583 2,601 II 305 4,599 2,681 Ill 305 4,604 2,705 IV 303 4,573 2.271 V 302 4,551 2,050 VI 301 4,533 2,395 XIV 109 4,975 2,236 grazing use (table 1), the correlations be- tween forage production and cow distri- bution on the different land classes within pastures were high and uniform for all the pastures (table 4). The correlations between forage production and cow dis- tribution for each land class for all pas- tures were high for all land classes except lowest producing class 8 (table 3). Differences in exposure did not appear to affect frequency of cattle use. In the entire study area, except for pasture I which does not contain all the land classes, the combined north exposures Table 3 ANALYSIS OF STUDY AREA BY LAND CLASS, COW DISTRIBUTION, AND FORAGE YIELDf Land class area Cow distribution Ratio: Area/cow distribution Forage yield per surface acre t Correlation coefficient : as percentage of total study area forage produced/cow distribution 1 5.2 1.2 1.9 3.5 6.5 27.4 31.8 7.5 15.0 26.5 2.7 3.4 5.7 7.9 18.0 22.7 2.5 10.6 1:5.1 1 :2.3 1 : 1.8 1 : 1.6 1 : 1.2 1 :0.7 1 :0.7 1 :0.3 1 :0.7 Pounds 4,400 3,040 2,660 1,980 1,800 980 980 495 1,260 0.87* 2 0.99** 3 0.97** 4 91** 5 99** 6 97** 7 92** 8 57 9 99** *P <0.05. **P <0.01. t Land class 10 not included. % From Bentley and Talbot, 1951. Table 4 CORRELATIONS BETWEEN COW DISTRIBUTION AND LAND CLASSES, AND FORAGE PRODUCTION Pasture Correlation coefficient : Land class areas/cow distribution Correlation coefficient: Forage production/cow distribution I 0.01 0.98** II 0.26 0.96** Ill 0.72* 0.96** IV 0.88** 0.92** V 0.94** 0.94** VI 0.39 0.81** XIV 0.94** 0.98** P <0.05. P < 0.01. (land classes 2, 4, 6 and 8) comprised 39.5 per cent of the area, produced 32.8 per cent of the forage, and had 29.7 per cent of the cows, whereas the combined south exposures (land classes 3, 5, 7 and 9) comprised 54.2 per cent of the area, produced 51.8 per cent of the forage and contained 45.1 per cent of the cows. Seasonal variation Previous studies at this station by Bent- ley and Talbot (1951) and Wagnon et al. (1959) showed that, despite the great similarity in forage developmental periods from year to year, these forage periods may also vary markedly in duration and productivity among years. Figure 4 shows 8] 1941 1942 1943 1944 1945 1946 AV. Piip i»..T;,.. -i-i £l*w •«•«?-, ft^n #?* iS£S AUG l£i sail "Hta Fig. 4. Periods during which pastures I through VI were stocked each year of the study. A is date of entry, B is average date of start of rapid forage growth, C is average date when bulk of the forage has dried, and D is date of removal of cattle. Average dates are for the base period 1936 through 1947. the duration of each of the grazing peri- ods on pastures I— VI, and cows were in pasture XIV when not in these pastures. Data on forage production for each land class each year of this study or for the different forage seasons each year are not available. Thus, frequency of cow distribution to the various land classes at different seasons of the year, or for high and low forage productive years, will have to be considered without their relationship to actual forage production data. To see if seasonal differences in forage development, within the forage year, had influence on cow distribution to the dif- ferent land classes, the data for the entire study period were summarized for monthly periods for combined pastures I-VI and for the dry forage and winter periods (which start with the onset of fall rains) for pasture XIV (table 5). From these data it is evident that seasonal changes of cow distribution to the differ- ent land classes did occur. The most marked changes occurred on land class 1 in pastures I— VI. From the time the cows were placed in the pasture until the start of rapid forage growth in late March (average) cow distribution to class 1 re- mained constant and about equal to that in class 7. Then marked increases in cow distribution occurred during April and May when the forage was growing rap- idly to maturity. During this time, com- pensating decreases in cow distribution [9] Table 5 COW DISTRIBUTION ON NINE LAND CLASSES BY MONTHS (PASTURES I-VI) AND DURING DRY FORAGE AND WINTER PERIODS (PASTURE XIV) Land class Jan. + Feb. Cow distribution Combined pastures I-VI Mar. Apr. May June July + Aug. Pasture XIV Dry forage period Winter period 1 2 3 4 5 6 7 22.9 2.7 3.4 4.8 9.3 13.8 22.9 3.2 17.0 Per cent 22.8 34.9 40.2 28.3 28.1 4.5 2.8 2.8 2.9 2.2 2.9 3.0 4.6 3.8 3.7 3.0 2.0 0.8 6.0 7.1 5.1 4.2 3.2 8.4 9.6 9.4 7.8 7.5 6.1 2.3 13.5 13.8 11.9 16.6 18.9 47.4 24.0 18.1 17.5 24.3 21.8 31.1 2.6 1.4 2.3 2.6 4.0 2.5 14.4 8.7 8.6 11.3 13.0 0.0 5.2 1.5 3.7 6.3 5.1 40.4 37.5 0.3 0.0 occurred on other land classes, but partic- ularly so in classes 6, 7 and 9. With ma- turity and drying of the forage in June, cow distribution in class 1 decreased sharply, to a level above that at the start of the grazing season while cow distribu- tion markedly increased in classes 6, 7 and 9. Even though the forage on land class 1 had been closely grazed, the cows continued to spend considerable time re- grazing these areas. Through this grazing period there were small changes in cow distribution between the land classes with north and south exposures. The average distributions of cows on land classes with northern exposures increased from 24.5 per cent at the period start to 29.0 per cent at the close, while land classes with southern exposures showed a decrease from 52.6 per cent to 42.9 per cent, re- spectively, for the same period. In pasture XIV changes in percentage of cow distribution to the different land classes between the dry forage and winter periods were less marked. There was practically no difference in the use of land class 1; the average distribution to the combined land classes with northern ex- posure decreased from 61.3 to 48.5 per cent; and that on the southern exposures increased from 34.2 to 46.3 per cent. The effects of variations in annual for- age production on percentage of distri- bution of cows to the different land classes is shown by the data in table 6. These data, collected in pastures I— VI, have been summarized for the years with above-average (1943 and 1945), average (1941 and 1942) and below-average for- age production (1944 and 1946) (see figure 2). Among these three different periods of total annual forage production there is little difference in average per- centage of cow distribution to the differ- ent land classes other than small progres- sive decreases, correlated with decreasing forage production, to land class 1 with compensating increases to the other land classes. However, within each of these annual periods we find monthly variations in the percentage of cow distribution to the different land classes that are similar to those averages for all years combined, discussed above, except for some differ- ences in use of land class 1. In this class, use was almost 10 per cent greater during the peak month May, for the above aver- age forage production period, as com- pared to that of the average period, and during the below-average period the peak month of use occurred in April. 10] Q £> £^ O^ *2 O H i— ' r^ H ^ D ^ PQ Q s ° Q O o o £ < o * ^ > 1 1 a _o 3 jQ og "3 O I OS C o3

-5 4 050CO«05COO«OCOO •ft^co^Ttieoio^t-- CO h « a 3 Tt<«00000-H«OOiTf"> c3 27.8 5.1 4 5 7.4 10.3 15.1 16.1 4.1 9.6 39.0 1.6 3.6 4.5 7.5 9.0 19.1 3.3 12 4 c3 21.2 2.1 3.4 2.6 8.1 17.3 23.4 5.2 16.7 Janu- ary + Feb- ruary 25.1 3.7 2.9 5.4 9.5 14.3 19.9 2.9 16.3 Sea- sonal aver- age 27.9 3.2 3.7 5.1 8.9 14.2 20.5 3.5 13.0 OS e c3 OS OJ M o3 eg 1-5 t^ioi«©co>ocor^r^ CO CO CO 0v C 3 1-3 eooicoococoiooo CO rH CO — >> c3 d-NMOO^^CB* CO ~+ ~ -h-*0500CO»-hOO-h03 CO — — — 22.1 2.6 3.5 6.7 10.5 14.5 25.5 2.4 12.2 Janu- ary + Feb- ruary lOrtiflOin^MtCM CO — ' CO i-H Sea- sonal aver- age cowNONCi^cq* CaNM>Offl'« l ' H N' H CO -h CO — d 03 CO a> (V ® 03 eg O X: July + Au- gust >— >r~-coco»oot^t^eo (DOM-MOCHNOO CO — ' CO ^ OJ C e-t^ooHH^o ococo>or^t^eoeoo CO H M H >> 03 t^OOiCOOOOOCOOO ONOlntDOOOO'-iN a < 34.4 2.0 3.9 9.2 8.5 15.3 18.8 0.6 7.3 Si u 03 m«HHB3t»01MN ■<*co- CO •-* CO »-i Sea- sonal aver- age cncoocooscot^coco O « •* * ^ n - 'Coco | co ~~ - T C 1 HNM'iflOONOOO LOCATION OF SALT LICKS A previous study (Wagnon et ah, 1942) found that salt consumption decreased if the salt licks were placed in inconveni- ent locations (in relation to cattle use of a pasture) within pastures, as compared with situations where salt was placed in convenient locations. Data were not avail- able to show if placing the lick in incon- venient locations resulted in an increase in the percentage of cattle utilizing the range in those areas. Selection of an inconvenient lick site within a pasture was based on observa- tions of cattle movements within the pas- tures through several annual grazing periods prior to this study. During this time an investigation of range rodents was based in the eastern half of pasture I (figure 1). Observations indicated that the frequent movement of personnel checking trap lines hindered the move- ment of cows utilizing this area. For this reason a salt lick was established during some years near the eastern end of the pasture, to see if it would induce the cattle to use the area more frequently. Shortly after the initiation of the present study the rodent investigations in the pas- ture were discontinued. As shown in table 7, the average salt consumption at the inconvenient site was comparable to those at the convenient location. Since both locations were in the eastern half of the pasture and within the areas of greater forage production this is not sur- prising. A more inconvenient location for the lick could have been found in the western end of the pasture as in pastures II and III (see figures 5 and 6). The degree of convenience or of in- convenience of the lick locations in one pasture were not considered comparable to those in the other pastures. This situa- tion would be difficult to establish be- tween pastures with gentle topography (pastures I, II and III) as compared to pastures with extensive steep slopes or canyons (pastures IV, V, VI, and XIV). Even so, the results of this study verify those of the previous study. Surprisingly, an inconvenient lick location causing a marked reduction in salt consumption was found in pasture III which is small in size, mostly of gentle terrain, and was very closely grazed. During those years in which the salt licks were at inconvenient locations in pastures II- VI the cows be- came notably salt hungry before the close of the grazing periods. To determine if placing the licks in inconvenient locations would induce greater numbers of cows to graze in those vicinities, an analysis was made of the dispersal of feeding cows on those areas when the licks were conveniently and inconveniently located (figures 5, 6, and 7). No significant differences were found. Table 7 VARIATION IN AVERAGE DAILY SALT CONSUMPTION PER ANIMAL UNIT FOR GRAZING PERIODS WHEN THE SALT LICK WAS AT CONVENIENT OR INCONVENIENT LOCATIONS WITHIN THE PASTURES Grazing periods Pasture 1941 1942 1943 1944 1945 1946 Average daily salt consumption per animal unit Ounces I II 0.72 0.78 0.92 0.54 0.59 0.76 0.62* 0.65* 1.02 0.34* 0.60 0.91 0.84 0.71 0.41* 0.85 0.38* 0.36* 0.85* 0.49* 0.95 0.46* 61 0.90 0.85 0.93 0.82 0.35* 0.80 0.25* 0.34* 0.51* 0.84* 69* Ill 1.11 IV 0.46* V VI 0.50 75 XIV 0.71 Salt lick placed at inconvenient location. [12 SUMMARY The dispersal of feeding cows on the vari- growth, the percentage of cows on north ous classes of land, comprising the experi- slopes decreased, with a corresponding mental pastures, was highly correlated increase in percentage of cows on south with the average annual forage produc- slopes. In years of above-average forage tion per acre of each land class. production, class- 1 land received heavier There were seasonal changes in cow use in May than in years of average or distribution to some of the land classes, below-average forage production. In be- These were most marked during the pe- low-average forage years, class 1 land had riod of forage growth and maturity. The its heaviest use in April, greatest change occurred on land class 1 Placing salt licks in inconvenient loca- which received heaviest use in May when tions within a pasture resulted in de- the bulk of the range forage on the other creased daily salt consumption per animal land classes had matured. As the forage unit as compared with placing the lick in matured and dried the percentage of cows a convenient location. Locating a lick in on the south slopes decreased, while the a less frequently used area of a pasture percentage of cows on the north slopes did not cause a significant increase in increased correspondingly. In the winter grazing cows in that area, months, when rains started new forage LITERATURE CITED Bentley, J. R., and M. W. Talbot 1951. Efficient use of annual plants on cattle ranges in the California foothills. U. S. Dept. Agr. Cir. 870:1-51. Green, L. R., K. A. Wagnon, and J. R. Bentley 1958. Diet and grazing habits of steers on foothill range fertilized with sulfur. Jour. Range Mgmt. ll(5):221-27. Hutchison, C. B., and E. I. Kotok 1942. The San Joaquin Experimental Range. Calif. Agr. Exp. Sta. Bui. 663:1-145. Moorfield, James G., and Harold H. Hopkins 1951. Grazing habits of cattle in a mixed-prairie pasture. Jour. Range Mgmt. 4(3): 151-57. Wagnon, Kenneth A. 1963. Behavior of beef cows on a California range. Calif. Agr. Exp. Sta. Bui. 799: 1-58. Wagnon, K. A., H. R. Guilbert, and G. H. Hart 1942. Experimental herd management, pp. 50-82 in: Hutchison and Kotok, 1942. 1959. Beef cattle investigations on the San Joaquin Experimental Range. Calif. Agr. Exp. Sta. Bui. 765:1-70. [13 B N 13** :'.*£*$ ••v i • • ■ *," '• v Wri lM: './••■•*■ • .*•'.- . _ : 5 ':■'. '" "• /-'•■ >-. " N MfteN'T' :. ..'•.•■ :C/3 ;/:.. . •••-.•••,• ; " - : '•' ■•'*&" "3- "• : • ■'■'V\ • : . ■': . «&!>■ ':.0-, -• ■''%>■■'■ :•*■' :"•■'■■. .' \\ •': '" ■■■' ..':; • / ; : --:v : y? : -; ; a H '"' M k- o ... y 0) >s a) -c *- >_ o **" __ — ^-, y > _c O 3 o k. -c — 0) k. 3 M D ■ y*" a c m • ••• »■*■ $ . • ■ y. ■ O u D> C "n ' "O •',..• . " — s ; a> 0) *o c ■' * .. o . • '••• -' 3 XI Q id a> a "*■?■&& £ , :^ • V ; • >." ". V. jf ; w'.- '."'' > X < CO I CO St V> «v.w*. o *- o o LU - *. :. •• % *1 *V tr> ' *t : d> 10m-3,'68(H7529)JF