Change of Milk Production with Housing System and Herd Expansion1,2

OUR INDUSTRY T O D A Y Change of Milk Production with Housing System and Herd Expansion ] ,2 R. J. N O R E L L and R. O. APPLEMAN University of Minnesota St. Paul 55108

ABSTRACT

Milk production per cow often declines following expansion of a dairy herd. In this study of 192 Minnesota herds, loss of production depended on the change in housing system and herd management during and immediately after expansion. Four housing switches were studied: 1) stanchion to tie stall, 2) loose housing to cold free stall, 3) stanchion to warm free stall, and 4) stanchion to cold free stall. Since year of new construction varied, data were adjusted to a base year with constants derived from control herds (70 stanchion and 70 loose housing herds). Deviations in production and income over feed cost following new construction then were related to yearly changes among control herds. Stanchion to tie stall herds produced 26 kg more 3.5% fat-corrected milk than control stanchion herds. Stanchion to warm or cold free stall herds produced nearly 200 kg less 3.5% fat-corrected milk than control stanchion herds. Yearly deviation in milk yield and income over feed cost did not vary significantly between changes of the four housing systems and control herds. INTRODUCTION

Dairymen considering herd expansion must make several important assumptions in their

Received November 30, 1979.

1Journal article number 1 t,080, University of Minnesota Agricultural Experiment Station, St. Paul. z Research was supported in part by a grant from the University of Minnesota Computing Center. This research was a contribution to the North Central Regional Project NC-119, Improving Large Dairy Herd Management Practices in partial fulfillment of the requirements for a MS degree. 1981 J Dairy Sci 64:1749-1755

financial planning, including expected milk yield per cow following expansion. Studies have delineated effects of expansion on milk yield. Rapid large expansions are more detrimental to herd average milk yield than small expansions (3, 7). Additionally, production losses are greater with large herds than in small herds when the percentage growth rates are equal (3). Herd expansions usually involve more than an increase in herd size. The dairyman may: 1) remodel the old barn and add stalls, 2) build completely new but maintain the same management concepts, or 3) build new and in so doing change the housing system and herd management practices. Changes in feed storage, feeds fed, materials handling equipment, and milking equipment may also occur. A general trend in housing dairy cattle has been conversion from traditional stanchion barn to loose housing or free stalls (5, 6). A housing change of this type alters herd management practices and cow environment. The influence of this housing switch on milk yield has been studied (2, 4, 7, 8), but results have differed. One study reported roughly an equal number of herds declined in production as gained following a switch from stanchion to free stall (8). Others reported average losses of production ranging from 370 to 506 kg during the first 2 yr in the new barn (4, 7). The lost production was not recovered until the 2nd or 4th yr (2, 4, 7). To the authors' knowledge, no studies have compared effects of changes of housing systems on milk yield in relation to previous production and herds not expanding. The objectives of this study were to compare yearly change in milk yield and income over feed cost between four housing changes and herds maintaining the same housing. The four housing changes were: 1) stanchion to tie stall, 2) loose housing to cold free stall, 3) stanchion to warm free stall, and 4) stanchion to cold free stall. The first two housing changes involve similar herd manage-

1749

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NORELL AND APPLEMAN

ment and cow environment between the old and new barns. In the second two housing changes, herd management and cow environment are different between barns. EXPERIMENTAL PROCEDURE

Minnesota dairymen enrolled in the Dairy Herd Improvement testing program (DHI)were surveyed in 1976. Survey questions were designed to determine the dairyman's management practices and type of dairy housing. From the 3,284 returned surveys, 192 Holstein herds which had changed housing from stanchion to tie stall, loose housing to cold free stall, stanchion to cold free stall, or stanchion to warm free stall housing were identified. These farms had built the new barn between 1970 and 1975, had more than 20 cows prior to the housing change, and had been on DHI testing at least 1 yr prior to the housing change. The four housing switches selected for study were those with the highest freuency. Housing changes not selected generally had less than 10 herds making that particular housing change. The number of DHI calendar year records and herds within each housing switch are in Table 1. The number of records for a particular herd ranged from three (barns build in 1975) to six records (barns built in the years 1970 through 1972). The first record was the DHI herd average for the calendar year prior to the housing switch; the second record was the year the barn was built; and the next records were DHI averages following the housing change. Data collected from each calendar year record included the rolling herd averages for milk (kg), fat (kg), feed index, grain (kg, dry

matter), forage (kg0 dry matter), percent days in milk, herd size, and income over feed cost (IOFC). Feed index is the ratio of energy fed (calculated from reported feed intake data) divided by the energy requirement (based on production, fat percent, growth, and body weight) times 100. Minnesota DHI calculates feed index for each cow plus a herd average feed index. The rolling herd average feed index was used in our study. Proportions of hay, pasture, and silage fed could not be differentiated from the total amount of forage fed. Herd average milk was adjusted to a 3.5% fatcorrected milk (FCM). Calendar year data for the study herds were adjusted to a 1973 base, the average year of new construction. This adjustment was tor two reasons: 1) to remove variation between herds within a housing switch from year of new construction (e.g., effects of calendar year on rates of grain and forage feeding, etc) and 2) to compare herds that changed housing and those that were maintained in the same housing. Adjustments for calendar year ( 1 9 7 3 ) w e r e constants derived from control stanchion and loose housing herds (70 in each group). The control herds had been enrolled in DHI testing continuously since 1967, maintained the same herd size (+ 2 cows), and maintained the same dairy housing from 1967 through 1976. Herds for controls were selected randomly from the set of herds meeting the above criteria. Only 70 loose housing herds met the criteria. Least square means for calendar years of 3.5% FCM, income over feed cost, grain fed, forage fed, and feed index for the two control groups were obtained from a one way classified model. The independent variate was

TABLE 1. Number of DHI calendar year records and herds within each housing switch.

Housing switch

Herds

Calendar year recordsa

Stanchion to tie stall Loose housing to cold free stall Stanchion to warm free stall Stanchion to cold free stall Total

106 24 19 43 192

522 130 101 216 969

alncludes the records from 1 yr prior to the housing switch. Data used in the least squares analysis were deviations from records 1 yr prior to the switch. Journal of Dairy Science Vol. 64, No. 8, 1981

OUR INDUSTRY TODAY

calendar year (1969 to 1976). Base year constants were calculated by subtracting the calendar year least square mean from the 1973 least square mean. Records from stanchion herds moved into a tie stall, warm free stall, or cold free stall barn were adjusted by subtracting the stanchion base year constants. Loose housing to cold free stall records were adjusted by subtracting the loose housing base-year constants. Deviations in 3.5% FCM, income over feed cost, grain fed, forage fed, feed index, percent days in milk, and herd size from herd average 1 yr prior to the housing change then were calculated for each study herd. Herd averages for these variables 1 yr prior to the housing change are in Table 2. Deviations were calculated for the year of the housing change (yr 1) through 4 y r after (yr 5). The statistical model for analyzing the data

1751

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1752

NORELL AND APPLEMAN

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herd making this housing switch changed milk yield or income over feed cost at the same rate as the control herd. If the mean were negative, the average herd changed milk yield or income over feed cost slower than control herds. An estimate of change in 3.5% FCM and income over feed cost relative to previous production was calculated b y adding the control herds' average annual increase to the least square mean. Control stanchion herds increased milk yield by 98 kg and income over feed cost b y $41 annually. Control loose housing herds increased milk yield and income over feed cost annually by 79 kg and $32 per cow. RESULTS AND DISCUSSION

Means and standard deviations of differences between herd averages 1 yr prior to the housing change and the years after are in Table 3. The means are the average change for each variable in relation to that variable's change by control herds. Deviation in herd size is expressed relative to average herd size prior to housing change and is not related to control herds. On the average, deviations of 3.5% FCM and income over feed cost were positive in herds changing from stanchion to tie stall or loose housing to cold free stall housing. These herds appear to have produced 25 to 75 kg more milk than control herds. Deviations in milk yield and income over feed cost were negative for herds involved in a stanchion to warm or cold free stall housing change. These herds appear to have produced 240 kg less milk than control stanchion herds. Herd expansion was two to three times larger in the stanchion to free stall switches than in the other housing switches (Table 3). Differences in herd expansion and change in DHI management variables between housing switches, justified a covariance analysis. Herd expansion and initial herd size were covariance adjusted to averages of 14 and 40 cows, respectively. The analysis of variance table for both dependent variables, change in 3.5% FCM and income over feed cost, are in Table 4. The main effect of change in housing system was highly significant for both dependent variables. Years from construction and interaction of the two main effects were not significant. Thus, the gain or loss in the dependent variable did not vary

O U R INDUSTRY T O D A Y

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T A B L E 4. Error mean squares and F from the analysis of variance tables for deviations in 3.5% FCM and income over feed cost. Dependent variable Income over feed 3.5% FCM

cost

Housing change Yr from construction Housing × yr

12.06 a .36 1.04

13.61 a .95 .88

Covariates Change in herd size Initial herd size Change in feed index Change in grain fed Change in forage fed Change in % days in milk

2.11 a 9.18 a 32.73 a 38.79 a 29.97 a

1.05 3.67 a 27.23 a 33.06 a 24.81 a 11.35 a

7.12 a

Error m e a n square

53078

7092

a(p<.Ol).

y e a r l y w i t h r e s p e c t to t h e c o n t r o l h e r d s o r b e t w e e n t h e c h a n g e s in h o u s i n g s y s t e m . L e a s t s q u a r e m e a n s o f d e v i a t i o n in m i l k p r o d u c t i o n a n d i n c o m e o v e r f e e d c o s t f o r c h a n g e in h o u s i n g s y s t e m a r e in T a b l e 5. D a t a are in r e l a t i o n to c h a n g e s o f p r o d u c t i o n a n d i n c o m e over feed cost by the control herds. A mean of z e r o i n d i c a t e d t h a t c h a n g e o f p r o d u c t i o n o r in-

come over feed cost was identical to that of control herds. H e r d s c h a n g i n g f r o m s t a n c h i o n t o tie s t a l l housing produced 26 kg more milk than control herds. Herds switching from stanchion to free stall o r l o o s e h o u s i n g t o c o l d free stall h o u s i n g p r o d u c e d less m i l k t h a n c o n t r o l h e r d s ( T a b l e 5).

T A B L E 5. Deviation in 3.5% FCM and income over feed cost least square m e a n s by housing system change and years from construction. Income

3.5 % FCM

SE

over feed cost

SE

Housing change Stanchion to tie stall Loose housing to cold free stall Stanchion to warm free stall Stanchion to cold free stall

26 a -43 a -171 b -184 b

21 30 31 24

32 a 12 a -17 b -25 b

5.2 7.5 7.9 6.2

Years from construction Year 1 Year 2 Year 3 Year 4 Year 5

-86 -114 -82 -113 -69

29 28 30 30 29

a a a a a

4.7 a -2.6 a 7.9 a 11.3 a 10.8 a

7.0 6.9 7,7 7,7 8,6

a'bMeans with different superscripts to differ at (P<.01). Journal of Dairy Science Vol. 64, No. 8, 1981

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NORELL AND APPLEMAN

The change relative to control stanchion herds was significantly different b e t w e e n stanchion to tie stall switch and a stanchion to free stall switch (P<.01). Stanchion to tie stall herds p r o d u c e d on the average 198 to 210 kg more milk than the stanchion to free stall herds. Herds switching f r o m stanchion to free stall housing lost p r o d u c t i o n relative to: a) control stanchion herds, and b) stanchion to tie stall herds. Production change was not significantly different b e t w e e n herds changing stanchion to warm free stall and stanchion to cold free stall housing (Table 5). Providing a warm environm e n t in free stall housing apparently does not prevent the drop of p r o d u c t i o n following change from stanchion to free stall housing. Minnesota DHI farms with cold free stall barns averaged 69 kg m o r e milk per cow than those with w a r m free stall barns (1). There appears to be little benefit in providing warm free stall housing over cold housing in Minnesota. I n c o m e over feed cost increased relative to c o n t r o l herds with stanchion to tie stall or loose-housing to cold free stall housing changes (Table 5). I n c o m e over feed cost decreased relative to control stanchion herds for those herds making a change f r o m stanchion to free stall housing. Deviation in i n c o m e over feed cost was significantly different b e t w e e n stanchion to

tie stall and stanchion to free stall housing switches. Estimates of p r o d u c t i o n and i n c o m e over feed cost change relative to herd average 1 yr prior to the housing change are in Table 6. Milk p r o d u c t i o n d r o p p e d by 73 kg and 86 kg in those herds changing from stanchion to warm free stall and stanchion to cold free stall housing the year the new barn was built. The lost p r o d u c t i o n was recovered after 1 full yr in the new barn. P r o d u c t i o n did not drop the year the new barn was built in herds changing stanchion to tie stall or loose-housing to cold free stall housing. I n c o m e over feed cost did not fall below herd average prior to the housing switch in all four changes o f housing (Table 6). This result was p r o b a b l y from increasing milk prices that p r e d o m i n a t e d during this study (1970 to 1976). P r o d u c t i o n losses following a stanchion to free stall housing change were smaller than those in (4, 7). Initial herd sizes prior to housing change were nearly two times larger, and herd expansions were two to six times larger in (4, 7) than in this study. Differences in expansion rate is assumed to a c c o u n t for the greater p r o d u c t i o n losses. Our changes in p r o d u c t i o n for a 40-cow herd undergoing an expansion o f 14 cows (35%

TABLE 6. Estimated yearly deviation in milk yield and income over feed cost from herd average 1 yr prior to the housing system change, a Year from construction 1

2

3

124 36 -73 -86

222 115 25 12

4

5

418 273 221 208

516 352 319 306

3.5% FCM (kg) Stanchion to tie stall Loose housing to cold free stall Stanchion to warm free stall Stanchion to cold free stall

320 194 123 110

Income over ~ed cost(S/cow) Stanchion to tie stall Loose housing to cold free stall Stanchion to warm free stall Stanchion to cold free stall

73 44 24 16

114 76 65 57

155 108 106 98

196 140 147 139

237 172 188 180

aEstimates were calculated by adding the annual increase of milk yield and income over feed cost by control herds to the least square means for the housing system main effect. Control stanchion herds increased milk yield and income over feed cost by 98 kg and $41 annually. Loose housing control herds increased milk yield by 79 kg and income over feed cost by $32 annually. Journal of Dairy Science Vol. 64, No. 8, 1981

OUR INDUSTRY TODAY growth) are different from (3). Their estimate was a 9-kg loss in herd average milk yield for an initial herd size of 26 to 50 cows and 30 to 50% growth. In the two housing switches where herd management remained essentially the same, i.e., stanchion to tie stall and loose-housing to cold free stall, we observed a gain of production the 1st yr in the new barn (Table 6). In the two housing switches where a significant change in herd management occurred; i.e., stanchion to free stall, we observed a 7 to 10 times greater production loss during the 1st yr. Charron (4) observed a 15 times greater production loss following a stanchion to free stall switch than that in (3) for an initial herd size of 74 cows and a 39% growth in herd size. Thus, production losses following a housing change are influenced by both expansion rate and herd management change. Two Michigan studies reported problems experienced by dairymen following a housing switch from stanchion barns to loose housing (2, 7). Those identified were: 1) production dropped with change in environment, 2) cows did not adjust, 3) inability to feed according to production, 4) incorrect management practices because of extra work, 5) increased reproductive problems, 6) poor feed quality, 7) lack of feed, 8) more mastitis, 9) increased number of 2-yr olds in the herd, 10) reduced culling, 11) increased calf losses, 12) less desirable timeliness of harvest, 13) extra land and equipment often was needed, 14) difficulty in obtaining quality hired labor, and 15) difficulty in purchasing quality cattle. The extent of these problems in our herds is not known.

CONCLUSIONS

Milk production generally decreases following expansion of the dairy herd. In this study, we observed that the loss of production depends on the housing system and herd manage-

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ment change during herd expansion. Milk yield did not decrease following a 14 cow expansion (35% growth) and change from stanchion to tie stall or loose-housing to cold free stall housing. Herd management practices and cow environment are similar between old and new barns. When a change from stanchion to free stall housing is made, herd management and cow environment change. Herds in this type of housing change produced nearly 200 kg less milk per cow than stanchion herds maintained in the same housing and herds in a stanchion to tie stall housing change. Production declined by 70 to 80 kg the year the new barn was built and cattle were moved into it. Warm free stalls were not advantageous over cold free stalls in preventing production loss following housing change and herd expansion. REFERENCES

1 Appleman, R. D., B. J. Conlin, M. F. Hutjens, J. W. Mudge, and G. R. Steuernagel. 1978. Trends in Minnesota dairying. Page 33 in Univ. Minnesota Agric. Ext. Serv. Dairy Rep. 2 Brake, J., J. Okay, and M. Wirth. 1968. Management problems in dairy farm expansion. Michigan Agric. Exp. Sm. Res. Rep. 68. 3 Brown, C. A., and J. M. White. 1973. Immediate effects of changing herd size upon milk production and other dairy herd improvement measures of management. J. Dairy Sci. 56:799. 4 Charron, E. C. 1970. The free stall-loose housing system for dairy cattle (environmental and economic considerations). Page 35 in Summarized proc. - Dairy Chore Reduction Syrup. Agway, Inc., Syracuse, NY. 5 Hoglund, C. R. 1973. Dairy facility investments and labor economics. J. Dairy Sci. 56:488. 6 Parsons, G. S., and J. D. George. 1964. Trend towards free stall housing in North Carolina. J. Dairy Sci. 47:435. (Abstr.) 7 Speicher, J. A., S. B. Nott, and T. L. Stoll. 1978. Changes in production, cash flow, and income with dairy herd expansion. J. Dairy Sci. 61:1242. 8 Wiggans,G. R., and L. D. Van Vleck. 1970. Variation within herds under different housing systems. J. Dairy Sci. 53:541.

Journal of Dairy Science Vol. 64, No. 8, 1981