Feeding Acidified Milk Replacer Ad Libitum to Calves Housed in Group Versus Individual Pens1

Feeding Acidified Milk Replacer Ad Libitum to Calves Housed in Group Versus Individual Pens 1 A. L. R I C H A R D , A. J. H E I N R I C H S , and L. D. M U L L E R Department of Dairy and Animal Science The Pennsylvania State University University Park 16802 ABSTRACT

have been exhibiting a form of purposeless behavior, ttigher milk replacer intake by group-fed calves did not result in greater carcass fat content at 6 wk of age.

The purpose of this study was to evaluate group versus individual housing with a cold ad libitum feeding system for calves. Twelve Holstein calves were assigned to group or individual housing at birth. The experiment had two replications, each consisting of one group of 3 calves and 3 individually housed calves. All calves were fed cold acidified milk replacer ad Iibitum plus calf starter and water. Behavior was studied for one 48-h period during wk 1, 3, and 6. Four male calves were slaughtered at wk 6 for determination of carcass composition. Milk replacer and water intakes in the preweaning period (wk 1 to 5) tended to be higher for group-fed calves. Calf starter intake was not different. Group-housed calves had a higher BW and a slightly higher (although not statistically significant) average daily gain than calves fed in individual pens. Packed cell volume was lower for group calves due to their higher liquid intake, but plasma glucose and urea N concentrations were similar. Individually housed calves spent more time using the nipple and group-fed calves spent more time drinking water. A m o u n t of time eating starter did not differ between treatments but differed with age. Carcass composition was not different between calves housed individually or in groups. Because individually housed calves spent more time using the nipple, but consumed less milk replacer, they may

INTRODUCTION

Received November 2, 1987. Accepted March 14, 1988. 1Authorized for publication as Paper Number 7797 in the Journal Series of the Pennsylvania Agricultural Experiment Station.

1988 J Dairy Sci 71:2203--2209

The "cold ad lib" concept of feeding dairy replacements is being utilized in the management of dairy calves, especially those housed in groups. With the cold acidified milk replacer feeding system, calves have ad libitum access to a milk replacer acidified with organic acids (5). Research has demonstrated that calves housed in individual pens and fed ad libitum consumed significantly more acidified milk replacer than those fed conventionally (two times per day), with (3, 8) or without (3, 4) concurrent increases in average daily gain (ADG). Warnick et aI. (7) reported no differences in ADG when calves were fed milk twice daily and housed in groups or individual pens. Nocek and Braund (3) observed no differences in milk replacer intake or ADG in calves fed ad libitum in groups compared with those housed individually. However, Barton and Broom (1) noted that those fed acidified milk when housed in isolation consumed less than calves in visual contact with a hungrier calf. Calves that had physical contact with a hungrier calf consumed more than those that had only visual contact. Ensminger and Olentine (2) stated that cattle mimic each other's behavior. In a study where calves were group-reared at different stocking rates and fed milk replacer ad libitum for the first 5 wk of life, calves housed at the higher stocking rate consumed more dry milk replacer than calves housed at the lower stocking rate (.8 v s . . 5 kg/d) (5). At the higher stocking rate, competition was thought to be the cause of the increased DM intake. Weight gain was similar for the groups at both stocking rates and for calves bucket-fed .3 kg of dry milk replacer/d. Thus, animal behavior appears to affect intake

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RICHARD ET AL.

of milk replacer, but the effects of group feeding o n growth, animal behavior, and o t h e r physiological measures are unclear. T h e objectives of this e x p e r i m e n t were to d e t e r m i n e t h e effects of feeding acidified milk replacer ad libitum to calves housed inside in g r o u p or individual pens.

MATERIALS AND METHODS

Twelve Holstein calves were assigned at birth to either group or individual housing in a c o m p l e t e r a n d o m i z e d design with two replications. Each replication consisted o f one group pen o f three calves (one female, two male) and three individually housed calves (one female, t w o male). D i m e n s i o n s of the group pen were 2.48 x 2.48 m and those of the individual pens were 1.96 x 1.17 m. Calves were m o v e d to the calf rearing facility, a thermostatically ventilated barn,

w i t h i n 1 d of birth and fed c o l o s t r u m for 3 d. T h e r e a f t e r , t h e y w e r e offered acidified milk replacer, calf starter (Table 1), and w a t e r ad libitum. Milk replacer was r e c o n s t i t u t e d at a rate of 12.5%. Feed intake and b o d y weight w e r e measured w e e k l y for 6 wk. Calves were w e a n e d gradually b e t w e e n wk 4 and 5 by restricting access to the milk replacer according to the f o l l o w i n g schedule: 29 to 32 d, 12 h; 33 to 34 d, 4 h; 35 d, 0 h. Behavior m e a s u r e m e n t s were o b t a i n e d o n l y on calves in the first replication. T o m o n i t o r behavior, the calves were filmed using time-lapse p h o t o g r a p h y (one picture taken every 20 s) for one 48-h period during wk 1, 3, and 6. T h e calves were r e c o r d e d as drinking milk replacer, drinking water, eating starter, standing, or lying for each f r a m e o f film. One c o m m o n pen (4.96 × 2.48 m) was used during wk 6 to see h o w individually housed calves w o u l d behave w h e n placed in a group-feeding pen. Calves were offered acidified

TABLE 1. Composition of milk replacer and calf starter. Diet composition Item Dry matter, %

Acidified milk replacer

Calf starter

90.0

87.5 (% of DM)

Ingredient Shelled corn Oats Legume/grass hay, chopped (3.2-cm cut) Soybean meal, 44% CP Dry molasses Dried brewers grain Trace mineralized salt Limestone Dicaleium phosphate Vitamin A and D Selenium premix Nutrient content Crude protein Ether extract Acid detergent fiber Crude fiber 1 Calcium Phosphorus Vitamin A, IU/kg ~ Vitamin D~, IU/kg I 1Guaranteed analysis, Milk Specialties Co., Dundee, IL. Journal of Dairy Science Vol. 71, No. 8, 1988

48.6 15.0 15.0 9.5 5.0 5.0 1.0 .6 .3 .02 .02 21.5 19.3 .4 .15 .57 .79 6750 1350

16.2 3.3 14.2

156 .45

ACIDIFIED MILK REPLACER FED AD LIBITUM milk replacer, calf starter, and water ad libitum, which were all located at the front of the pen. Blood samples were collected via jugular venipuncture once a week until calves were weaned at wk 5. Three samples at 8-h intervals were taken on each sampling day to ensure a more representative sample. Blood was analyzed for packed cell volume (PCV), then centrifuged at 1000 x g. Plasma was frozen at - 2 0 ° C and later analyzed for glucose, urea N, and minerals (Ca, P, Na, C1, K, Mg). Glucose analysis was performed using the glucose oxidase method (Sigma Chemical Co., St. Louis, MO). Urea N and P were analyzed on the Technicon autoanalyzer (Technicon Instruments, Tarrytown, NY). Calcium and Mg were determined by atomic absorption analysis (Perkin-Elmer 303, Norwalk, CT). Sodium, C1, and K were analyzed on a NOVA 5 analyzer which contains an ion selective electrode (Nova, Waltham, MA). At the end of the 6th wk, the four male calves in the second replication were slaughtered for determination of carcass composition. The entire right half of the carcass, including bones, was ground (three times) and analyzed for moisture by drying in a laboratory oven at 60°C. Crude protein was analyzed using the Kjeldahl procedure and lipid was determined using Goldfisch extraction. Samples were ashed in a muffle furnace at 600°C. Data were analyzed statistically using the General Linear Models procedure of SAS (6). However, intake data were not analyzed because individual intake for the group-fed calves could not be measured. Initial BW was used as a covariate in the analysis of BW and ADG. Initial height was used as a covariate for wither height analysis. Analysis of covariance was not used for the carcass composition data. Data were analyzed according to the model: Yijk = P + si + hj + (s × h)ij + BXijk + eijk where: is the overall mean, si is the effect of the ith season, hj is the effect of the jth treatment (housing type), (s × h)ij is the interaction due to the combination of the ith season with the jth treatment, Xij k is the value of covariate (weight or

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height at birth) measured on the kth calf on the ith season, jth treatment, and eijk is the error term associated with kth calf experimental unit. A separate analysis for blood metabolites and behavior was conducted using the model: Yijkl = P + hi + calfj(h)i + Wk + (w x h)ki + eijkl where: /a is the overall mean, h i is the effect of the jth treatment (housing type), calfj(h)iis the error term used to test effects in the main plot, w k is the effect due to week of sampiing, (w × h)ki represents the interaction due to the combination of the k th week with the ith treatment, and eijkliS the error term used to test effects in the subplot. RESULTS A N D DISCUSSION

In the preweaning period, wk 1 to 5, calves housed in group pens tended to consume more milk replacer, water, and total liquid than calves in individual pens (Table 2). Intake of milk replacer was higher than previously reported for calves housed in group and individual pens (3, 4). Intake of milk replacer was 1.48 and 1.20 kg/d for calves in group and

TABLE 2. Intake of acidified milk replacer, calf starter, water, and total liquid by calves fed ad libitum in group versus individual pens during the preweaning period (wk 1 to 5).

Variable

Group 1

No. calves Dry milk replacer, kg/d Calf starter, kg DM/d Free choice water, kg/d Total liquid, kg/d

6 1.48 .08 1.27 11.62

Treatment Individual 6 1.20 .09 .45 8.85

1Values are reported on a per calf basis. Journal of Dairy Science Vol. 71, No. 8, 1988

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RICHARD ET AL.

liquid with group housing. In this regard, calves were exhibiting aUelomimetic or mutual mim. Milk fleplacer / InOivl0ual ~5 icking behavior (2). Calf starter intake was similar for both treatments and did not int crease until wk 5 when weaning occurred ~ --0-S~~ Calf 5tavteo (Figure 1). InO~v1oual .5 Calves housed in groups had a higher BW and /,f~ ---~".~v" .... :~i_g ADG, but a similar wither height when com=====================================-- , L ° ~ pared to individually housed calves in the 2 3 ~ 5 B Week preweaning period (Table 3). Calves housed in Figure 1. Average daily intakes, by week, of dry groups were heavier due to two possible reamilk replacer and starter for calves fed acidified milk sons. First, group-fed calves most likely had replacer ad libitum and housed in group or individual more gut fill because of their higher total liquid pens. intake. In addition, the higher milk replacer intake may have produced slightly higher weight gains. The ADG observed in this trial for individual pens, respectively, compared with both group-reared and individually reared .86 kg/d for calves housed in individual pens in animals were substantially higher than ADG a previous trial (4). Nocek and Braund (3) reported earlier for calves fed acidified milk reported average daily intakes to be .87 and .81 replacer ad libitum (3, 4). Nocek and Braund kg for calves fed ad libitum and housed in (3), however, reported no differences in weight group and individual pens, respectively. How- gain between calves housed in group or inever, the present trial was conducted during dividual pens. In the present study, calves on warm weather as opposed to the cold weather both treatments appeared to be similar for all conditions used in the previous trial (4). Higher measurements of growth during wk 6, although ambient temperature may have stimulated the there was a large but nonsignificant difference calves to consume more liquid than in other in ADG. For wk 2, 3, and 4, calves housed in experiments. Competition and social interac- groups had higher (P<.06) BW than those tion between the calves housed together also housed in individual pens (Figure 2). During wk 5, when weaning occurred, those housed in may have caused this increased consumption of Milk ~ e p l a c e r Grouo

. . . .

TABLE 3. Body weight, average daily gain, and wither height for calves fed acidified milk replacer ad libitum in group and individual pens during the preweaning (wk 1 to 5), postweaning (wk 6), and overall (wk 1 to 6) periods. 1 Treatment Variable Preweaning period (wk 1 to 5) Body weight, kg Avg. daily gain, kg Wither height, cm Postweaning period (wk 6) Body weight, kg Avg. daily gain, kg Wither height, cm Overall (wk i to 6) Body weight, kg Avg. daily gain, kg Wither height, cm

Group

Individual

SE

P<

62.9 .79 80.6

58.2 .70 79.1

1.2 .03 .7

.03 .10 .19

72.8 .54 84.3

72.3 .90 82.8

1.3 .14 .7

.81 .12 .18

64.5 .75 81.2

60.5 .73 79.7

1.1 .03 .7

.04 .69 .18

aMeans over the individual periods. Journal of Dairy Science Vol. 71, No. 8, 1988

ACIDIFIED MILK REPLACER FED AD LIBITUM 75

Group

70

Individual

65

~

6o 55 5O 45 4O 35

0

~

2

3

,1

5

6

Wk o f Age

Figure 2. Body weights, by week, of calves fed acidified milk replacer ad libitum and housed in group or individual pens.

groups lost weight whereas calves fed in individual pens gained weight; but the grouphoused calves stil tended to be heavier (68.6 vs. 65.5 kg). However, in wk 6, BW for calves on both treatments were similar (P>.80), due to a high rate of gain by the calves fed milk replacer in individual pens. Week 6 data were based on one observation per calf with a small number of calves. Overall, for wk 1 to 6, body weight was higher for the group-fed calves but ADG and wither height were not significantly different between treatments. Analysis of blood samples revealed a lower PCV for calves housed in groups (Table 4). The higher liquid intake by these calves caused them

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to be more hydrated than the individually housed calves: group-fed calves had significantly lower PCV than calves housed individually for each wk 1 to 4 (prior to weaning) (Figure 3). Yet during wk 5, PCV were not as different betwoen treatments (Figure 3). A significant treatment by age interaction was present for glucose (Figure 4), and plasma urea N was significantly increased with age (P<.01). For group-fed calves, plasma glucose increased between wk 1 and 2 and decreased thereafter. Calves housed in individual pens showed a decrease in plasma glucose beginning at wk 1. The initial rise in glucose concentration for group-housed calves was probably due to an increasing intake of milk replacer. The decrease in plasma glucose and simultaneous increase in plasma urea N for calves on both treatments occurred as calves consumed larger quantities of the starter diet and began the conversion from preruminant to ruminant animal. In a previous study (4), plasma glucose was higher for calves fed acidified milk replacer ad libitum vs. those fed twice daily due to higher intake of replacer. Although not significant, the group-fed calves tended to have higher plasma glucose (119.6 vs. 100.0 mg/dl), possibly due to their higher intake of replacer. Plasma Ca, P, Mg, Na, K, and CI were not significantly different between calves housed in group or individual pens (Table 4).

TABLE 4. Packed cell volume and plasma metabolite and mineral concentration in calves fed acidified milk replacer ad libitum in group and individual pens. 1 Treatment Variable

Group

Individual

SE

P<

Packed cell volume, % Plasma metabolites Glucose, mg/dl Urea nitrogen, mg/dl

29.6

37.2

2.5

.10

119.6 4.5

100.0 5.4

8.7 1.1

.19 .55

Plasma minerals Calcium, mg/dl Magnesium, mg/dl Phosphorus, mg/dl Sodium, meq/L Potassium, meq/L Chloride, meq/L

11.4 2.2 10.0 145.5 4.8 107.2

11.0 2.0 9.0 146.0 5.0 109.8

.1 .1 .4 .7 .1 .8

.09 .14 .19 .62 .20 .08

Over all sampling times for calves 1 to 5 wk of age. Journal of Dairy Science Vol. 71, No. 8:1988

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RICHARD ET AL.

g0,000

~o

t

2

3

4

~

J

5

2

3

4

Gvoug

5

Week

Week

Figure 3. Effect of housing type on packed cell volume in calves fed acidified milk replacer ad libitum (housing X week interaction, P<.O1, SE
Figure 4. Effect of housing type on plasma glucose concentration in calves fed acidified milk replacer ad libitum (housing X week interaction, P<.03, SE<7.9).

Behavior of the calves was affected by age as well as type of housing (Table 5). As calves became older, they spent less time drinking replacer, and it appears that calves housed individually spent more time than group-housed calves in this activity only during wk 1. Because the calves reared in individual pens spent more time drinking from the nipple, but consumed less milk replacer, they may have used the nipple for amusement rather than actually drinking some of the time. Woodford et al. (8) reported that calves fed acidified milk' replacer ad libitum consumed 14.3 meals per day, but this was highly variable. The amount of time drinking water increased with age. Obviously,

once calves were weaned, they drank more water, because milk replacer was no longer available to provide liquid. There was also a housing × week interaction for a m o u n t of time drinking water. Calves in the group pen appeared to spend more time drinking than calves in individual pens, and this time increased with age until wk 6 when there was no significant difference due tO housing (P>.34). Time spent eating calf starter was not different between the two housing types but increased with age. Once calves were weaned, more starter ration was consumed. Finally, when the calves were placed in one large pen for the wk-6 observations, there were no differences due to

TABLE 5. Effect of age and group versus individual housing on time apparently spent per day drinking milk replacer, water, and eating starter in calves fed acidified milk replacer ad libitum. Treatment (Trt) Variable

Group

P<

Individual

Trt

Week

T XW

Time drinking replacer, min wk 1 wk 3 wk 6

59.5 66.2 0

120.7 52.8 0

.17

.01

.05

Time drinking water, rain wk 1 wk 3 wk 6

10.7 8.2 16.2

2.0 2.0 18.5

.02

.01

.03

Time eating starter, rain wk 1 wk 3 wk 6

14.2 18.0 185.7

3.7 14.2 151.5

.27

.01

.64

Journal of Dairy Science Vol. 71, No. 8~ 1988

ACIDIFIED MILK REPLACER FED AD LIBITUM

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TABLE 6. Half carcass composition of calves, 6 wk of age, fed acidified milk replacer ad libitum in group and individual pens. Treatment Item

Group

Individual

SE

P<

No. calves Protein, % Lipid, % Moisture, % Ash, %

2 18.9 7.5 68.8 4.9

2 18.3 6.4 70.5 4.8

.8 1.1 1.0 .8

.65 .53 .32 .93

previous housing t y p e in the a m o u n t o f t i m e eating starter (P>.16) o r drinking water. Based on this i n f o r m a t i o n , calves previously housed in individual pens were able to c o m p e t e well w i t h the group-reared calves. Carcass c o m p o s i t i o n data are s h o w n in Table 6. T h e r e were no differences in protein, lipid, moisture, or ash c o n t e n t b e t w e e n calves fed individually or in groups. A f t e r weaning, PCV for all calves were similar (Figure 3), which explains w h y there was no difference in carcass m o i s t u r e content. We recognize that our sample size is smali. However, it is also w o r t h n o t i n g t h a t the standard errors are low and t h a t published carcass c o m p o s i t i o n data on very y o u n g calves are limited.

CONCLUSIONS

Calves housed in group pens c o n s u m e d m o r e milk replacer and were heavier than calves housed in individual pens to 5 w k of age. Individually housed calves spent m o r e t i m e engaged in oral behavior unrelated to drinking. Packed cell v o l u m e was lower for group-fed calves due to their higher liquid intake, and carcass c o m p o s i t i o n was not d i f f e r e n t b e t w e e n treatments. A n y additional fat t h a t m a y have b e e n deposited as a result of higher milk replacer intake was dissipated by wk 6.

ACKNOWLEDGMENTS

The authors express thanks to A g w a y Inc., Syracuse, NY and Milk Specialties Co., D u n d e e , IL for their partial financial and t e c h n i c a l support. REFERENCES

1 Barton, M. A., and D. M. Broom. 1985. Social factors affecting the performance of teat-fed calves. Anim. Prod. 40:525. 2 Ensminger, M. E., and C. G. Olentine, Jr. 1978. Pages 282-289 in Feeds and nutrition. 1st ed. Ensminger Publ. Co., Clovis, CA. 3 Nocek, J. E., and D. G. Braund. 1986. Performance, health, and postweaning growth on calves fed cold, acidified milk replacer ad libitum. J. Dairy Sci. 69:1871. 4 Richard, A. L., L. D. Muller, and A. J. Heinrichs. 1988. Ad libitum or twice daily feeding of acidified milk replacer to calves housed individually in warm or cold environments. J. Dairy Sci. 71: 2193. 5 Roy, J.H.B. 1980. The calf. 4th ed. Butterworth, Inc., Woburn, MA. 6 Statistical Analysis System. 1982. SAS User's guide. SAS Inst., Caw, NC. 7 Warniek, V. D., C. W. Arave, and C. H. Mickelsen. 1977. Effects of group, individual, and isolated rearing of calves on weight gain and behavior. J. Dairy Sci. 60:947. 8 Woodford, S. T., H. D. Whetstone, M. R. Murphy, and C. L. Davis. 1987. Abomasal pH, nutrient digestibility, and growth of Holstein bull calves fed acidified milk replacer. J. Dairy Sci. 70:888.

Journal of Dairy Science Vol. 71, No. 8, 1988