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Evaluation of High Starch and High Fat Rations for Dairy Calves1
Evaluation of High Starch and High Fat Rations for Dairy Calves 1 G. D. S T E W A R T 2 and D. J. S C H I N G O E T H E
Dairy Science Department South Dakota State University Brookings, 57007 ABSTRACT
parent digestibilities of the respective diets were: dry matter, 81.3, 77.7, and 76.1%; energy, 80.1, 76.5, and 75.9%; nitrogen, 83.4, 77.8, and 76.1%; and ether extract, 89.0, 80.0, and 90.0%.
Sixty-four Holstein calves were in a 3 x 2 factorial experiment of 12 wk starting at 3 days of age to evaluate growth performance when calves were fed control, high starch, and high fat pelleted diets separately or with a supplemental concentrate mix offered the first 6 wk. High starch and high fat diets were formulated to contain more digestible energy (3.48 Mcal/kg dry matter) than the control diet (3.31 Mcal/kg dry matter). Calves received whole milk the first 5 wk plus one of these rations ad libimm wk 1 thru 12. The control diet contained corn, oats, and soybean meal; the high starch diet contained corn and soybean meal; and the high fat diet contained corn and an extruded whole soybean product. All pelleted diets contained 20% ground alfalfa-bromegrass hay, 5% dry molasses, and 1% each of dicaIcium phosphate, trace mineral salt, and antibiotic premix. The supplemental concentrate mix contained corn, oats, and soybean meal, 9% liquid molasses, minerals, and vitamins. Weight gains, feed intakes, and ratios of feed to gain were similar for all three pelleted diets with or without the supplemental concentrate mix during wk 1 thru 5, 6 thru 12, and 1 thru 12. Calves offered the supplemental concentrate mix during wk 1 thru 6 tended to consume more total feed than calves offered only pellets. Apparent digestibilities of control, high starch, or high fat diets measured for twenty 13-wk old male calves were generally highest for the control diet. Ap-
INTRODUCTION
Calves have been raised successfully in hutches at South Dakota State University for more than 20 yr (2, 10, 17) as well as at other research stations (11, 13) where climatic conditions may be cold in winter. However, weight gains were usually lowest during times of lowest (~-10°C) and highest (~>20°C) average ambient temperatures (2, 17). Although feed intakes were not reported in (2, 17), calves did not consume more feed when housed in hutches instead of indoors (10), although appetite is usually increased during cold weather (26). Calves that seemed most stressed were those that were weaned about the time of extremely cold weather. The intent of our research was to evaluate two methods of increasing energy intake of calves from dry feeds. Methods evaluated were: 1) increasing the energy density of the pelleted calf starter feed or 2) providing access to a supplemental grain mix during the milk feeding period. MATERIALS Growth Trial
Received July 18, 1983. 1Published with approval of the director of the South Dakota Agricultural Experiment Station as Publication No. 1944 of the Journal Series. 2Milk Specialties Co., Dundee, IL 60118. 1984 J Dairy Sci 67:598-605
AND METHODS
598
Sixty-four Holstein calves, 44 females and 20 males, were in a 3 × 2 factorial experiment to compare three pelleted complete rations (control, high starch, and high fat) fed with or without an unpelleted supplemental concentrate mix (USCM). Within each sex, calves were assigned randomly at birth to one of the six treatment regimens. Numbers of calves starting on experiment during January through December were: 7, 7, 7, 5, 5, 3, 5, 1, 6, 8, 6, and 4, respectively. Each calf received colostrum the first 3 days of life and started on the experiment at 3 days of age. All calves were fed
HIGH STARCH AND FAT RATIONS FOR CALVES
599
TABLE 1. Ingredient composition of three pelleted calf diets and unpelleted supplemental concentrate mix (USCM).a Diet
High
High fat u
USCM
50.3 ...
36.0 36.0 16.0 ... ... . 910 1.0 1.0 1.0
Ingredient
Control b
starchb
Rolled corn Rolled oats Soybean meal [47.5% (crude protein) CP] Heat treated soybeansc (34.5% CP) Alfalfa-brome grass hay (ground) Dry molasses Liquid molasses Dicalcium phosphate Trace mineralized salt Antibiotic premix d
30.4 30.4 11.2 ... 20.0 5.0
57.7
2010 5.0
2117 20.0 5.0
" 110 1.0 1.0
' 110 1.0 1.0
" iiO 1.0 1.0
(% as fed)
1413
aAll rations contained 1800 IU of vitamin A and 180 IU of vitamin D/kg. bpelleted. C
Commercially available extruded product containing 90% soybeans. dAurovet antibiotic, American Cyanamid, Princeton, NJ.
3.63 kg of whole milk per day for 4 wk and 1.82 kg per day the 5th wk. Calves received 100 mg antibiotic 3 per day in their milk, and all calves were weaned at the end of their 5th wk on trial. Pelleted starters were offered for ad libitum consumption throughout the 12 wk trial. Unpelleted supplemental concentrate mix was offered separately the first 6 wk to one-half of the calves in each pelleted starter group to see if it would stimulate additional intake of dry matter to help calves during the stress of weaning and if it was preferred over the pelleted starters during the period of milk feeding. Feed consumption was measured daily throughout the entire 12 wk trial. Calves were weighed at birth, 3 days of age, and weekly thereafter. Calves were housed in hutches with outside feeding as described by Durland (5). This growth trial was from January 1980 to May 1981. Temperature data were from Weather Research on the campus of South Dakota State University for the purpose of examining the effect of higher energy rations on calf per-
3Terramycin, Elanco Products Co., Indianapolis, IN.
formance during cold (winter) and hot (summer) weather. For evaluation of temperature affects on weight gains, weekly weight gains were plotted by average weekly temperature (average of day time high and night time low). Data were analyzed by both linear and quadratic regression analyses (24). Ingredient composition of the three pelleted calf diets and the USCM are in Table 1. All diets were formulated to be isonitrogenous at 16.5% crude protein (dry matter). The high starch and high fat diets were formulated to contain more digestible energy (3.48 Mcal/kg dry matter) than the control diet (3.31 Mcal/kg dry matter). The high starch diet contained shelled corn as the only grain ingredient whereas the control diet contained equal amounts of corn and oats. Extruded whole soybeans served as the source of additional fat in the high fat diet. We intended that the high fat diet contain about 6% fat because more than 8% fat may cause digestive upsets or reduced palatability (18). Chemical composition of the starters and the USCM is in Table 2. Feeds were sampled weekly and samples frozen for later analyses. Samples were oven dried at 57°C for 48 h and ground through a 2-mm screen in a Wiley Mill. All analyses were of dried samples. Analyses included proximate Journal of Dairy Science Vol. 67, No. 3, 1984
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STEWART AND SCHINGOETHE
TABLE 2. Chemical composition of three pelleted calf diets and unpelleted supplemental concentrate mix (USCM) used in growth trial. Diet Measurement
Control
High starch
Dry matter (DM)
93.0
92.2
Crude protein N-free extract Ether extract Acid detergent fiber Neutral detergent fiber Ash
16.3 60.6 2.2 14.6 24.7 6.6
16.8 64.0 2.5 12.1 20.4 6.4
High fat
USCM
93.2
91.9
16.1
16.5 66.6 3.0 11.8 25.9 4.9
(%) (% of DM)
analyses (1), acid detergent fiber (9), and neutral detergent fiber. Neutral detergent fiber was measured by the procedure of Robertson and Van Soest (21) as modified by Mertens (Personal communication, 1982) for feeds with high starch content. Approximately .5 g of dried feed sample was weighed and put into a 600-ml Berzelius beaker; 50 ml of neutral detergent solution at room temperature then was added. The beaker was placed on a refluxing apparatus, solution was brought to a boil, then allowed to reflux for 40 min as times from the onset of boiling. After refluxing, the beaker was removed, and 50 ml of neutral detergent solution at room temperature was added along with 2 ml of a 2% a-amylase solution. 4 The beaker was reheated, and the solution was refluxed for 20 rain. It then was removed from the heat, allowed to settle, and filtered by suction through a tared Gooch crucible. The beaker was rinsed with hot distilled water, cleaned with a rubber policeman, and contents poured into crucible. The residue in the crucible finally was washed with acetone until rinse was clear. Crucibles were dried overnight at 100°C and weighed.
4Two grams a-amylase No. A-1278, Sigma Chemical Co., St. Louis, MO, in 90 ml distilled water, filtered through Whatman No. 54 filter paper, and 10 ml of 2-ethoxy-ethanol added as preservative. Solution was made fresh weekly. SDouble valve, automatic temperature control, Parr oxygen bomb calorimeter, Parr Instrument Co., Moline, IL. Journal of Dairy Science Vol. 67, No. 3, 1984
57.6
6.3 12.7 20.8 7.3
Data were analyzed by analysis of variance for a 3 x 2 x 2 factorial design as described by Steel and Torrie (24). Factors evaluated were: three pelleted calf diets, with or without supplemental concentrate mix, and sex of calves. Sex of calf had no influence on weight gains or feed intake, so data from both heifer and bull calves were combined in the reported data as a 3 x 2 factoral. Only data from the 64 calves that completed the trial were included in statistical analyses. Differences among feed intakes during different weeks were determined by the Waller-Duncan test (24), and Tukey's test (24) was used for comparing starting weights. Data also were analyzed by covariate analyses with starting weight and ambient temperature covariates. Digestion Trial
After the 12-wk growth trial, male calves were placed in digestion stalls and continued to be fed their respective pelleted diets. After 4 days for adjustment, feed intake and fecal output were measured, recorded, and sampled for 5 consecutive days. Samples were frozen for later analyses. Samples were dried and processed as described. Analyses included proximate analyses (1), acid detergent fiber (9), energy by oxygen bomb calorimeter, s and neutral detergent fiber as described earlier. Body weights were recorded on the 1st and 9th day of the digestion trial. Data were analyzed by analysis of variance according to Steel and Torrie (22) with dif-
HIGH STARCH AND FAT RATIONS FOR CALVES ferences among treatments evaluated through orthogonal comparisons. Comparisons evaluated were: 1) control versus high starch and high fat diets and 2) high starch versus high fat diets. Least significant difference was used for differences in crude protein of pelleted diets fed during the digestion trial.
RESULTS A N D DISCUSSION Growth Trial
Results of the growth trial are in Table 3. Daily dry feed intake (dry matter) does not include dry matter calves received from milk. All calves consumed .43 kg dry matter from milk wk 1 thru 4 and .22 kg per day wk 5. Intakes of total dry feeds were similar wk 1 thru 5, wk 6 thru 12, and wk 1 thru 12 for all groups of calves. Feed intakes were affected by week (P<.01), especially for wk 1 thru 5 as would be expected, because as calves grow they consume considerably more feed. Calves offered USCM, regardless of pelleted diet, consumed less pellets (P<.01) during wk 1 thru 6 than did calves offered only pellets (Figure 1). By individual weeks calves offered the USCM consumed less pellets (P<.05) during wk 2 and 6. The decreased pellet intake during wk 1 thru 6 was more than offset by intake of USCM. Calves offered USCM during wk 1 thru 6 tended to consume more total feed than those calves offered only pellets, but differences were not significant (P>.05). Combining hay and concentrate in a pellet in this trial did not affect adversely feed intake as reported by Gardner (8). Palatability of the high fat ration was not affected adversely as it was for others (6, 14) when 10 to 20% fat was included in calf rations. Starting body weights were similar for all groups of calves, except for calves fed the pelleted control diet without USCM, which had lower starting weights (P<.05). However, starting weights had no apparent affect on weight gains, so weight gain data in Table 3 are actual data rather than data adjusted for starting weights. Average daily gains were similar (P>.05) with all pelleted rations during all periods, although calves receiving the high fat diet had the lowest gains (P>.05) during all periods. In (22) weight gains were similar when calves
601
were fed diets containing corn or oats as the grain ingredient. Others (8, 14, 25) observed no difference in weight gains whereas Fisher (5) observed increased weight gains of calves fed added fat. Admittedly, a 5% difference in digestible energy content of diets would not be expected to have a marked affect on weight gains, unless calves were under stressful conditions. Then, the added energy may be sufficient to help them through the stress. Weight gains were similar for calves wk 1 thru 5, 6 thru 12, and 1 thru 12, whether they received USCM during the first 6 wk of the experiment. Calves receiving the USCM during the milk feeding period (wk 1 thru 6) gained slightly more weight in all except the 1st and 6th wk, but none of these differences approached statistical significance. Gains of all calves in this experiment compared favorably with gains of calves fed similar rations from birth to 12 wk of age (3, 5, 7, 15, 23, 25). Feed dry matter intakes per kilogram of gain were similar (P>.05) for all diets in all periods. General health of all calves was good throughout the trial. No calves receiving the control diet died. Two calves fed the high starch diet died, one at 5 days of age from u n k n o w n cause; the other died of bloat at 10 wk of age. Two calves fed the high fat diet died of bloat during wk 9. Data from those four animals were not included in the analyses. Environmental temperature had no effect on intake, average daily gain, or efficiencies of feed utilization for any age periods of calves evaluated. Slopes of regression lines of weight gains on ambient temperatures were not different from zero for calves fed any diets during any weeks of age. Data covariate adjusted for ambient temperature were similar to actual, unadjusted data. This lack of effect of temperature was likely, because the two winters of this trial (1979-1980 and 1980-1981) were mild by local weather standards. Thus, most calves were under thermal neutral conditions (26) most of the time. Average weekly temperatures ranged from a low of - 1 5 ° C (average of day time high and night time low) in winter to a high of 25vC in summer. We hypothesized that the high starch and high fat diets would be more beneficial than the control diet to calves subjected to severe cold stress, especially severe cold weather about the time or shortly after weaning. No severely stressful weather conditions o c Journal of Dairy Science Vol. 67, No. 3, 1984
t-
t7
bO
TABLE 3. Feed intakes, starting weights, average daily gains, and feed efficiencies of calves fed control, high starch, or high fat pelleted diets with or w i t h o u t access to unpelleted supplemental concentrate mix (USCM). Main effect and interaction Control
<
Z o
oo
Number of calves Male Female Dry feed intake/day, kg DM f Wk 1 to 5 Wk 6 to 12 Wk 1 to 12 Starting weight, kg Average daily gain, kg Wk 1 to 5 Wk 6 to 12 Wk 1 to 12 Feed dry matter, kg/gain, kg h Wk 1 to 5 Wk 6 to 12 Wk 1 to 12
Trt ×
_
i0 3 7
10
3 7
,34 2.33 1.50 40.0g
.42 2.44 1.59 45.3
.36 2.38 1.53 45.7
.42 2.38 1.56 45.4
.40 2,28 1.49 45,4
,37 2.37 1.54 43.9
.159 .405 .276 4.03
NS NS NS NS
NS NS NS NS
NS NS NS *
.48 .89 .72
.48 .87 .71
.50 .87 .72
.48 :89 .71
.44 .81 .66
.42 .83 .70
.141 .173 .126
NS NS NS
NS NS NS
NS NS NS
1.58 2.65 2.32
1.75
1.65 2.82 2.41
2.10 2.66 2.41
1.85 2.92 2.59
1.49
.724 .460 .357
NS NS NS
NS NS NS
NS NS NS
acalves not offered USCM.
CStandard deviation. dcontrol versus high starch versus high fat. eUSCM versus no USCM. fMilk dry matter (DM) not included.
hMilk dry matter included.
High fat
+b
bCalves offered USCM.
gP<.05.
High Starch
_a
2.79
2.48
+
-
+
sc
10
11
15
8
.
.
.
.
.
.
.
.
.
.
.
.
4 6
5 6
5 10
3 5
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
2.89 2.42
Trt d
Supp e
supp
*q .~m ~q > Z I~ ¢~ Z O ,.] ~1
HIGH STARCH AND FAT RATIONS FOR CALVES
603
curred during the winters in this trial. Covariate analyses with data adjusted for starting weight and t e m p e r a t u r e resulted in no significant differences a m o n g diet treatments. Jorgenson et al. (10) observed no differences in growth, feed intake, health, or weaning age of calves housed in hutches as c o m p a r e d to calves housed indoors at this same research facility•
1.61.4~1.2l.Oml
Digestion Trial
.6.4.2-
1
2
3
4
5
6
WEEK
Figure 1. Feed intake (kg/day) of pelleted diets and unpelleted supplemental concentrate mix (USCM) during first 6 wk on trial.
A p p a r e n t digestibilities of the three pelleted calf diets as measured with 13-wk old male calves are in Table 4. T h e control diet was generally m o r e digestible than the high starch and high fat diets for all n u t r i e n t measures. Gross energy c o n t e n t s of the pelleted diets were similar (P>.05), although the high fat diet c o n t a i n e d slightly m o r e energy, as e x p e c t e d because of its higher fat content. Gross energy was m o r e digestible (P<.05) for the control diet than for the high starch and high fat diets. This contrasted with what was e x p e c t e d f r o m r e p o r t e d digestibilities for the dietary in-
TABLE 4. Daily weight change, daily dry matter intake, and apparent digestibility of control, high starch, and high fat rations by male calves. Diet Control No. of animals Avg weight at start, kg Avg weight at end, kg Daily wt change, kg Dry matter intake, kg/day Ration Energy, Mcal/kg DMb Crude protein, % of DM Coefficients of digestibility, % Dry matter Energy Nitrogen Ether extract Acid detergent fiber Neutral detergent fiber Ash
6 99.6
103.4 .42 2.63
High starch
High fat
sa
7
7
104.2
106.3
. . . . , ,
107.4
107,3
° . .
.35 2.52
.08 2.33
"1:10
3.98 16.2 cd
4.00 17.0 c
4.10 15.9 d
1.02 .66
81.3 80.1 c
77.7 76.5 77.8 80.0 33.6 42.7 65.8
76.1 75.9 76.1 90.0 e 37.3 42.5 59.5
4.82 3.97 4.06 4.16 12.18 11.74 6.32
83.4 d
89.0 c 48.6 c 50.7 72.4 d
aStandard deviation. bDry matter. CDifferent from high starch and high fat (P<.05). dDifferent from high starch and high fat (P<.01). eHigh fat different from high starch. (P<.01). Journal of Dairy Science Vol. 67, No. 3, 1984
604
STEWART AND SCHINGOETHE
gredients (18). The high starch diet fed during the digestion trial c o n t a i n e d m o r e crude protein (P<.05) than the high fat diet, even though all diets were f o r m u l a t e d to be isonitrogenous. A p p a r e n t nitrogen digestibility of the c o n t r o l diet was greater (P<.01) than of the high starch and high fat diets. This m a y be because corn represented only 16% of the protein fraction of the control diet but 36 and 31% of the protein fraction f r o m the high starch and high fat diets. Corn protein is quite insoluble (19) and at the p r o p o r t i o n s in the high starch and high fat diets also m a y have caused an increase of rate of passage, further reducing protein digestibility. A p p a r e n t digestibility of the ether extract in the control diet was higher (P<.05) than that of the high starch and high fat diets c o m b i n e d . However, the high fat diet was actually numerically m o r e digestible than the control diet, with the high starch diet being m u c h less digestible (P<.01) than the high fat diet. O t h e r researchers (4, 6, 10, 12) also observed higher digestibilities of ether extract with ruminants fed diets high in fats or oils than in animals fed a basal or control ration. However, Roberts and McKirdy (20) r e p o r t e d that the ether e x t r a c t m e t h o d of analyzing feces does n o t r e m o v e all of the fat because some is in a b o u n d form. This could explain the high apparent digestibility percentages for the ether extract c o m p o n e n t , especially in the high fat diet. Acid detergent fiber and ash c o m p o n e n t s of the control diet were also m o r e digestible (P<.05) than the acid detergent fiber and ash c o m p o n e n t s of either high starch or high fat diets. Dry m a t t e r and neutral detergent fiber digestibilities were n o t different (P>.05) b e t w e e n control, high starch, and high fat diets or high starch and high fat diets, although trends were similar to trends of digestibilities of other c o m p o n e n t s , suggesting that rate of passage o f the two diets containing m o r e than 50% corn was rapid enough to deter digestibilities in the y o u n g ruminant. This trial indicated no benefit in weight gains, feed intake, or health of calves attributable to increasing the starch f r o m corn or the fat f r o m soybeans in calf diets. Providing a supplemental grain m i x during the milk feeding period m a y stimulate some additional dry feed c o n s u m p t i o n , which could help calves through the stressful time around weaning. Workers at our research farm feel this practice is beneficial Journal of Dairy Science Vol. 67, No. 3, 1984
even t h o u g h our research data did n o t show a significant benefit. However, weather conditions during this trial were n o t sufficiently severe to subject calves to e x t r e m e l y stressful conditions. ACKNOWLEDGMENTS
Appreciation is e x t e n d e d to Lennis Baumiller and o t h e r personnel at the Dairy Cattle Research Unit of South D a k o t a State University for care of the calves, and to W. L. Tucker, E x p e r i m e n t Station Statistician, for assistance in statistical analyses of the data. E x t r u d e d soybean p r o d u c t used in this research was furnished by Triple " F " , Inc., Des Moines, IA. REFERENCES
1 Association of Official Analytical Chemists. 1975. Official methods of analysis. 12th ed. Assoc. Offic. Anal. Chem., Washington, DC. 2 Clark, A. K. 1982. Raising dairy calves in hutches. South Dakota State Univ. Dairy Sci. Update 82-3. 3 Daniels, L. B., and C. Flynn. 1976. Using full-fat processed soybeans in calf starter rations. Arkansas Farm Res. 25:5. 4 Delvin, T. J., J. R. Ingalls, and H. R. Sharma. 1977. Evaluation of high fat oats in rations of growing and finishing ruminants. Calves, sheep. Can. J. Anim. Sci. 57:735. 5 Durland, G. R. 1982. Calf hutches. South Dakota State Univ., Dairy Sci. Update 82-8. 6 Fisher, L. J. 1980. A comparison of rapeseed meal and soybean meal as a source of protein and protected lipid as a source of supplemental energy for calf starter diets. Can. J. Anita. Sci. 60:359. 7 Gardner, R. W. 1967. Acceptability and nutritional response comparisons between calf starters. J. Dairy Sci. 50:729. 8 Gardner, R. W. 1968. Digestible protein requirements of calves fed high energy rations ad libitum. J. Dairy Sci. 51:888. 9 Goering, H. K., and P. J. Van Soest. 1970. Forage fiber analysis. Agric. Handbook No. 379, Agric. Res. Serv., USDA, Washington, DC. 10 Jorgenson, L. J., N. A. Jorgensen, D. J. Schingoethe, and M. J. Owens. 1970. Indoor versus outdoor calf rearing at three weaning ages. J. Dairy Sci. 53:813. 11 Larsen, H. J., G. H. Tempas, and C. Cramer. 1977. Rearing young calves in cold and warm environments. Msh-201-6023-77, Univ. Wisconsin, Madison. 12 Macleod, G. K., and J. G. Buchanan-Smith. 1972. Digestibility of hydrogenated tallow, saturated fatty acids, and soybean oil-supplemented diets by sheep. J. Anim. Sci. 35:890. 13 McKnight, D. R. 1978. Performance of newborn dairy calves in hutch housing. Can. J. Anim. Sci. 58:517. 14 Miller, W. J. 1962. Comparison of lard, tallow, butter, and hydrogenated cottonseed oil in starters and of pelleted versus nonpelleted coastal Bermuda
HIGH STARCH AND FAT RATIONS FOR CALVES grass hay for calves. J. Dairy Sci. 45:759. 15 Miller, W. J., Y. G. Martin, and P. R. Fowler. 1969. Effects of addition of fiber to simplified and to complex starters fed to young dairy calves. J. Dairy Sci. 52:672. 16 Milligan, J. D., and C. M. Grieve. 1970. Effect of diet on growth and development of early weaned Holstein-Friesian calves. J. Anim. Sci. 50:147. 17 Muller, L. D., and M. J. Owens. 1976. Fifteen years experience with calf hutches. Hoard's Dairyman 121:1107. 18 National Research Council. 1978. Nutrient requirements of domestic animals. No. 3. Nutrient requirements of dairy cattle. 5th rev. ed. Washington, DC. 19 Owens, F. N. 1981. Calcium nutrition and buffers for feedlot cattle. Page 21 in Proc. 41st Semiannu. Mtg., Am. Feed Manuf. Assoc. Nutr. Counc., Lexington, KY. 20 Roberts, W. K., and J. A. McKirdy. 1964. Weight gains, carcass fat, characteristics, and ration digestibility in steers as affected by dietary rapeseed oil, sunflower seed oil, and animal tallow. J. Anim. Sci. 23:682. 21 Robertson, J. B., and P. J. Van Soest. 1977.
22
23
24 25
26
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Dietary fiber estimation in concentrate feedstuffs. Page 254 in Am. Soc. Anim. Sci. 69th Annu. Mtg. (Abstr.) Schingoethe, D. J., H. H. Voelker, and F. C. Ludens. 1982. High protein oats grain for lactating dairy cows and growing calves. J. Anim. Sci. 55:1200. Schuh, J. D., J.D.A. Lima, W. H. Hale, and B. Theurer. 1970. Steam-processed flaked grains versus steam-rolled grains for dairy calves. J. Dairy Sci. 53:475. Steel, R.G.D., and J. H. Torrie. 1980. Principles and procedures of statistics. 2nd ed. McGraw-Hill Book Co., New York, NY. Waldern, D. E., and L. J. Fisher. 1978. Effect of steam processed barley, source o f protein, and fat on the intake and utilization of starter rations by dairy calves. J. Dairy Sci. 61:221. Young, B. A. 1977. Effect of cold environments on nutrient requirements of animals. Pages 4 9 1 - 4 9 6 in Proc. 1st Intl. Symp., feed composition, animal nutrient requirements, and computerization of data, P. V. Fonnesbeck, L. E. Harris, and L. C. Kearl, ed., Utah Agric. Exp. Sm., Utah State Univ., Logan.
Journal of Dairy Science Vol. 67, No. 3, 1984
Dairy Science Department South Dakota State University Brookings, 57007 ABSTRACT
parent digestibilities of the respective diets were: dry matter, 81.3, 77.7, and 76.1%; energy, 80.1, 76.5, and 75.9%; nitrogen, 83.4, 77.8, and 76.1%; and ether extract, 89.0, 80.0, and 90.0%.
Sixty-four Holstein calves were in a 3 x 2 factorial experiment of 12 wk starting at 3 days of age to evaluate growth performance when calves were fed control, high starch, and high fat pelleted diets separately or with a supplemental concentrate mix offered the first 6 wk. High starch and high fat diets were formulated to contain more digestible energy (3.48 Mcal/kg dry matter) than the control diet (3.31 Mcal/kg dry matter). Calves received whole milk the first 5 wk plus one of these rations ad libimm wk 1 thru 12. The control diet contained corn, oats, and soybean meal; the high starch diet contained corn and soybean meal; and the high fat diet contained corn and an extruded whole soybean product. All pelleted diets contained 20% ground alfalfa-bromegrass hay, 5% dry molasses, and 1% each of dicaIcium phosphate, trace mineral salt, and antibiotic premix. The supplemental concentrate mix contained corn, oats, and soybean meal, 9% liquid molasses, minerals, and vitamins. Weight gains, feed intakes, and ratios of feed to gain were similar for all three pelleted diets with or without the supplemental concentrate mix during wk 1 thru 5, 6 thru 12, and 1 thru 12. Calves offered the supplemental concentrate mix during wk 1 thru 6 tended to consume more total feed than calves offered only pellets. Apparent digestibilities of control, high starch, or high fat diets measured for twenty 13-wk old male calves were generally highest for the control diet. Ap-
INTRODUCTION
Calves have been raised successfully in hutches at South Dakota State University for more than 20 yr (2, 10, 17) as well as at other research stations (11, 13) where climatic conditions may be cold in winter. However, weight gains were usually lowest during times of lowest (~-10°C) and highest (~>20°C) average ambient temperatures (2, 17). Although feed intakes were not reported in (2, 17), calves did not consume more feed when housed in hutches instead of indoors (10), although appetite is usually increased during cold weather (26). Calves that seemed most stressed were those that were weaned about the time of extremely cold weather. The intent of our research was to evaluate two methods of increasing energy intake of calves from dry feeds. Methods evaluated were: 1) increasing the energy density of the pelleted calf starter feed or 2) providing access to a supplemental grain mix during the milk feeding period. MATERIALS Growth Trial
Received July 18, 1983. 1Published with approval of the director of the South Dakota Agricultural Experiment Station as Publication No. 1944 of the Journal Series. 2Milk Specialties Co., Dundee, IL 60118. 1984 J Dairy Sci 67:598-605
AND METHODS
598
Sixty-four Holstein calves, 44 females and 20 males, were in a 3 × 2 factorial experiment to compare three pelleted complete rations (control, high starch, and high fat) fed with or without an unpelleted supplemental concentrate mix (USCM). Within each sex, calves were assigned randomly at birth to one of the six treatment regimens. Numbers of calves starting on experiment during January through December were: 7, 7, 7, 5, 5, 3, 5, 1, 6, 8, 6, and 4, respectively. Each calf received colostrum the first 3 days of life and started on the experiment at 3 days of age. All calves were fed
HIGH STARCH AND FAT RATIONS FOR CALVES
599
TABLE 1. Ingredient composition of three pelleted calf diets and unpelleted supplemental concentrate mix (USCM).a Diet
High
High fat u
USCM
50.3 ...
36.0 36.0 16.0 ... ... . 910 1.0 1.0 1.0
Ingredient
Control b
starchb
Rolled corn Rolled oats Soybean meal [47.5% (crude protein) CP] Heat treated soybeansc (34.5% CP) Alfalfa-brome grass hay (ground) Dry molasses Liquid molasses Dicalcium phosphate Trace mineralized salt Antibiotic premix d
30.4 30.4 11.2 ... 20.0 5.0
57.7
2010 5.0
2117 20.0 5.0
" 110 1.0 1.0
' 110 1.0 1.0
" iiO 1.0 1.0
(% as fed)
1413
aAll rations contained 1800 IU of vitamin A and 180 IU of vitamin D/kg. bpelleted. C
Commercially available extruded product containing 90% soybeans. dAurovet antibiotic, American Cyanamid, Princeton, NJ.
3.63 kg of whole milk per day for 4 wk and 1.82 kg per day the 5th wk. Calves received 100 mg antibiotic 3 per day in their milk, and all calves were weaned at the end of their 5th wk on trial. Pelleted starters were offered for ad libitum consumption throughout the 12 wk trial. Unpelleted supplemental concentrate mix was offered separately the first 6 wk to one-half of the calves in each pelleted starter group to see if it would stimulate additional intake of dry matter to help calves during the stress of weaning and if it was preferred over the pelleted starters during the period of milk feeding. Feed consumption was measured daily throughout the entire 12 wk trial. Calves were weighed at birth, 3 days of age, and weekly thereafter. Calves were housed in hutches with outside feeding as described by Durland (5). This growth trial was from January 1980 to May 1981. Temperature data were from Weather Research on the campus of South Dakota State University for the purpose of examining the effect of higher energy rations on calf per-
3Terramycin, Elanco Products Co., Indianapolis, IN.
formance during cold (winter) and hot (summer) weather. For evaluation of temperature affects on weight gains, weekly weight gains were plotted by average weekly temperature (average of day time high and night time low). Data were analyzed by both linear and quadratic regression analyses (24). Ingredient composition of the three pelleted calf diets and the USCM are in Table 1. All diets were formulated to be isonitrogenous at 16.5% crude protein (dry matter). The high starch and high fat diets were formulated to contain more digestible energy (3.48 Mcal/kg dry matter) than the control diet (3.31 Mcal/kg dry matter). The high starch diet contained shelled corn as the only grain ingredient whereas the control diet contained equal amounts of corn and oats. Extruded whole soybeans served as the source of additional fat in the high fat diet. We intended that the high fat diet contain about 6% fat because more than 8% fat may cause digestive upsets or reduced palatability (18). Chemical composition of the starters and the USCM is in Table 2. Feeds were sampled weekly and samples frozen for later analyses. Samples were oven dried at 57°C for 48 h and ground through a 2-mm screen in a Wiley Mill. All analyses were of dried samples. Analyses included proximate Journal of Dairy Science Vol. 67, No. 3, 1984
600
STEWART AND SCHINGOETHE
TABLE 2. Chemical composition of three pelleted calf diets and unpelleted supplemental concentrate mix (USCM) used in growth trial. Diet Measurement
Control
High starch
Dry matter (DM)
93.0
92.2
Crude protein N-free extract Ether extract Acid detergent fiber Neutral detergent fiber Ash
16.3 60.6 2.2 14.6 24.7 6.6
16.8 64.0 2.5 12.1 20.4 6.4
High fat
USCM
93.2
91.9
16.1
16.5 66.6 3.0 11.8 25.9 4.9
(%) (% of DM)
analyses (1), acid detergent fiber (9), and neutral detergent fiber. Neutral detergent fiber was measured by the procedure of Robertson and Van Soest (21) as modified by Mertens (Personal communication, 1982) for feeds with high starch content. Approximately .5 g of dried feed sample was weighed and put into a 600-ml Berzelius beaker; 50 ml of neutral detergent solution at room temperature then was added. The beaker was placed on a refluxing apparatus, solution was brought to a boil, then allowed to reflux for 40 min as times from the onset of boiling. After refluxing, the beaker was removed, and 50 ml of neutral detergent solution at room temperature was added along with 2 ml of a 2% a-amylase solution. 4 The beaker was reheated, and the solution was refluxed for 20 rain. It then was removed from the heat, allowed to settle, and filtered by suction through a tared Gooch crucible. The beaker was rinsed with hot distilled water, cleaned with a rubber policeman, and contents poured into crucible. The residue in the crucible finally was washed with acetone until rinse was clear. Crucibles were dried overnight at 100°C and weighed.
4Two grams a-amylase No. A-1278, Sigma Chemical Co., St. Louis, MO, in 90 ml distilled water, filtered through Whatman No. 54 filter paper, and 10 ml of 2-ethoxy-ethanol added as preservative. Solution was made fresh weekly. SDouble valve, automatic temperature control, Parr oxygen bomb calorimeter, Parr Instrument Co., Moline, IL. Journal of Dairy Science Vol. 67, No. 3, 1984
57.6
6.3 12.7 20.8 7.3
Data were analyzed by analysis of variance for a 3 x 2 x 2 factorial design as described by Steel and Torrie (24). Factors evaluated were: three pelleted calf diets, with or without supplemental concentrate mix, and sex of calves. Sex of calf had no influence on weight gains or feed intake, so data from both heifer and bull calves were combined in the reported data as a 3 x 2 factoral. Only data from the 64 calves that completed the trial were included in statistical analyses. Differences among feed intakes during different weeks were determined by the Waller-Duncan test (24), and Tukey's test (24) was used for comparing starting weights. Data also were analyzed by covariate analyses with starting weight and ambient temperature covariates. Digestion Trial
After the 12-wk growth trial, male calves were placed in digestion stalls and continued to be fed their respective pelleted diets. After 4 days for adjustment, feed intake and fecal output were measured, recorded, and sampled for 5 consecutive days. Samples were frozen for later analyses. Samples were dried and processed as described. Analyses included proximate analyses (1), acid detergent fiber (9), energy by oxygen bomb calorimeter, s and neutral detergent fiber as described earlier. Body weights were recorded on the 1st and 9th day of the digestion trial. Data were analyzed by analysis of variance according to Steel and Torrie (22) with dif-
HIGH STARCH AND FAT RATIONS FOR CALVES ferences among treatments evaluated through orthogonal comparisons. Comparisons evaluated were: 1) control versus high starch and high fat diets and 2) high starch versus high fat diets. Least significant difference was used for differences in crude protein of pelleted diets fed during the digestion trial.
RESULTS A N D DISCUSSION Growth Trial
Results of the growth trial are in Table 3. Daily dry feed intake (dry matter) does not include dry matter calves received from milk. All calves consumed .43 kg dry matter from milk wk 1 thru 4 and .22 kg per day wk 5. Intakes of total dry feeds were similar wk 1 thru 5, wk 6 thru 12, and wk 1 thru 12 for all groups of calves. Feed intakes were affected by week (P<.01), especially for wk 1 thru 5 as would be expected, because as calves grow they consume considerably more feed. Calves offered USCM, regardless of pelleted diet, consumed less pellets (P<.01) during wk 1 thru 6 than did calves offered only pellets (Figure 1). By individual weeks calves offered the USCM consumed less pellets (P<.05) during wk 2 and 6. The decreased pellet intake during wk 1 thru 6 was more than offset by intake of USCM. Calves offered USCM during wk 1 thru 6 tended to consume more total feed than those calves offered only pellets, but differences were not significant (P>.05). Combining hay and concentrate in a pellet in this trial did not affect adversely feed intake as reported by Gardner (8). Palatability of the high fat ration was not affected adversely as it was for others (6, 14) when 10 to 20% fat was included in calf rations. Starting body weights were similar for all groups of calves, except for calves fed the pelleted control diet without USCM, which had lower starting weights (P<.05). However, starting weights had no apparent affect on weight gains, so weight gain data in Table 3 are actual data rather than data adjusted for starting weights. Average daily gains were similar (P>.05) with all pelleted rations during all periods, although calves receiving the high fat diet had the lowest gains (P>.05) during all periods. In (22) weight gains were similar when calves
601
were fed diets containing corn or oats as the grain ingredient. Others (8, 14, 25) observed no difference in weight gains whereas Fisher (5) observed increased weight gains of calves fed added fat. Admittedly, a 5% difference in digestible energy content of diets would not be expected to have a marked affect on weight gains, unless calves were under stressful conditions. Then, the added energy may be sufficient to help them through the stress. Weight gains were similar for calves wk 1 thru 5, 6 thru 12, and 1 thru 12, whether they received USCM during the first 6 wk of the experiment. Calves receiving the USCM during the milk feeding period (wk 1 thru 6) gained slightly more weight in all except the 1st and 6th wk, but none of these differences approached statistical significance. Gains of all calves in this experiment compared favorably with gains of calves fed similar rations from birth to 12 wk of age (3, 5, 7, 15, 23, 25). Feed dry matter intakes per kilogram of gain were similar (P>.05) for all diets in all periods. General health of all calves was good throughout the trial. No calves receiving the control diet died. Two calves fed the high starch diet died, one at 5 days of age from u n k n o w n cause; the other died of bloat at 10 wk of age. Two calves fed the high fat diet died of bloat during wk 9. Data from those four animals were not included in the analyses. Environmental temperature had no effect on intake, average daily gain, or efficiencies of feed utilization for any age periods of calves evaluated. Slopes of regression lines of weight gains on ambient temperatures were not different from zero for calves fed any diets during any weeks of age. Data covariate adjusted for ambient temperature were similar to actual, unadjusted data. This lack of effect of temperature was likely, because the two winters of this trial (1979-1980 and 1980-1981) were mild by local weather standards. Thus, most calves were under thermal neutral conditions (26) most of the time. Average weekly temperatures ranged from a low of - 1 5 ° C (average of day time high and night time low) in winter to a high of 25vC in summer. We hypothesized that the high starch and high fat diets would be more beneficial than the control diet to calves subjected to severe cold stress, especially severe cold weather about the time or shortly after weaning. No severely stressful weather conditions o c Journal of Dairy Science Vol. 67, No. 3, 1984
t-
t7
bO
TABLE 3. Feed intakes, starting weights, average daily gains, and feed efficiencies of calves fed control, high starch, or high fat pelleted diets with or w i t h o u t access to unpelleted supplemental concentrate mix (USCM). Main effect and interaction Control
<
Z o
oo
Number of calves Male Female Dry feed intake/day, kg DM f Wk 1 to 5 Wk 6 to 12 Wk 1 to 12 Starting weight, kg Average daily gain, kg Wk 1 to 5 Wk 6 to 12 Wk 1 to 12 Feed dry matter, kg/gain, kg h Wk 1 to 5 Wk 6 to 12 Wk 1 to 12
Trt ×
_
i0 3 7
10
3 7
,34 2.33 1.50 40.0g
.42 2.44 1.59 45.3
.36 2.38 1.53 45.7
.42 2.38 1.56 45.4
.40 2,28 1.49 45,4
,37 2.37 1.54 43.9
.159 .405 .276 4.03
NS NS NS NS
NS NS NS NS
NS NS NS *
.48 .89 .72
.48 .87 .71
.50 .87 .72
.48 :89 .71
.44 .81 .66
.42 .83 .70
.141 .173 .126
NS NS NS
NS NS NS
NS NS NS
1.58 2.65 2.32
1.75
1.65 2.82 2.41
2.10 2.66 2.41
1.85 2.92 2.59
1.49
.724 .460 .357
NS NS NS
NS NS NS
NS NS NS
acalves not offered USCM.
CStandard deviation. dcontrol versus high starch versus high fat. eUSCM versus no USCM. fMilk dry matter (DM) not included.
hMilk dry matter included.
High fat
+b
bCalves offered USCM.
gP<.05.
High Starch
_a
2.79
2.48
+
-
+
sc
10
11
15
8
.
.
.
.
.
.
.
.
.
.
.
.
4 6
5 6
5 10
3 5
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
2.89 2.42
Trt d
Supp e
supp
*q .~m ~q > Z I~ ¢~ Z O ,.] ~1
HIGH STARCH AND FAT RATIONS FOR CALVES
603
curred during the winters in this trial. Covariate analyses with data adjusted for starting weight and t e m p e r a t u r e resulted in no significant differences a m o n g diet treatments. Jorgenson et al. (10) observed no differences in growth, feed intake, health, or weaning age of calves housed in hutches as c o m p a r e d to calves housed indoors at this same research facility•
1.61.4~1.2l.Oml
Digestion Trial
.6.4.2-
1
2
3
4
5
6
WEEK
Figure 1. Feed intake (kg/day) of pelleted diets and unpelleted supplemental concentrate mix (USCM) during first 6 wk on trial.
A p p a r e n t digestibilities of the three pelleted calf diets as measured with 13-wk old male calves are in Table 4. T h e control diet was generally m o r e digestible than the high starch and high fat diets for all n u t r i e n t measures. Gross energy c o n t e n t s of the pelleted diets were similar (P>.05), although the high fat diet c o n t a i n e d slightly m o r e energy, as e x p e c t e d because of its higher fat content. Gross energy was m o r e digestible (P<.05) for the control diet than for the high starch and high fat diets. This contrasted with what was e x p e c t e d f r o m r e p o r t e d digestibilities for the dietary in-
TABLE 4. Daily weight change, daily dry matter intake, and apparent digestibility of control, high starch, and high fat rations by male calves. Diet Control No. of animals Avg weight at start, kg Avg weight at end, kg Daily wt change, kg Dry matter intake, kg/day Ration Energy, Mcal/kg DMb Crude protein, % of DM Coefficients of digestibility, % Dry matter Energy Nitrogen Ether extract Acid detergent fiber Neutral detergent fiber Ash
6 99.6
103.4 .42 2.63
High starch
High fat
sa
7
7
104.2
106.3
. . . . , ,
107.4
107,3
° . .
.35 2.52
.08 2.33
"1:10
3.98 16.2 cd
4.00 17.0 c
4.10 15.9 d
1.02 .66
81.3 80.1 c
77.7 76.5 77.8 80.0 33.6 42.7 65.8
76.1 75.9 76.1 90.0 e 37.3 42.5 59.5
4.82 3.97 4.06 4.16 12.18 11.74 6.32
83.4 d
89.0 c 48.6 c 50.7 72.4 d
aStandard deviation. bDry matter. CDifferent from high starch and high fat (P<.05). dDifferent from high starch and high fat (P<.01). eHigh fat different from high starch. (P<.01). Journal of Dairy Science Vol. 67, No. 3, 1984
604
STEWART AND SCHINGOETHE
gredients (18). The high starch diet fed during the digestion trial c o n t a i n e d m o r e crude protein (P<.05) than the high fat diet, even though all diets were f o r m u l a t e d to be isonitrogenous. A p p a r e n t nitrogen digestibility of the c o n t r o l diet was greater (P<.01) than of the high starch and high fat diets. This m a y be because corn represented only 16% of the protein fraction of the control diet but 36 and 31% of the protein fraction f r o m the high starch and high fat diets. Corn protein is quite insoluble (19) and at the p r o p o r t i o n s in the high starch and high fat diets also m a y have caused an increase of rate of passage, further reducing protein digestibility. A p p a r e n t digestibility of the ether extract in the control diet was higher (P<.05) than that of the high starch and high fat diets c o m b i n e d . However, the high fat diet was actually numerically m o r e digestible than the control diet, with the high starch diet being m u c h less digestible (P<.01) than the high fat diet. O t h e r researchers (4, 6, 10, 12) also observed higher digestibilities of ether extract with ruminants fed diets high in fats or oils than in animals fed a basal or control ration. However, Roberts and McKirdy (20) r e p o r t e d that the ether e x t r a c t m e t h o d of analyzing feces does n o t r e m o v e all of the fat because some is in a b o u n d form. This could explain the high apparent digestibility percentages for the ether extract c o m p o n e n t , especially in the high fat diet. Acid detergent fiber and ash c o m p o n e n t s of the control diet were also m o r e digestible (P<.05) than the acid detergent fiber and ash c o m p o n e n t s of either high starch or high fat diets. Dry m a t t e r and neutral detergent fiber digestibilities were n o t different (P>.05) b e t w e e n control, high starch, and high fat diets or high starch and high fat diets, although trends were similar to trends of digestibilities of other c o m p o n e n t s , suggesting that rate of passage o f the two diets containing m o r e than 50% corn was rapid enough to deter digestibilities in the y o u n g ruminant. This trial indicated no benefit in weight gains, feed intake, or health of calves attributable to increasing the starch f r o m corn or the fat f r o m soybeans in calf diets. Providing a supplemental grain m i x during the milk feeding period m a y stimulate some additional dry feed c o n s u m p t i o n , which could help calves through the stressful time around weaning. Workers at our research farm feel this practice is beneficial Journal of Dairy Science Vol. 67, No. 3, 1984
even t h o u g h our research data did n o t show a significant benefit. However, weather conditions during this trial were n o t sufficiently severe to subject calves to e x t r e m e l y stressful conditions. ACKNOWLEDGMENTS
Appreciation is e x t e n d e d to Lennis Baumiller and o t h e r personnel at the Dairy Cattle Research Unit of South D a k o t a State University for care of the calves, and to W. L. Tucker, E x p e r i m e n t Station Statistician, for assistance in statistical analyses of the data. E x t r u d e d soybean p r o d u c t used in this research was furnished by Triple " F " , Inc., Des Moines, IA. REFERENCES
1 Association of Official Analytical Chemists. 1975. Official methods of analysis. 12th ed. Assoc. Offic. Anal. Chem., Washington, DC. 2 Clark, A. K. 1982. Raising dairy calves in hutches. South Dakota State Univ. Dairy Sci. Update 82-3. 3 Daniels, L. B., and C. Flynn. 1976. Using full-fat processed soybeans in calf starter rations. Arkansas Farm Res. 25:5. 4 Delvin, T. J., J. R. Ingalls, and H. R. Sharma. 1977. Evaluation of high fat oats in rations of growing and finishing ruminants. Calves, sheep. Can. J. Anim. Sci. 57:735. 5 Durland, G. R. 1982. Calf hutches. South Dakota State Univ., Dairy Sci. Update 82-8. 6 Fisher, L. J. 1980. A comparison of rapeseed meal and soybean meal as a source of protein and protected lipid as a source of supplemental energy for calf starter diets. Can. J. Anita. Sci. 60:359. 7 Gardner, R. W. 1967. Acceptability and nutritional response comparisons between calf starters. J. Dairy Sci. 50:729. 8 Gardner, R. W. 1968. Digestible protein requirements of calves fed high energy rations ad libitum. J. Dairy Sci. 51:888. 9 Goering, H. K., and P. J. Van Soest. 1970. Forage fiber analysis. Agric. Handbook No. 379, Agric. Res. Serv., USDA, Washington, DC. 10 Jorgenson, L. J., N. A. Jorgensen, D. J. Schingoethe, and M. J. Owens. 1970. Indoor versus outdoor calf rearing at three weaning ages. J. Dairy Sci. 53:813. 11 Larsen, H. J., G. H. Tempas, and C. Cramer. 1977. Rearing young calves in cold and warm environments. Msh-201-6023-77, Univ. Wisconsin, Madison. 12 Macleod, G. K., and J. G. Buchanan-Smith. 1972. Digestibility of hydrogenated tallow, saturated fatty acids, and soybean oil-supplemented diets by sheep. J. Anim. Sci. 35:890. 13 McKnight, D. R. 1978. Performance of newborn dairy calves in hutch housing. Can. J. Anim. Sci. 58:517. 14 Miller, W. J. 1962. Comparison of lard, tallow, butter, and hydrogenated cottonseed oil in starters and of pelleted versus nonpelleted coastal Bermuda
HIGH STARCH AND FAT RATIONS FOR CALVES grass hay for calves. J. Dairy Sci. 45:759. 15 Miller, W. J., Y. G. Martin, and P. R. Fowler. 1969. Effects of addition of fiber to simplified and to complex starters fed to young dairy calves. J. Dairy Sci. 52:672. 16 Milligan, J. D., and C. M. Grieve. 1970. Effect of diet on growth and development of early weaned Holstein-Friesian calves. J. Anim. Sci. 50:147. 17 Muller, L. D., and M. J. Owens. 1976. Fifteen years experience with calf hutches. Hoard's Dairyman 121:1107. 18 National Research Council. 1978. Nutrient requirements of domestic animals. No. 3. Nutrient requirements of dairy cattle. 5th rev. ed. Washington, DC. 19 Owens, F. N. 1981. Calcium nutrition and buffers for feedlot cattle. Page 21 in Proc. 41st Semiannu. Mtg., Am. Feed Manuf. Assoc. Nutr. Counc., Lexington, KY. 20 Roberts, W. K., and J. A. McKirdy. 1964. Weight gains, carcass fat, characteristics, and ration digestibility in steers as affected by dietary rapeseed oil, sunflower seed oil, and animal tallow. J. Anim. Sci. 23:682. 21 Robertson, J. B., and P. J. Van Soest. 1977.
22
23
24 25
26
605
Dietary fiber estimation in concentrate feedstuffs. Page 254 in Am. Soc. Anim. Sci. 69th Annu. Mtg. (Abstr.) Schingoethe, D. J., H. H. Voelker, and F. C. Ludens. 1982. High protein oats grain for lactating dairy cows and growing calves. J. Anim. Sci. 55:1200. Schuh, J. D., J.D.A. Lima, W. H. Hale, and B. Theurer. 1970. Steam-processed flaked grains versus steam-rolled grains for dairy calves. J. Dairy Sci. 53:475. Steel, R.G.D., and J. H. Torrie. 1980. Principles and procedures of statistics. 2nd ed. McGraw-Hill Book Co., New York, NY. Waldern, D. E., and L. J. Fisher. 1978. Effect of steam processed barley, source o f protein, and fat on the intake and utilization of starter rations by dairy calves. J. Dairy Sci. 61:221. Young, B. A. 1977. Effect of cold environments on nutrient requirements of animals. Pages 4 9 1 - 4 9 6 in Proc. 1st Intl. Symp., feed composition, animal nutrient requirements, and computerization of data, P. V. Fonnesbeck, L. E. Harris, and L. C. Kearl, ed., Utah Agric. Exp. Sm., Utah State Univ., Logan.
Journal of Dairy Science Vol. 67, No. 3, 1984