- Email: [email protected]
Corn Gluten Meal and Blood Meal Mixture for Dairy Cows in Midlactation1
PRODUCTION TECHNICAL NOTES Corn Gluten Meal and Blood Meal Mixture for Dairy Cows in Midlactation I M. DE GRACIA, 2 F. G. OWEN, 2 and S. R. LOWRY 3 University of Nebraska Lincoln 68583-0908
that the dietary protein and undegradable protein concentration needed by midlactation Holstein fed complete mixed diets may be lower than generally recommended.
ABSTRACT
Twelve midlactation Holstein cows were assigned to a switchback design with 4-wk periods to compare a corn gluten meal and blood meal mixture with soybean meal as supplemental protein sources. All experimental diets contained 60% ammoniated corn silage, on a dry basis, and a corn and oats (2:1) basal concentrate mixture. Diets were: urea control (12.5% CP); soybean meal (16.1% CP); low protein (14.3% CP) corn gluten and blood meal mixture; and high protein (16.8% CP) corn gluten and blood meal mixture. Cows fed the control diet consumed less DM, and produced less milk containing a lower percentage of protein than cows fed other diets. Protein efficiency and milk fat percentage were higher for cows fed the control diet than for cows fed the natural protein diets. Fat-corrected milk and fat yields did not differ among diets. The high protein diets (16.1 and 16.8% CP) decreased protein efficiency and increased SNF percentage. Milk yield per unit of D M intake was higher when cows were fed the lower degradable protein source (corn gluten-blood meal) than when they were fed soybean meal. The low degradable protein mixture produced a similar lactation response to soybean meal at both the high and low concentrations of total dietary protein. This study indicates
INTRODUCTION
The N requirement of the dairy cow, as for other ruminants, is a balance between the requirements of the rumen microorganisms and the systemic requirements (12, 21, 24). Increasing protein in the diet is associated with increasing milk yield (14, 23). The protein supplement utilized to increase dietary protein should be of high nutritive value and low rumen degradability (19). Non-protein N could be used to supply the ammonia required by ruminal microorganisms and the natural protein sources to provide additional metabolizable protein (19, 24). During early lactation, microbial protein synthesized in the rumen is inadequate to supply the amino acids required postruminally (9, 15). However, during later periods of lactation the value of low degradable protein has received little attention (18). The objective of this study was to compare a mixture of corn gluten meal (CGM) and blood meal (BM), at two dietary concentrations of protein, with soybean meal (SBM) in diets of dairy cows in midlactation. MATERIALS AND METHODS
Received July 11, 1988. Accepted May 22, 1989. ~Published as Paper Number 8383, Journal Series, Nebraska Agricultural Research Division. 2Department of Animal Science. 3Agricultural Experiment Station, University of Kentucky. 1989 J Dairy Sci 72:3064-3069
Twelve multiparous Holstein cows, with an average initial weight of 614 kg, were randomly assigned to treatment sequences in a switchback design with three periods of 4 wk each (11). Due to difference in calving dates, cows were assigned to two blocks; one of eight and the other of four cows. Cows started the experiment at least 12 wk after calving and
3064
PRODUCTION TECHNICAL NOTE finished the experiment before the 7th m o of gestation. Prior to the experiment, all cows received a c o m m o n diet with 16% CP. Cows received the assigned diets during each 4-wk period. The first 2 wk of each period were for adjustment, the last 2 wk were for comparison. All diets contained 60% (dry basis) a m m o n i a t e d corn silage (12% CP) and a grain mixture c o m p o s e d of corn and oats (2:1) in addition to a mineral and vitamin premix (Table 1), Urea was added to the control diet (C) to provide 11% C P in the total ration D M . The mixture of C G M and BM contained a 50:50 ratio of protein f r o m each of these sources of proteins with low r u m e n degradability. The degradability of the protein in the B M was 17% and in the C G M was 20% (6). The low value for C G M c o m p a r e d with previous
3065
d a t a (40%) m a y have been the result of clogging of pores in the d a c r o n bags used in the procedures. Consequently, the 40% value was used in c o m p u t i n g dietary degradable protein. The low mixture provided 19% of the total dietary C P and the high mixture provided 28% of the total dietary CP. The diet with high r u m e n degradable protein contained S B M as the supplemental protein source. The C P in the C, the low mixture (LM), the high mixture ( H M ) and the S B M diets were 12.5, 14.3, 16.8 and 16.1%, respectively. The c o m p u t e d undegradability of the protein in these diets ranged f r o m 25 to 33% (Table 1), all below the requirements derived f r o m appendix Table 5 of N R C (13). All diets were prepared as complete mixed diets and were fed for ad libitum intake once daily. Samples of forage and of each grain
TABLE I. Composition of experimental diets. Corn gluten and blood meal Item
Control
Low
High
60.00 32.72 3.89 .20 ... ...
60.00 29.23 4.00 "2.'04 150
'3.'59
(% of DM), 60.00 26.89 3.75
Soybean meal
Ingredients Corn silage (ammoniated) Corn-oat mix (2:1) Molasses Urea Corn gluten meal Blood meal Soybean meal Premix 1 Chemical composition (analyzed) Dry matter Crude protein Acid detergent fiber ADIN2 IVDMD2 Undegradable protein 3 Calcium4 Phosphorus 4
"3.'19
"3~23
"3716
10.80 3.06
41.10 12.46 19.10 .30 72.10 25 1.00 .45
41.00 14.33 18.80 .50 72.10 32 1.00 .45
40.40 16.85 19.50 .60 71.60 33
41.30 16.14 19.50 .30 71.70 27
1.00
1.00
.45
Estimated NE4
76.21
75.89
.45 (Mcal/kg) 75.65
60.00 22.14 4.00
iii
2.61
75.62
1The ADE vitamin premix contain (USP units/.454 kg) vitamin A, 4,000,000; vitamin D3,800,000; and vitamin E, 1000. Added at 2% of the mixture, salt (NaC1) 14.0%, calcium sulfate 14.0%, limestone 31.50%, dicalcium phosphate 35.00% of the mixture. Trace mineral mix: copper 1.5%, zinc 12.0% manganese 8.0%, iron 10.0%, cobalt. 10%, iodine 0.20%, calcium 13.0%. Added at 3.5% of the mixture. 2Acid detergent insoluble nitrogen (ADIN), in vitro dry matter disappearance (IVDMD). 3percentage of total crude protein, calculated from NRC (13) values, except for corn gluten meal and blood meal, which were 60% and 83% (6). 4Calculated from ingredient values (13). Journal of Dairy Science Vol. 72, No. 11, 1989
3066
DE GRACIA ET AL.
mix and complete mixed ration were taken weekly. Feed samples were composited by periods and anlyzed for D M , C P (1), A D I N , A D F , and in vitro D M disappearance (7). Milk yields were recorded at each milking. Milk samples were taken at two consecutive milkings on the last day of wk 2, 3, and 4, composited weekly, and analyzed for protein, fat, and lactose using a M i l k o - S c a n 300 (Hillerod, DK). The S N F was estimated as percentage protein + percentage lactose + .7%. B o d y weights were recorded on the last 2 d before the first period began and at the end of the 4th wk of each period. Blood samples were taken f r o m the jugular vein during the last 2 d of the experiment at 5 to 6 h after feeding. P l a s m a was deproteinized with sulfosalicylic acid according to procedures of Perry and Hansen (17) for determination of plasma amino acids. A m i n o acid
analysis was performed on each day's samples by ion exchange c h r o m a t o g r a p h y with post c o l u m n fluorescence detection. Lactation response data were analyzed as a switchback design, blocked for two starting times, and adjustment for missing values (one cow was lost because of abortion), according to Lucas (11). Differences a m o n g treatments were evaluated by using o r t h o g o n a l contrasts to c o m p a r e control versus other treatments, H M versus S B M , and L M versus H M (20). Blood plasma amino acids were analyzed as a split plot design over time, using cows as subsamples and including day (sample time) as a source of variation. Least squares difference was used to detect differences a m o n g treatment means when significant (P<.05) treatment effect resulted. No difference due to sampling time was found; consequently, mean analysis was pooled across days.
TABLE 2. Dry matter intake, milk production and composition, and dry matter and protein efficiency. Corn gluten and blood meal
Dry matter intake, • kg/d Milk yield,b kg/d 3.5% FCM, kg/d Dry matter efficiency,° milk yield/DM intake Milk protein, • % kg/d Protein efficiencyd (protein yield/total protein intake), % Milk fat, %e kg/d Milk SNF, %f kg/d b
Control (C)
Low (LM)
High (HM)
Soybean meal SE (SBM)
19.3 24.0 25.3
19.9 24.5 25.4
20.2 25.7 25.9
21.0 24.8 25.5
.79 1.01 1.08
1.24
1.22
t.27
1.18
.07
3.31 .79
3.39 .82
3.40 .87
3.40 .83
.05 .04
32.85
28.76
25.56
24.49
.6I
3.83 .91
3.74 .91
3.58 .91
3.67 .91
.08 .04
8.94 2.14
8.99 2.20
9.12 2.34
9.01 2.22
.09 .11
•C vs. LM, HM, and SBM (P<.05). bC vs. LM, HM, and SBM (P<.10). oHM vs. SBM (P<.10). dC vs. LM, HM, and SBM (P<.005), LM vs. HM and SBM (P<.005), HM vs. SBM (P<.05). eC vs. LM, HM, and SBM (P<.01), LM vs. HM and SBM (P
Journal of Dairy Science Vot. 72, No. 11, 1989
PRODUCTION TECHNICALNOTE RESULTS AND DISCUSSION
Cows consumed 1 kg less DM (P<.05) daily when they received the C diet than when they received diets supplemented with natural protein, whereas DM consumption did not differ among cows fed the natural protein supplements (Table 2). The greater DM intake for cows fed higher protein diets is well documented (2, 12, 21) However, no important differences were found in in vitro DM digestibility between the control (NPN) diet and the mean for the natural protein diets (Table 1). Milk yields were slightly, but not significantly lower for cows fed the C diet than for cows fed other diets. Others also found urea supplementation associated with lower milk production (3, 10, 22, 25). Milk yields did not differ (P>.10) between cows fed the low and high concentrations of protein or between the low degradable (HM) and high degradable (SBM) sources, indicating that cows received adequate CP even at the low concentration
(14.3%). Milk fat percentage was higher (P<.01) for diet C than for other diets (3.83 vs. 3.65%). This resulted in similar 3.5% FCM yields from all diets. The lower dietary protein diets favored somewhat higher (P<.05) milk fat percentages than higher protein diets. However, no differences in fat production were observed among treatments. In previous research (3, 10, 22, 25), the effect of urea supplementation on milk fat content was variable. There is no apparent explanation for the higher milk fat percentage for cows fed the C diet. Cows fed the HM diet were more efficient (milk yield/DM intake) than cows fed the SBM diet (P<.10). This was related to both the slightly higher milk yields from cows fed the HM diet and higher DM intake of cows fed the SBM diet. Milk protein percentage and milk protein yield were lower (P<.05) for cows fed the C diet than for cows fed the diets supplemented with natural protein. This agrees with earlier studies (12, 21). However, as a consequence of the lower protein intake, protein efficiency (protein yield/protein intake) was better (P<.005) when the C diet was fed (32.8%)
3067
compared with the average for the natural protein diets (26.3%). Protein efficiency was also higher (P<.005) for cows fed the LM diet in comparison with cows fed the HM and SBM diets. Other differences in efficiency were small. Although the NRC (13) recommends protein concentrations above that of the C diet and approximately that of the LM diet, it is evident that the three diets of higher protein were consumed in amounts to supply excessive protein. These efficiency data demonstrate this fact. However, intakes of undegradable protein ranged from about .06 to 1.1 kg daily, which is below the recommended amounts (13) for cows used in this experiment. Huber et al. (10) attributed lower milk protein with urea feeding to lower energy intake. In the present study, DM intake was less (P<.05) in cows fed the urea diet (C). Generally, the amount of dietary protein has little or no effect on milk protein concentration (8, 16), unless the diet is deficient in protein. Differences in SNF percentages and yields among diets were small; however, yields tended to be lower (P<.10) for cows fed C than for those fed the natural protein diets. The mixture of C G M - B M and SBM produced similar patterns of plasma amino acids (Table 3). In general, those amino acids present in greater proportions in the C G M - B M supplement were also present in plasma of cows fed HM in higher concentrations than in plasma of cows fed C or SBM diets, or both. These include histidine, leucine, phenylalanine, threonine, and valine. Higher values for isoleucine, lysine, tryptophan, and tryosine also tended to be present in plasma of cows receiving the C G M - B M supplement, even though the concentration of these amino acids were lower in this supplement than in SBM. In addition, increased concentration of amino acids in plasma was related to feeding HM compared with LM. This may be an indication that more dietary protein reached the small intestine because of lower degradability of the protein in the C G M - B M mixture. Similar responses in plasma amino acids were reported by others (4, 5). Plasma patterns of amino acids were similar for cows fed the C and SBM diets. Possibly the high degradability of SBM in the rumen reduced the outflow Journal of Dairy ScienceVot. 72, No. ll, 1989
3068
DE GRACIA ET AL.
TABLE 3. Pattern of amino acids in protein supplements and in plasma. Diet I
Supplement ~ Amino acid
CGM-BM
SBM
C
(amino acids, % of protein) Histidine 3.82 Isoleucine 2.62 Leucine 15.11 Lysine 5.24 Methionine 2.02 Phenylalanine 7.04 Threonine 4.20 Tryptophan .86 Tyrosine 3.98 Valine 7.22
2.38 4.55 7.31 5.99 1.16 4.73 3.71 1.42 4.51 4.51
LM
HM
SBM
SE 2
(plasma amino acids, %), 1.19ab 1.37b 2.24b 1.54b .29ab .84b .90 a .49 1.05b 2.53 b
1.33a 1.36b 3.52~b 1.9 lab .27 b 1.02a .90 a .52 .94 b 3.81 b
1.26ab 1.89a 4.90a 2.12 a .34 a 1.12~ 1.01a .55 1.30a 5.57 a
1.05b 1.55ab 2.22b 1.68ab .28 ab .80b .74 b .38 .89 b 2.94 b
.08 .06 .13 .15 .02 .06 .ll .09 .10 .19
a,bMeans within rows within diet with different superscript differ (P<. 10). ICorn gluten meal (CGM), blood meal (BM), control (C), low mixture level (LM), high mixture level (HM), soybean meal (SBM). 2Standard error for plasma amino acids.
of amino acids with this supplement. With high degradable p r o t e i n s u c h as S B M , microbes account for most of the amino acids in the intestine and would be expected to produce a pattern similar to that of the C diet with NPN. In conclusion, results indicated that cows in midlactation can sustain normal milk prod u c t i o n w i t h b e t w e e n 12.5 a n d 14.3 % p r o t e i n in the diet, which apparently supplied the m i n i m u m q u a n t i t a t i v e r e q u i r e m e n t s (13) o f the cows involved even though undegradable protein intakes were below recommended a m o u n t s (13). R o b i n s o n a n d K e n n e l l y (18) came to a similar conclusion. Higher protein did not increase DM intake or milk yield. Low rumen degradable protein supplements (CGM-BM) did not benefit lactation performance compared with SBM; however, they resulted in higher plasma amino acids.
REFERENCES 1 Association of Official Analytical Chemists. 1980. Official methods of analyses. 13th ed. Assoc. Offic. Anal. Chem., Washington, DC. 2 Barney, D. J., D. G. Crieve, G. K. MacLeod, and L. G. Young. 1981. Response of cows to crude protein during midlactation. J. Dairy Sci. 64:655. 3 Casper, D. P., and D. J. Schingoethe. 1986. Evaluation of urea and dried whey in diets of cows during early lactation. J. Dairy Sci. 69:1346. Journal of Dairy Science Vol. 72, No. 11, 1989
4 Chalupa, W. 1975. Rumen by-pass and protection of proteins and amino acids. J. Dairy Sci. 59:1198. 5 Clark, J. H. 1975. Lactation responses to postruminal administration of proteins and amino acids. J. Dairy Sci. 58:1178. 6 Goedeken, F., T. Klopfenstein, R. Stock, and R. Britton. 1987. Hydrolyzed feather meal as a protein source for growing ruminants. Page 50 in Beef Cattle Rep. MP 52. Agric. Res. Div., Inst. Agric. National Resources., Univ. Nebraska-Lincoln. 7 Goering, H. K., and P. J. Van Soest. 1970. Forage fiber analyses; apparatus, reagents, procedures and some applications. Agric. Handbook 379. USDA, ARS, Washington, DC. 8 Gordon, F. J., 1977. The effect of protein content on the response of lactating cows to level of concentrate feeding. Anim. Prod. 25:181. 9 Huber, J. T., and L. Kung, Jr. 1981. Protein and nonprotein nitrogen utilization in dairy cattle. J. Dairy Sci. 64:1170. 10 Huber, J. T., R. A. Sandy, C. E. Polan, H. T. Bryant, and R. E. Blaser. 1967. Varying levels of urea for dairy cows fed corn silage as the only forage. J. Dairy Sci. 50:1241. 11 Lucas, H. L., Jr. 1983. Design and analysis of feeding experiments with milking dairy cattle. Inst., Mimeo Ser. 18, North Carolina State Univ. Raleigh, NC. 12 Nocek, J. E., and J. B. Russell. 1988. Protein and energy as an integrated system. Relationship of ruminal protein and carbohydrate availability to microbial synthesis and milk production. J. Dairy Sci. 71:2070. 13 National Research Council. 1988. Nutrient requirements of domestic animals. Nutrient requirements of dairy cattle. 6th rev. ed. Natl. Acad. Sci., Washington, DC.
PRODUCTION TECHNICAL NOTE
14 Oldham, J. D. 1984. Protein-energy interrelationships in dairy cows. J. Dairy Sci. 67:1090. 15 Owens, F. N., and W. G. Bergen. 1983. Nitrogen metabolism of ruminant animals: historical perspective, current understanding and future implications. J. Anim. Sci. 57:498. 16 Paquay, R., Godeau, J. M., R. De Baere, and A. Lousse. 1973. The effects of the protein content of the diet on the performance of the lactating cows. J. Dairy Res. 40:93. 17 Perry, C., and J. Hansen. 1969. Technical pitfalls leading to errors in the quantitation of plasma amino acids. Clin. Chem. Acta 25:53. 18 Robinson, P. H., and J. J. Kennelly. 1988. Influence of intake of rumen undegradable protein on milk production of late lactation Holstein cows. J. Dairy Sci. 71:2135. 19 Satter, Larry. 1982. A metabolizable protein system keyed to ruminal ammonia concentration - The Wisconsin system. Page 245 in Protein requirements for cattle: symposium. F.N. Owens, ed. M P 109. Oklahoma State Univ., Stillwater. 20 Steel, R. C. D., and J. H. Torrie. 1980. Principles and procedures of statistics. A biometrical
3069
approach. 2nd ed. McGraw-Hill, New York, NY. 21 Van Horn, H. H., 1982. Empirical value of crude protein system for dairy rations. Page 218 in Protein requirements for cattle: symposium. F. N. Owens, ed. MP-I09, Oklahoma State Univ., Stillwater. 22 Van Horn, H. H., C. F. Foreman, and J. E. Rodriguez. 1967. Effect of high urea supplementation on feed intake and milk production of dairy cows. J. Dairy Sci. 50:709. 23 Van Horn, H. H., and C. A. Zometa. 1978. Optimum protein in complete rations for high producing lactating cows. Feedstuffs 50:34:22. 24 Van Soest, P. J., C. J. Sniffen, D. R. Mertens, D. G. Fox, P. H. Robinson, and U. Krisnamoorthy. 1982. A net protein system for cattle: The rumen submodel for nitrogen. Page 265 in Protein requirements for cattle: symposium. F. N. Owens, ed. M P 109, Oklahoma State Univ., Stillwater. 25 Wolhlt, J. E., and J. H. Clark. 1978. Nutritional value of urea versus preformed protein for ruminants. I. Lactation of dairy cows fed corn based diets containing supplemental nitrogen from urea and/or soybean meal. J. Dairy Sci. 61:902.
Journal of Dairy Science Vol. 72, No. 11, 1989
that the dietary protein and undegradable protein concentration needed by midlactation Holstein fed complete mixed diets may be lower than generally recommended.
ABSTRACT
Twelve midlactation Holstein cows were assigned to a switchback design with 4-wk periods to compare a corn gluten meal and blood meal mixture with soybean meal as supplemental protein sources. All experimental diets contained 60% ammoniated corn silage, on a dry basis, and a corn and oats (2:1) basal concentrate mixture. Diets were: urea control (12.5% CP); soybean meal (16.1% CP); low protein (14.3% CP) corn gluten and blood meal mixture; and high protein (16.8% CP) corn gluten and blood meal mixture. Cows fed the control diet consumed less DM, and produced less milk containing a lower percentage of protein than cows fed other diets. Protein efficiency and milk fat percentage were higher for cows fed the control diet than for cows fed the natural protein diets. Fat-corrected milk and fat yields did not differ among diets. The high protein diets (16.1 and 16.8% CP) decreased protein efficiency and increased SNF percentage. Milk yield per unit of D M intake was higher when cows were fed the lower degradable protein source (corn gluten-blood meal) than when they were fed soybean meal. The low degradable protein mixture produced a similar lactation response to soybean meal at both the high and low concentrations of total dietary protein. This study indicates
INTRODUCTION
The N requirement of the dairy cow, as for other ruminants, is a balance between the requirements of the rumen microorganisms and the systemic requirements (12, 21, 24). Increasing protein in the diet is associated with increasing milk yield (14, 23). The protein supplement utilized to increase dietary protein should be of high nutritive value and low rumen degradability (19). Non-protein N could be used to supply the ammonia required by ruminal microorganisms and the natural protein sources to provide additional metabolizable protein (19, 24). During early lactation, microbial protein synthesized in the rumen is inadequate to supply the amino acids required postruminally (9, 15). However, during later periods of lactation the value of low degradable protein has received little attention (18). The objective of this study was to compare a mixture of corn gluten meal (CGM) and blood meal (BM), at two dietary concentrations of protein, with soybean meal (SBM) in diets of dairy cows in midlactation. MATERIALS AND METHODS
Received July 11, 1988. Accepted May 22, 1989. ~Published as Paper Number 8383, Journal Series, Nebraska Agricultural Research Division. 2Department of Animal Science. 3Agricultural Experiment Station, University of Kentucky. 1989 J Dairy Sci 72:3064-3069
Twelve multiparous Holstein cows, with an average initial weight of 614 kg, were randomly assigned to treatment sequences in a switchback design with three periods of 4 wk each (11). Due to difference in calving dates, cows were assigned to two blocks; one of eight and the other of four cows. Cows started the experiment at least 12 wk after calving and
3064
PRODUCTION TECHNICAL NOTE finished the experiment before the 7th m o of gestation. Prior to the experiment, all cows received a c o m m o n diet with 16% CP. Cows received the assigned diets during each 4-wk period. The first 2 wk of each period were for adjustment, the last 2 wk were for comparison. All diets contained 60% (dry basis) a m m o n i a t e d corn silage (12% CP) and a grain mixture c o m p o s e d of corn and oats (2:1) in addition to a mineral and vitamin premix (Table 1), Urea was added to the control diet (C) to provide 11% C P in the total ration D M . The mixture of C G M and BM contained a 50:50 ratio of protein f r o m each of these sources of proteins with low r u m e n degradability. The degradability of the protein in the B M was 17% and in the C G M was 20% (6). The low value for C G M c o m p a r e d with previous
3065
d a t a (40%) m a y have been the result of clogging of pores in the d a c r o n bags used in the procedures. Consequently, the 40% value was used in c o m p u t i n g dietary degradable protein. The low mixture provided 19% of the total dietary C P and the high mixture provided 28% of the total dietary CP. The diet with high r u m e n degradable protein contained S B M as the supplemental protein source. The C P in the C, the low mixture (LM), the high mixture ( H M ) and the S B M diets were 12.5, 14.3, 16.8 and 16.1%, respectively. The c o m p u t e d undegradability of the protein in these diets ranged f r o m 25 to 33% (Table 1), all below the requirements derived f r o m appendix Table 5 of N R C (13). All diets were prepared as complete mixed diets and were fed for ad libitum intake once daily. Samples of forage and of each grain
TABLE I. Composition of experimental diets. Corn gluten and blood meal Item
Control
Low
High
60.00 32.72 3.89 .20 ... ...
60.00 29.23 4.00 "2.'04 150
'3.'59
(% of DM), 60.00 26.89 3.75
Soybean meal
Ingredients Corn silage (ammoniated) Corn-oat mix (2:1) Molasses Urea Corn gluten meal Blood meal Soybean meal Premix 1 Chemical composition (analyzed) Dry matter Crude protein Acid detergent fiber ADIN2 IVDMD2 Undegradable protein 3 Calcium4 Phosphorus 4
"3.'19
"3~23
"3716
10.80 3.06
41.10 12.46 19.10 .30 72.10 25 1.00 .45
41.00 14.33 18.80 .50 72.10 32 1.00 .45
40.40 16.85 19.50 .60 71.60 33
41.30 16.14 19.50 .30 71.70 27
1.00
1.00
.45
Estimated NE4
76.21
75.89
.45 (Mcal/kg) 75.65
60.00 22.14 4.00
iii
2.61
75.62
1The ADE vitamin premix contain (USP units/.454 kg) vitamin A, 4,000,000; vitamin D3,800,000; and vitamin E, 1000. Added at 2% of the mixture, salt (NaC1) 14.0%, calcium sulfate 14.0%, limestone 31.50%, dicalcium phosphate 35.00% of the mixture. Trace mineral mix: copper 1.5%, zinc 12.0% manganese 8.0%, iron 10.0%, cobalt. 10%, iodine 0.20%, calcium 13.0%. Added at 3.5% of the mixture. 2Acid detergent insoluble nitrogen (ADIN), in vitro dry matter disappearance (IVDMD). 3percentage of total crude protein, calculated from NRC (13) values, except for corn gluten meal and blood meal, which were 60% and 83% (6). 4Calculated from ingredient values (13). Journal of Dairy Science Vol. 72, No. 11, 1989
3066
DE GRACIA ET AL.
mix and complete mixed ration were taken weekly. Feed samples were composited by periods and anlyzed for D M , C P (1), A D I N , A D F , and in vitro D M disappearance (7). Milk yields were recorded at each milking. Milk samples were taken at two consecutive milkings on the last day of wk 2, 3, and 4, composited weekly, and analyzed for protein, fat, and lactose using a M i l k o - S c a n 300 (Hillerod, DK). The S N F was estimated as percentage protein + percentage lactose + .7%. B o d y weights were recorded on the last 2 d before the first period began and at the end of the 4th wk of each period. Blood samples were taken f r o m the jugular vein during the last 2 d of the experiment at 5 to 6 h after feeding. P l a s m a was deproteinized with sulfosalicylic acid according to procedures of Perry and Hansen (17) for determination of plasma amino acids. A m i n o acid
analysis was performed on each day's samples by ion exchange c h r o m a t o g r a p h y with post c o l u m n fluorescence detection. Lactation response data were analyzed as a switchback design, blocked for two starting times, and adjustment for missing values (one cow was lost because of abortion), according to Lucas (11). Differences a m o n g treatments were evaluated by using o r t h o g o n a l contrasts to c o m p a r e control versus other treatments, H M versus S B M , and L M versus H M (20). Blood plasma amino acids were analyzed as a split plot design over time, using cows as subsamples and including day (sample time) as a source of variation. Least squares difference was used to detect differences a m o n g treatment means when significant (P<.05) treatment effect resulted. No difference due to sampling time was found; consequently, mean analysis was pooled across days.
TABLE 2. Dry matter intake, milk production and composition, and dry matter and protein efficiency. Corn gluten and blood meal
Dry matter intake, • kg/d Milk yield,b kg/d 3.5% FCM, kg/d Dry matter efficiency,° milk yield/DM intake Milk protein, • % kg/d Protein efficiencyd (protein yield/total protein intake), % Milk fat, %e kg/d Milk SNF, %f kg/d b
Control (C)
Low (LM)
High (HM)
Soybean meal SE (SBM)
19.3 24.0 25.3
19.9 24.5 25.4
20.2 25.7 25.9
21.0 24.8 25.5
.79 1.01 1.08
1.24
1.22
t.27
1.18
.07
3.31 .79
3.39 .82
3.40 .87
3.40 .83
.05 .04
32.85
28.76
25.56
24.49
.6I
3.83 .91
3.74 .91
3.58 .91
3.67 .91
.08 .04
8.94 2.14
8.99 2.20
9.12 2.34
9.01 2.22
.09 .11
•C vs. LM, HM, and SBM (P<.05). bC vs. LM, HM, and SBM (P<.10). oHM vs. SBM (P<.10). dC vs. LM, HM, and SBM (P<.005), LM vs. HM and SBM (P<.005), HM vs. SBM (P<.05). eC vs. LM, HM, and SBM (P<.01), LM vs. HM and SBM (P
Journal of Dairy Science Vot. 72, No. 11, 1989
PRODUCTION TECHNICALNOTE RESULTS AND DISCUSSION
Cows consumed 1 kg less DM (P<.05) daily when they received the C diet than when they received diets supplemented with natural protein, whereas DM consumption did not differ among cows fed the natural protein supplements (Table 2). The greater DM intake for cows fed higher protein diets is well documented (2, 12, 21) However, no important differences were found in in vitro DM digestibility between the control (NPN) diet and the mean for the natural protein diets (Table 1). Milk yields were slightly, but not significantly lower for cows fed the C diet than for cows fed other diets. Others also found urea supplementation associated with lower milk production (3, 10, 22, 25). Milk yields did not differ (P>.10) between cows fed the low and high concentrations of protein or between the low degradable (HM) and high degradable (SBM) sources, indicating that cows received adequate CP even at the low concentration
(14.3%). Milk fat percentage was higher (P<.01) for diet C than for other diets (3.83 vs. 3.65%). This resulted in similar 3.5% FCM yields from all diets. The lower dietary protein diets favored somewhat higher (P<.05) milk fat percentages than higher protein diets. However, no differences in fat production were observed among treatments. In previous research (3, 10, 22, 25), the effect of urea supplementation on milk fat content was variable. There is no apparent explanation for the higher milk fat percentage for cows fed the C diet. Cows fed the HM diet were more efficient (milk yield/DM intake) than cows fed the SBM diet (P<.10). This was related to both the slightly higher milk yields from cows fed the HM diet and higher DM intake of cows fed the SBM diet. Milk protein percentage and milk protein yield were lower (P<.05) for cows fed the C diet than for cows fed the diets supplemented with natural protein. This agrees with earlier studies (12, 21). However, as a consequence of the lower protein intake, protein efficiency (protein yield/protein intake) was better (P<.005) when the C diet was fed (32.8%)
3067
compared with the average for the natural protein diets (26.3%). Protein efficiency was also higher (P<.005) for cows fed the LM diet in comparison with cows fed the HM and SBM diets. Other differences in efficiency were small. Although the NRC (13) recommends protein concentrations above that of the C diet and approximately that of the LM diet, it is evident that the three diets of higher protein were consumed in amounts to supply excessive protein. These efficiency data demonstrate this fact. However, intakes of undegradable protein ranged from about .06 to 1.1 kg daily, which is below the recommended amounts (13) for cows used in this experiment. Huber et al. (10) attributed lower milk protein with urea feeding to lower energy intake. In the present study, DM intake was less (P<.05) in cows fed the urea diet (C). Generally, the amount of dietary protein has little or no effect on milk protein concentration (8, 16), unless the diet is deficient in protein. Differences in SNF percentages and yields among diets were small; however, yields tended to be lower (P<.10) for cows fed C than for those fed the natural protein diets. The mixture of C G M - B M and SBM produced similar patterns of plasma amino acids (Table 3). In general, those amino acids present in greater proportions in the C G M - B M supplement were also present in plasma of cows fed HM in higher concentrations than in plasma of cows fed C or SBM diets, or both. These include histidine, leucine, phenylalanine, threonine, and valine. Higher values for isoleucine, lysine, tryptophan, and tryosine also tended to be present in plasma of cows receiving the C G M - B M supplement, even though the concentration of these amino acids were lower in this supplement than in SBM. In addition, increased concentration of amino acids in plasma was related to feeding HM compared with LM. This may be an indication that more dietary protein reached the small intestine because of lower degradability of the protein in the C G M - B M mixture. Similar responses in plasma amino acids were reported by others (4, 5). Plasma patterns of amino acids were similar for cows fed the C and SBM diets. Possibly the high degradability of SBM in the rumen reduced the outflow Journal of Dairy ScienceVot. 72, No. ll, 1989
3068
DE GRACIA ET AL.
TABLE 3. Pattern of amino acids in protein supplements and in plasma. Diet I
Supplement ~ Amino acid
CGM-BM
SBM
C
(amino acids, % of protein) Histidine 3.82 Isoleucine 2.62 Leucine 15.11 Lysine 5.24 Methionine 2.02 Phenylalanine 7.04 Threonine 4.20 Tryptophan .86 Tyrosine 3.98 Valine 7.22
2.38 4.55 7.31 5.99 1.16 4.73 3.71 1.42 4.51 4.51
LM
HM
SBM
SE 2
(plasma amino acids, %), 1.19ab 1.37b 2.24b 1.54b .29ab .84b .90 a .49 1.05b 2.53 b
1.33a 1.36b 3.52~b 1.9 lab .27 b 1.02a .90 a .52 .94 b 3.81 b
1.26ab 1.89a 4.90a 2.12 a .34 a 1.12~ 1.01a .55 1.30a 5.57 a
1.05b 1.55ab 2.22b 1.68ab .28 ab .80b .74 b .38 .89 b 2.94 b
.08 .06 .13 .15 .02 .06 .ll .09 .10 .19
a,bMeans within rows within diet with different superscript differ (P<. 10). ICorn gluten meal (CGM), blood meal (BM), control (C), low mixture level (LM), high mixture level (HM), soybean meal (SBM). 2Standard error for plasma amino acids.
of amino acids with this supplement. With high degradable p r o t e i n s u c h as S B M , microbes account for most of the amino acids in the intestine and would be expected to produce a pattern similar to that of the C diet with NPN. In conclusion, results indicated that cows in midlactation can sustain normal milk prod u c t i o n w i t h b e t w e e n 12.5 a n d 14.3 % p r o t e i n in the diet, which apparently supplied the m i n i m u m q u a n t i t a t i v e r e q u i r e m e n t s (13) o f the cows involved even though undegradable protein intakes were below recommended a m o u n t s (13). R o b i n s o n a n d K e n n e l l y (18) came to a similar conclusion. Higher protein did not increase DM intake or milk yield. Low rumen degradable protein supplements (CGM-BM) did not benefit lactation performance compared with SBM; however, they resulted in higher plasma amino acids.
REFERENCES 1 Association of Official Analytical Chemists. 1980. Official methods of analyses. 13th ed. Assoc. Offic. Anal. Chem., Washington, DC. 2 Barney, D. J., D. G. Crieve, G. K. MacLeod, and L. G. Young. 1981. Response of cows to crude protein during midlactation. J. Dairy Sci. 64:655. 3 Casper, D. P., and D. J. Schingoethe. 1986. Evaluation of urea and dried whey in diets of cows during early lactation. J. Dairy Sci. 69:1346. Journal of Dairy Science Vol. 72, No. 11, 1989
4 Chalupa, W. 1975. Rumen by-pass and protection of proteins and amino acids. J. Dairy Sci. 59:1198. 5 Clark, J. H. 1975. Lactation responses to postruminal administration of proteins and amino acids. J. Dairy Sci. 58:1178. 6 Goedeken, F., T. Klopfenstein, R. Stock, and R. Britton. 1987. Hydrolyzed feather meal as a protein source for growing ruminants. Page 50 in Beef Cattle Rep. MP 52. Agric. Res. Div., Inst. Agric. National Resources., Univ. Nebraska-Lincoln. 7 Goering, H. K., and P. J. Van Soest. 1970. Forage fiber analyses; apparatus, reagents, procedures and some applications. Agric. Handbook 379. USDA, ARS, Washington, DC. 8 Gordon, F. J., 1977. The effect of protein content on the response of lactating cows to level of concentrate feeding. Anim. Prod. 25:181. 9 Huber, J. T., and L. Kung, Jr. 1981. Protein and nonprotein nitrogen utilization in dairy cattle. J. Dairy Sci. 64:1170. 10 Huber, J. T., R. A. Sandy, C. E. Polan, H. T. Bryant, and R. E. Blaser. 1967. Varying levels of urea for dairy cows fed corn silage as the only forage. J. Dairy Sci. 50:1241. 11 Lucas, H. L., Jr. 1983. Design and analysis of feeding experiments with milking dairy cattle. Inst., Mimeo Ser. 18, North Carolina State Univ. Raleigh, NC. 12 Nocek, J. E., and J. B. Russell. 1988. Protein and energy as an integrated system. Relationship of ruminal protein and carbohydrate availability to microbial synthesis and milk production. J. Dairy Sci. 71:2070. 13 National Research Council. 1988. Nutrient requirements of domestic animals. Nutrient requirements of dairy cattle. 6th rev. ed. Natl. Acad. Sci., Washington, DC.
PRODUCTION TECHNICAL NOTE
14 Oldham, J. D. 1984. Protein-energy interrelationships in dairy cows. J. Dairy Sci. 67:1090. 15 Owens, F. N., and W. G. Bergen. 1983. Nitrogen metabolism of ruminant animals: historical perspective, current understanding and future implications. J. Anim. Sci. 57:498. 16 Paquay, R., Godeau, J. M., R. De Baere, and A. Lousse. 1973. The effects of the protein content of the diet on the performance of the lactating cows. J. Dairy Res. 40:93. 17 Perry, C., and J. Hansen. 1969. Technical pitfalls leading to errors in the quantitation of plasma amino acids. Clin. Chem. Acta 25:53. 18 Robinson, P. H., and J. J. Kennelly. 1988. Influence of intake of rumen undegradable protein on milk production of late lactation Holstein cows. J. Dairy Sci. 71:2135. 19 Satter, Larry. 1982. A metabolizable protein system keyed to ruminal ammonia concentration - The Wisconsin system. Page 245 in Protein requirements for cattle: symposium. F.N. Owens, ed. M P 109. Oklahoma State Univ., Stillwater. 20 Steel, R. C. D., and J. H. Torrie. 1980. Principles and procedures of statistics. A biometrical
3069
approach. 2nd ed. McGraw-Hill, New York, NY. 21 Van Horn, H. H., 1982. Empirical value of crude protein system for dairy rations. Page 218 in Protein requirements for cattle: symposium. F. N. Owens, ed. MP-I09, Oklahoma State Univ., Stillwater. 22 Van Horn, H. H., C. F. Foreman, and J. E. Rodriguez. 1967. Effect of high urea supplementation on feed intake and milk production of dairy cows. J. Dairy Sci. 50:709. 23 Van Horn, H. H., and C. A. Zometa. 1978. Optimum protein in complete rations for high producing lactating cows. Feedstuffs 50:34:22. 24 Van Soest, P. J., C. J. Sniffen, D. R. Mertens, D. G. Fox, P. H. Robinson, and U. Krisnamoorthy. 1982. A net protein system for cattle: The rumen submodel for nitrogen. Page 265 in Protein requirements for cattle: symposium. F. N. Owens, ed. M P 109, Oklahoma State Univ., Stillwater. 25 Wolhlt, J. E., and J. H. Clark. 1978. Nutritional value of urea versus preformed protein for ruminants. I. Lactation of dairy cows fed corn based diets containing supplemental nitrogen from urea and/or soybean meal. J. Dairy Sci. 61:902.
Journal of Dairy Science Vol. 72, No. 11, 1989