High Moisture Corn for Dairy Cattle

High Moisture Corn for Dairy Cattle by Howard H. Voelker Dairy Science Department South Dakota State University, Brookings, SD 57007

(6)Sometimes wet spring weather delays planting resulting in immature corn in fall. This can be used as high moisture corn. Dry Matter Intakes

Summary

In cattle feeding studies, well preserved high moisture corn usually was readily consumed (1, 2, 1 1 , 1 2, 1 7, 21). HMC fed in total mixed rations compared to DC resulted in similar dry matter consumption by dairy cows. Where dry matter intakes were low, HMC may have been poorly preserved and contained more than 30% moisture (2, 13, 14, 15).

High moisture corn (HMC) has been used for dairy cattle feeding for some time. With cattle fed HMC, milk production, composition, body weight changes and growth of young animals were comparable to dry corn (DC) in most experiments. Preservatives such as organic acids, especially propionic acid, have improved the preservation of HMC. Certain acid derivatives are less irritating to skin and less corrosive to metal than propionic acid and appear promising. Biological additives (cultures) have generally not been as effective and dependable as organic acids. HMC can be successfully preserved in several types of silos if proper management procedures are used.

Milk production and Composition Reviews by Clark (1,2) showed that total milk yields, fat %, and milk per unit of dry matter intake were usually similar for HMC and DC whether HMC was ensiled or acid treated. In three trials (21) milk yields, fat %, protein %, and solids not fat % were all normal when HMC and DC were fed in complete mixed rations. A summary of milk produced, fat %, and efficiency of feed utilization for milk production is in Table 1 . This summary of numerous studies taken from reviews and individual reports showed that HMC as ensiled or organic acid treated which contained less than 30% moisture usually gave responses similar to DC. It was generally concluded that HMC stored at 20 to 30% moisture and properly preserved can be fed with very acceptable milk yields.

Introduction Feeding of high moisture corn to dairy cattle has become practical and wide spread for a number of years. Corn (maize) is North America's primary grain for livestock. HMC is not dry enough for conventional storage as it may range from 20 to 40% in moisture, but it usually contains 25 to 35%. The objectives of this article are to review relevant data from research reports and reviews, highlighted by our own research and experiences, and to make recommendations for HMC use in dairy cattle feeding.

Rumen Violatile Fatty Acids (VFA) Several studies (1, 2) indicated that molar proportions of VFA were not altered appreciably by feeding ensiled HMC unless forage intakes were decreased (13, 14, 15). Research at South Dakota State University (21) showed molar concentrations of acetate in ruminal con-

Advantages of High Moisture Corn A number of important advantages of using HMC are as follows: (1 )Reduced field losses especially ear dropping. (2)Harvesting can be done earlier and often during more desirable weather (in Northern climates especially). (3)Costs of extra handling and drying are eliminated. (4)HMC, properly preserved and managed, is very palatable to livestock. (5)Later maturing, higher yielding corn varieties can be used especially in northern areas which often have early frost.

TABLE 1. Milk Produced, Milk Fat Percent. and Milk per Unit of Dry Matter Consumed . 30 ____________________________________~--

Type of Corn

Dry Corn Ensiled HM Corn Acid treated HM Corn

Published with the approval of director of the South Dakota Agricultuaral Experiment Station as Publication 21 86 of the Journal Series. Reviewed by G.W. Thrasher

No. of Cows

Milk Milk Produced Fat (kg per cow daily) (%)

447 348

22.0 21.4

3.62 3.62

1.17

270

22.3

3.68

1.15

aFMC = 4% fat-corrected milk.

37

kg 4070 FCM a per kg feed Dry Matter consumed 1.15

38

VOELKER

tents were lower and propionate concentrations were higher for cows fed HMC than DC. Forage dry matter levels averaged 57 .6 % of total dry matter intakes. Changes in acetate to propionate ratios resulting from feeding H~Y~C sometimes have been related to milk fat depression (2, 13, 14, 15). Fiber intake and forage to concentrate proportions may be important considerations in causing milk fat depression. Perhaps acid detergent fiber levels should be at least 21 % of OM intakes in order to maintain milk fat levels. Rumen VFA values in three trials with 60 cows (21) showed that milk fat % was not Significantly reduced from feeding HMC even though ruminal acetate to propionate ratios were altered somewhat. Processing HMC

HMC is often stored as whole kernel corn in oxygen lim iting storage and rolled or ground before feeding . In concrete tower or bunker silos corn is conventionally ground as ensiled . Rolling of HMSC before feeding to dairy cows improved digestibiiity. efficiency of utiiization, and increased milk production by about 2 kg per cow per day (1, 2). Ear versus Shelled Corn

. t d Larsen (11) compare d h·Ig h mOls ure groun ear corn (HMEC) with high moisture shelled corn (HMSC). Dry matter consumption was similar for both types of corn. Milk production, fat %, and 4% fat-corrected milk were higher for HMEC than HMSC. Feed efficiency for milk production also favored the ear corn . USDA research (16) showed similar metabolizable energy for HMEC and HMSC for lactating cows. The ground ear corn was perhaps too high in moisture (37%) for best responses . Marx (12) observed that cows pro-

compared with DC, with DC fed at 2.3 kg per heifer daily and equivalent OM from HMC . Alfalfa hay was fed at 3 kg per heifer daily. The heifers had an average daily gain of .82 kg on HMC and . 77 kg on DC. Tabla 2 is a summary of daily gains and efficiency of feed utilization by young growing cattle taken from reviews and individual experiments. This shows that DC and H~..~C feeding may result in similar 'vveight gains ~AJhil efficiency may be about 5% better from HMC than DC. Storage Methods

Each farmer will use a storage method for HMC that fits his farming operation . Field drying of corn, artificial drying, ensiling, and using preservatives are alternatives. There are advantages and disadvantages to each system which should be considered before selecting a harvesting and storage system. Problems to overcome include reduction in dry matter losses, especially preventing of heating and mold growth. In South Dakota State University research oxygen-limiting storage, concrete bunkers, and "pilottype" small silos were used (17,18,19,20,21,22). Propionic acid and other additives were successfully used in concrete bunkers and small silo research. In research using large silos, HMC preserved in oxygenlimiting storage resulted in 7 .5% of corn DM loss between ensiling and feeding. HMEC preserved in a concrete bunker carefully covered with plastic and preserved with 1 % propionic acid resulted in 13.6% DM loss . The corn was ground before storage. When .5 % propionic acid was used with HMC, there was 12.5% DM loss. Feeding trials were started soon after ensiling, and the corn was fed during a 15-week subsequent period during cold weather.

In three trials with small silos (18), propionic acid at 1 % of corn weight resulted in 6.8% DM loss while con ---'drrce-c:t-4-:-S-OAnrrore-milirin-early-lactations-trom-rolled---~~~~'--!.'.~~~~"'-"'-'~:!....'.!..~~~='--'-"'-"""----'-'--'-'-'-'-"'--"""'-'---trol (no additive) corn averaged 23 .8% OM loss. Plastic HMSC than HMEC. However, in late lactations produccovers on silos reduced temperature, pH, OM losses, tion was similar. Although no direct comparisons were and mold growth on tops of silos (18) . Hoffman and Self (6) compared oxygen -limiting made within trials and years, cows produced very satl'sfactorily on either HMSC or HMEC in comparison storage and concrete stave silo storage of HMSC . ThEH'e'" with a standard dry corn-containing ration (21). was a loss of 6.0% of corn dry matter in oxygen-limiting The immature cobs of HMEC apparently have con system and 12.5% loss in concrete stave system (P siderable feed value. When higher yields of energy per .10). acre are considered for ear corn, along with other advantages such as maintaining milk fat %, cows having less tendency to go "off feed", less rumen disturbance, etc., HMEC may be the system of choice(11). TABLE 2. Average Daily Gains and Efficiency of Feed Use by Growin g Cattle.

Growing Animals

HMC is an excellent feed for growing animals when properly supplemented (1, 2). Growing animals gained about equally on HMC as on DC-containing rations, with feed efficiencies 6 to 8% higher for HMC than for DC (1, 2).

A South Dakota State University study used Holstein heifers averaging 1 51 kg at the start of a trial. HMC was

Type of

No . of

Av. daily

Corn

An imals (kg/day)

gains

kg DM intake per kg gain

Dry Corn

648

108

7.7 8

Ensiled corn

564

106

7.43

242

103

7 .32

Ac i d cor n

HIGH MOISTURE CORN FOR DAIRY CATTLE Additives and Preservatives

Organic acid and cultures have been investigated for use in HMC preservation (2, 3,4,5,7,8,9,10,15,17, 18, 19, 20, 21, 22, 23). Corn may mold when moisture exceeds 20% and air temperatures and humidity are high enough to induce mold growth. Propionic acid is used most commonly although acetic, propionic, and other acids or their combinations may be used. Economic implications of these preservatives suggest that they may be competitive with artificial dryin especially when fuels used in drying become expensive. Certain derivatives of propionic acid in combination with other preservatives appear to be less irritating to skin and corrosive to metal. These need further research, however (20, 22 - Table 3).

Larsen et al (10) made recommendations for use of propionic acid with corn at different moisture levels and months of storage. At moisture levels of corn at 20 25 30, and 35% for 6 months storage, proPionic' acid should be used at .5, .6, .8, and 1 % of weight. For 12 month storage 1.5 times as much propionic acid was recommended. In our own research, it was not necessary to use more than 1 % propionic acid when care was taken to keep air from the corn in bunker and small silo preservation. Various researchers have used microbial cultures on HMC (4, 5, 18, 19,20, 22). The cultures were often of L. plantarum type. Results have been somewhat variable. Often the cultures were combined with other ingredients in commercial products so that it is difficult or impossible to measure the culture effects. Care of the cultures and their management appear to be very necessary to obtain beneficial results. In general, bacterial cultures have not been nearly as effective or beneficial as the organic acids or their derivatives in preservation of HMC. Recommendations

Oxygen-limiting structures have been used successfully. Corn is best stored between 20 and 30% moisture as shelled corn and rolled before feeding . In tower open-top, top unloading concrete silos and in bunkers, a minimum of 2 inches of corn removal daily is recommended. In warm weather more corn must be

TABLE 3. Effects of Additives and Preservatives on High Moisture Corn. Esters of No Additive Propionic Acid Level, % of corn: 0 74.2 Corn dry matter, % Dry matter loss, % 15.3 Maximum temperatures (top 30cm of corn, CO) 35.5 Moldscores (0 to 5) 3.5 pH 5.2

Biological

Propionic

Additive

Acid

.5 1.0 74.8 73.8 4.6 3.1

0.1 74.7 9.6

1.0 74.5 1.7

20.3 17.0 .9 0.0 4.7 4.4

32.4 1.4 5.0

17.0 0.0 3.9

39

removed daily. Bunkers should be covered with plastic and weighted down to exclude as much air as possible and to protect corn from rain and snow . Preservatives should be used at recommended levels. A common mistake is to use no preservative or to use too Iowa level of it for adequate preservation in bunkers. HMC from oxygen-limiting systems should be ground or rolled before feeding. In tower silos or bunkers, corn should be ground as ensiled. Especially in bunkers a preservative such as propionic acid should be used at an adequate level. Beware of recommendations using very small amounts of preservatives or dultures that have not been proven to be beneficial. More research is needed with cultures before they can be recommended. HMC should be fed in balanced rations. Various forages and concentrates have been fed successfully with HMC. When properly preserved at moisture levels not over 30% and when corn was fed with good quality roughages (21), there were no major feeding problems. High moisture ear corn has a number of advantages over HMC (shelled) (11) including higher yields per acre. Ear corn can be fed safely at fairly high levels with less problems in dairy cattle including fewer cows "off feed", problems of low milk fat tests, and rumen disturbances than with HMC . Literature Cited

1. Clark, J. H. 1975. Proc. 2nd Int. Silage Res. Conf. Nat'!. Silo Assoc., Cedar Falls, IA. Page 205. 2. Clark, J. H., 1980. Proc. 41 st Minn. Nutr. Cont., Minneapolis. (pages 1-11). 3. Clark, P. W., and G. T. Lane. 1979. Extension Service, Univ. of Kentucky, Lexington . Personal Communication. 4. Flores-Galarza, R. A., B. A. Glatz , C. J. Bern and L. D. Fossen. 1985. J. Food Protection 48(5):407 5. Glatz, R. A., B. A. Bern, C. J . Van Fossen. 1985. J. Food Protection 48(5):407. 6. Hoffman, M. P., and H. L. Self. 1975. J. Animal Sci. 41 (2):500 7. Jones, G. M., D. N. Mowat, J. I. Elliot. and E. T. Morgan, Jr. 1974. Canad. J . Animal Sci. 54:499. 8. Jorgensen, N. A., H. J. Larsen, and G. P. Barrington. 1980 . Research Bul. R3057, U. of Wis ., Madison. 9. Larsen, H. J. and N. A. Jorgensen. 1980. J . Dairy Sci. 63(Suppl. 1): 148. (Abstr.). 10. Larsen, H. J., N. A. Jorgensen, and G. P. Barrington . 1980. Bul. A3095 . U. of Wisc., Madison, WI. 11. Larsen, H. J. 1981 . MSH 6003-81-8. University of Wis., Marshfield. 12. Marx, G. D. 1984. J. Dairy Sci. 67(Suppl. 1): 11 7. (Abstr.).

40 13. Palmquist, D. L. 1970. Ohio Rep. 55(6): 117 . 14. Palmquist, D. L. and H. R. Conrad. 1970 . J. Dairy Sci. 53:649. (Abstr.) . 15. Shockey, W. L., and H. R. Conrad. 1984. J. Dairy Sci. 67:969. 16. Tyrrell, H. F., and G. A. Varga. 1984. J . Dairy Sci. 67(Suppl. 1 ):131. (Abstr.). 17. Voelker, H. H. , D. J. Schingoethe, A. K. Clark, F. C. Ludens, and J. K. Drackley. 1983. J. Dairy Sci. 66(Suppl. 1 ):165. (Abstr.). 18. Voelker, H. H., C . C . Rakshit, and R. M. Luther. 1983. J. Dairy Sci. 66(Suppl. 1):177. (Abstr.).

VOELKER 19 . Voelker, H. H., and C. C. Rackshit. 1984. J . Dairy Sci. 67(Suppl. 1): 117 . (Abstr.). 20. Voelker, H. H., M. Sulaiman, and R. M . Luther. 1985. J . Dairy Sci. 68(Suppl. 1 ):158. (Abstr.). 21. Voelker, H. H., D. J. Schingoethe, J . K. Drackley and A. K. Clark. 1985. J. Dairy Sci. 68 :2602 . 22. Voelker, H. H., S. S. Ray, and R. M. Luther. 1986. J . Dairy Sci. 69(Suppl. 1 ):139. (Abstr.). 23 . Zhivotnovdni, N. 1982. Bulgarian Scientific Literature Abstracts. B 1983(3):300. (Summary in English).