Survey of Nutritional Management Practices and Metabolic Disorders in West Virginia Dairy Herds1

OUR INDUSTRY T O D A Y Survey of Nutritional Management Practices and Metabolic Disorders in West Virginia Dairy Herds 1 G. A. V A R G A , 2 W. H. H O O V E R , and R. A. D A I L E Y Division of Animal and Veterinary Sciences West Virginia University Morgantown 26506 ABSTRACT

by dairy farmers trying to achieve top production (2, 7). Economic losses can occur when dairy producers do not feed cows a balanced diet, particularly in early lactation. In addition, failure to control metabolic and nutritional disorders during the dry period and early lactation can result in further losses (8). An initial survey of 80 West Virginia dairy farms (unpublished) provided general information on feeding and herd health management and identified problem areas. Approximately 40% of the farmers expressed a need for more information on feeding. The present survey was to determine specific aspects of the feeding program that required attention and to identify herd health disorders that could be related to nutritional imbalances.

Sixteen farmers, representing three major dairy counties in West Virginia, were interviewed to determine cuTrent dairy management practices. Herd health records were used to determine the incidence of metabolic and digestive disorders. All feedstuffs used on these farms were sampled for chemical analyses. The total number of cows on the 16 farms surveyed was 1870 with an average herd size of 117 and 6387 kg milk produced per cow per year. Fourteen of the 16 farmers used forage testing services, obtained professional advice on feeding and nutrition, and attempted to feed according to production. Eleven of sixteen farmers increased grain 2 weeks prior to calving and all gradually adjusted the intake of grain to cows recently freshened. Ration imbalance problems included both excesses and deficiencies of energy, protein, phosphorus, and calcium. Excess calcium, phosphorous, and crude protein were correlated (P<.01, r 2 = . 7 4 ) w i t h the incidence of fat cows. The incidence of metabolic disorders in these herds was low to average and the most prevalent management problem encountered was low butter fat.

MATERIALS AND METHODS

INTRODUCTION

Reaching peak milk yield within 60 days after freshening is one of the challenges faced

Received September 10, 1984. 1Published with the approval of the Director of the West Virginia Agriculture and Forestry Experiment Station as Scientific Paper No. 1923. This research was supported by West Virginia Agricultural and Forestry Experiment Station Project No. 194. a Ruminant Nutrition Laboratory, USDA, Animal Science Institute, Beltsville, MD 20705. 1985 J Dairy Sci 68:1507-1512

Sixteen farms with a total of 1870 cows were surveyed. These farms were chosen based on the results of the previous general survey of 80 farms in West Virginia and were located in three of the major dairy counties in the State. Daily individual cow herd health records were kept on all farms. Both farm and veterinarian's records were available in 13 herds, although veterinarian's records only were used on three farms. Breeds on these farms included two Jersey, one Ayrshire, and 13 Holstein herds. All farmers participated in the Dairy Herd Improvement records program. A 6-page survey was developed and divided into five categories: 1) general information, 2) dry cow program, 3) early lactation feeding program, 4) feeding management, and 5) herd health. All stored forages, grains, and high moisture feeds were sampled for chemical analyses. Grains included purchased protein sources as well as home mixed feeds. Ensiled forages and high moisture feeds were dried (50°C) and analyzed for dry matter prior to being sent to the New York Dairy Herd Improvement Cooperative Lab-

1507

1508

VARGA ET AL.

TABLE 1. General information on animal numbers and average milk production of farms surveyed. Item

Mean

Cows in milk Dry cows Bred heifers Open heifers Calves < 6 mo Milk production, kg/lactation All breeds Holsteins

o r a t o r y for analyses of crude protein (CP), acid detergent fiber (ADF), calcium (Ca), and p h o s p h o r o u s (P). A calculated net energy for lactation (NE1) also was provided. Individual cow health records were used to determine the incidence of digestive and metabolic disorders for 2-yr. These were ketosis, displaced a b o m a s u m , milk fever, tetany, off feed, d o w n e r cow, and fat cows. A d o w n e r cow was any cow that went d o w n and could not get up for at least a day w i t h o u t an identifiable diagnosis. Fat cows were identified subjectively by each individual farmer. RESULTS A N D DISCUSSION

General i n f o r m a t i o n on animal numbers and p r o d u c t i o n levels is in Table 1. The dairy herds represented by these 16 farms averaged 117 cows and 6387 kg milk per cow per farm. Loose housing was used on all but one farm. Corn silage was fed on all farms and 10 harvested primarily alfalfa for hay crop silage. The chop length for corn silage ranged f r o m 13 to 26 m m , while the chop length for hay crop silage varied f r o m 6 to 38 m m . In general, farmers a t t e m p t e d to keep within the r e c o m m e n d e d 16 m m theoretical cut (5). Ten farmers fed conventional shelled corn harvested on the farm, two fed high moisture ear corn, and two fed high moisture shelled corn. All but one farmer harvested hay, of which 62.5% was alfalfa with the remainder an alfalfa-grass m i x t u r e . One-third of these farmers stored hay as large round bales. F o u r t e e n o f the 16 farmers had ensiled forages tested at least once a year. Hay was not usually tested. As the primary source o f nutritional and feeding i n f o r m a t i o n , eight used some combinaJournal of Dairy Science Vol. 68, No. 6, 1985

Range

117 22 41 39 29

46 7 14 20 2

6387 6891

-

270 50 138 60 215

4185 - 7589 5987 - 7589

tion of a feed c o m p a n y representative, veterinarian, c o u n t y agent, and themselves. T w o used o n l y a feed c o m p a n y representative, and two others e m p l o y e d feed consultants. The two remaining farmers relied solely on themselves for determining their feeding program. Farmers in general t h o u g h t t h e y did n o t have adequate i n f o r m a t i o n on feeding. Management and feeding data of the dry cow are presented in Table 2. All but t w o of the farmers separated the dry and lactating cattle. The average n u m b e r of days dry was 58, indicating ample t i m e was provided to rest and build up b o d y reserves for the subsequent lactation (2). Studies by C o p p o c k et al. (3) d e m o n s t r a t e d that cows with dry periods of 40 + 10 days p r o d u c e d as m u c h milk as cows with

TABLE 2. Dry cow management. Item Dry cows separated from milk cows Dried off by complete cessation of milking Dry cow treatment Average days dry Increase grain 2 wk prior to calving Gradual Abrupt Vitamin or mineral prior to calving2 A,D,E, selenium (Se) Se only 1Range of days dry. 2All injected.

Number of farms

14 14 16 58 (42-65) 1 6 5 2 1

OUR INDUSTRY TODAY TABLE 3. Dry cow feeding. Item

Mean

Range

Grain, kg/cow/day 1 Hay, kg/cow/day i Silage, kg/cow/day I Pasture, months 2

1.0 6.7 7.2 9.0

0 0 0 6

- 4.1 - 13.6 - 29.5 - 12

aAmount fed when dry cows were not on pasture, as fed basis. 2All farmers provided minerals to cows while on pasture.

50 to 60 days dry. Cows were dried off abruptly on 14 of the 16 farms; the remaining two removed grain and milked once daily. All farmers dry-treated all quarters at the time cows were dried off. This has been important in the prevention of mastitis during the dry period as well as for the next lactation (12). Eleven farmers increased the grain offered approximately 2 wk prior to calving (Table 2), suggesting a high percentage of farmers realized the importance of adjusting the dry cow to the milking ration (1). Six of the 11 gradually increased the grain prior to calving, and 5 abruptly offered an amount equivalent to the requirement of cows producing less than 18 kg of milk. Three farmers regarded the use of vitamin or mineral injections as necessary immediately prior to calving. Table 3 presents the range in amounts and types of feed provided to dry cows. In general, pasture was used 75% of the year and stored feeds during the winter months. All farmers increased grain in the rations for the 2 wk after calving (Table 4). In half of the herds, approximately 4 kg of grain was provided per cow per day the first week. The other half of the farmers could not give an estimate of grain fed, because cows were either placed in a low production group for 2 weeks or given access to grain via magnetic feeders. It was evident that farmers attempted to feed cows according to production; 11 of the 16 farmers had at least two groups. However, this was in part confounded by farmers that were not feeding totally mixed rations, as 12 of the 16 fed grain in the parlor. Magnetic feeders were used on five farms to provide higher producers extra grain throughout the

1509

day. Fourteen of the 16 had feed in front of the cows all day; 11 offered this as hay and silage, and the remaining three provided hay throughout the day. Ten farmers fed buffers; 7 of these fed a mixture of sodium bicarbonate and magnesium oxide and 3 fed only sodium bicarbonate. Five fed buffers year around while 5 fed buffers only in response to decreased butter fat production. Others attempted to correct low butter fat production by either increasing hay or decreasing grain feeding. Buffers have been demonstrated to increase milk fat and milk production (6, 9). Table 5 presents the range in chemical analyses of the forages harvested and stored at the time the farms were surveyed. Corn silage ranged in crude protein content from 5.9 to 9.5%. Alfalfa silage ranged from 15.9 to 21.2% CP, and alfalfa-grass silage ranged from 7.3 to 15.4%. Values for ADF, Ca, P, and NE 1 of the ensiled forages were within the range of values found for corn, alfalfa, and the alfalfa-grass silages (10, 11). Hay represented alfalfa, orchardgrass, clover, and mixtures of legumes and grasses.

TABLE 4. Management and feeding of lactating cows. Item

Number of farms

Method of increasing grain after calving Provided % 4 kg cow/day for 1st wk Provided limited grain 1 Placed in low group or on magnetic feeders Number of production groups 3 or more 2 1 0 Grain in parlor Magnetic feeders Feed available at all times Type of feed available2 Hay and silage Hay only

8 4 4 7 4 3 2 12 5 14 11 3

1These farmers could not estimate the exact amount fed, but attempted to feed less than to other lactating cows. 2Represents those farms providing feed at all times. Journal of Dairy Science Vol. 68, No. 6, 1985

1510

VARGA ET AL.

TABLE 5. Range of chemical analyses of forages (dry matter basis). I Silage Item

Hay

Corn

Dry matter,% Crude protein, % NEI, 2 Mcal/kg Calcium, % Phosphorus, % Acid detergent fiber, %

83.7 14.8 .92 .36 .27

-91.5 - 20.5 - 1.36 - 1.66 .42

30 5.9 1.32 .15 .19

34.2

- 46.4

16.6

Alfalfa

Legume-grass

-50 - 9.5 - 1.65 .64 .30

36 15.9 .88 .82 .28

-67 - 21.2 - 1.36 - 1.76 .45

26 7.3 .95 .33 .23

-51 - 15.4 - 1.23 - 1.31 .46

- 49.4

34.2

- 49.4

35.5

- 47.3

1All values are ranges found on 16 farms. 2NE 1 = Net energy for lactation.

Chemical c o m p o s i t i o n o f the rations fed lactating c o w s is in Table 6. As a p o i n t o f reference, t h e daily a l l o t m e n t o f CP, P, NE1, and A D F , w h e n averaged for all cows, all m e t t h e r e q u i r e m e n t s (10) o f a 600-kg c o w producing 28 kg o f 3.5% fat milk. Based o n the individual f a r m rolling herd average p r o d u c t i o n and b u t t e r fat test, 50% o f t h e f a r m e r s were u n d e r f e e d i n g and 50% o v e r f e e d i n g p r o t e i n . Only one f a r m e r c a m e w i t h i n 100 g o f t h e e s t i m a t e d p r o t e i n r e q u i r e m e n t . In five o f t h e herds, t h e NE 1 p r o v i d e d was w i t h i n -+ 2 Mcal o f N R C (10) r e c o m m e n d a t i o n s (Table 6). The r e m a i n i n g h e r d s w e r e e i t h e r u n d e r f e d or overfed energy. A c i d d e t e r g e n t fiber was greater t h a n 21% in all b u t o n e h e r d , indicating adeq u a t e fiber was n o t a p r o b l e m ; h o w e v e r , in s o m e cases it was m a i n t a i n e d at t h e e x p e n s e o f energy and p r o t e i n . Cows were overfed Ca on

over half o f t h e farms, b u t 70% o f the f a r m e r s u n d e r f e d p h o s p h o r o u s . A l t h o u g h all b u t t w o f a r m e r s had s o m e aid in r a t i o n balancing, in m a n y h e r d s t h e r a t i o n s were e i t h e r i m p r o p e r l y f o r m u l a t e d or n o t a c c u r a t e l y m i x e d . The i n c i d e n c e o f m e t a b o l i c and digestive disorders in the h e r d s is p r e s e n t e d in Table 7. The i n c i d e n c e o f ketosis was greater t h a n 5% in five o f the herds. Etgen and Reaves (4) i n d i c a t e d t h a t t h e i n c i d e n c e o f ketosis is generally 10% in c o w s over 36 m o o f age. T h e r e was n o relationship b e t w e e n t h e i n c i d e n c e o f ketosis and dry m a t t e r or e n e r g y intake in t h e s e herds. The i n c i d e n c e o f milk fever o b s e r v e d in this s t u d y was l o w e r t h a n t h e range o f 6 to 8% cited b y E t g e n and Reaves (4) for cows in the U n i t e d States. R e l a t i o n s h i p s a m o n g various n u t r i t i o n a l m e a s u r e m e n t s and t h e i n c i d e n c e o f m e t a b o l i c

TABLE 6. Chemical composition of rations fed to lactating cows. 1,~ Item

NRC 3

Mean

Range

Dry matter fed, kg Crude protein, kg Acid detergent fiber, % NE14 , Mcal Calcium, g Phosphorous, g

19.0 2.79 21.0 29.0 93.8 66

18.8 2.78 25.2 28.2 135.4 69.6

15 1.85 18.5 14.3 25 25

1Three of the farmers also had pasture available as a feed source. 2Minerals were fed free choice on 5 of the farms in addition to that in feeds. 3Requirements for a 600 kg cow producing 28 kg of 3.5% milk (National Research Council, 1978). *NE1 = Net energy for lactation. Journal of Dairy Science Vol. 68, No. 6, 1985

-- 25.5 -3.99 29.9. -- 37.6 -- 303.5 -- 153

OUR INDUSTRY TODAY TABLE 7. Incidence of metabolic and digestive disorders. Item

Mean %

Milk fever Ketosis Displaced abomasum Tetany Off feed Downer cow t Fat cows 2

4.92 3.21 1.71 0 1.76 1.00 2.30

Range %

0 0

.6 - 12.96 - 13.54 - 5.00

0 0 0

- 5.70 -- 4.35 -- 7.24

Cows that were down for longer than 24 hr for unknown causes. 2This is a visual appraisal made by the farmer.

and digestive disorders were d e t e r m i n e d . T h e i n c i d e n c e o f m i l k fever was positively c o r r e l a t e d w i t h t h e d i e t a r y Ca:P r a t i o ( P < . 0 0 8 , R = .67) a n d was negatively c o r r e l a t e d w i t h t h e NE 1 c o n c e n t r a t i o n in t h e r a t i o n ( P < . 0 0 6 , R = - . 6 7 ) a n d t h e t o t a l daily e n e r g y i n t a k e (P<.045, R = -.54). The incidence of fat cows was c o r r e l a t e d w i t h t h e d i e t a r y c o n t e n t o f P ( P < . 0 0 0 1 , R = .77), Ca ( P < . 0 5 , R = .53), a n d p e r c e n t CP ( P < . 0 2 , R = .63) a n d to t h e t o t a l daily p r o t e i n i n t a k e ( P < .05, R = . 53). Regression analysis was c o n d u c t e d to d e t e r m i n e t h e i m p o r t a n c e o f these f a c t o r s in t h e i n c i d e n c e o f fat cows (IFC). T h e regression e q u a t i o n b e s t describing t h e r e l a t i o n s h i p was: IFC = - . 0 1 3 + .191 (P) + . 0 0 5 7 (Ca); ( P < . 0 1 , R = .74). A m i n e r a l i m b a l a n c e at t h e last p a r t o f l a c t a t i o n m a y be r e l a t e d to t h e fat cow p r o b l e m . H o w e v e r , o n l y d r y cows a n d early l a c t a t i o n p r o g r a m s were e v a l u a t e d in this survey. Dry m a t t e r i n t a k e was highly c o r r e l a t e d w i t h t h e t o t a l e n e r g y c o n t e n t o f t h e diet ( P < . 0 0 0 1 , R = .94) a n d daily p r o t e i n i n t a k e ( P < . 0 0 0 1 , R = .85) a n d was negatively c o r r e l a t e d w i t h m i l k fat c o n t e n t ( P < . 0 0 9 , R = - . 6 7 ) . T h e c r u d e p r o t e i n c o n t e n t o f t h e diet was c o r r e l a t e d w i t h t h e n u m b e r o f d o w n e r cows ( P < . 0 1 2 , R = .65) a n d t h e n u m b e r o f f a t cows ( P < . 0 4 , R = .55). Milk f a t p e r c e n t a g e was negatively c o r r e l a t e d w i t h p r o d u c t i o n ( P < . 0 0 0 7 , R -- --.79), DM i n t a k e ( P < . 0 0 9 , R -- - . 6 7 ) , e n e r g y c o n t e n t o f t h e diet ( P < . 0 1 , R = - . 6 4 ) , a n d daily p r o t e i n i n t a k e ( P < . 0 5 , R = --.52). Increase in t o t a l c r u d e p r o t e i n i n t a k e was positively associated w i t h t h e e n e r g y c o n t e n t o f t h e diet ( P < . 0 0 1 , R = . 7 0 ) a n d negatively

1511

related to t h e m i l k f a t c o n t e n t ( P < . 0 5 , R = -.52). In c o n c l u s i o n , b a s e d o n t h e i n f o r m a t i o n collected w i t h this survey, f a r m e r s used professional advice o n f e e d i n g a n d h a d t h e i r ensiled forages t e s t e d at least o n c e a year. F a r m e r s a t t e m p t e d t o p r o v i d e an a d e q u a t e d r y p e r i o d to allow a m p l e t i m e to restore b o d y reserves for t h e s u b s e q u e n t lactation. M o s t f a r m e r s t h o u g h t it was i m p o r t a n t to increase grain 2 weeks p r i o r to calving a n d all g r a d u a l l y a d j u s t e d t h e grain i n t a k e of t h e cows r e c e n t l y calved. In a d d i t i o n , a high p e r c e n t a g e o f t h e s e f a r m e r s a t t e m p t e d to f e e d t h e i r cows a c c o r d i n g to p r o d u c t i o n . T h e m o s t p r e v a l e n t p r o b l e m was low b u t t e r fat test. A l t h o u g h p r o f e s s i o n a l advice o n feeding was o b t a i n e d , m o s t h e r d r a t i o n s were n o t p r o p e r l y b a l a n c e d f o r all n u t r i e n t s or n o t i m p l e m e n t e d a c c o r d i n g t o r e c o m m e n d a t i o n s . This m a y reflect e r r o n e o u s values for DM c o n s u m e d , changes in forage c o m p o s i t i o n , or using N R C values for forages i n s t e a d of c h e m i c a l analyses. C o r r e l a t i o n s b e t w e e n m e t a b o l i c disorders and n u t r i t i o n i m p l i e d r e l a t i o n s h i p s o f b o t h m i l k fever a n d f a t cows w i t h m i n e r a l m e t a b o l i s m . F a t cows were associated w i t h excessive d i e t a r y Ca a n d P. In a d d i t i o n , b o t h f a t cows a n d d o w n e r cows were c o r r e l a t e d w i t h excessive d i e t a r y p r o t e i n .

REFERENCES

1 Chase, L. E., 1977. Feedingthe dry cow. Page 139 in Proc. Cornell Nutr. Conf. 2 Clark, J. H., and C. L. Davis. 1980. Some aspects of feeding high producing cows. J. Dairy Sci. 63:873. 3 Coppock, C. E., R. W. Everett, R. P. Natzke and H. R. Ainsile. 1975. Effect of dry period length on Holstein milk production and selected disorders at parturition. J. Dairy Sci. 57:712. 4 Etgen, W. M., and P. M. Reaves. 1978. Dairy cattle feeding and management. 6th ed. John Wiley and Sons, New York, NY. 5 Erdman, R. E. 1980. Buffers help stabilize pH in cow rumen. Maryland Farmer, Jan. issue. 6 Erdman, R. A., R. L. Botts, R. W. Hemken, and L. S. Bull. 1980. Effect of dietary sodium bicarbonate and magnesium oxide on production and physiology in early lactation. J. Dairy Sci. 63:923. 7 Hutjens, M. F. 1980. Researching peak production is dairyman's challenge. Illinois Dairy Rep. 8 Hutjens, M. F., and D. E. Otterby. 1978. Transitional nutritional management - The dry and fresh cow. Minnesota Dairy Rep.:55. 9 Kilmer, L. H., L. D. Muller, and P. J. Wangness. 1979. Sodium bicarbonate addition to rations of Journal of Dairy Science Vol. 68, No. 6, 1985

1512

V A R G A ET AL.

pre- and p o s t p a r t u m cows. J. Dairy Sci. 65:231. 10 National Research Council. 1978. Nutrient requirements of dairy cattle. Natl. Acad. Sci., Washington, DC. 11 National Research Council. 1982. United States-

Journal o f Dairy Science Vol. 68, No. 6, 1985

Canadian tables of feed composition. Natl. Acad. Sci., Washington, DC. 12 Whitlow, L. W., and F. N. Knot. 1981. Dry cow feeding and m a n a g e m e n t . North Carolina State Univ. Ext., Res. Teaching. ANS Rep. No. 232:40.