Variables associated with peripartum traits in dairy cows. I. Effect of dietary forages and disorders on voluntary intake of feed, body weight and milk yield

THERIOGENOLOGY

VARIABLES ASSOCIATED WITH PERIPARTUM TRAITS IN DAIRY COWS. I. EFFECT OF DIETARY FORAGES AND DISORDERS ON VOLUNTARY INTAKE OF FEED, BODY WEIGHT AND MILK YIELDa Claudie

N. Zametb,

V. F. Colenbranderb, C. J. Call;hanc, R. E. Erbb, and N. J. Moeller

B. P. Chewb,

bDepartment of Animal Sciences and 'Large Animal Clinics, Purdue University, West Lafayette, Indiana 47907 U.S.A. Received

for Publication:

January

10, 1979

ABSTRACT Daily voluntary intakes of feed by each of 89 Holstein cows were compared between day 220 of gestation and day 30 postpartum over a 21month period. Diets designed to meet NRC requirements and which contained either chopped hay (29 cows), hay crop silage (HCS; 30 cows) or corn silage (CS; 30 cows) were compared prepartum (27 to 0 days), peripartum (1 day before to 3 days after calving) and postpartum (days Mixed rations, fed during lactation, were 60% 4 to 30 postpartum). forage and 40% concentrate dry matter (DM). Cow management was similar to commercial operations. The experimental hypothesis was that predisposition for partum and postpartum disorders (abnormal) could be related either to voluntary intake of different diets or to physical Intakes (DM or estimated net energy) across diets decreased 30% traits. between days 7 and 1 prepartum and averaged 18% and 20% lower peripartum in abnormal cows than in control cows. and postpartum, respectively, Seasonal effects on intakes were significant. In general, changes in body weight and condition and differences in udder edema and milk yield reflected intakes. The results support the original hypothesis. INTRODUCTION An assumption has been made that liberal feeding of the cow during the last 3 mo of gestation insures adequate body condition for maximum milk production after parturition (1). However, when cows are fed and managed in a group during the dry period, some become overconditioned and are predisposed to postpartum complications and mortality (2, 3, 4, Postpartum complications have included retained fetal membranes 5, 6). (RFM) (5, 6), displaced abomasum (7, for review), parturient paresis, metritis, mastitis, and a combination of metabolic, digestive and reproductive tract disorders which collectively have been classified fat cow syndrome (5). Metritis, whether or not preceded by RFM, appears associated positively with either displaced abomasum (7) or fat cow syndrome (5). Excess intake of energy during the last 1 to 3 mo of pregnancy has been associated with both of the latter disorders (3, 5, 7). Partum and early postpartum disorders seem to be increasing in dairy herds as intensity of operations increase (8), but possible a.Journal Paper 7468, Purdue University Agricultural Experiment Station. Supported in part by the Indiana Farm Bureau Cooperative Association, Inc. (Grant No. 455 4-47-1151) and is a contribution to NC-143 entitled "Optimizing the Nutritional Utilization of Forage by Dairy Cattle".

MARCH 1979 VOL. 11 NO. 3

229

THERIOGENOLOGY predisposing variables prepartum have not been studied extensively. It is known that voluntary intake of dry mattec (DM) decreases prepartum and decreases less in young cows than in older cows (7, 9, 10, 11, 12). These observations suggest that various pareun and postpartum disorders may be signaled by greater than normal depression of voluntary feed intake prepartum or to characteristics of the diet. Tine objectives of this study were to compare the prepa-turn and postpartum effects of feeding hay, hay crop silage (HCS) or corn silage (CS) on intake of feed, incidence of disorders (health status) and the Other collected interaction between intake of feed and health status. data included (a) blood traits, (b) the interrelationships among disorders and (c) the effects of disorders on intake of feed, milk producThe latter data are reported in tion and reproductive efficiency. companion papers (13, 14). It was hypothesized that incidence of disorders a?d predisposition for their occurrence could be related either to characteristics of the diet or to voluntary intake of feed prepartum and postpartum. The purpose of this paper is to compare interrelated effects of diet and health status on voluntary intake of feed during the dry period and for 30 days postpartum as well as effects on milk yield, body weight ald udder edema. EXPERIMENTAL

PROCEDURE

During 21 consecutive months, 89 Holstein cows were each assigned, as they reached day 220 of gestation (beginning of dry period), to a diet of either hay, HCS or CS. The COWS were continued on these forages through day 30 postpartum. The system of housing and management was similar to many commercial operations. Daily feed intake by individuals was measured in an 18-gate Calan electronic systemb. A covered feeding area and adjacent facilities were divided to permit separate management of prepartum aid postpartum cows in groups of 1 to 18. Prepartum, cows across diets had free access to a .5 ha exercise lot and one end of a barn with a total capacity of 25 free-stalls. Postpartum, cows across groups had free access to the other end of the barn (capacity adjustable) and the adjacent concrete paved area (about 7 m X 10 m). Peripartum (2 or 3 days), a cow was either housed in a maternity stall in an adjacent barn during November through April or was allornred to calve outdoors in the exercise lot from i4ay through 0stoSe-r. Cows were observed preparturn , partum ald postpartum for various calving traits and wealth problems (13). A cow that had one or more disorders diagnosed and treated prior to day-30 postpartum was classified as abnormal while the remaining cows were classified as controls. Tine cows were weighed and body condition was scored subjectively on a scale of 1 (thin) to 10 (very fat) on days 220 and 253 of gestaiion, 24 !lr Also, udder edema was preparturn, and 24 hr and 33 days postpartum. scored peripartum on a scale of 1 (none) to 10 (extensive congestion including even extra mammary regions). Cows were milked :wice dailg in a milking parlor and mi1L weights were firs t recorded on day 4 postpartum. The experimental rations were fed twice daily and unc.ons:l:ne.d feed was weighed balzk before each morsing feeding. The cows also had free access to water and a 1:l mixture of dicalciun phosphate and itrace mineralized salt. Chopped -lay and HCS jYere fed without supplement prepartum but CS ----b American Calan System, Route 4, Northwood, New Hampshire.

230

MARCH 1979 VOL. 11 NO. 3

THERIOGENOLOGY

TABLE

I.

INGREDIENT COMPOSITION OF PREPARTUM AND POSTPARTUM CONCENTRATE MIXTURES USED IN DIETS OF COWS FED HAY, HAY CROP SILAGE (HCS), AND CORN SILAGE (CS)

Ingredients

Forage group Hay or HCS ---_t%, air dry)

cs

Prepartuma Soybean meal (48% crude protein) Calcium carbonate (36% calcium) Dicalcium phosphate Magnesium oxide Sulfur Salt, trace mineralized Vitamin premixb

89.5 4.7 1.5 .5 .4 2.3 1.2

PostpartumC Soybean meal Grcund corn Calcium carbonate Dicalcium phosphate Magnesium oxide Sulfur Salt, trace mineralized Vitamin premixb

16.0Zd 80.17d 1.70 1.56 ----1.10 .40

38.54d 54.8Sd 3.35 .63 .03 .10 1.15 .40

Ratio of forage to concentrate mixture on a DM basis was 9O:lO. Included 2200 IIJ of vitamin A and 400 IU of vitamin D per gram. Ratio of forage to concentrate mixture on a DM basis was 60:40. Crude protein content was adjusted in concentrate mixtures periodically to compensate for the variations in each forage in order to maintain cruCe protein content of the total ration at NRC (1) requirements. was fed with a supplement (90% CS to 10% supplement DM) to increase protej.n, minerals and vitamins A and D (Table I). Lactation rations which were 60:40 DM ratios of forage to concentrates were first fed freechoice on day 1 postpartum (day 0 was day of calving) as complete mixed Chopped hay was top-dressed with 2.7 kg rations to groups HCS and CS. of concentrate mixture on day 1 postpartum and concentrate was increased .5 kg per day until the daily ration contained 11.8 kg. Any cow fed hay and producing more than 35 kg of milk per day was fed additional concentrate. Ingredients of concentrate mixtures fed postpartum were adjusted (Table I) to compensate for variable crude protein in the forages (Table II) to meet NRC requirements (1). The cows were returned to the they were fed a Thereafter, main herd at the end of the experiment. complete mixed ration of 60% forage DM (80% CS and 20% HCS) and 40% To avoid a sudden change in diet upon their return to concentrate DM.

MARCH 1979 VOL. 11 NO. 3

231

THERIOGENOLOGY

TABLE II. AVERAGE COMPOSITION AND PARTICLE SIZE OF THE EXPERIMENTAL FORAGES Silage Hay crop

Measurement

-_

Dry matter (%) Crude proteinc(%)b ENE &al/kg) Calcium (Ca) (%) Phosphorus (P) (%) Ca/P (ratio)

88.2 ? 19.0 1.35 .86 .34 2.5:1

.22a .52 .Ol .03 .02

37.0 ? 19.8 1.34 1.09 .36 3.O:l

.46 .60 .02 .05 .Ol

3.61

.05

3.22

.04

3.46

.04

3.3 4.2 2.6

.13 .12 .09

2.2 4.8 3.2

.ll .09 .08

3.1 4.6 2.4

.13 .09 .09

Particle sizee Modulus of fineness Modulus of uniformity Coarse Medium Fine

Hay

Corn

33.6 + .48 8.21 .18 1.56 .Ol -20 .02 .23 .Ol .9:ld

a b c d

Mean + standard error. Total nitrogen X 6.25 X 100. Estimated net energy. Was 1.65:1 in dry matter as fed nrepartum because concentrate mixture was 10% and corn silage was 90% of the prepartum CS diet (Table I). e Estimated by use of technique described for concentrates (15, 16) with sieve mesh diameters (mm) of 9.53, 4.65 (coarse), 3.33, 1.65 (medium), 1.17 and .OO (fine), respectively.

the main herd, cows fed hay were adjusted to CS over a 7-day period. Forage samples, collected each week, were used to measure DM (oven drying to constant weight at 60 C.) and particle size (Table II). Forage samples, cornpositedby months, were assayed for contents of crude protein (17), acid detergent fiber (18), calcium (19) and inorganic phosphorus (20). Also, crude protein was assayed in corn grain of the postpartum concentrate mixtures. Intakes of DM and of estimated net energy (ENE) were expressed as % of body weight and Mcal/lOO kg of body weight, respectively. Each measure will be referred to hereafter as intakes of DM and ENE, respectively. The acid detergent fiber (18) procedure was used to estimate ENE using prediction equations for alfalfa (21), grasses (21), CS (22) and concentrate mixtures (23). The equations for alfalfa and grasses (21) were combined to represent the approximate proportions of alfalfa (75%) and orchardgrass (25%) in hay and HCS. The ENE in forage and concentrate mixtures were calculated separately and combined in proportion to the DM of each in the diets as fed. Effects of independent variables on intakes of DM and ENE (dependent variables)were evaluated by least squares analyses of variance (24). Main effects included diet, health status (control vs. abnormal), age of cow in years, days relative to calving as well as season and gestation length codes. Two-way interactions among health status, diets,

232

MARCH 1979 VOL. 11 NO. 3

THERIOGENOLOGY

days and season also were included. Preliminary analyses had been used to develop the final statistical model wherein certain months of the year wfzrecombined and gestation length code was omitted from the twoway interactions. Seasons were coded 1 (October through January), 2 (February through May), 4 (June and July) and 5 (August and September). Gestation lengths were coded 1 to 5 (< 275, 276 to 278, 279 to 281, 282 to 284 and > 284 days, respectively). Also in preliminary least squares analyses (24), it was found that intakes of DM and ENE within diets and health status were not different (P > .LO) among days 48 to 27 prepartum. Therefore, three different periods were analyzed separately as follows: (a) day 27 prepartum to parturition (prepartum), (b) day 1 prepartum to day 3 postpartum (peripartum) and (c) days 4 to 30 postpartum (postpartum). EEfects of diet, health status and age class (2nd or 3rd gestation vs. fo,lror more gestations) on body weight and weight changes, body condition scores and udder edema were evaluated by analyses of variance (26) a:ida multiple range test (27). RESULTS AND DISCUSSION Feed Intake General. Effects of independent variables on intakes of DM and ENE -were similar because, as expected, DM and ENE were correlated highly across diets (r = .95 prepartum and .99 peripartum and postpartum). Therefore, intakes of DM and ENE will be discussed together unless probability levels within a comparison were different. Since effects of coded gestation length and the two-way interactions were not significant (P > .115)in any analysis (Table III), further discussion of the latter variables will be minimal. Seasonal effects on intakes of DM and ENE were evident across (Table III) and within diets (25) prepartum, peripartum and postpartum (P < .~31to P > .lO) and generally were of lesser magnitude among cows fed hay (25). Intakes were lowest during June and July, highest during October through January (P < .Ol) and intermediate during February throug'lMay, and August and September. Across diets intake of ENE during Ju:aeand July averaged 39%, 39% and 14% lower prepartum, peripartum and postpartum, respectively, than during October through February (25). Across Diets. Intakes of DM and ENE decreased gradually between days 23 and 7 prepartum (P < .Ol) and then decreased 30% to the lowest intake; during day 1 prepartum (Fig. 1; Tables III and IV). The profile oE intake of DM appears similar to other data (7, 9, 10, 12). Intakes postpartum averaged 67% greater in DM and 97% greater in ENE than prepartum (last column, Table IV). ealth Status Across Diets. Differences between 45 abnormal and 44 control cows (13) in intakes of DM and ENE averaged across days were not significant prepartum and were significant peripartum and postpartum (Table,;III and IV). When averaged across days and diets, intakes averaged a-?proximately7, 18 and 20% lower in abnormal cows than in normal cows prepartum, peripartum and postpartum, respectively. Decreased daily :intakesof DM and ENE by abnormal cows were not detectable until about .Zweeks prepartum and averaged 25% lower than control cows on day 1 prepartum and on day 30 postpartum (Fig. 2 and 3).

MARCH 1979 VOL. 11 NO. 3

233

df

27 27 2253

.46

2.4"" .2 .2

11.2+ 5.0 25.4** .3 6.6+ 1.3 .6 .6 3.7

DM

.53

4.6** .6 .4

136.2** 11.4 62.4** 1.1 14.5 3.5 1.5 .9 8.3

ENE

4 4 398

2 1 3 4 7 2 6 3 58

df

.43

9.7** .l .4

6.6* 6.3* 5.3* .4 1.7 .4 1.4 .6 1.8

DM

Time period Peripartum

.48

37.1** .3 1.1

31.7** 14.8+ 15.1" 1.6 4.6 .7 4.2 2.3 4.8

ENE

2 1 3 4 6e 2 6 3 57

df

26 26 2215

~-

.47

10.4** .l .4

8.6 112.4** 17.0 3.7 22.0 1.3 5.1 6.1 11.8

DM

Postparum ENE

.49

34.3"" .4 1.3

50.4 335.4** 53.0 13.0 64.5+ 2.9 14.1 19.4 34.0

a Health status where control was code 1 and abnormal across disorders was code 2. b Season where code 1 was October through January, code 2 was February through May, code 4 was June and July and code 5 was August and September. c Gestation code where codes 1 to 5 were less than 276, 276 to 278, 279 to 281, 282 to 284 and greater than 284 days, respectively. d Age at calving codes 2 to 9 years. e Only cow in age code 9 died on day 19 postpartum. and >k>k P < .lO, P < .05 and P < .Ol, respectively. + , ;r;

R squared

Days H X days Residual

Diet (D) 2 Health (II): 1 Season (S) 3 GCCd 4 Age 7 DXH 2 DXS 6 HXS 3 Among cows 58

Source of variance

Prepartum

TABLE III. MEAN SQUARES FROM ANALYSES OF VARIANCE OF DRY MATTER (DM) AND ESTIMATED NET ENERGY (ENE) INTAKE DURING TIME PERIODS PREPARTUM, PERIPARTUM AND POSTPARTUM ACROSS DIETS

$

4

8

!! z!

c3

Control Abnormal Mean

Control Abnormal Mean

Control

Post

Pre

Peri

5.07 3.90 4.48

2.96 2.55 2.77

2.05 1.86 1.95

3.07 2.38 2.72

.11 06* .06

.21 .16 .13

.05 .04 .03

.06 .03* .04

.13 .lO .08

--

5.33 4.32 4.82

3.02 2.66 2.84

2.83 2.81 2.82

3.00 2.42 2.71

1.73 1.50 1.62

.09 .06** .06

.18 .14 .13

.04 .03 .03

.05 .04** .03

.ll .09 .08

4.98 4.01 4.50

2.72 2.24 2.48

2.31 2.27 2.29

2.93 2.35 2.64

1.69 1.37 1.53

.05 .04** .04

.12 .10+ .09c

.03 .02 .02c

-03 .02** .02

.07 .06* .05c-

g

g e(

3

$

.07 .08 .05

.14 .17* .12

.03 .04* .03

.04 .04 .03

1.87 1.61 1.74

1.64 + .02 1.52 .02 1.58 .01c-

Across diets

19 10 21, (hayand diet); 14 and (HCS diet), and 11 and The 19 (CS diet) prepartum peripartum, and 17,and 9 and 10 and 20, 16 respectively,postpartum. decrease in controland cows postpartumand was12 due to cases of either metritis or mastitis. b Least squares mean and standard error. c Differences among diets are significant (P < .Ol or P < .05; Table III). f, * and ** P < .lO, P < .05 and P < .Ol; abnormal cows lower than control cows.

4.61 3.80 4.21

1.84

2.18

2.(?4

1.88

2.20

2.73 2.26 2.50

.09 .10* .07

Corn 1.75 * .03 1.73 .02 1.74 .02

Silage

3

Control Abnormal Mean-

__-_____ .____ _____~~_ Hay crop

Hay 1.60 t .02b 1.57 f .03 1.39 .03+-------A_1.45 02 1.50 .02 1.51 .02 1.47 1.00 -- 1.24

-

Numbers of cows within control and abnormal groups were, respectively,

Post

Mean

-_--_1.5o Abnormal

Control Abnormal Mean

Peri

Pre

Healtha status -__I_ Control Abnormal -__~ Mean

Partum period

SUMMARY OF LEAST SQUARES MEANS FOR DRY MATTER (DM) AND ESTIMATED NET ENERGY (ENE) INTAKE DAILY PER 100 KG OF BODY WEIGHT BY DIET GROUP AND HEALTH STATUS WITHIN TIME PERIODS

a Defined in footnote a, Table III.

ENE, Meal

DM, kg

Dependent variable -~

TABLE IV.

THERIOGENOLOGY

o Dry Matter(% of body welghf 0 Estimated Net Energy(hlcOl/ h MItk

Weld (!Qperday\

Pig. 1 Least squares means of dry matter and estimated net energy intake and milk yield across diets b. days in relation to calving (day 0).

I

I

2725 20 I5 IO 5

0

()I

I

I

-PREPARTUM

I

-

II 5

111 IO 10 I5 20 25 30

-POSTPARTUM

-

DAYS

Intakes of DM and ENE differed signifiDiet and Health Status. cantly among diets prepartum and peripartum but not postpartum (Tables III and IV). The differences in intakes among diets were due primarily to (a) lower intakes of DM (12%) and ENE (28X) by cows fed hay and HCS prepartum than by cows fed CS and (b) to lower intakes of DM (23%) and ENE (32%) by cows fed hay peripartum than by cows fed CS and HCS. Intakes of hay DM and ENE also were 4 to 10% lower postpartum than intakes of CS and HCS but the differences were not significant (P>.lO). Effects of health status on intakes of DM and ENE were not consistent among diets within time periods (Table IV; Fig. 4 and 5). Intakes of DM and ENE by abnormal cows fed CS were nearly equal to control cows fed CS prepartum and peripartum whereas abnormal cows fed hay and HCS consumed 32% (P < .O5) and 17% less than their respective controls. In contrast, the postpartum difference between control and abnormal cows fed hay was less (6%) than cows fed CS (18%; P < -10) or HCS (29%; P < .Ol). Intake of ENE by control and abnormCompared to NRC Requirements. al cows exceeded NRC (1) requirements until at least day 5 prepartum aver(ratios > 1.0; Fig. 6). Ratios of intake of ENE to requirements aged 25% higher prepartum in cows fed CS than cows fed hay and HCS (P < .Ol; 25). Intakes of ENE in relation to requirements were substantially lower in abnormal cows than control cows between day 6 prepartum and day 30 postpartum (Pig. 6). Average intake of crude protein exceeded requirements prepartum in each diet group (ratios 2.1, 2.2 and 1.4 by cows fed hay, HCS and CS, respectively) and averaged 1.91-fold of requirement across diets (25). It is generally conceded that high producing dairy cows do not consume their daily requirements early in lactation and that it is important to stop weight loss as soon as possible after calving (12, 31). It can be seen in Fig. 6 that control cows met their daily requirements for crude

236

MARCH 1979 VOL. 11 NO. 3

THERIOGENOLOGY

4.0

Fig. 2. Least squares means of dry matter intake by control and abnormal cows from day 27 prepartum to day 30 postpartum.

& L3

-i?

=

-

PREPARTUM --

POSTPARTUM -

DAYS

I,

I I,, l

Milk Yield

m

Milk Yield

, , , , , ,

Z6.0 Y Q 5.0 Iz

_

g4.0

0

E

24 d F

630

t-’ Y 0 2.0

Fig. 3. Least squares means of estimated net energy intake and milk yield by control and abnormal cows by days in relation to calvine. I. (dav _ 0).

p s p 1.0 m 272520 15 10 5 W PREPARTUM -

0 -

5

IO 15 20 25 POSTPARTUM -

30

DAYS

MAR’CH 1979 VOL. 11 NO. 3

237

THERIOGENOLOGY

3.0 =1 5 2.0

Fig. 4. Least squares means of dry matter intake by control and abnormal cows within diet-group from day 27 prepartum to day 30 postpartum.

Y ~ 1.0 Ii 8 3.0 W

y 2.0 ? z I.0

III

I

I

I

I

2725 20 I5 IO 5 - PREPARTUM -

I

1

5

IO 15 20 25 30

-

I

I

1

II

I

0

POSTPARTUM -

DAYS

0 Control Milk Yield Abnormal Milk Yield

n

Fig. 5. Least squares means of estimated net energy intake and milk yield by control and abnormal cows by days in relation to calving (day 0).

o’527 25 20 15 IO 5 PREPARTUM -

0 5 IO I5 20 N--POSTPARTUM-

25

50

DAYS

238

MARCH 1979 VOL. 11 NO. 3

THERIOGENOLOGY

Fig. 6. Ratios between daily intakes and NRC (1971) requirements for estimated net energy and crude protein by control and abnormal cows across diets. A ratio of 1.0 indicates intake equivalent to the NRC requirement as shown by the dashed line.

z 1.1 pc

ii

w

1.0

4 .9 .I3 ;

Q

.7

zw

.6

z

25 -

20 I5 IO 5 PREPARTUM -

0 -

5

IO 15 20 25 POSTPARTUM-

30

DAYS

protein and ENE by day 17 whereas abnormal cows were still below requireThese results ments on day 30 when the feeding trial was terminated. show that peripartum disorders may cause chronic negative energy balances in lactating cows even when the rations were designed to meet NRC requirements (1). ?filk E'ield Least squares means of daily milk yields from days 4 to 30 postpartum (days 1 to 27 of lactation) are shown in Fig. 1, 3 and 5 to Pay-to-day visualize comparisons between milk yield and intake of ENE. increases in milk yield were much greater in control cows than in abnormal COWS across (Fig. 3) and within diets, especially in cows fed HCS and CS (Fig. 5). Abnormal cows produced 12% less milk during days 4 to 30 However, differences in of lactation than control cows (P < .Ol; 25). averac;e milk yields among diets were not significant either for days 4 The 200-day to 30: 31 to 63, 1 to 200 or 1 to 305 days of lactation. mature equivalent (ME) yields of 4% fat-corrected milk (FCM; 28) were (x + standard error) 5040 + 123, 5234 + 100 and 5409 2 164 kg, respectiveMorely, for cows fed hay, HCS and CS the first 30 days postpartum. over, mastitis alone or in combination with other disorders during the first 30 days was the only disorder to reduce (I? < .05; 25) ME yield of FCPl in 200 days (4835 f 114 vs. 5493 + 118 for controls and 5305 + 139 kg Effects of diet on average across disorders other than mastitis). yields of total protein and solids-not-fat of milk during days 3 to 30 In contrast, milk fat were similar to those described for milk yield. yield by abnormal cows was not significantly (P > .lO) lower because percentage fat averaged higher than in control cows (.3, .4 and 1.1

MARCH 1979 VOL. 11 NO. 3

239

THERIOGENOLOGY

percentage points in cows fed hay, HCS and CS!,respectively). Others have reported that cows fed CS produced milk higher in percentage fat than cows fed hay (29, 30). Body Weight and Condition. Effects of diet, age class and health status on changes in body weight prepartum and postpartum are summarized in Table V. Greater gains in weight prepartum by young cows (2nrior 3rd gestation) fed CS was the only significant difference associated with diet (footnote e, Table V). Young cows fed CS gained more weight (72 ? 8 kg) prepartum than any other diet-age class subgroup (rarlge28 f 8 to 42 lr. 9 kg) including mature cows (with four or more gestations). Mature cows averaged heavier than young cows on day 1 .postpartumwithin (I'< .05 to P < .Ol) and across diets (P < .Ol). There was no effect of health status (control vs. abnormal, Table V) on the average body weight of cows 1 day postpartum but control cows terldedto gain more weight prepartum (P < .lO) and to lose less weig'htperipartum and postpartum (P < .lO). The latter differences in weight changes were probably due to less rumen fill in abnormal cows (Fig..2 and 3) rather than to real changes in body weight. Weight loss associated with parturition (75 + 3 kg) was about 10% of body weight l-day prepartum. Across diets, cows lost an additional 63 ? 4 kg of body weight between days 1 and 30 postpartum which represented 19% of their weight 24 hr preparitumand 14% of their weight on day 220 of gestation. Scores of body condition periparttlmaveraged 6.4 + .l. Young cows averaged lower than mature cows across diets (6.0 + .2 vs. 6.8 t .2; P < .05) due to differences among cows fed hay (P < .OlTor HCS (P < .05>. Young cows fed CS was the only subgroup to increase markedly in body condition prepartum and they ;spproachedthe condition score of mature cows fed CS (6.7 ? .3 vs. 6.9 + .3) and were higher than young cows fed hay (5.7 fi .3) or HCr(5.6 2. .4). In general, relatively few cows across diets were considered far:terthan desirable at calving. Udder Edema Udder edema averaged 4.3 ?I .2 across diets and health status, were not different between control and albnormalcows or between young and mature cows within diets (25). Horgever,both young and mature cows fed CS had higher (P < .05; 25) udder lademascores (5.0 2 .4 and 5.3 + -5, respectively) than their respective subgroups fed hay (3.9 f .3 and 4.2 + .4) or HCS (3.6 f .4 and 3.9 2 .4). The increased udder edema in cows fed CS compared to cows fed 1lay or HCS is not in agreement with other studies wherein levels of d.ietaryenergy were compared prepartum (32, 33, 34). Increased udder edema due to high intake of dietary energy was observed in first-gest.ationheifers but not in cows of the latter studies. General Interpretation Results from this phase of data analyses supports a hypothesis that either predisposition or possibly pre-clinical signs for partum and early

240

MARCH 1979 VOL. 11 NO. 3

THERIOGENOLOGY

TABLE V.

EFFECTS OF DIET, AGE CLASS AND HEALTH STATUS ON CHANGES IN BODY WEIGHT.

cow group

cows l-day (No,) postpartum

Body weight Calvin Prepartum lossP gain

30-da lossi:

(kg) bY

29

654 f 12d

30 + 6

69 f 5

63 + 6

HCSd

30

641

13

35

7

84

5

56

6

CSd

30

672

14

57

7e

73

4

70

7

Youngf Control Abnormal Mean

27 17 44

626 620 624

12 22 11

49 48 48

7 9 6*

70 76 72

4 6 4

46 63 53

4+ 6+ 4**

Maturef ~ Control Abnormal Mean

17 28 45

682 689 686

13 10 8**

45 26 33

7+ 7+ 5*

70 83 78

6 6 4

68 75 72

10 7 6**

Mean Control Abnormal Mean

44 45 89

648 663 656

10 11 7

47 35 41

5+ 6+ 4

70 80 75

3+ 4+ 3

55 70 63

5* 5* 4

a b c d e

Difference between weights 24 hr prepartum and 24 hr postpartum. Weight loss between days 1 and 30 postpartum. Mean + standard error. Hay crop silage and corn silage, respectively. Different (P < .05) from other diets due to larger gains by young cows fed CS than any other diet-age class subgroup (P < .05>. f Young cows = 2nd and 3rd gestation; mature cows = > four gestations. + P < .lO, * P C .05 or ** P < .Ol Different between either young and mature cows or control and abnormal cows within the same group sub&lass. postpartum disorders may be reflected in reduced voluntary intake of feed prepartum. This effect was observed within diets peripartum and postpaxtum and within the hay and HCS diets as early as 2 weeks prepartum (Fig. 2. to 5). Apart from the observation that abnormal cows fed CS consumed slightly more feed (2% more; Table IV) than control cows fed CS until perips.rtum,other interactions between diet and health status were not significant (Table III). However, there was evidence of a lower incidence of partum disorders in cows fed hay (34%) than in cows fed HCS (53%) or CS (63%) (calculated from distributions in footnote a, Table IV). The latter phase'of Eataanalysis is presented in a companion paper along with relative effects of common partum and early postpartum disorder:,on feed intake, milk yield and subsequent reproductive efficiciency

MARCH 1979 VOL. 11 NO. 3

241

THERIOGENOLOGY

(13). Therefore, further discussions of results will be deferred. REFERENCES 1.

National Academy of sciences, National Research Council. Nutrient requirements of dairy cows. 4th ed., rev. Washington, DC (1971).

2.

Rako, A., Jakovac, M., Zindrick, M., and Dumanovsky, F. Feeding dairy cattle on silage; its effect on yield, reproduction and health. Nutr. Abstr. Rev. 24:585 (1964).

3.

Morrow, D. A., Tyrrell, H. F., and Trimberger, G. W. Effects of liberal concentrate feeding on reproduction in dairy cattle. J. Amer. Vet. Med. Assoc. 155:1946-1954 (1969).

4.

Trimberger, G. W., Tyrrell, H. F., Morrow, D. A., Reid, J. T., Wright, M. J., Shipe, W. F., Merrill, W. G., Loosli, J. K., Coppock, C. E., Morrow, L. A., and Gordon, C. H. Effects of liberal concentrate feeding on health, reproductive efficiency, economy of milk production, and other related responses of the dairy cow. New York Food Life Sci. Bull. 8, Animal Sci. l:l-72 (1972).

5.

Morrow, D. A.

6.

Johnson, D. G., and Otterby, D. E. Effect of dry period diet on postpartum health and performance of Holstein cows. Proc. Amer. Dairy Sci. Assoc. 71st annual meeting (Abstr.) page 84 (1976).

7.

Coppock, C. E., Noller, C. H., Callahan, C. J., and Baker, J. S. Effects of forage-concentrate ratio in complete feeds fed ad libitum on feed intake and the occurrence of abomasal displacement in dairy cows. J. Dairy Sci. 55:783-789 (1972).

8.

Wagner, W. C. Intensified dairy operations and their effect on periparturient diseases and postpartum reproduction. J. Dairy Sci. 57~354-360 (1974).

Fat cow dyndrome. J. Dairy Sci. 59:1625-1629 (1976).

9. Moodie, E. W., and Robertson, A. Dietary intake of the parturient cow. Res. Vet. Sci. 2:217-226 (1974). 10.

Moodie, E. W., and Robertson, A. Some aspects of calcium metabolism in the dairy cow. Res. Vet. Sci. 3:470 (1962).

11.

Coppock, C. E., and Stone, J. B. Corn silage in the ration of dairy cattle. Cornell Univ. Bull. 89., Ithaca, NY (1968).

12.

Marquardt, J. R., Horst, R. L., and Jorgensen, N. A. Effect of parity on dry matter intake at parturition in dairy cattle. J. Dairy Sci. 60:929-934 (1977).

13.

Zamet, C. N., Colenbrander, V. F., Erb, R. E., Callahan, C. J., Chew, B. P., Moeller, N. J. Variables associated with peripartum traits in dairy cows. II. Interrelationships among disorders and their effects on intake of feed and on reproductive efficiency. Theriogenology 11: 245-260 (1979).

242

MARCH 1979 VOL. 11 NO. 3

THERIOGENOLOGY

14.

Zamet, C. N., Colenbrander, V. F., Erb, R. E., Chew, B. P., and Callahan, C. J. Variables associated with peripartum traits in dairy cows. III. Effects of diets and disorders on certain blood traits. Theriogenology 11: 261-272. (1979).

15.

Cadle, R. D. Particle size determination. Interscience No. 7. Interscience Publishers Inc. NY (1955).

16.

Feed Manufacturing Technology. Feed Production Council, H. B. Pfost and C. E. Swinehart, ed. American Feed Manufactures Association, Inc.,Arlington, VA (1970).

17.

Association of Official Analytical Chemists. In W. Horwitz, ed. Official Methods of Analysis, 11th ed. AOAC, Washington, DC (1970).

18.

Goering, H. K., and Van Soest, P. J. Forage fiber analyses (apparatus, reagents, procedures, and some application). ARS. U.S. Dept. Agr. Handbook No. 379 (1970).

19.

Chapman, H. D., and Pratt, P. F, Methods of analysis for soils, plants and waters, Univ. of California, Davis (1961).

20.

Harris, W. D., and Popat, P. Determination of the phosphorus content of lipids. J. Amer. Oil Chem. Sot. 31:124-127 (1954).

21.

Mertens, D. R. Application of theoretical mathematical models to cell wall digestion and forage intake in ruminants. Ph.D. dissertation, Cornell Univ., Ithaca, NY (1973).

22.

Adams, R. S. Synthesized. In R. S. Adams, ed. Equations and conversions used by the Penn State forage testing service. Penn. State Univ., State College, PA (1974).

23.

Moe, P. W., and Flatt, W. P. Net energy value of feedstuffs for lactation. J. Dairy Sci. (Abstr.) 52:928 (1969).

24.

Harvey, W. R. Least squares analysis of data with unequal subclass numbers. USDA ARS H-4:1-157 (1975).

25.

Zamet, C. N. Variables associated with peripartum traits in dairy cows: Dietary forage, feed intake, disorders, performance, environmental and physiological factors. Ph.D. thesis, Purdue University, West Lafayette, IN (1978).

26.

Snedecor, G. W., and Cochran, W. G. Statistical methods. 6th ed. The Iowa State Univ. Press, Ames, Iowa (1967).

27.

Kramer, C. Y. Extension of multipLe range test to group means with unequal numbers of replications. Biometrics 12:307-310 (1956).

28.

Gaines, W. L. The energy basis of measuring yield in dairy 308 (1928). cattle. Illinois Agr. Exp. S&a. Bull.

29,

Thomas, J. W., Brown, L. I).,and Emery, R. S. Corn silage compared to alfalfa hay for milking cows when fed various levels of grain. J. Dairy Sci. 53:342-350 (1970).

30.

Halter, J. B., Urban, Jr., W. E., Kennett, W. S., and Sniffen, C. J. Corn silage with and without grass hay for lactating dairy cows. J. Dairy Sci. 56:915-922 (1973).

MARCH 1979 VOL. 11 NO. 3

243

THERIOGENOLOGY

31.

Van Soest, P. J. Ruminal fat metabolism with particular reference to factors affecting low milk fat and feed efficiency. A review. J. Dairy Sci. 46:204-216 (1963).

32.

Emery, R. S., Hafs, H. D., Armstrong, D., and Snyder W. W. Prepartum grain feeding effects on milk production, mammary edema, and incidence of diseases. J. Dairy Sci. 52:345-351 (1969).

33.

Greenhalgh, J. F. D., and Gardner, K. E. Effect of heavy concentrate feeding before calving upon lactation and mammary gland edema. J. Dairy Sci. 41:822-829 (1958).

34.

Schmidt, G. H., and Schultz, L. H. Effect of three levels of grain feeding during the dry period on the incidence of ketosis, severity of udder edema, and subsequent milk production of dairy cows. J. Dairy Sci. 42:170-179 (1959).

244

MARCH 1979 VOL. 11 NO. 3