Nutritional Management of Transition and Fresh Cowsfor Optimal Performanc e

David K. BeedeDept. Animal Science

Michigan State University, East Lansing

Introduction

Optimal nutritional management of fresh cows begins long before calving . Investment inthe next lactation must start with appropriate management of pregnant cows beginning the las ttrimester of the previous lactation, through the dry period, and into early lactation .

The transition period typically is defined as the 3 wk before calving through the 3 wkafter calving. Also, the last 100 d of the previous lactation may impact management practices andstrategies employed during the transition period to prepare cows for parturition and the nextlactation. Proper management of dairy cows during transition potentially has profound effects o nsubsequent health, lactational and reproductive performance, and profitability . Expenditure oftime, labor and money in the transition period is an excellent investment for which dividend spotentially can be collected in the subsequent lactation .

A crucial concept is that cows progress through four physiological states from 100 dbefore dry-off through early lactation --- late lactation, non-lactation and pregnant, parturition ,and early lactation and non-pregnant . Moreover, cows have different nutritional needs in each ofthese states; thus, requiring different energy and nutrient supplementation in each state to prepar efor the succeeding state . Nutritionally, the main objective in the transition period is to preven tnutrient and energy deficiencies or excesses which can lead to health problems of fresh cows inearly lactation (Beede et al ., 1996; Dyk et al ., 1996a; Dyk and Emery, 1996b) .

Guidelines for Late Lactation

It is during the last 100 d of the previous lactation that proper adjustments should be madeto the nutrition program to ensure that cows are in proper body condition at dry-off .

Key considerations are :

1.

the goal is to dry-off cows at 3 .0 to 3 .25 body condition score (BCS = 5 .0 pointscale) ;

2.

if BCS needs adjustment, make ration changes during the last 100 d of lactation,not during the dry period ;

3. if many cows are over-conditioned, establish a "fat cow group" for late lactationcows and feed 0 .7 Mcal net energy lactation (NEL)/lb dry matter (DM) or less ;and (or) ,

4. if many cows are under-conditioned, establish a "thin cow group" and feed alactation ration with the proper NEL content to cause desired weight gain as wel las to support milk production; as a point of reference, a change in BCS of 1 .0 unitis equal to about 100 lb body weight change .

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Dry Period

General guidelines . It is very important for cows to have a total dry period length of atleast 6 to 8 wk. Dry periods of less than 6 wk resulted in lower milk yields in the next lactation(Coppock et al ., 1974; Funk et al ., 1987) . Two possible explanations for this are : 1) insufficienttime for proper mammary involution and development of natural immune protection agains tmastitis (Mellenberger et al ., 1996) and 2) inadequate time to prepare the cow nutritionally andmetabolically for the next lactation . Dry periods shorter than 6 to 8 wk most commonly resultfrom lack of accurate information about the actual breeding dates (e .g., from natural service) .

Using over 6,000 lactation records from 102 Michigan dairies, Troyer (1990) found thatnatural service-bred cows had greater variation (± 10 d = 1 standard deviation) around theaverage dry period length compared with cows bred by artificial insemination (with know nbreeding dates) . This was because breeding dates, and thus expected calving dates, were unknow nfor natural service-breedings. Imperfect knowledge about actual breeding dates by natural servic eforces dairy producers to guess the future calving dates of particular cows . These cows may notbe moved to the proper dry cow group at the appropriate time and may not have been in thatgroup for an adequate length of time for nutritional and metabolic preparation for calving an dthe next lactation. Thus, potential maximum lactational performance will not be realized .

Two groups of dry cows are recommended; the early-dry group (8 to 3 wk befor eexpected calving) and a close-up group (3 wk to calving) .

Cows should be switched from the early-dry to the close-up group about 3 wk befor ecalving . At all times during the dry period, feed cows as much as they will eat, and strive fo rmaximum DM intake ; NEVER limit-feed cows during the dry period .

If early-dry cows are in proper body condition and eating more than predicted to meettheir requirements, it may be necessary to lower the energy and nutrient density of the ration b yre-formulating with more lower quality forages . Knowing the average amount of feed consume ddaily per cow is essential to be able to make appropriate adjustments .

The critical point is to never try to reduce BCS or body weight of dry cows during an ystage of the dry period, no matter how fat ; this will lead to fatty liver, ketosis, and problems afte rcalving (Dyk et al ., 1996) .

Early-dry period guidelines . Again, the goal is to achieve a BCS of 3 .0 to 3 .25 at dry-off. If BCS is correct at dry-off, then cows should gain about 0 .7 to 1 .0 lb/d to increase BCS b y0.25 to 0.35 units during the early-dry period .

In specific cases :

1.

if the majority of cows have a BCS of 3 .0 or greater, then feed 0 .60 Mcal NEL/l bDM, 14% crude protein; or,

2.

if most cows have a BCS of less than 3 .0, then feed 0 .64 Mcal NEL/lb DM, 15 %crude protein .

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Close-up period guidelines . In most cases, when average daily feed intake is greater than25 lb of ration DM/cow per d, feed 0 .73 Mcal NEL/Ib DM, but no higher, and 16% crudeprotein, dry basis (Dyk and Emery, 1996) . In a recent MSU study, feeding greater than 0 .73 MealNEL/Ib ration DM, resulted in an increased incidence of abomasal displacement (unpublisheddata, R. Emery, personal communication, Michigan State University) .

Achieving feed intake of 25 lbs DM/cow per d or more sometimes can be difficult in theclose-up group, especially if there are many cows close to calving, if the group has a hig hpercentage of pregnant heifers, or during hot weather . A separate close-up group for pregnantheifers might be a beneficial management strategy in farms if adequate facilities are available(Grant and Albright, 1995) .

One effective strategy to help ensure that every cow in the group receives he rrequirements for energy and essential nutrients is to formulate the ration for 22 to 24 lb of DMintake, yet strive for maximum DM intake. One does not need to be concerned about close-upcows over-eating and becoming over-conditioned in this short period of time, if they eat morethan 22 to 24 lb DM/cow per d . It is much more critical to make sure that the cows' nutrient an denergy needs are met and they are in positive energy status, even if feed intake declines a scalving approaches (Grant and Albright, 1995 ; Grammer, 1995) .

Other key nutritional management considerations include:

1.

feed should always be available in the bunk 24 h a d ;2. feed the close-up group a total mixed ration (TMR) to ensure adequate control of

the nutrient composition of every bite of ration the cow consumes ; close-up cowsshould not be given the choice of selecting individual feedstuffs ; round bales are

1

,.r

made for beef cows only;3. use readily fermentable grains (coarsely ground dry corn, hominy, or high

moisture corn) to enhance development of the ruminal epithelia and adaptation ofthe rumen microbes; feeding some grain in the close-up ration helps greatly to ge tthe rumen ready for digestion and absorption of energy and nutrients which wil lbe present in larger amounts in the ration during early lactation ;

4.

bypass protein and supplemental fat are not needed in most cases and are costly ;5.

provide abundant high quality drinking water at all times ; and6.

make and keep potassium and sodium contents of the ration as low as possible ; in

..~

ration formulation try to achieve 1 .2% potassium (or less) and 0 .1% sodium, drybasis .

Keeping total ration potassium and sodium at these recommended concentrations helps t ocontrol and reduce metabolic disorders associated with low blood calcium after calving (Goff an dHorst, 1995). Low blood calcium (hypocalcemia) can cause a cascade of metabolic problems infresh cows (e .g., retained placenta, slower uterine involution and greater uterine infection, poo rfeed intake, and abomasal displacement ; Figure 1) .

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HYPOCALCEMIA (subclinical / clinical)

. .Uterine motility

.

t1 Uterine involution

Metritis

,• t,

REPRODUCTIVE PERFORMANC E

Figure 1 . Early postpartum hypocalcemic cascade of dairy cows .

k'

t1 DA

I Feed intake

1 Body reserve mobilization

Kettosis

EB

Smooth muscle function

1 Rumen, digestive tract motilit y

t

MILK YIELD

Nutritional management strategies in the close-up group to help eliminate low bloodcalcium and other metabolic problems around calving include the following :

1. of the forage portion of the TMR (e .g., 50 to 60% of ration DM), about two-thirdsof the forage should be corn silage and about one-third alfalfa or grass forage ; thiswill help limit potassium content of the final ration because corn silage on averagecontains much less potassium (about 1 .0%) compared with alfalfa or grass forages(2.0 to over 4 .0%, dry basis) ;

2.

if incidences of milk fever, displaced abomasum, retained placenta, and uterin einfections are high in early fresh cows consider using anionic salts or other fee d

- ingredients which provide greater supplemental chlorine and sulfur compared withpotassium and sodium to make a close-up ration with a lower or negative dietar ycation-anion difference (DCAD) ; DCAD is expressed as : milliequivalents of [(K+ Na) - (CI + total S)]/100 grams of total ration DM ; a DCAD close to zero ornegative helps reduce the incidence of metabolic disorders ; note that the acidifyingcapability of dietary sulfur recently has been brought into question (Goff an dHorst, 1997) ; in their research, sulfur appears to have only about one-fourth theacidifying power of chloride (HCI vs . H 2 SO4) to reduce urine pH ; ultimately thi smay result in a change in the DCAD equation to discount or eliminate th econtribution of sulfur ; doubtless, this will be examined by researchers in th eimmediate future ;

3. a target DCAD of 0 to -10 meq/100 grams of DM is recommended ; as a point ofinformation, in the Spartan Dairy Ration Evaluator 2 .0, the target DCAD shouldbe 0 meq/100 grams of DM, because the program calculates the DCAD using onlythe sulfur contributed by supplemental mineral sources, instead of total sulfur(VandeHaar et al ., 1992) ;

4. an effective monitoring tool is to check urine pH of close-up cows after they havebeen fed the ration with a low or negative DCAD for at least a week ; if urine pHis greater than 7 .0 on average for several cows, low blood calcium and milk feve rmay occur in early fresh cows ; a urine pH of 6 .5 to 6.0 indicates better potentia lcontrol of milk fever and improved blood calcium status at calving ;

5.

if the target negative DCAD is achieved, formulate the close-up ration with 1 . 5to 1 .8% dietary Ca and 0 .45 to 0 .55% dietary P, dry basis ; and,

6. contact your nutrition consultant or Extension Dairy Agent for assistance or mor edetailed information about formulating a ration for close-up cows with a low ornegative DCAD ; more details also are provided in the Michigan State University' s

. . .

Managing the Dry Cow for More Profit Notebook (see note next page) .

For fat cows or cows with a history of problems at calving one might consider drenchin gwith propylene glycol for the last 2 wk before calving (0 .4 quart/d; about 12 ounces per d) .Propylene glycol, as a supplemental energy source, will help maintain positive energy balanc eas calving approaches and reduce the likelihood of body fat mobilization and fatty liver, even ifor when feed intake is declining (Grammer, 1995) . Feeding this quantity of propylene glycol i na TMR has been done (R. Grammer, personal communication) .

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Fresh Cow Guidelines

The primary goal for early fresh cows is to maximize carbohydrate, protein, an dnutrient intake, and provide adequate fiber to meet requirements for increasing milk production .

In order to make sure that cows are meeting energy and nutrient requirements during th efirst 2 to 3 wk after calving, the ration should be balanced for 35 to 42 lb DM intake/cow pe rd, depending upon the specific feed intake of fresh cows in the herd . Because it typically takesawhile for intake to increase after calving, balancing the ration at lower predicted intake than wil loccur later in lactation will ensure meeting nutrient and energy requirements .

Optimal nutritional management, maximum DM intake, and performance can be achieve dbest by :

1.

making sure fresh feed is available at all times ;2. feeding a ration that contains 28 to 30% NDF with an adequate length of cut o f

high quality forages, and 40% non-fiber carbohydrate with corn grain or hominyas the major source ;

3.

feeding a ration with 0 .77 to 0.79 Meal NEL/lb DM with no more than about 5to 6% total dietary fat ;

4.

feeding a ration with 18 to 20% crude protein; some bypass protein may bedesirable, depending upon level of intake and fermentability of the ration ;

5.

a TMR which works best to help stabilize the rumen environment and to hel pensure that the ration formulated is the ration that the cows consume ;

6.

feeding only palatable feedstuffs with no mold ; and,7.

providing a fresh supply of drinking water at all times .

Note: Notebooks from Michigan State University's " Managing the Dry Cow for MoreProfit" program (1996) are still available . If you would like to obtain a Notebook which give smore details and background information than is provided in this paper, please contact Rita Hous e(517-353-4570) or write her at MSU, Dept . Animal Science, 220 Anthony Hall, East Lansing,MI 48824-1225 . Cost is $20 (including mailing and tax) .

References

Beede, D., S . Moore, C. Burns, and H. Bucholtz, 1996 . Mineral and vitamin nutrition, an dfeeding management practices . Iw Managing the Dry Cow for More Profit Notebook, Michiga nState University, Dairy Programs Group .

Coppock, C .E., R.W. Everett, R.P. Natzke, and H.R. Ainsle. 1974. Effect of dry period lengthon Holstein milk production and selected disorders at parturition . J . Dairy Sci. 57 :712.

Dyk, P ., M. VandeHaar, H. Bucholtz, R. Emery, and J. Jones-Endsley. 1996a . Energy and proteinnutrition, feed intake and body reserves . In: Managing the Dry Cow for More Profit Notebook ,Michigan State University, Dairy Programs Group .

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Dyk, P . and R. Emery . 1996b . Reducing the incidence of peripartum health problems . Proc. Tri-State Nutrition Conference, Ft . Wayne, IN, p . 41 .

Funk, D.A., A.E. Freeman, and P.J. Berger. 1987. Effects of previous days open, previous daysdry, and present days open on lactation yield . J . Dairy Sci . 70:2366 .

Goff, J .P., and R.L. Horst . 1997. Comparison of sulfuric acid with hydrochloric acid as a sourc eof acidifying anions . J . Anim. Sci. 75 (Suppl . 1): 98 (Abstr .) .

Goff, J .P., and R.L. Horst . 1995 . Dietary potassium, but not calcium (Ca), induces milk fever i ndairy cows. J. Dairy Sci. 78 (Suppl . 1) : 185 (Abstr .) .

Grant, R .J. and J.L . Albright. 1995 . Feeding behavior and management factors during thetransition period in dairy cattle . J . Dairy Sci. 73 :2791 .

Grommer, RR. 1996. Impact of changes in organic nutrient metabolism on feeding in th etransition dairy cow . J. Dairy Sci . 73:2820 .

Troyer, B. 1990. Effect of knowledge of due date on subsequent lactation yield [a function o ftype of mating : AI or non-AI] and economic comparisons of various ratios of AI to non-Almatings within herd. M.S. Thesis, Michigan State Univ., East Lansing .

VandeHaar, M .J., H. Bucholtz, R. Beverly, R. Emery, M. Allen, C. Sniffen, and R. Black. 1992 .Spartan Ration Evaluator/Balancer . Michigan State University, East Lansing .

o .tom

. .

. .:Y.41 ' . .

, .

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Mellenberger, R., P. Sears, R. Erskine, and M . McFadden. 1996. Dry cows : Health and mastiti smanagement. In: Managing the Dry Cow for More Profit Notebook, Michigan State University ,Dairy Programs Group .