Transition cow feeding programs continue to be one "key" to high production, optimal health, and cow longevity. A University of Illinois 2000 survey of several top U.S. Jersey herds indicated that transition cow feeding programs were a major feed related reason for their success. In a parallel survey of thirty-one feed consultants and dairy veterinarians, they concluded transition cow feeding was the third most critical problem and opportunity seen on their clientele's farms (forage quality was the first area and feed bunk management was the second area). Research and on-farm testimonials continue to send mixed guidelines concerning nutritional aspects of transition cows.

• Wisconsin researchers report success with higher levels of starch in close-up rations.
• Illinois workers conclude far off dry cows can benefit from restricted energy diets.
• Added fat can reduce feed intake in one study while another research group reported improved liver health with added fat.
• A Maryland dairy manager reported 2 to 4 pounds of wheat straw is a must.
• A Wisconsin veterinarian indicates fewer problems when shifting cows directly from a far off ration to the high group diet after calving with no transition diet.
• Illinois extension workers recommend three distinct rations: far off dry cow, close up dry cow, and fresh cows.
• Feed additive choices are numerous including anionic products, niacin, propylene glycol, calcium propionate, protected choline, yeast culture, and probiotics.
• Higher levels of fat soluble vitamins and organic trace minerals are recommended by field consultants.
• Dairy managers, veterinarian, and consultants as what is right, why do different recommendation exist, and how do they sort out fact from fiction. The following sections can assist and inform decision makers.

Energy Requirements

Energy balance (EB) is critical for optimal cow health, limit weight change, and future milk production. Illinois workers illustrate that current energy needs for close up dry cows may be low (Table 1).

Table 1. Energy comparisons of large breed springing heifers and mature cows using NRC 1989 and Illinois maximum guidelines (Drackley, 2000).

The maximum values are significant as they represent nearly 40 percent higher energy needed or an extra six pounds of dry matter (0.70 Mcal / pound x 6 pounds = 4.2 Mcal). However, dry matter intake can be dropping 10 to 30 percent as cows approach calving. Higher pregnancy requirements reflect recent published data reported by Cornell workers. The unborn calf is rapidly growing and requiring more energy as calving approaches. Another concern is the higher rates of twinning in U.S. dairy cows that would inflate this number even more. Mammary gland development (commonly referred to as bagging up) and colostrum synthesis add to energy needs. If the environment factors (such as heat stress and cold weather) are not in the cow's thermal neutral range, energy maintenance needs can also increase 10 to 20 percent. Values in Table 1 can be interpreted that close up dry cows and heifers may experience greater energy shortages during the close-up dry cow phase. The values in Table 1 also indicate that the close-up heifer can't reach energy needs unless higher dry matter intakes are achieved (NE lactation value of 0.94 Mcal per pound of dry matter is not feasible).

Role of Body Condition Score (BCS)

Wisconsin workers have illustrated that we should share common guidelines on optimal body condition score. The following factors should be considered.

• Heavy dry cows consume less dry matter at calving and drop sooner prior to calving.
• Increasing BCS from 2 to 3 increased milk yield 708 pounds in the first 90 days after calving. Increasing BCS from 3 to 4 increased milk yield 73 pounds in the initial 90 days. No increase was reported in cows after BCS 4.
• Optimal milk yield in all lactations (1^st, 2^nd, and 3^rd plus) occurred in cows with BSC from 3.0 to 4.0.
• With thin dry cows, adding one BCS can increase milk yield (+1200 pounds) and improved reproductive performance.
• Cows with BCS over 3 lose more body weight as they increase from 3 to 3.25 to 3.5 to over 4.
• Cows losing more than one BCS after calving to first breeding have conception rates of 38.3 percent compared to 50 percent (no change in BSC) and 61.7 percent (cows gaining 1 BCS).
• Cows carrying twins will begin losing BCS in the far-off dry cow period, consume less dry matter, and must received additional nutrients.

In summary, BCS should be stable during the transition period (no decrease or increase), does not have a direct effect on milk yield (unless very thin or heavy), will effect the amount of weight loss in early lactation, and will reduce reproductive performance with large drops.

Dry Matter Intake

Dry matter intake (DMI) dictates the actual amount of nutrients (pounds of fat, pounds of fiber, grams of starch, and calculated megacalories of net energy). Dairy cows require pounds, not percent of nutrients. Three risk factors can occur with lower dry matter intake according to Wisconsin workers.

1. Low DMI leads to fat mobilization (cow attempts to provide energy from her body) leading to fatty liver development and ketosis ending in impaired liver function.
2. Low DMI leads to poor immune function ending in a higher mastitis and metritis risks.
3. Low DMI leads to an empty rumen (less fill) ending in displaced abomasum.

Close up dry cow consuming more dry matter one day prior to calving had higher dry matter intake 21 days after calving has been reported by Wisconsin researchers. Any management or ration factor that will increase DMI at calving is a positive for transition cows. Many controversial points at the beginning of the article can be related to DMI.

• Adding starch can increase rumen microbial digestion and rate of feed passage providing more nutrients for the cow.
• Including 2 to 4 pounds of wheat straw can maintain rumen fill and pH, avoid empty rumen syndrome leading to DA, and maintain fiber digesting bacteria.
• Placing far off dry cows on a restricted or lower energy ration can avoid heavy cows (leading to lower DMI).
• Feeding higher levels of corn silage (over 10 pounds of dry matter) in the close up ration may increase dry matter intake, raise forage quality, reduce diet potassium levels, improve ration palatability and stability, and increase fermentable starch in the rumen.
• Maintaining the same ration prior to calving and constant DMI, close-up cows may transition more smoothly.
• By using a series of rations (far-off dry cow, close-up dry cow, and fresh cow), cows meet increasing nutrient intake and do not go off feed as changes are small allowing cows to step up nutrient concentration.
• If adding an anionic product reduces DMI, expect problems related to energy intake. If anionic salts improve blood calcium levels, DMI can increase (smooth muscle contraction) and metabolic disorders can be minimized.

Protein Status of Transition Cow

Protein requirements may parallel energy dynamics and requirements listed in Table 1. Cornell workers established protein guidelines for the unborn calf that rapidly increase the amount of amino acids needed as calving approaches. Dairy NRC 2001 recommends 12 percent crude protein for far and close up mature dry cows and 14 to 15 percent crude protein for close up pregnant heifers (extra protein needed for mammary gland development, growth, and colostrum synthesis). The Dairy NRC committee calculated mammary gland growth is about 130 grams of crude protein or an increase of 1.3 percentage units above baseline crude protein needs. One major concern is if dry matter intake drops significantly, the total amount of amino acids may be limiting.

Higher levels of crude protein and undegradable protein before calving have resulted in variable results. In some research studies, reproductive performance and higher levels of milk protein were reported. Milk yield has not been improved with higher protein intakes. Supplementation of first limiting amino acids may be beneficial when fed before and after calving. Higher levels of crude protein have lower dry matter intake. Feeding excess crude protein could be problem because the liver may not be able to detoxify excess ammonia related to fatty liver development. The following guidelines can be considered with close up dry cows.

• Mature cows need a ration containing 12 percent crude protein cow.
• Pregnant heifers need a ration containing 14.3 to 15 percent crude protein.
• If dry matter intake is reduced below anticipated levels, higher level of protein maybe needed.
• When increasing crude protein levels in the close-up dry cow ration, the source of undegraded protein and its amino acid profile should be considered.
• Protected amino acids maybe beneficial in close-up rations based on amino acid model predictions and accurate feed analysis.
• Stimulating microbial growth should improve amino acid supply to the close-up dry cow.

Transitioning the Close-Up Heifer

The springing or close-up heifer is a unique nutrient requirements as the mammary gland is developing, grow continues (over one and one half pounds a day), and a pregnancy needs are increasing (Table 1). The nutrient requirements are higher compared to mature cows and may be underestimated compared to traditional requirements. Dry matter intake is lower in heifers compared to older cows (Table 2). Body condition score will have less impact on dry matter intake in heifers compared to older cows. Protein requirements in close up springing heifers are two percentage points higher (14 percent crude protein) compared to mature cows (12 percent). The rumen papilla and microbes have not been challenged with higher energy rations. The rumen may not be able to absorb volatile fatty acids as effectively as older cows. Wisconsin worker report young cows are more at risk for subacute rumen acidosis (SARA) and laminitis.

Table 2. Dry matter intake of pregnant cows (young cows and mature cows) in the close-up dry cow period.

To meet these challenges, dairy managers may need to develop a specific springing heifer group increasing nutrient density of the far-off and close-up pregnant heifer. Increasing trace mineral levels and fat-soluble vitamins can impact calf health, improve colostrums quality, and minimize metabolic disorders. Anionic products are not recommended for close-up heifers (reduces feed costs). Springing heifers may need more bunk space and less competition to maintain feed intake.

Growth guidelines for large breed heifers include 52 to 54 inches at the withers, body condition score of 3 to 3.25, and body weight over 1250 pounds (not including the unborn calf, fluids, and membranes), and under 24 months of age. If young cows grow more than two inches in the first lactation, heifers were not properly grown prior calving and may divert nutrients to growth and away from milk production based on Canadian guidelines. Colorado workers reported for every 100 pounds of true stature below target body weights can result in 600 pounds less milk in the first lactation.

Heifers within several weeks of calving should be grouped separately and adapted to their calving environment after calving. Cows that undergo abrupt environmental and social changes during the transition period may exhibit undesirable feeding behavior leading to metabolic disorders. Allowing heifers to pass through the milking parlor prior to calving can improve transition according to Purdue workers. New Mexico workers reported that close up cows consumed less dry matter when barn capacity exceed 90 percent of assigned free stalls and bunk space. In the field, some dairy managers report that removing head locks in the transition pens can increase feed consumption and cow adjustment with first lactation cows.

Behavior Characteristics of Young Cows

First lactation cows can benefit from a separate group due to a smaller body size, greater persistency in the lactation, and lower position in the dominance hierarch. Competition with older cows resulted in less dry matter intake and milk production compared to older cows (Table 3). The difference in performance was proportional to the difference in body size between young and mature cows.

Table 3. Performance of first lactation cows when grouped separately or mixed with older cows (Konggaard and Krohn, 1978).

Michigan workers reported that high producing older cows consume more feed, ate larger meals more quickly, ruminated longer and more efficiently, and drank more water than lower producing younger cows.

Fresh cows are vulnerable to excessive competition brought on by improper grouping. These cows are fatigued with weak hind limbs. If these cows are forced to compete for feed and water, they can be injured or lower feed intake. Dominant cows and cows in estrus may prey on cows in transition or smaller, young cows. Swedish workers reported dominant cows consumed 14 percent more feed than submissive cows and increased to 23 percent when more cow pressure occurred was placed on feeding stations.

Dominance at the feed bunk is based on age (older cows), body size (bigger cows), seniority in the herd (more days in milk), and newly formed groups of cows. Feed bunk competition occurs when returning from milking, when fresh feed is offered, and the maximum effect occurs in the initial 30 to 45 minutes. The interaction of overcrowding and head gates suggest 45 to 66 percent of the cows were eating when not crowded compared to 30 to 38 percent for overcrowded cows. Percent of cows eating meal at feeding time was 32 to 43 when not crowded compared to 21 to 27 percent for overcrowded cows. Over crowded cows prefer free stalls to eating after calving and spent more time in the alley waiting to lie down than eating. Overcrowded cows averaged 28 percent ruminating while 37 percent of cows were ruminating when not crowded.

Feed Management in Early Lactation

Dry matter intake after calving lags mature cows by 4 to 8 pounds compared to mature cows (Table 4). The level of starch, concentrates, and fats must be evaluated based on lower intake.

Table 4. Dry matter intake of first lactation and mature cows in early lactation.