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Calving season is all the time on dairy farms

Spring is just busier and more crowded! 

Managing the Spring rush is associated with calving season on beef cattle operations with spring calving herds.  Many dairy farms will notice a seasonal increase in calving during the spring as well.  Grazing dairies will calve in the spring to match the nutrient demand with the available forage.  Traditional confinement operations often see an increase in spring calving for two reasons.  Many operations do not calve first calf heifers in the coldest winter months. Increased spring calving of mature cows is often a result of heat stress.  Cows that fail to conceive due to the heat of July and August will often become pregnant in September.  These cows will enter the dry cow pens starting in March with subsequent calving in April through June.  The net result is often an overcrowded situation in the dry cow, pre-fresh and fresh pens.  Overcrowding in these pens leads to increased fresh cow problems after calving, most notably ketosis and uterine infections.

Dairy Cow Body Condition Score Implication

Ketosis is an energy availability issue which is related to overall dry matter and energy intake.  Managing body condition score (BCS) of the animals is critical.  The dairy cow BCS system uses a 1-5 scale where as beef BCS uses a 1-9 scale.  Cows that conceive later than desired can be over conditioned due to the extended time on the lactation diet.   Excessive BCS can be a risk factor for ketosis due to fact that high BCS cows and heifers will eat less than cows and heifers with a BCS of 3-3.5. 

Cow Social Factors

First calf dairy heifers are often 200-400 lbs. lighter and eat 20-25% less than mature cows.  Often the first time a heifer competes with a mature cow at the feed bunk is during this critical period around the time of calving.  This added social stress contributes to reduced feed intake for heifers.  The ideal stocking rate for pre-fresh and fresh pens is 90% or 9 animals for every 10 stalls.  We never build calving barns big enough.  The pens may be big enough for the “normal” month, but not for heavy calving events in the spring.  Regardless of parity, when the pre-fresh and fresh pens are over-crowded DMI will decline, energy intake will decline and ketosis risk significantly increases.

Limitation of AVERAGE DMI in balancing pre-fresh and post fresh diets

Above we discussed how DMI is 20-25% less for heifers compared to mature cows.  Mature dry cows will consume between 28-32 lbs. of dry matter.  Pre-partum first calf heifers will consume 20-25 lbs. of dry matter.  In a mixed group of mature cows and first calf heifer, what is the correct DMI to balance the diet?  Adding to the challenge of selecting a correct average DMI is the fact that cows consume less as they approach calving.  Researchers at The University of British Columbia conducted one of the most detailed trials on 101 cows documenting individual DMI and the relationship of DMI to uterine infections.  The data showed that DMI began to decline -7 days prior to calving for all animals and was most severe for animals that developed metritis.  The change was most dramatic on days -1 and day +1 relative to calving.  This raises the question, “Did they get sick because they ate less or did they eat less because they were sick?”.  The answer is yes and yes.  Metritis is a bacterial infection of the uterus and can only occur after calving.  Eating less prior to calving was a risk factor for metritis and metritis decreased DMI after calving.  Table 1 shows the change in DMI and milk production on Day 21.

CRYSTALYX® Self-Fed Supplements as a TMR Safety Net™ in Pre-fresh and fresh pen diets.

CRYSTALYX® Self-Fed Supplements offer a variety of low moisture blocks that help in delivering key trace minerals and vitamins regardless of the intake of the TMR.  The barrels are easy to use and provide additional confidence that each cow is receiving the nutrition she needs.  We could over fortify the TMR by balancing at the lowest possible intake; however, this can be expensive and not very practical.  CRYSTALYX® Self-Fed Supplements such as Dry Cow™ Formula, Close Up™ Formula and Transition Stress™ Formula offer the convenience of multiple products to fit most feeding and housing situations.