Dr. Joe

Published on Thu, 12/15/2016 - 10:18am

Tis the season to remember Healthy Cows equals Healthy Calves!

By Joseph W. Ward, Ph.D

Management practices during the last trimester of pregnancy is a critical time in the yearly cycle of the cow.  How we manage all aspects of a cow’s needs including nutrition, housing and immune status during the last 30 to 90 days of pregnancy has a direct impact on the health and survivability of a newborn calf.  Being prepared, reviewing rations, understanding the importance of the cow’s body condition at the time of calving, viewing your farm’s vaccination program, proper shelter, hospital pens,  calving equipment, assembling supplies for cow and calf treatments all play a vital role of a well-managed successful dairy cow herd.
Producers should make every effort to maintain cows and replacement heifers in proper body condition especially during the last trimester of pregnancy.  The vast majority of fetal growth occurs in the 3rd trimester of pregnancy and this critical time plays an extremely import role in the overall health and performance of both the dam and her newborn calf.  Following conception, the major nutritional demand of a cow occurs during the lactation period.  It is extremely beneficial for the cow’s well-being as well as the potential health of the newborn calf that extra time and effort is taken to review the nutritional requirements of the cow and to review of all vaccines therapies prior to calving period.
In most operations, it is beneficial for cows to gain weight during last trimester.  Improving energy reserves, and thus body condition score, will help her prepare for the milk production demands placed upon her after calving.  Fall calving herds often rely on stored feedstuffs by this time and encounter inclement weather, whereas spring calving herds may experience elevated temperatures and declining forage quality.
Cow’s vaccination programs should be reviewed at least annually.  It is very important to discuss with your farm veterinarian on the proper vaccination regimen for your area of the country.  Well throughout vaccination programs administered on a timely basis provides a foundation for the passive immunity that the newborn calf will receive from their mothers.  Vaccinations are given to cows prior to calving in order to pass antibody protection to calves through the colostrum.  The quality of the colostrum the newborn calf receives from their mothers is directly correlated to the immune status of the cow as well has her nutritional status at the time of calving.  Remember that healthy cows have healthy calves.
During the final 50 to 60 days of gestation, approximately 65 to 80 percent of fetal growth occurs.  It is paramount that cows receive adequate nutrition during this time period.  Review your feedstuffs and vitamin/minerals formulations with your nutritionist and your veterinarian to make sure your cows are receiving adequate nutrient fortification and that your vaccination program is correct during this time.  When possible it is a good time to separate thin cows and first calf heifers so that thinner cows can be fed more energy and nutrients to compensate for their lower body condition scores.  To meet the nutritional needs of the different groups that make up the dairy cow herd, whenever possible, divide them into groups with the same needs such as:  1) replacement heifer calves, 2) first calf heifers, 3) older thin cows and 4) lactation number.
Cows receiving inadequate nutrition direct nutrients away from other demands to meet fetal growth requirements.  Poor nutrition especially during this time in the gestation cycle can result in weak labor, increased dystocia, and extended postpartum anestrous internal, impaired milk quality and production, reduced calving and weaning weights, and poor breed back performance.  On the other hand, gross overfeeding during last 30 to 90 days can result in reduced birth weight, deceased milk production, increased dystocia and neonatal death loss.  Research studies have demonstrated that birth weight deceased as a cow’s body condition score deceased.  The eye of the master is important so that at calving time all cows are in proper body condition, have received all necessary vaccinations and are receiving adequate mineral and vitamin fortification to produce a healthy robust calf.
Providing dairy cows with a dry period of 6 to 8 weeks is needed to rebuild worn mammary gland tissue and replace body reserves of energy, protein and minerals.  Research has demonstrated that cows deprived of a normal dry period, have reduced milk production during the next lactation and do not achieve their genetic potential to produce milk.   Provide a clean dry calving area to reduce the incidence of scours and disease.  Rotating the calving area on some farms is somewhat problematic and cannot be accomplished.  As much as possible, keeping these areas cleared of cleanings and the speedy removal of dead calves and cows to minimize the incidence of infecting other animals is always a good practice.  Being prepared for the calving is critical to minimize death losses.  Unfortunately, calf death losses continues to average between 12 - 18 %.  Hospital pens should be ready prior to calving that are dry, sheltered and convenient to work in.  Adequate housing considerations depending on the time of the year and your farm’s geographical location should not be overlooked.   Calving areas should always be clean and dry.  
There are several items to consider having on-hand prior to the calving.  These items include: injectable antibiotics, drench or oral feeding bags, electrolytes, 7% iodine for treating calf navels, frozen colostrum (thaw slowly) or commercial colostrum substitutes, obstetrical assistance equipment and disinfectants. Having on-hand readily accessible frozen colostrum, electrolytes for liquid supplementation, clean bottles, nipples and probe feeders will greatly improve the survival rates of compromised newborn calves.  Being prepare minimizes unexpected stressors for you as well as the cows and calves.  Remember calving losses can be high in heifers due to calving difficulties.  Using good judgment to determine which calving problems require immediate professional help is important.  Early intervention with professional assistance can dramatically reduce calving and cow losses.
Research has shown that feeding pregnant cows after 6:00 pm in the evening results in more calves being born in the daylight hours. It is much easier to monitor cows during the daylight hours and predators of newborn calves are more likely to keep their distance for fear of being seen.  Minimizing handling stressors as much as possible with well-designed facilities.  Having access to appropriate free choice mineral for cow’s can dramatically affect milk production.  Proper nutrient formulation for the time of the year as well as complementing the forages and feedstuffs being fed has a direct impact on profits.  Providing sound nutrition, proper vaccinations and adequate shelter has been shown to substantially increase economic returns.   
In conclusion, the last trimester of pregnancy is a critical time in the yearly cycle of the cow.   The way she is managed and fed during this time will have a direct impact on the health of the calf, milk production and her rebreeding schedule.  When it comes to raising healthy dairy calves, close attention needs to be paid to all aspects of calf management practices.  The nutritional needs of a cow increase rapidly during the last three months of pregnancy because the fetus makes 70% of its growth during the last 3 months.  Group feeding, according to body condition and lactation number, is best if possible on the farm.  The pre-calving nutrition of the mother cow has many implications on the resistance of the calf to stressors and diseases.  Extra nutrients are required 90 days pre-calving to assure proper fetal growth, a healthy calf at birth and a cow that can milk.  A truly concerned attitude and a “caring eye” to confirm that the dairy calf’s every day needs are being met has a significant impact on heifer quality for herd replacements.  The eye of the master is still your most valuable tool on the farm.  You are the key to a successful enterprise.  Being aware, observant and prepared is paramount and separates those who just have milk cows verses the professional dairymen. 
The author, Joseph W. Ward, has a BS in Animal Science, a MS in Animal Nutrition from Purdue University and a Ph.D. from Oklahoma State University in Ruminant Nutrition.  Born and raised in Indiana on a livestock farm, Dr. Ward has consulted in Europe, the Far East, Oceania, and South Africa.  He has been active in animal production and animal feed manufacturing/processing since the early 80’s.  He is an organic inspector for crops, livestock and processing.  Currently, he serves as North America Product Manager for Phileo Lesaffre Animal Care. Dr. Joe can be reached at j.ward@phileo.lesaffre.com.