Managing for healthy beef calves (Proceedings)
One key for profitability for cow-calf producers is pounds of calf weaned in the fall. The best way to increase the total number of pounds weaned is to have more calves alive at weaning. Typically most calf death loss occurs within the first 3 weeks of life. Proper management focus during this time is an efficient means to enhance productivity and reduce sickness and death loss.
The first priority is getting a live calf on the ground. Dystocia increases the risk of neonatal calf death by 4 times. Proper observation of females during the calving season can identify dystocia to allow for timely intervention. Ideally, females should be observed every two hours. A recent USDA NAHMS report (http://nahms.aphis.usda.gov/beefcowcalf/index.htm) reported that 50% of producers observe females more than twice a day and less than 15% observe more than 4 times a day. Once a calf is born alive they must intake colostrum for an adequate immune function. Dystocia calves should be administered colostrum via a bottle or esophageal tube instead of relying on them standing and nursing. Beef calves that do not have adequate colostrum intake and absorption may be 9 times as likely to become ill in the preweaning period than calves that had received and absorbed enough colostrum. As usual, protect newborn calves from extreme environmental conditions when necessary.Nutrition
Proper nutrition is crucial to a successful outcome for the cow and calf. Body Condition Scoring (BCS) can be used to assess the nutritional program of the beef herd.
Historically, there was some thought that protein and energy supplementation was responsible for dystocia problems. Actually many studies have shown that cattle fed low energy diets prior to calving have a higher percentage of dystocia then medium or high energy diets unless cows are overly conditioned with fat deposits in the birth canal. Calves from cows fed adequate energy and protein did have increased birth weights but decreased dystocia rates. Therefore it is important to remember that you cannot starve calving difficulty out of cows.
One of the most important factors is the effect of dam nutrition on calves. Proper energy and protein levels are vital for calf vigor after calving. Calves from energy or protein restricted dams during gestation have decreased calf vigor and ability to generate body heat. Weak calves will be less likely to intake adequate amounts of colostrum and are more prone to increased morbidity and mortality.
Cows should calve at a BCS of 5 (heifers at BCS 6) at calving. Up to 80% of fetal growth occurs in the last 50 days of gestation. Females during this period of gestation need approximately 11 Mcal of energy and 1.7 lbs of crude protein per day.
There are multiple potential factors that are involved with the weak calf syndrome including nutrition and BVD virus. Additionally, the inciting cause of many cases of weak calf syndrome is not diagnosed. Typically, weak calves are born alive but die shortly after birth. Many of these calves never stand and nurse by themselves. If they do stand they are very slow in getting up and never do well, usually dying within 3 days. With intensive management these calves can be nursed along but some will die no matter how exhaustive the therapy.
Pre-partum nutrition is key for preparing the calf for life outside the uterus. Upto 80% of fetal growth occurs in the last 50 days of gestation. Therefore the dam needs adequate nutrition to support the tremendous required growth in the fetus and supply enough additional nutrition to for the calf to have enough reserve to be able to stand and survive after birth.
Protein is one of the biggest nutritional components necessary for fetal development. Calves born from protein restricted dams have decreased calf vigor, decreased thermal heat production, and increased time from birth to standing. A good rule of thumb is that late gestation cows need 2 lbs of protein per day.
Energy is also important for the fetal calf. Fetal brown fat supplies the energy needed for the calf to survive until adequate colostrum and subsequently milk is ingested. Cows need at least 11 Mcal of energy per day. However, during extreme cold weather this requirement increases. Producers need to adapt and feed their cows to fit the environmental conditions. It is important to recognize that although pregnant cows can be roughed through much of the winter, this practice should not include late gestation. Calves born to cows that were losing weight during late gestation will have lower energy stores and longer interval from birth to calving. Additionally, these cows will take longer to breed back.
BVD virus has also been associated with weak calves. This virus is capable of causing multiple congenital problems depending upon the stage of development that the calf was infected. Calves that have had an in-utero BVDV infection have been reported to have hydrocephalous, immature, dummies, or weak in general. If BVDV is suspected contact your veterinarian so that a targeted testing program can be instituted.
Producers should also focus on good management practices during calving. Birth in general is a traumatic event for the calf and dystocia can further exacerbate problems. Dystocia calves will also have decreased calf vigor, weaker and a longer interval from birth until standing. As always a clean dry calving environment helps the calf get off to right start. A calf that is born into a cold wet environment is going to have to spend more energy keeping itself warm before it ever has a chance to stand and nurse.
To prevent subsequent neonatal loss due to infectious diseases calving areas should be as clean and dry as possible. Additionally, since neonatal calves amplify pathogen levels it is important to keep newborn calves separate from older calves to break the pathogen cycle. This can be accomplished either by removing pairs from calving area daily or by moving cows that haven't calved to new clean pastures every week; leaving the pairs behind.
Calves should be observed at least once daily for signs of scours and other neonatal diseases. Calves that develop diarrhea need immediate care because dehydration and subsequent death can occur rapidly. Oral fluids can be used to maintain hydration although some calves will require more intensive IV fluids. It is important to remember that although most calves survive a bout of calf scours the cost of treatment and decreased performance are costly. Prevention of calf scours by minimizing length of dystocia, assuring adequate colostral intake and maintaining clean calving areas can enhance the pounds of calf weaned and overall productivity of the beef herd.