Strategies to Decrease Neonatal Calf Loss in Beef Herds

Chapter 68
Strategies to Decrease Neonatal Calf Loss in Beef Herds

David R. Smith

Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Starkville, Mississippi, USA


Calving is a highly anticipated event for the beef cow-calf producer. The first few weeks of each calf’s life are critical to its future health and productivity, and collectively the health and productivity of the herd as well as the financial success of the enterprise. Successful calving seasons are planned in advance, with much consideration to minimizing the likelihood and costs of the known hazards of this phase of cattle production. Important hazards during the calving season are birthing problems, dangers from the environment, and sickness or death from disease. Understanding these hazards allows the cattle producer to make long-term and near-term plans to minimize risk. Veterinarians can help beef cattle producers take appropriate actions to prevent neonatal calf losses by conducting a herd-specific risk assessment.

Risk assessment is a process of:

  1. evaluating the likelihood and costs (or benefits) of potential hazards (or opportunities), termed risk analysis;
  2. determining what actions, at what relative cost, can be taken to mitigate those hazards, termed risk management; and
  3. sharing the action plan with all members of the team, as well as keeping records to show what was done and whether the actions were successful, termed risk communication.

The process of risk assessment can be iterative to provide a continuum of actions toward ongoing improvement.1 A risk assessment may be completed formally or informally, and the process may be qualitative or quantitative.2,3 As part of the risk analysis phase it may be necessary, or at least useful, to supplement published evidence with herd-specific data from health records,4 outbreak investigation,5 or clinical trials.6 It is possible to recognize important hazards and estimate their costs without quantitative data during the risk analysis stage, but it is more difficult to evaluate progress or compliance in the risk management stage without using records.

Unfortunately, few cow-calf operations collect animal health data in a format that is easily analyzed.7 The lack of a simple record-keeping system on many farms hinders the process of recognizing important hazards and their costs, makes it difficult to document that risk management actions were implemented, or to evaluate if those actions were effective. If records exist at all they may be on paper (e.g., in pocket-sized health record books) or in a computerized digital format (e.g., spreadsheets or databases) with free text fields, none of which allow the veterinarian or the producer to quickly and easily discover animal health relationships.7 Some proprietary database systems capture health information and may present information in standardized graphs or summaries, but do not always allow easy querying of other health relationships. Free text fields are difficult or impossible to analyze because of misspelled words, multiple names or descriptors for the same disease (e.g., diarrhea, scours, loose, enteric), and multiple pieces of information in the same field. Often it is too costly to wade through inefficient record systems to get the needed information from which a risk assessment can be performed. Therefore, it may be beneficial for the veterinarian to help the cattle producer establish a system for capturing and analyzing health and performance data.

A desirable system for evaluating calf health and performance captures data on all calves at risk, not just treated calves. Useful information includes the calf’s identification, the identification of the dam, the age of the dam, the calf’s birth date, date of onset of health concerns, and information describing variables of interest (e.g., birth and weaning weights, risk factors for disease, economic data).

A risk assessment evaluates the reasons for the occurrence of hazards, the likelihood of the hazard, and its cost. In the absence of farm specific information, risk assessments are often based on published information and expert opinion. For example, based on a national survey of beef cattle herds completed in 2007–2008,7 2.9% of calves were born dead and another 3.5% died or were lost prior to weaning. These rates were similar regardless of the herd size. In this survey, the reasons for beef calves to die in the first 3 weeks of life, in order of frequency, were (i) birth related (25.7% of deaths); (ii) weather related (25.6%); (iii) unknown causes (18.6%); (iv) digestive system related (14%); (v) respiratory disease (8.2%); and (vi) predation or injury (6.2%). Note that these are population averages and not every beef herd experiences losses according to this distribution. However, in the absence of herd-specific information, these data inform us that on average the important hazards to the survival of neonatal calves are problems occurring during calving, dangers from the environment, and contagious diseases.

Managing risks requires greater understanding of the factors associated with those hazards, how to mitigate those factors, and the associated costs.1 Economics should not be the sole basis for making decisions about the care of animals. However, the cost of healthcare remains an important financial constraint to most cattle producers, and is therefore an important consideration. The relative costs of disease prevention and control practices are relevant to risk management decisions. Comparing the relative costs of different approaches to managing risk can help inform animal care decisions.

The cost of even highly effective risk management practices should not be overlooked. As a simplified example, assume that a vaccine is 75% effective and costs $10 per head to administer (e.g., for product, labor, and supplies). If the disease occurs at an annual incidence of 40 cases per 10 000 head, then vaccination would reduce the incidence to 10 cases per 10 000 head per year. The annual cost to prevent 30 cases in a population of 10 000 would be $100 000, or $3333 to prevent each case. In this scenario, use of the vaccine might only be economically justified to prevent extremely costly diseases (e.g., causing high mortality in herds of high value). If the annual incidence of disease were 400 cases per 10 000, the cost of preventing each case would be $333. In this scenario, if the cost of the disease (e.g., costs for labor to treat, medications, lost performance, and deaths) averaged $100 per case, then use of the vaccine would not be economically justified unless the expected incidence in the absence of vaccine was 1333 cases per 10 000.

Other factors besides direct monetary costs or benefits play into a farmer’s decision to use a preventive intervention. It might be more useful to consider units of utility rather than units of money in the calculation of risk management costs and benefits.1 For example, in addition to the animals’ monetary value, a particular farmer’s unit of utility might also include their concern for the health and welfare of their cattle or pride of owning healthy and productive cattle. Also, average or expected values do not consider the impact of extreme events. For example, the occurrence of infectious diseases may cluster in time and place as an outbreak. Therefore, just as with many insurance plans, the decisions to use vaccines or to take other preventive actions may be based on minimizing the risk of a catastrophic outbreak, even if the average cost of the prevention is greater than the average cost of the disease. Finally, the relative level of risk aversion of the individual producer may affect the utility breakpoint at which a risk management practice is adopted.1

What follows are qualitative risk assessments with generalized approaches to managing the risk of the most common hazards of the neonatal period in beef herds. The veterinary practitioner may be able to provide a more tailored approach to managing health risks within specific cattle herds using specific herd data. The emphasis of this chapter is on disease and injury prevention; however, timely and effective treatment is also important in managing the overall cost of disease or injury.

Risk assessment of calving hazards

Successful calving occurs when a live calf is born without complications to the calf or the dam. Problems with the birthing process are called dystocia. Dystocia may be due to factors of the calf or factors of the dam.8

Calf factors of dystocia

The factors of dystocia related to the calf are size, posture, and presentation. Large calves are more likely to experience dystocia because they have difficulty fitting through the dam’s pelvis. Posture refers to the position of the calf’s head and legs as the calf enters the birth canal. Presentation refers to the calf’s orientation relative to the dam. The most normal presentation and posture at birth is the calf upright, facing toward the rear of the cow, with the head between extended front legs. A breech birth is an example of both abnormal posture and presentation; the calf is backwards with the rear legs folded under the body. Of these factors, calf size is the most common problem and most preventable, through genetic selection.8

The consequences of dystocia to the calf are metabolic or physical injury that may result in death during or following the birthing process. Lack of oxygen in the blood causes injury to cells and results in acidosis and low blood sugar. Physical injuries include congestion and swelling of the head and tongue which may prevent nursing, or broken bones due to excessive force during calving assistance.

Dam factors of dystocia

Factors of dystocia attributable to the dam are age, pelvic size, and metabolic health.8 Dystocia is more common among heifers, and also cows with small pelvic dimensions. Common metabolic problems at calving are from muscle weakness due to protein–energy malnutrition, exhaustion during prolonged muscular contractions, and low blood levels of calcium or magnesium. The dam may experience metabolic or physical injury during or following the birthing process. The most common problems for the dam are exhaustion from muscular contractions, pressure injury to leg muscles while being recumbent, and bruises or tears to the uterus and vagina. The consequences of these problems include failure of the dam to get up after calving, prolapse of the uterus, excessive bleeding, or infection of the reproductive tract. Each may ultimately be fatal.

Managing the risk of dystocia

There are long-term and near-term strategies for preventing problems associated with dystocia.9 Long-term strategies include genetic selection for calving ease and pelvic size, and implementing sound heifer breeding and development programs. Near-term strategies include providing exercise and balanced nutrition to heifers and cows prior to and after calving, frequent monitoring of calving progress, early and appropriate calving assistance, ready access to the appropriate tools for calving assistance, copious use of lubricants, and attention to sanitation (e.g., use of soap and water) during birthing assistance. Describing methods for calving assistance are beyond the scope of this chapter; however, an important aspect of managing dystocia risk is helping producers know when veterinary assistance should be sought. Cattle producers should seek veterinary assistance when they:

  • do not know what is wrong;
  • know what is wrong, but either do not know what to do or recognize it is beyond their abilities; or
  • know what is wrong and what to do about it, but have been unsuccessful after 30 min of trying.10

Risk assessment of environmental hazards

The environmental conditions in the neonatal period are important to the health and well-being of the dam and her calf.

Environmental hazards to the calf

Common environmental factors that present a hazard to the neonatal calf are weather extremes, crowding, predators, and physical sources of injury. At birth the calf is limited in its ability to regulate its body temperature so extremely warm or cold environmental conditions present a risk for hyperthermia or hypothermia, respectively, especially when accompanied by wet and muddy or dry and dusty conditions. Crowded herd conditions increase the chance for injury from being stepped on, butted or otherwise injured by others in the herd, and increase opportunities for pathogen exposure and transmission. Predators present the greatest hazard to calves recently born, or calves weakened by illness or injury. Calves may become injured from a variety of physical hazards in the calving environment including protruding nails, broken posts, loose wire, holes, steep embankments, standing water, various sources of electricity, and toxins (e.g., from lead batteries or chemical containers).

Environmental hazards to the dam

Cows are less susceptible to weather stressors compared to their calves, but dystocia or metabolic disease increases their risk for hypothermia or hyperthermia. During the periparturient period cows may be more likely to slip and fall, and the likelihood further increases when the floor surface has a steep slope or is slippery due to snow, ice, or mud. Cows calving near ditches and streams or other low spots are at risk to fall or not be able to rise after lying down. As with calves, cows may be injured by a variety of physical hazards that may be present in the calving environment.

Risk management of environmental hazards

The risk of injury to cow or calf can be minimized by providing favorable environmental conditions. Long-term strategies include breeding in a time frame such that calving occurs during favorable weather conditions and designing and using calving facilities with minimal physical hazards. Near-term strategies for environmental safety include a pre-calving survey of the environment and facilities for potential sources of injury, and frequent surveillance of the herd during the calving season.

Aug 24, 2017 | Posted by in GENERAL | Comments Off on Strategies to Decrease Neonatal Calf Loss in Beef Herds
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