Research »   Neonatal Disease

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One of the most important production factors influencing the economics of the beef cow calf farm is the calf crop percentage. This is defined as the percentage of cows exposed to the bull that raise a calf to weaning. In order to achieve this, a cow must become pregnant, successfully carry the calf through to term, give birth to a live calf and raise it to weaning age. Many factors can influence the calf crop percentage including reproductive management as well as calf losses through abortions, stillbirths, and other mortalities. A number of studies have demonstrated the importance of perinatal and neonatal losses in beef cattle in affecting the calf crop percentage.


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Introduction

Research suggests that over 8% of the calf crop is lost after the cow becomes pregnant. A large research study on Western Canadian cow-calf herds provides an overview of the reasons for calf losses. The results give a snapshot of what the ‘normal’ level of calf losses are in Western Canadian cow-calf herds. The study found that during that breeding and calving season:
Research suggests that over 8% of calves are lost between the time a cow becomes pregnant and weaning.
      • 1.6% of the pregnant cows aborted
      • 2.6% of the calves were stillborn
      • 4.0 % of the calves born alive died before reaching weaning age

These numbers are similar to what has been seen in other studies in other parts of North America.

For the average beef producer, most calf losses occur between birth and the first 7 days of life. A number of factors can contribute to these losses including:

NeoNatal Disease
      • Dystocia (calving difficulty)
      • Maternal nutrition
      • Maternal behaviour
      • Climate
      • Infectious agents and environment

Dystocia Management

In one extensive study of cow-calf herds, 69% of pre-weaning mortality occurred within the first 96 hours of birth (Bellows et al, 1987). Almost 2/3 of these losses were directly attributable to dystocia (calving difficulty).
Calves that survive dystocia are more susceptible to death and disease following birth.

In one extensive study of cow-calf herds, 69% of pre-weaning mortality occurred within the first 96 hours of birth (Bellows et al, 1987). Almost 2/3 of these losses were directly attributable to dystocia (calving difficulty).

Dystocia can directly cause a calf's death or indirect losses by increasing the susceptibility to infectious disease. Calves that survive dystocia have been shown to be 2.4 times more likely to become sick during the first 45 days of life. Calves that experience dystocia are 13 times more likely to die within 12 hours of birth.

Producers can minimize dystocia by utilizing some of the following management tools:

Select bulls with a low EPD for birth weights

Birth weight has been consistently demonstrated to be the most important contributing factor contributing to dystocia. Birth weights account for 30-50% of the variability in dystocia rates.

Birth weight is a function of genetic and environmental factors and is moderately heritable. Wherever possible, a bull with a low Expected Progeny Difference (EPD) for birth weight should be selected. Selecting an easy-calving breed of bull for use with replacement heifers is another option when EPD's are not available.

Ensure heifers are 85% of mature weight and cows are in good body condition (2.5-3)

The risk of dystocia is greatest in replacement heifers. The heifer rearing program should be adequate so that heifers have reached 85% of their mature weight at calving time. Cows should be at a body condition of 2.5-3 at the time of calving to minimize calving problems. Avoid overconditioning. Nutritional intake in late gestation should not be restricted as it will have no impact on birth weights. Although pelvic measurements have been used as a method of selecting heifers with larger pelvises, they tend to be of limited value.

Adequate surveillance

Early assistance in the calving process affects subsequent reproductive capacity of the dam. Early assistance can lead up to a 9% increase in the number of animals cycling at the onset of the breeding season and a 14% increase in the fall pregnancy rate. Furthermore, early assistance will greatly increase the chance of producing a live calf if an animal does have dystocia. Producers should be familiar with the normal sequence of calving.

Lighted calving area and adequate facilities

Adequate light makes surveillance easier at night. Producers should have one 8 x 10 maternity pen for every 20 cows, depending on season of calving and climate. Adequate facilities are needed to catch, handle and restrain cows with dystocia or mothering problems.

Calve heifers separately 2-3 weeks before cows

Calving heifers prior to cows allows for concentrated surveillance on the high risk group for dystocias. Heifers are more likely to have dystocia and mothering problems. Early calving for heifers also provides them a clean calving area with no pathogen build-up. Heifers need more time to return to estrus than cows.

Know when to intervene in calving

Cows should be examined by trained personnel to make a decision about assisting with calving if any of the following scenarios occur:

  • Cow actively strains for 40 minutes with no progress
  • 90 minutes have passed since the waterbag first appeared
  • The legs emerge with the surface of the hooves pointing up
  • Only the head or tail emerges
  • An un-calved cow is mothering another calf
  • A cow demonstrated greater than 5-6 hours of anxiety (i.e.: walking about, tail extended)

Maximize General Immunity

Newborn calves are born with virtually no immunity of their own. The cow’s placenta does not allow antibodies to pass from the mother to the calf during pregnancy, which means the calf must receive its initial immunity from the antibody rich colostrum, or first milk of the cow. This initial immunity is essential because it provides protective antibodies against many of the diseases that affect newborn calves, such as calf scours, navel abscesses, arthritis and pneumonia. Even the vaccines used to prevent scours in calves rely on this passive transfer of immunity in the colostrum.

Intake of colostrum within the first 12 hours after birth is vital to develop a calf’s immunity. Two litres of colostrum within the first six hours is ideal.

The calf is only able to absorb these antibodies at significant levels during the first 12 hours of life. The gut’s closure to antibody absorption is a gradual process but begins to decline rapidly at 12 hours until complete closure occurs at about 24 hours of age. After the gut closes, the antibodies can still have local effect within the gut, but they can no longer be absorbed into the blood stream.

Calves that do not receive adequate amounts of colostrum immediately after birth are at a much higher risk of becoming sick and are also more likely to die. Many cases of diarrhea, navel ill, blood poisoning and pneumonia in calves are a result of failing to receive an adequate level of colostral immunity.

NeoNatal Disease
 

Ideally, a calf needs at least two liters of colostrum within the first six hours of life to provide optimal levels of immunity, but the required volume depends on the concentrations of antibodies in the first milk of the cow. Beef calves should get up quickly after birth and begins to suckle within the first few hours. Calves that have not nursed properly within the first two to three hours should be noted and observed more closely.

In colder weather, calves will become hypothermic and may be less vigorous and less likely to suckle immediately. These calves should be tube fed colostrum and placed in a warming box. A calf can probably be given more time to suckle properly on a warm day, but it should be tube fed colostrum if it has not suckled by six to eight hours.

The calves that are at the highest risk of failing to receive adequate colostral immunity:

  • had a difficult birth
  • were abandoned or mismothered
  • are hypothermic in cold weather

Pendulous udders and large teats can also make suckling difficult, even for vigorous newborn calves. Colostrum can be collected by milking the cow or by using reconstituted freeze dried colostrum substitutes. The quality of colostrum substitutes vary, so ask your veterinarian to recommend a good substitute.

Extra colostrum can be kept in the refrigerator for up to 24 hours to be used for other newborns. Extra colostrum can also be kept frozen for up to one year. Frozen colostrum should be gradually thawed in a warm water bath because high heat can destroy antibodies.
Extra colostrum can be collected and kept in the refrigerator for 24 hours, or frozen for up to one year. Frozen colostrum should be thawed in a warm, not hot, water bath.

Utilize a Vaccination Program to Enhance Immunity

Work with your veterinarian to design a vaccination program to enhance the immunity of the calf to specific diseases. Vaccines for scours are usually given to the cow in late pregnancy to promote the production of specific antibodies against bacteria and viruses that cause neonatal calf diarrhea. However, the calf can only receive these antibodies through the cow’s colostrum to receive the benefit of this protection.

Decrease the Infection Pressure

Reducing the amount of exposure of young calves to manure is an important aspect of preventing disease in the newborn. Most of the disease agents that cause diseases such as scours in young calves are carried normally by the adult cow, and are often found in the manure of normal cows.

The following strategies may help with reducing the infection pressure and minimizing the manure exposure to young calves.

  • Minimize confinement of the cow herd
  • Utilize separate wintering and calving areas
  • Move cows onto calving area less than 2 weeks before calving
  • Avoid crowding in calving area
  • Rotate calving area from year to year
  • Remove snow and provide adequate bedding
  • Separate nursery areas for cow-calf pairs
  • Avoid restricted feeding/bedding areas
  • Provide creep areas or "Calf Condos"
  • Quarantine diarrheic calves
References

Kasari TR and Wikse SE (editors): Perinatal Mortality in Beef Herds. Veterinary Clinics of North America 1994.

Waldner CL et al: Gross Postmortem and Histologic Findings from Abortion Losses and Calf Mortalities in Western Canadian Beef Herds. Canadian Veterinary Journal 2010; 51: 1227-1238.

Bellows RA et al: Occurrence of neonatal and postnatal mortality in range beef cattle.
Theriogenology 1987 Volume: 28 Issue: 5 Pages: 557-571.

Learn More

Calf Scours Overview: General Principles
Farm Animal Council of Saskatchewan
http://www.facs.sk.ca

Calving: When and How to Help
Farm Animal Council of Saskatchewan
http://www.facs.sk.ca

Colostrum: It’s Important
Farm Animal Council of Saskatchewan
http://www.facs.sk.ca

The Importance of Colostrum for Calves
Alberta Agriculture and Rural Development
http://www1.agric.gov.ab.ca

Calving
Alberta Agriculture and Rural Development
http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex3451

 

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Acknowledgments

Thanks to Dr. John Campbell, University of Saskatchewan Researcher and Head of the Large Animal Clinical Sciences Department for contributing his time and expertise to writing this page.

This topic was last revised on February 29, 2016 at 09:02 AM.

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