How to manage difficult calvings in beef cattle
© Nigel Baker/Adobe Stock A growing evidence base can be used by farmers to pre-empt difficulties in the calving shed and stay a step ahead of issues.
Once a hygienic and safe environment is provided for man and beast through provisions such as ample clean bedding, calving gates and lighting, there are five areas to evaluate for easy calving.
This is according to Rachel Bragg, farm animal clinician at the University of Edinburgh’s Royal (Dick) School of Veterinary Studies.
Dr Bragg draws on experience from UK and New Zealand farms as well as a 2020 study she was lead author on, Risk factor analysis for beef calves requiring assisted vaginal delivery in Great Britain.
Below, she discusses how to manage difficult calvings.
See also: How a Yorkshire suckler herd is achieving 96% calves weaned
1. Thin and fat cows
One of the biggest take-home messages from the study is that a thin cow can be as bad as a fat cow when it comes to calving difficulties.
Thin cows may not have the energy to push their calf out, while fat cows may deposit fat in the birth canal.
- Strive to have cows in target body condition score (BCS) a month before calving starts. This is 2.5 for spring calvers and 3 for first and second-time calvers and autumn calvers. Restricted feeding in the final month can do more harm than good.
- Avoid big changes in BCS through the year – vary by 0.5-1 BCS score at most.
- A thin cow (BCS 2) rebreeds a cycle later and has a calving interval of 382 days – 18 days longer than an ideal (2.5-3 BCS) cow.
- Try to group thin cows with heifers for closer supervision and additional nutritional support.
When to intervene
A natural calving can take two hours. General advice is to intervene:
- After 30 minutes of non-progressive labour (active pushing) after the vaginal mucus is seen
- Or two hours after the water bag has been seen and no progression or pushing has started.
2. Sire selection
A balanced view of maternal and terminal traits, functionality and type can help find a bull, with each farm having its own unique requirements.
- When selecting a terminal sire, many farms look for calving ease (direct) alongside low gestation length and good growth figures.
- Looking at maternal calving ease (indirect) along with gestation length can help avoid bulls that will breed replacement females that are excessively narrow.
3. Twins and bull calves
Some farms are using skilled scanning technicians to identify twin-bearing cows and bull calves, as both increase risk of dystocia, although early scanning is required.
- Recommended timings for identifying twins is at 40-70 days after service.
- Identifying bull calves can be done within 50-60 days of breeding.
4. Big calves
Calf weight has a “sweet spot” where calves are developed and strong, but not so big that they cause protracted calvings.
Calf size is also relative to cow size and pelvic dimensions.
Breedplan uses 41kg as a mid-point, but in this study, 49kg was the average weight of a newborn calf, with a range of 25-96kg (excluding dead calves and caesareans), and cow weights were 528-860kg.
- Calf weight to adult weight ratio (CWAWR) is a relatively new but potentially useful measure, taken at calving
- Farmers recording cow and calf weights could calculate this to figure out their optimal calf size by cross-referencing it with calving records and any difficulties.
- The results of the study suggested a CWAWR of 8% (for example, a 49kg calf and a 612kg cow at calving) or below would reduce dystocia risk.
5. Heifers
Statistically, a heifer is far more likely to have trouble calving on her own. She may need help both calving and suckling her calf.
- Run the heifers as a group until they have weaned their second calf, if possible, and least until their first calving.
- A heifer needs to get to 423kg at mating to hit the recommended 65% of her mature weight of 650kg. A heifer will probably be rearing her third calf before she is close to mature weight.
- After calving, your first calver needs to be 85% of her mature weight, which is 553kg.
- Many farms calve heifers first so focus can be put on them.
Keep records to inform herd management decisions
- Calving ease: Log this against the dam and sire on herd records/software to inform culling and breeding decisions. A universal scale across the industry is needed, although some use a zero to five scale 0 = unassisted and 5 = caesarean.
- Calving date: Herd management software can be used to tighten up your calving pattern. Late calvers are typically late again.
- Feeding issues: Was there any problem with the calf feeding from the cow and why? (dystocia/calf or cow behaviour)
- Twins: There is a genetic component to twinning, so take note and adjust your plans depending on your system.
- Aggression: Is the cow maternal, protective, aggressive, or dangerous?
Keep them alive
Post-mortem vet Ben Strugnell, of Farm Post Mortems, County Durham, says the most frequent reasons for dead newborn calves are:
- Insufficient colostrum leading to scour and septicaemia – up to 15% of calves may not receive any maternal transfer of antibodies and a further 22% could have only a partial transfer, a study found.
- Navel infections – spreading to the abdominal cavity of the calf.
- Oxygen – a “dopey” calf may have been trapped in the birth canal and starved of oxygen, making it acidotic (too much acid in the blood). These calves are often slow to stand and suckle, which on dirty bedding quickly becomes a problem.
Actions to take
Colostrum
- Quantity: 10% of a calf’s bodyweight needs to be fed – for example, four litres for a 40kg calf. Split this into two feeds to avoid milk from the abomasum overflowing into the rumen, which is not designed for milk digestion. Cow colostrum can be refrigerated for seven days or frozen for six months. If replacer is to be used then products should deliver more than 100g of immunoglobulins a dose.
- Quality: A Brix refractometer or colostrometer can be used to assess cow colostrum for levels of immunoglobulins, although harvesting colostrum from suckler cows is challenging. A reading of 22% or above on a Brix refractometer indicates good quality. Forage analysis and ration adjustments can be made to help the cow produce good colostrum.
- Quickly: A colostrum feed is needed within six hours of birth. The first drink stimulates the guts to start closing to large molecules like immunoglobulins, so it’s always worth trying to ensure the first feed is of dam’s colostrum.
Navels
- Spray or dip the naval as quickly as possible after the calf is born and check their nostrils are clean and unblocked.
- A 10% iodine solution remains popular but may be 30-100% more expensive this year due to supply issues. Ask your vet/registered animal medicines adviser about the drying times of alternatives.
Oxygen
- To help a newborn calf breathe more easily, put it in “sternal recumbency” with its front legs tucked underneath its body to prop it up and the head out straight.
- This allows both lungs to inflate fully. Avoid swinging calves or hanging them over gates as this can create pressure on the lungs.