Plan ahead to avoid calving time pitfalls
22 June 2012
Winter is no time to rest on your laurels. For southern beef producers with spring calving herds, it’s a time to make some sage decisions about grazing strategies to make the most of any extra feed while protecting herd health.
Cattle veterinarian Rod Manning urges southern producers to plan ahead to avoid the major pitfalls of good springs – dystocia in heifers, disease and mineral deficiencies leading to metabolic disturbances such as milk fever and grass tetany.
“One of the main issues is allocating feed correctly to different animal classes. Work out how much energy is required per animal per day and adjust your stocking rate accordingly,” he said.
“Ideally older cows should have a fat score of about three (not above 3.5 and not below 2.5) and heifers should have a fat score of no-more-than three otherwise you can have increased problems with dystocia (calving difficulties). Hill paddocks, where they can walk, are ideal for heifers.”
Rod emphasised the importance of keeping a herd in condition score of high twos to low threes to control body weight and an increasing plane of nutrition post calving to aid a rapid return to oestrus post-calving.
“If cattle are overweight you run more risk of calving difficulties, if cattle are underweight you can have a slow return to oestrus post calving and effect reproductive performance,” he said.
“Ideally you want a cow back in calf by day 82 post-calving to maintain the same calving period each year. At the end of the day, it’s about getting kilograms of beef out the gate – you don’t get paid for over feeding a fat cow sitting in the paddock. That extra feed would be better allocated finishing off young stock.”
BetterBeef Network (BBN) presenter and consultant with the Mackinnon Project at the University of Melbourne, John Webb Ware also highlighted a number of post-calving issues producers should be aware of.
“The low calcium levels in very lush feed can cause lazy calving syndrome where the heifers don’t push very well during labour,” he said.
“Sometimes all the producer will notice is a dead calf in the paddock. This is more common during seasons when there’s been green feed all the way through. Putting animals in paddocks with roughage or feeding out hay can help boost calcium availability and can go some way to reducing this.”
In lush seasons older cows are at increased risk of milk fever (hypocalcaemia), particularly in the first week post-calving, as well as the onset of grass tetany a little later in the gestation usually in the first 4–6 weeks post-calving.
In situations with these high risk older cows, they need access to low risk paddocks that contain more roughage and no history of recent potash application.
“If you wait until you’ve got losses, it’s almost too late to get an effective response from blocks and dry licks as it’s hard to gauge how many cows actually bother to use them and it takes time to get all the cattle interested in eating salt,” John said.
Clostridial diseases such as black leg and pulpy kidney are also a concern, particularly to weaners during good seasons that don’t have a full, effective vaccination program in place.
The risk of selenium deficiency is higher in rapidly growing young stock in lush seasons in certain areas and supplementation should be implemented to improve growth if selenium deficiency is known to be a problem in your area.
- Spring-calving cows should be body condition score three and heifers no more than three to reduce risk of calving difficulties
- Low calcium levels in lush feed increases the risk of lazy calving syndrome (uterine inertia) and milk fever in the first week post-calving
- Vaccinate, particularly young cattle, against clostridial diseases such as black leg and pulpy kidney with at least two shots four to six weeks apart before the onset of high quality feed in the spring
- Prevention is the best cure - develop a feed allocation strategy for different stock classes and get stock used to supplements such as magnesium, calcium and selenium blocks months before the critical risk periods
- Run the older, high risk grass tetany cows (third lactation or better) on the lower risk paddocks that have higher clover, more standing dry feed and no recent history of potash application