Keeping focused on a successful calving season

A successful calving period is crucial for subsequent fertility and output of the herd. Farmers only start to consider preparing for calving when the first cow shows the initial signs of labour, but preparation for a successful calving period starts many months before this.

Pre-calving minerals

Pre-calving minerals should be fed for a six- to eight-week period prior to calving. Mineral deficiencies can result in problems such as weak calves at birth, retained placenta (cleanings), milk fever, or subsequent poor fertility or delayed oestrus.

After the wet summer, mineral test results of silage analysis are below average.

To create a profile of the mineral status of a herd, some farmers will take blood samples from cows and have them analysed. This can give a snapshot of the mineral status of the herd and can highlight specific mineral deficiencies such as copper, selenium, iodine, cobalt, etc.

Ensure that pre-calving minerals are not fed to cows post-partum as the calcium content will not be sufficient to meet dietary needs of a cow in milk and could increase the risk of milk fever.

Calving facilities

Having adequate handling facilities for calving is crucial. A good rule of thumb for a herd where there is a tight calving pattern is to have at least one calving pen for every 15 cows. Having at least one calving pen with a head restraint and calving gate can help to improve safety and reduce the risk of injury for both the calf and the cow.

Most calving gates will allow for certain sections to be opened which can result in the cow being restrained while a caesarean section is completed or to allow the calf to suckle the cow while she is restrained.

Safety at calving is crucial. Cows can become extremely agitated around calving time.

Cleanliness

Cleanliness is critical to attaining subsequent fertility.

Harmful pathogens and bacteria can enter the birth canal when cows are being handled at calving. Farmers should ensure that they have protective gloves and lubricant on hand in advance of calving. Cows should clean naturally within 24 hours of birth.

If a cow has a retained placenta after that, then consult your vet. Retained cleanings can result in infections that will reduce fertility substantially.

Where a calving jack is being used, ensure that both the jack and the ropes have been cleaned thoroughly and disinfected prior to use. Continue this practice between calvings.

Calving pens should be cleaned out after each calving and disinfected. Once dry, they should be bedded with approximately six inches of straw to ensure a clean, dry bed for the cow and calf.

Moving cows to calving pens

Cows that are showing signs of calving should be moved into calving pens approximately 12 hours before the onset of labour to reduce stress and allow her to settle in the pen. Cows often get agitated when labour commences and moving her to a calving pen at that stage can slow the natural progression of the calf along the birth canal.

Once she has settled in the pen, she should be observed at least once per hour to monitor her progression.

When the water bag is showing, the cow/heifer should be monitored more regularly. If calving is not progressing after one to two hours, the cow should be handled using gloves to ensure that the cow is sufficiently dilated and the calf is in the correct position.

Know your limitations

If the calf is too big, it is advisable to seek veterinary assistance before the calf becomes breeched as this will significantly reduce the calf’s chances of survival.

After calving

Once the calf has been taken from the cow, the first port of call should be to ensure the calf is breathing correctly.

Calves that sound ‘‘croaky’’ when breathing may have fluid in their lungs or airways. In such a case, the calf should be hung upside down by its rear legs for a minute or two to allow the fluid to drain.

Where there are no signs of fluid on the lungs, do not attempt to hang the calf over a gate or upside down. The naval of the calf is the next area that needs attention. It should be disinfected using iodine to reduce the risk of naval/joint-ill.

Colostrum

The calf’s ability to absorb antibodies from colostrum reduces from two hours after birth. For this reason, it is advisable to ensure that the calf receives two litres of colostrum within the first two hours.

This can be done in most cases by ensuring the calf suckles the cow. If the calf is too weak, the cow should be milked and the calf fed via a nipple feeder or a stomach tube.

In some cases, cows or more often heifers will calve with insufficient colostrum. It will be advantageous to have frozen colostrum on farm. Colostrum should be taken from milky cows on the farm and frozen to ensure a supply exists on the farm.

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