Therefore, it’s vital that cows are properly managed during this time because diseases can have far-reaching effects on their reproductive performance, production, and longevity.

Trigger points

It’s important to recognise what a normal level of disease is around calving, so you can identify when to intervene. Look out for any of these red flags below.

• More than five percent of the herd require hands-on assistance to calve.
• More than two percent of the herd have retained foetal membranes 24 hours after calving.
• More than five percent of cows become lame in a month.
• More than five percent of the herd have clinical mastitis in the month after calving.
• More than five percent of the herd suffer any other health problems at calving or during early lactation.

For more information see Cow health for reproduction.

Physiological changes

The calving process causes big changes in the body. A cow’s immune function is compromised, and teat canals open during a time when unfavourable ground conditions are common. These risk factors can lead to an increase in mastitis rates. Many of the clinical mastitis cases seen in the first two weeks after calving, when the cow comes into milk, are actually contracted in the late dry period.

To make calving easier hormones relax the cow’s pelvic tendons and ligaments.  However, the hormones affect all the tendons and ligaments in the body including the foot. This creates a less stable foot that’s more prone to damage. In addition, body condition loss after calving affects all areas of fat in the body including the fat cushion in the foot, reducing the foot’s ability to absorb shock. These two factors make the risk of getting lame much higher. Poor stockmanship and management around calving can result in increased lameness (more than five percent of the herd per month) around mating and further into the season.

Tips for managing calving cows

Despite the challenges a cow faces around calving, there are strategies you can employ to protect her through this period.

Avoid Over-feeding Springers

Although it was recommended for years, springer cows should not be over-fed. Determine how much they should eat by estimating liveweight at calving:

• 450kg cows should consume 90 megajoules of metabolisable energy per day (MJ ME/day)
• 500kg cows 100MJ ME/day, and 550kg cows 110MJ ME/day.

Allow for wastage

A cow immediately pre-calving is 'full of calf' and it takes her longer to consume what she is offered. It is best to run these animals separately if possible.

Check Springers Regularly

Check your springer cows at least twice a day and intervene early if you see any calving issues.

Magnesium

Magnesium for springers is important to prevent milk fever at calving and for lactating cows to prevent grass staggers after calving. Aim to supplement cows and heifers for two to four weeks before calving and for up to four months post-calving. For details, see DairyNZ Farmfact 3-1.

Colostrum Cows need Calcium

Colostrum cows should be offered calcium, usually in the form of limeflour at 150g/cow/day (may need to be doubled if dusting). Springers should not be offered calcium.

Trace Elements support immune function

Supplement cows with minerals such as selenium, copper and iodine as these are critical for general immune function around calving and reproduction.

Patience Prevents Lameness

As cows have ‘fragile’ feet at this time, be patient with them to prevent lameness. It’s crucial that you don’t rush stock on the races and that you never see ‘heads up’ in the yard.

Hygiene Prevents Infection

Practise good hygiene during milking, to help prevent infection from entering cows’ udder. Wear gloves during milking, fix up, or reduce use of muddy areas in the raceways where possible, and avoid putting calving cows in soggy paddocks.

Teat Spray to keep the Bugs Away

To control rates of clinical mastitis in early lactation, use an approved teat spray that keep teats soft and disinfected.

Water Makes Milk

Ensure cows have access to clean drinking water at all times.

To set your team up for success over calving, see Setting up for calving.