As dairy cows transition from dry to milking animals, they undergo physiological changes that leave them susceptible to many health conditions. It’s vital that cows are properly managed during this time because diseases can have far-reaching effects on their reproductive performance, production, and survival in the herd.
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.
Learn more about these points by visiting dairynz.co.nz/incalf.
During calving, a cow’s immune function is compromised, its teat canals open and 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.
Another physiological change at calving is that the cow’s pelvic tendons and ligaments will relax so it can calve easily. This affects all the tendons and ligaments in the cow’s body and can lead to a less stable foot that’s more prone to damage.
Also, a cow’s body condition loss after calving can reduce its foot’s ability to absorb shock. These two factors make a dairy cow’s foot more susceptible to lameness. Poor stockmanship and management at this time 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.
- Although it was recommended for years, springer cows should not be over-fed. We can determine how much they should eat by estimating their 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. Remember to 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 your cows at least twice a day around calving and intervene early if you see any calving issues.
- 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 postcalving. For details, see DairyNZ Farmfact 3-1.
- 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.
- Supplement cows with minerals such as selenium, copper and iodine as these are critical for general immune function around calving and reproduction.
- 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.
- Practise good hygiene during milking, as this will help prevent infection from entering cows’ glands. Wear gloves when you’re milking cows, pay attention to muddy areas in the raceways, and avoid putting calving cows in soggy paddocks.
- To control rates of clinical mastitis in early lactation, use an approved teat spray that keep teats soft and disinfected.
- Ensure cows have access to clean drinking water at all times.
- Cows are more vulnerable to diseases at calving.
- Monitor levels of disease and issues at calving, and act early if you see any issues.
- Caring for the transition cow sets her up for a great season.
DairyNZ has launched five new videos to help dairy farmers and their staff learn about looking after fragile cows and delicate new calves.
Use the videos to train new staff, or as a refresher during your team meetings. Topics covered include:
- calving cows and collecting calves – how to check springers, and pick up and record calves
- transporting calves from paddock to shed
- setting up and maintaining the calf shed
- how to check a calf is fit for transport
- keeping yourself safe and healthy during calving.
Also, check out DairyNZ’s ‘Caring for calves’ guide, designed to help managers create calf care procedures tailored to an individual farm. Order your copy now at dairynz.co.nz/calves.
This article was originally published in Inside Dairy June 2017