A stand at the Teagasc Moorepark Open Day outlined some results from trials investigating the impact of two different cow-calf contact-rearing systems compared to the conventional Irish calf-rearing system.
The on the vast majority of Irish dairy farms cows and calves are separated soon after birth.
This is done for a number of reasons, one being that it allows for cows to be managed with the rest of the milking herd and calves can be artificially reared by the farmer, ensuring proper colostrum intake and reduced risk of disease exposure.
Historically, early separation was thought to be a more welfare-positive experience for the pair as it prevents the formation of the maternal bond between cow and calf.
But the dairy sector has seen this view come under scrutiny by researchers and consumers.
Cow-calf contact study
The Teagasc investigations compared the conventional Irish calf-rearing system on dairy cow and calf production, health, and welfare, as well as the differences in labour between the different systems.
The study used 54 cow-calf pairs (18 pairs/system) balanced across the three systems: Full-time access (FT), part-time access (PT), and no access (control).
The FT pairs had constant access to each other. After three days of bonding indoors, cows and calves were turned out to pasture full-time.
The PT pairs meanwhile, had contact by night. Calves were kept indoors in a straw-bedded pen, their dams grazed from 8:00a.m to 3:00p.m, cows were then housed in a cubicle area adjoining the calves, to allow calf access.
The PT cows were milked once a day (OAD) in the morning, while the FT and control cows were milked twice a day (TAD).
The control pairs were separated immediately after birth, after which the calf was artificially reared and the cow joined a conventional herd of cows at grass.
All calves were weaned at eight weeks; control calves were gradually weaned by the automatic feeder, while the FT and PT calves were weaned and separated from their dams in a seven-day gradual process, where PT cows switched to TAD milking.
From birth to three weeks post-weaning, calf health and labour were evaluated twice-weekly, and calf weight and behaviour were recorded weekly.
Cow production (milk yield, milk solids, and somatic cell count (SCC)) was measured weekly for the duration of the lactation.
Cow weight and body condition score (BCS) were evaluated weekly during the first 12 weeks of lactation and at week 35 (end of lactation).
Calf results
The results from the trial have shown some interesting results with four of the 18 FT calves or 26% of the calves removed from the system due to illness.
It also found that the FT and PT calves were more likely to require antibiotic treatment than the controls.
Faecal and eye issues were more common in PT calves than both control and FT calves.
Abnormal behaviours, such as cross suckling, were seen most often in the PT group, which can indicate challenged welfare, according to Teagasc.
Calf growth was similar for FT and PT calves, while the control calves weighed less than both groups at day 28 (49.0kg vs. 55.5kg), day 56 (69.0kg vs. 82.1kg) and day 77 (81.8kg vs 90.8 kg).
Calving labour was 90% greater for the control system than the FT and PT systems, while the weekly labour input was 51% greater for the FT system than control and PT systems.
Teagasc also noted that separating cows and calves daily poses a health and safety risk to farmers.
Weaning labour was negligible for control calves (due to automatic feeder), but considerably higher for both FT and PT systems (including cow-calf separation and movement).
Consequently, according to Teagasc, the labour was highest for the FT treatment.
Production and health
The FT and PT cows had lower parlour milk yields than the controls, due to calf intake and OAD milking of the PT cows.
After weaning and separation, the FT and PT cows’ milk yields increased, but never reached the level of the controls.
on average daily parlour milk yield (kg/d) across the first 35-weeks of lactation
Cumulative 35-week milk yield for the FT and PT cows were 24% and 32% respectively, which is lower than the controls (5,034kg).
Cumulative milk solids yield was similarly affected; the controls (449kg) produced the most, followed by the FT cows (332kg) and then the PT cows (291kg).
Neither mastitis incidence or SCC differed between systems throughout the entire 35-week lactation.
After eight weeks of lactation, the PT cows (519kg) were heavier and in better BCS (3.16) than control and FT cows which were similar weight (481kg), but BCS of FT was greater than the controls (3.03 and 2.94, respectively).
The PT cows (535kg) remained heavier than the FT (502kg), but not the control cows (523kg), at the end of the lactation, and were in better condition (3.20) to the similar control and FT cows (3.02).
Is it an option?
The results from the investigation found the calves that had contact with their dam, increased growth pre-weaning, and lowered calving labour.
But these calves had increased levels of sickness, changes to their behaviour and reduced post-weaning growth.
The investigations also found that the daily labour required for the two cow-calf contact systems was higher than the control system.
Cows in the cow-calf contact systems had contact with their calves without an increase in SCC or mastitis incidences.
However, milk yield and milk solids yield were substantially reduced for FT and PT cows during and after the cow-calf contact period, leading to lower cumulative 35-week lactation yields.