COW-CALF contact in dairy herds was the subject of a recent Teagasc study at their Moorepark centre in Cork – a project carried out in the context of ‘societal scrutiny’ as regards the practice of separating calves from their mothers at birth.

A summary of the study published in the latest edition of Teagasc TResearch magazine pointed to a public preference for more natural husbandry systems, allowing animals to express natural behaviours like suckling and socialisation.

The study – carried out by Emer Kennedy, Sarah McPherson and Alison Sinnott, all from Teagasc Moorepark – looked at three systems of calf rearing in dairy herds.

Those were: 1, Full-time cow-calf contact [FT] with only two hours of separation for milking; 2, Part-time contact indoors [PT]; and 3, Conventional practice [Conv] where dams and calves were separated at birth.

Emer Kennedy pointed out that morbidity requiring antibiotic treatment was highest in the full-time contact calves with illness complications, leading to four out of 18 FT calves being removed from the experiment.

“This was attributed to environmental exposure to changeable weather experienced by the calves outdoors at young ages.

“The risks associated with turning young calves to pasture in late winter/early spring – especially cold stress which diverts energy towards heat production – are relevant concerns in Irish pasture-based systems.

“In contrast, no calves were removed due to illness complications by the conventional or PT [part-time contact indoors] calves,” Teagasc Dairy Enterprise Leader at Moorepark, Emer Kennedy stated in the report.

However, in terms of calf growth and performance, both the FT and PT calves achieved higher average daily weight gains than the calves separated at birth, reflecting unrestricted milk intake through suckling.

“At 56 days, contact calves averaged 82kgs compared with 69kgs for CONV [separated at birth] calves. However, at weaning, the contact calves were weaned from milk and separated from their mothers, which caused a sharp post-weaning decline in growth,” Emer Kennedy stated.

Between the 57-days-old and 70-days of age, the CONV calves continued to grow better, ‘likely because of the stress from changes in diet, separation and housing’, the report points out.

As might be expected, the study showed that CONV cows had higher milk yields than the FT and PT cows due to the unrestricted suckling of the contact calves. Cows in all three systems, showed good clinical health, with no difference in somatic cell scores.

In terms of labour demands, the study showed that conventional calves required significantly more labour immediately after calving in terms of colostrum collection and feeding. However, during later daily routines the FT calves required the most labour in terms of separating them from their mothers for milking, while also raising animal handling/safety issues.

“While CCC [cow calf contact] can be incorporated into pasture based systems, the associated milk production losses may limit its practical adoption.

“A modified PT [part-time contact], where calves are kept indoors with night-time cow-calf contact, and cows graze by day while being milked twice daily, may offer a better balance between animal welfare and productivity.

“Further research is needed to understand the mechanism between milk yield reductions and to develop strategies to mitigate these effects,” Emer Kennedy concluded.

■ Sarah McPherson is a Sustainability Technologist and Alison Sinnott is a PhD Walsh Scholar – both at Moorepark.