An extended suckling system for pasture-based dairies

Agricultural productivity and sustainability are central issues for maintaining food production in the new global context. Dairy systems where animals can be produced to high welfare standards can help improve long-term herd productivity while also addressing societal concerns to ensure the future sustainability of the industry. While animal welfare benefits from extended suckling have been explored internationally in indoor dairy systems, research on pasture-based systems are lacking. The objective of this study was to examine the effect of a pasture-based extended suckling system on milk production and udder health of dairy cows. Thirty cows (Friesian x Holstein, Jersey) were used in the study. Sixteen cows were managed in a pasture-based cow-calf suckling system. The cow-calf herd was kept together for 10 weeks from calving to weaning. They grazed together during the day and were separated with fence-line contact overnight. Dams were milked once per day in the morning before being reunited with their calves. The remaining 14 cow were separated from their calves at birth and commercially managed with twice-a-day milking. Cow milk production was recorded daily until 10 weeks post-weaning. Milk somatic cell count (SCC) was collected at one-month pre-weaning and one-month post-weaning. Mastitis risk (SCC >200,000) did not differ between treatments during pre-weaning (X2(1, n=30)=0.02, p=0.9, phi=-0.13) or post-weaning periods (X2(1, n=30)=0.02, p=0.9, phi=-0.13). Suckled-cow's milk yield was lower than commercial cows during the 10-week suckling period (mean±SD 16.3±2.9 Vs 25.2±3.0 litres, p<0.001), but daily milk production in the 10-weeks post-weaning was comparable between the treatments (25.7±2.0 and 24.5±2.7 litres respectively, p=0.16). Total lactation milk yield was lower on suckled than commercial cows (6213±495 and 6730±557 litres; p=0.015). Suckling calves were consuming an estimated 9.9 L milk/day at 10 weeks of age. The extended suckling system did not increase the risk of mastitis or compromise suckled-cows productive performance after weaning. A dam rearing system with half-day contact and once-a-day milking may be a feasible option in developing alternative dairy industry practices that are aligned with public expectations for improved animal welfare.