Overnight access to pasture does not reduce milk production or feed intake in dairy cattle

• Published in: Livestock science 2010-04, Vol.129 (1), p.104-110
• Main Authors: Chapinal, N., Goldhawk, C., de Passillé, A.M., von Keyserlingk, M.A.G., Weary, D.M., Rushen, J.
• Format: Article
• Language: English
• Subjects: animal age; animal behavior; cow feeding; dairy cows; diurnal variation; dry matter intake; feed intake; feed rations; feeding behavior; free stalls; hooves; Lameness; Lying behavior; Milk production; milk yield; parity (reproduction); parturition; Pasture; pastures
• ISSN: 1871-1413; 1878-0490
• DOI: 10.1016/j.livsci.2010.01.011

Zero-grazing has been related to a higher incidence of lameness and other maladies, but continuous access to pasture can compromise dry matter intake (DMI) and milk production. The objective of the present study was to assess the effect of housing cows overnight on pasture on productivity and lameness. Fifty Holstein cows were balanced for calving date, bodyweight, parity and initial gait score and semi-randomly assigned to either continuous housing in a free-stall barn (CONTROL) or housing in a free-stall barn from the morning milking to 2000 h and on pasture overnight (PASTURE). Treatments were applied from week − 4 to week + 8 relative to calving. Gait was scored every 4 weeks beginning 4 weeks before parturition to week 24 after calving whereas lying behavior was monitored continuously throughout the experiment. For 30 cows, DMI of the TMR was monitored continuously throughout the experiment. Gait score (1 = not lame, 5 = severely lame) did not differ between treatments ( P = 0.62) but primiparous cows had better gait compared to multiparous cows (2.0 ± 0.1 vs. 2.5 ± 0.1, P < 0.001). Overall gait scores increased from 4 weeks before calving to 4 weeks after calving (increase = 0.55 ± 0.07, P < 0.001), but did not change thereafter. Overnight pasture increased hoof net growth rate (2.2 ± 0.5 vs. 1.0 ± 0.5 mm/month, P = 0.03). There were no differences ( P > 0.10) between treatments in DMI from TMR with cows on average consuming 15.5 ± 1.0 kg/day in the 8 weeks after calving. Most interestingly, milk production did not differ between the treatment groups with cows producing an average of 38.2 ± 1.1 kg/day over the 12 weeks after calving. Daily lying time (578 ± 18 min/day) also did not differ between treatment groups. Parturition and parity are critical risk factors for lameness. Housing on pasture overnight is a practical way of increasing access to pasture without reducing TMR intake or milk production or increasing the risk of lameness.