Abstract

In wet spring conditions, cows are often stood off pasture reducing their pasture intake. However, studies indicate that despite reduced grazing access, pasture intake and milk production can be maintained. This study restricted daily grazing access to eight hours in early lactation to determine the effect on pasture intake, milk production, and urination distribution. Forty-eight Holstein-Friesian cows were allocated to three duplicated treatments. Cows had access to pasture for either four hours after each milking (2x4), eight hours between milkings (1x8), or for 24 hours, excluding milking times (Control). When not grazing, the 2x4 and 1x8 treatments were stood off on a bark pad. The 1x8 cows ate less pasture (10.9 kgDM/cow/d; P <0.05) than the Control (13.6 kgDM/cow/d), but the 2x4 intake (13.0 kgDM/cow/d; P = 0.46) was not different to the Control. The 1x8 and 2x4 cows produced less milk (20.2 and 21.5 kg milk/cow/d respectively; P <0.05), relative to the Control (23.3 kg milk/cow/d). Urinations on pasture and races were reduced (P <0.05) from 90% (Control) to 62% (1x8) and 65% (2x4) of total urinations. Eight-hours grazing per day should be offered as two four-hour periods to maintain cow pasture intakes, although milk yields are reduced. Corresponding changes in urination distribution may have environmental benefits.

KLM, McLeod, CEF Clark, CB Glassey, P Gregorini, DA Costall, K Betteridge, and JG Jago

Proceedings of the New Zealand Society of Animal Production, Volume 69, Christchurch, 15-19, 2009