Abstract

Three pasture types (Wana cocksfoot, Roa tall fescue, and Ruanui perennial ryegrass/Huia white clover) were ranked on short term rates of intake, measured using boxed turfs indoors and short grazing periods at pasture. In the first experiment 12 turfs of each pasture type were offered to each of 3 heifers indoors in a latin square design. In a second experiment at pasture, 3 heifers grazed each pasture type for a day again in a latin square design. Intake rate in the first experiment was estimated from pre- and post- grazing weight of turfs with correction for respiratory and evaporative weight loss. At pasture in the second experiment intake rate was the difference between pre and post grazing weight of the heifers corrected for insensible weight loss. Rankings of grass cultivars indoors and outdoors were similar even though animal and sward maturity differed. Intake rate of ryegrass/white clover was lower both indoors and outdoors than for Roa tall fescue or Wana cocksfoot (indoors 103 vs 131 and 148, and outdoors 65 vs 161 and 102 mgDM/kg/W/min). Bite weight (2.1 vs 2.7 and 2.8 mgDM/kgW) and bite depth (5.9 vs 6.4 and 6.7 cm) for ryegrass/white clover indoors were lower than for tall fescue or cocksfoot. Allocation/intake relationships derived for ryegrass/white clover may not be applicable to other pasture species.

DJ, Garrick

Proceedings of the New Zealand Society of Animal Production, Volume 51, , 411-416, 1991