Bite weight, bite rate, and bite dimensions (depth, area, and volume) were compared among six sheep and six goats individually confined indoors in metabolism crates, grazing monoculture turves (41 x 27 cm) of five grasses and four legumes at the vegetative and reproductive stages of growth. Each sampling period was restricted to 12-17 bites. Leguminous swards resulted in a greater overall fresh bite weight (1253 versus 994 mg fresh matter (FM), SE = 41, P < 0.001) despite a shallower bite depth (6.1 versus 22.1 cm, SE = 0.6, P < 0.001) compared with gramineous swards. Animals also obtained a faster bite rate on legumes than on grasses (28 versus 24 bites/min, SE = 0.8, P < 0.001). The taller reproductive swards led to greater bite weight (1297 versus 920 mg FM, SE = 37, P < 0.001), but lower bite rate than vegetative swards (18 versus 33 bites/min, SE = 1; P < 0.001). Consequently, short-term intake rate did not change significantly with increased maturity (6.1 versus 5.7 g DM/min, SE = 0.2). Mean bite weight was greater for sheep than goats on both vegetative (1282 versus 914 mg FM, SE = 92, P < 0.05) and reproductive legume swards (1514 versus 1301 mg FM, SE = 92, P < 0.1), and was similar between the two species on vegetative grass (786 versus 771 mg FM, SE = 82) swards. However, goats had substantially heavier bites on reproductive grass (1410 versus 1008 mg FM, SE = 82, P < 0.01) swards. When swards changed from the vegetative to reproductive growth stage, intake rate of sheep decreased (from 7.0 to 5.8 g DM/min, SE = 0.2, P < 0.05) because an increase in bite weight was countered by a fall in biting rate, whereas intake rate of goats tended to increase slightly (from 5.1 to 5.7 g DM/min, SE = 0.2) as a result of an increase in bite weight and a relatively small fall in bite rate compared with sheep. Sheep showed a greater tendency on vegetative swards to penetrate into the canopy to take deep bites whereas, except on reproductive grasses, goats were shallow grazers from the top downwards. However, when tall, stemmy reproductive grasses were grazed, sheep appeared to penetrate into the canopies to graze the leafy components, and rejected seedhead and stalk components within the grazed area, whereas goats were less selective and prehended mouthfuls of herbage which included rigid stems occurring within the defined grazed area.
