Effects of restricted periods of feed access on feed intake, digestion, behaviour, heat energy, and performance of Alpine goats

Abstract

Fifty Alpine goats at 125 +/- 3.0 days-in-milk were given access in Calan gate feeders to a 40% forage diet for 12 wk continuously (Control), during daytime (Day) or night (Night), or for 2 or 4h/day after milking in the morning and afternoon (2Hour and 4Hour, respectively), resulting in few significant effects. In a second 12-wk experiment, average daily gain (ADG) by 40 Alpines at 14 +/- 0.7 days-in-milk (73, 39, 11, 24, and 21g) was greater for Control than for the average of other treatments, milk yield was similar among treatments, milk fat was lower (P=.089) for Control (3.41%, 3.88%, 4.21%, 3.70%, and 3.49%), and milk energy was not affected (8.20, 7.36, 9.53, 8.56, and 6.91MJ/day for Control, 2Hour, 4Hour, Day, and Night, respectively). Metabolizable energy intake (31.25, 22.69, 25.92, 26.69, and 23.46MJ/day) and heat energy (17.51, 13.34, 14.09, 15.54, and 15.25MJ/day) were greater and milk energy relative to ME intake was lower for Control (26.0%, 31.9%, 37.6%, 31.4%, and 30.0% for Control, 2Hour, 4Hour, Day, and Night, respectively). In conclusion, continuous diet access of dairy goats in early to mid-lactation can affect partitioning of nutrients between milk synthesis and tissue accretion differently than some restricted feeder access treatments.