Supplements of lactating meat goat does grazing grass/forb pastures

摘要

Lactating Boer does grazing grass/forb pastures were used in a 16-wk study starting 22 days after birth. Treatments were no supplementation (CO), access to a 20% crude protein supplement block (SB), and placement in a supplement pasture with mimosa ( Albizia julibrissin ) trees for 6 h 1 day/wk (1X) or twice weekly for 3 h/day (2X). Available forage dry matter in nonsupplement pastures ranged between 2423 and 3477 kg/ha. Treatment did not affect doe average daily gain (ADG), although kid ADG in the first 12 wk differed ( P <0.05) between type of supplement and frequency of supplement pasture access (121, 111, 120, and 134 g for CO, SB, 1X, and 2X, respectively). Lactating Spanish does were used in a 12-wk study starting 66 days after kidding. The same CO and SB treatments were employed, but access to supplement pastures was for 24 h 1 day/wk (1X) or 2 days for 6 h/day (2X). Forage dry matter ranged only from 750 to 1530 kg/ha; thus, 0.6 kg/day (as feed) per doe of grass hay was fed after 4 wk. Kid ADG in wk 1?￠????8 was not affected by treatment. Doe ADG was affected by supplementation ( P < 0.05) and supplement type ( P <0.09) (?￠????44, ?￠????33, ?￠????23, and ?￠????12 g for CO, SB, 1X, and 2X, respectively). In conclusion, the use of SB was not beneficial, and infrequent access to supplement pastures had relatively small effects on ADG, perhaps because forage availability and nutritive value were not severely limiting.