This paper discusses the potential use of feed blocks as supplements for grazing goats under a harsh arid zone of northern Mexico. The study was carried out during fall and winter. A flock of 64 goats was randomly allotted into two groups (equal number of animals and categories of goats) both groups were fed a total mixed ration containing 50% ground corn stover, 40% spineless cladodes of Opuntia spp. and 10% corn grain. Additionally, at night, one group had access to a urea-prickly pear-molasses block supplementation, whereas the other group was not supplemented (Control). The block supplementation increased (PB0.05) litter size (1.3 vs. 1.5), litter weight (4.8 vs. 5.2) and daily milk yield in twin bearing does. Results indicate that providing a block supplementation could ameliorate the depressing effect of scarce forage, with a marked improvement in litter size and weight, as well as an increased milk yield in those goats raising twins.