ChileanJAR

In 1979 and 1980 two trials were conducted at the Carillanca Exp. Sta. (INIA), Temuco, testing the factibility of obtaining bullocks with optimum slaughter weight at 20 months of age, sustained mainl v on an improved dryland pasture (Trifolium repens - T. pratense - LoIium perenne - L. muítiflorum - DacyIis gIomerata), established in 1977. In both years, 34 bullocks born in autumn were randomly assigned to two treatments afterweaning (6-7 months) in December/January. In 1979, half of the bullocks were supplemented during winter with silage at libitum, and half with silage plus 1.5 kgconcentrate/animal/day. In 1980, the differential winter supplementations were: silage plus 1.5 kg/an./day concentrate versus silage plus 2.5 kg/ an./day concentrate. Around 670 kg of live weightlha were produced without concentrate (silage at Iibitum winter supplementation coming from the same pasture). Naturally, the use of concentrate increased this level of production; and cost calculations based on data obtained in these experiments, indicate that supplementation with 1.5 kg/an./day, during 52 to 59 days, was the best economical alternative, but final weights were below the slaughter weight demanded by the market (480 kg/head).