The objective of this trial was to compare the effect of different feeding strategies with or without ionophore (monensin) supplementation on performance of dairy heifers. Twenty Brown-Swiss heifers averaging 200 kg of body weight and five months of age were used in a completely randomized design with a 2 x 2 factorial arrangement of treatments. Treatments were: two feeding regimes (conventional vs. compensatory growth) with (200 mg/animal/day) or without monensin supplementation. Animals in the conventional feeding regime were fed ad […]

A static and deterministic model, synthesizing published experimental information, was used to simulate the productivity and biological efficiency of beef cattle life-cycle production systems in Rio Grande do Sul, differing in heifers’ age at first calving (IP, months) and steer age at slaughter (IA, months): “Traditional System” (ST), IP48, IA54; “Improved System” (SM), IP36, with two slaughter ages, IA36 (SM-I) and IA24 (SM-II); “One Year System” (SU), IP24, with three slaughter ages, IA36 (SU-I), IA24 (SU-II) and IA18 (SU-III). For […]

A simulation model was used to evaluate productivity and efficiency of beef cow-calf systems in Rio Grande do Sul State with different heifers first calving age (CA, years) and calving rates (CR): “Traditional System” (TS) CA=4; “Improved System (IS)” CA=3; “One Year System (OYS)” CA=2. In each system it was studied the effect of CR varying from 50 to 90%. A statistic deterministic model was used. The effect of reducing CA on productivity and efficiency was dependent of CR. IS […]