Revista Brasileira de Zootecnia
On-line version ISSN 1806-9290
AGUINAGA, Angelo Antonio Queirolo et al. Production of beef steers grazing oat plus annual ryegrass pasture managed at different heights. R. Bras. Zootec. [online]. 2006, vol.35, n.4, suppl., pp. 1765-1773. ISSN 1806-9290. http://dx.doi.org/10.1590/S1516-35982006000600026.
The objective of this trial was to evaluate production and carcass characteristics of young steers grazing a mixture of black oat and Italian ryegrass pasture. Treatments were four different pasture heights (10, 20, 30, and 40 cm) that were obtained with different stocking rates. Fifty-five beef steers averaging 210 kg of body weight and 10 months of age at the beginning of the trial were used in a randomized complete block design with three replicates. The observed increase in the average daily weight gain (ADG) was associated with the quality and/or amount of available forage because herbage allowance increased from 6 to 51 kg DM/100 kg BW when pasture height was enhanced from 10 to 40 cm. Therefore, the ADG was 0.73 and 1.14 kg/animal/day for the treatments with the lowest and highest ADG, which corresponds to 10 and 30 cm pasture height. Considering the low ADG, the greatest gain/area observed on the 10 cm treatment may be explained by a greater stocking rate; both ADG and stocking rate decreased linearly by increasing pasture height. Body weight and hot carcass weight increased until 30 cm of pasture height but decreased at 40 cm because of poorer pasture quality. There was no difference on carcass yield, which averaged 51% among treatments. The body condition score and carcass fat thickness followed the ADG in this trial.
Keywords : average daily gain; forage allowance; gain per area; pasture height; stocking rate.