Finishing of British steers under grazing conditions, supplemented with high-tannin sorghum grain

Abstract

The objective of this experiment was to finish British steers with 18 years of age and 380 kg of LW, with the lowest possible production cost. The impact of high-tannin sorghum grain on meat production was also evaluated. The research was conducted at the experimental field Cesáreo Naredo of the INTA Bordenave, in Buenos Aires, Argentina, during two stages; in the first one (254 days) the treatments were: T1) 20 pure red Aberdeen Angus (AAr) calves, of 183,4 kg LW and T2) 18 bull calves AAr x Shorthorn (AAr x Sh) of 183,6 kg LW; and in the second one (247 days), 45 calves AAr x Sh of 218,4 kg LW, in just one treatment. A mixed pasture based on alfalfa and supplements of dried and ground sorghum grain at a rate of 1 % of the LW were used. The grain intake was 2,97 and 3,38 kg grain head-1 day-1, while the daily weight gain was 0,891 and 0,969 kg-1 head-1 day-1 for the first and the second stage, respectively. Meat production was 452,12 and 567,24 kg ha-1, and the production cost was 0,57 and 0,54 USD per produced kilogram, respectively. In the first stage the quadratic model showed a better adjustment with high R2 (0,99) and lower mean squared error (MSE 33,26). In the second stage the linear model showed the best adjustment with high R2 (0,99) and lower MSE (44,78). The productive and economic values were very adequate. No negative effect of tannins was observed in the evaluated indicators.