SciELO - Scientific Electronic Library Online

 
vol.25 issue1Multicriteria sustainability evaluation of thirteen extensive rearing and full-cycle family livestock farming systems of Uruguay author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Journal

Article

Related links

Share


Agrociencia Uruguay

On-line version ISSN 2730-5066

Abstract

CLARIGET, J. M. et al. Estimated beef cattle performance under intensive grazing systems in Uruguay. Agrocienc. Urug. [online]. 2021, vol.25, n.1, e107.  Epub June 01, 2021. ISSN 2730-5066.  https://doi.org/10.31285/agro.25.107.

The objective of this study was to analyze the effect of the quantity and quality of the feed offered on the performance of male beef cattle, >6 months old, on intensive grazing systems in Uruguay. Two hundred and fifty-four results from different experimental trials (nexp=68) performed between 1991 and 2020 by different research institutions in Uruguay were compiled and analyzed. The experiments included feeding studies with cultivated pastures as a single nutritional source (nexp=61), as well as supplementation studies on the same type of pastures (nexp=49). Simple, quadratic, multiple linear regressions and recursive partitions were performed to synthesize the information. Quadratic relationships between forage allowance (fa) and average daily gain (adg) were observed for the different animal categories and seasons of the year. Including other parameters such as initial body weight and supplementation with energy concentrates or silages allowed to predict the adg of animals under a wide range of feeding alternatives. Briefly, low fa levels (≤1.75 %bw) limit animal performance to maintenance gain conditions (0.2 kg/day). To achieve adequate levels of adg (0.6-0.7 kg/day), with a low to moderate fa (between 1.75 to 3.5 %bw), the nutritional value of pasture needs to reach at least level 3 of quality (>58 %odm, >13 %cp, <50 %ndf, >21 %Leg and <19 %dr). These daily gains can be exceeded if the fa is >3.5 %bw (adg in the range of 0.7 to 1.0 kg/day). The increased response in additional adg (0.4-0.5 kg/day) by the effect of supplementation with energy concentrate was achieved with low fa levels (≤2.25 %bw). The prediction of additional adg using a multiple linear regression parameter allows evaluating whether supplementation is appropriate.

Keywords : review; rearing; fattening; supplementation; cultivated pasture.

        · abstract in Spanish | Portuguese     · text in English     · English ( pdf )