Rehydration and ensilage of corn grains with different grain sizes and inclusion in the diet for beef cattle

Abstract

The aim of this study was to evaluate the strategies of supply of rehydrated corn grain silage with different processes in the performance and metabolism of Nellore cattle. Three experiments will be performed. In the first experiment, the in situ degradability, fermentation profile and aerobic stability of the silage processed in a hammer mill with different particle sizes were evaluated. The treatments were represented by the sieves: 1 ) 3 mm sieve (P3); 2) 5 mm sieve (P5); 3) 8 mm sieve (P8); 4) 12 mm sieve (P12); 5) 15 mm sieve (P15). Five replicates will be made, and the silages will be stored for 15, 30, 60, 120 and 240 days. The experiment will consist of a completely randomized design with measures repeated in time. For the choice of the treatments of Experiment 2, the treatments of Experiment 1 will be divided into two groups: coarse particles (P15, P12 and P8) and fine particles (P5 and P3). A treatment of each group that achieves greater degradability in situ at 60 days of silage will be selected, and so, in Experiment 2, ruminal parameters (pH, N-NH3 and short chain fatty acids), microbial protein and total starch digestibility of eight cannulated animals in the rumen, which will consume diets with concentrate composed exclusively of rehydrated grain silage or the silage associated with dry corn, forming four treatments: 1) small particle silage chosen from experiment 1 as 100% of the maize used P100); 2) small particle silage chosen from experiment 1 as 50% of maize used (P50); 3) large particle silage chosen from experiment 1 as 100% of maize used (G100); 4) large particle silage chosen from experiment 1 as 50% of the corn used (G50). The experiment will be analyzed through two 4x4 Latin squares. In the third experiment, the consumption and performance of 128 confined Nellore cattle consuming the same diet of experiment 2 will be evaluated. Analyzes related to slaughter and meat quality as well as evaluation of blood D-lactate, feces score, starch digestibility and evaluation of ruminal papillae will be performed. The experiment will be a randomized block design. Statistical analysis will be done using SAS 9.2 software (SAS, 2008). (AU)