CHEMICAL COMPOSITION OF LEGUMINOUS TREE FOLIAGE AND EFFECT OF POLYETHYLENE GLYCOL ON GAS PRODUCTION AND IN VITRO DIGESTION PARAMETERS

The objective was to determine the chemical composition, digestibility and in vitro digestion parameters in ten legume tree foliage using the in vitro gas-production method with and without polyethylene glycol (PEG). The foliages with higher protein content (P<0.001) (167.1 to 180.3 g/kg DM) were A. cochliacantha, L. esculenta, E. cyclocarpum and A. farnesiana; from the total phenols (P<0.001) (365.9 to 680.6 g/kg DM) L. divaricata, H. brasiletto and C. coriaria and condensed tannins (P<0.001) (35.4 to 88.0 g/kg DM) E. cyclocarpum, A. farnesiana, P. dulce, P. acatlense and G. sepium. The in vitro dry matter digestibility was different (P<0.001) among the foliages. The in vitro gas production (IVGP), in vitro organic matter digestibility, metabolizable energy (ME), gas yield (GY24h), short chain fatty acids (SCFA) and microbial mass production (PMM), were different (P<0.0001) among the foliage as a result of the species. The use of PEG increased (P<0.0001) IVGP, ME, GY24h and SCFA in H brasiletto, C. coriaria, L. esculenta and A. cochliacantha, but affect (P<0.0001) the partition factor and the PMM. The nutritional composition and fermentation parameters in vitro between foliages differ by effect of tree and use of PEG. It is concluded that chemical composition in the foliages affect the digestibility and fermentation parameters and use of PEG increased fermentation parameters in the foliages high in secondary compounds

Simulating Inbred-Maize Yields with CERES-IM

CERES-Maize, which was designed for simulation of hybrid maize (Zea mays L.), cannot be applied directly to seed-producing inbred maize because of specific field operations and physiological traits of inbred maize plants. We developed CERES-IM, a modified version of CERES-Maize 3.0 that accommodates these inbred-specific operations and traits, using a set of phenological measurements conducted in Nebraska (NE), and further tested this model with a set of field data from Michigan (MI). Detasseling (i.e., removal of the tassels from the female plants) was conducted prior to silking. Male rows were removed approximately 10 d following 75% silking. The thermal time from emergence to the end of the juvenile phase (P1) and the potential number of kernels per plant (G2) were assessed from field data, and were the only two coefficients allowed to vary according to the inbred line. Rate of leaf appearance of the inbreds was accurately simulated using a measured phyllochron interval of 54 degree-days (°Cd). Simulation of detasseling and male-row removal improved grain yield simulation for inbreds. For a set of 35 inbred-site-year simulations, the model simulated grain yield with satisfactory accuracy (RMSE 5 429 kg ha-1). Average grain yields were 4556 and 4721 kg ha-1 for the measured and simulated values, respectively. CERES- IM simulations suggest that the effect of male-row removal on grain yield is extremely sensitive to the precise date at which this operation is conducted. This would explain the inconsistent effect of male-row removal on female grain yields reported in the literature