Abstract #W150

# W150
Additive effect and in vitro gas production of diets based on silage of poultry litter, pig manure, urea with cane molasses, and bakery by-product.
D. Trujillo Gutiérrez1, I. A. Domínguez Vara1, J. L. Bórquez Gastelum1, S. S. Gonzalez Muñoz*2, J. M. Pinos Rodríguez3, J. E. Ramírez Bribiesca2, 1Facultad de Medicina Veterinaria y Zootecnia, Nutrición de Rumiantes, Universidad Autónoma del Estado de México, 2IREGEP-Ganadería, Campus Montecillo, Colegio de Postgraduados, México, 3Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Veracruz, México.

The objective of this experiment was to evaluate the additive effect of corn stalk silage (CS), 3 nitrogen sources (pig manure, PM; poultry litter, PL; urea, UR) and 2 energy sources (cane molasses, CM; bakery byproduct, BBP), on a diet (145 g CP/DM). Silages composition (g/kg DM) was: 1) 384.6 CS, 384.6 PL, 230.0 CM or BBP; 2) 294.1 CS, 529.4 p.m., 176.5 CM or BBP; 3) 630.0 CS, 30 UR, 340 CM or BBP. The diet contained (g/kg DM): silage 400:600 supplement (corn grain, soybean meal, wheat bran, fish meal, vitamins and minerals). Each silage and concentrate of each treatment were analyzed separately. A factorial arrangement of 3 N sources (PM, PL, UR) × 2 energy sources (CM, BBP) was used in this experiment. The statistical analysis was performed with 2 methods: 1) Mixed lineal procedure (PROC MIXED) assigning literals of treatments with Macro pdmix800.sas (Tukey, P < 0.05); 2) adjustment of gas production with NLMIXED to the model Yij = β1i1/1+(β2i2) e3t + ei, where: maximum asymptote of accumulated gas (mL/g DM) at 72 h, β2 = Ymax/2 (h) and β3 = fractional rate of degradation (g DM/h). Diets PL-CM and PM-CM had greater gas production (P < 0.05) during 72 h, whereas PL-CM concentrate and PL-BBP silage produced more gas (P < 0.05) at 72 h. Regarding β1, diet (273.65) and concentrate (297.86) of PL-CM were greater than the others (P < 0.05), but silage PL-BBP (222.58) produced more gas. Besides, there was an additive effect of the combination silage plus concentrate of PM-CM, regarding β1, which agrees with gas production (153.12) during all the fermentation. For gas production adjustment to the model, the concentrate and PL-CM diet as well as PL-BBP silage, showed greater β1 and a higher limit which was higher than the others; besides, β2 was constant between treatments and β3 was lower in silages. Thus, it may be concluded that PL-CM and PM-CM combinations have a larger potential for gas production due to the additive effect of their components.

Key Words: sheep nutrition, waste and by-products, in vitro gas production