In vitro and in situ evaluation of feed lot rations with different levels of complete ear of the corn (Zea mays) in lambs

Abstract

The study was conducted to evaluate the nutritive value of the complete ear of the corn (Zea mays) and diets with 0, 15 and 30% whole ear of the corn (WEC) by two stage in vitro technique and nylon bag techniques, respectively using Pelibuey lambs. For in situ evaluation, diets had equal CP (14% DM basis) and metabolizable energy (ME, 11.0 MJ/kg DM) content. Three non-castrated Pelibuey male lambs fitted with permanent rumen cannula were utilized in a 3 × 3 Latin square design. Each experimental period consisted of 10 d of adaptation followed by sampling in in situ evaluation. Corn grain had higher IVDMD than cob and husk, which was similar between them. Bags containing the 6 g substrate were incubated in the rumen in pairs for 4, 8, 12, 24 and 48 h. The washing loss and potential degradation was similar among the treatments. WEC level did not influence the degradation rate or the effective degradation at passage rate (k) of 0.01, however at passage rate of 0.05, it was higher in T2 than T1 and T3 and at 0.10 T2 was higher than T1, and T3 was similar to T2 and T1. It was concluded that high concentrate diets with WEC had high DM degradability. The incorporation of whole ear of the corn (grain, cob and husk) in diets for feedlot lambs may reduce cost of production