s:1191:"TI Intake, digestibility and nitrogen utilization by sheep fed with provenances of Calliandra calothyrsus Meissner with different tannin structure 
AU Lascano Aguilar, C.E. 
AU Avila Vargas, P. 
AU Stewart, J. 
AB A trial with sheep (housed in metabolic cages, and fitted with ruminal and duodenal cannulas) fed sun-dried forage of two Calliandra calothyrsus provenances (San Ramon —CIAT 22310 and Patulul CIAT— 22316) harvested in sites with contrasting soil fertility was carried out to further define the biological significance of the different chemical structure in the tannin of Calliandra provenances. Six African-type sheep were assigned to one of four treatments (T1: San Ramón grown in Quilichao with infertile soils, T2: Patulul grown in Quilichao with infertile soils, T3: San Ramón grown in Palmira with fertile soils, and T4: Patulul grown in Palmira with fertile soils) arranged in an Unbalanced Simple Crossover Design. Results showed that extractable tannins in Patulul comprised mainly procyanidin subunits, whereas the tannin fraction in San Ramón was composed largely of prodelphinidin subunits. The DM intake and digestibility of Calliandra were greater (P 
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