Composição química e degradabilidade in situ da ração em ovinos em área de caatinga no sertão de Pernambuco

Abstract

This work was conducted with the objective of evaluating the effect of the type of fistula and time of collection on the chemical composition and in situ digestibility of dry matter, neutral detergent fiber and crude protein in the caatinga region. The experiment was conducted between September 2004 and July 2005. Ten Santa Inês castrated sheep, five with permanent ruminal cannula and five with esophageal cannula, were used. Samples were collected from both cannulas at 7:00 am and 2:00 pm. Sheep had free access to water and mineral mix. The percentage of DM, MM, CP, EE, NDF, ADF, NDIP, ADIP, CHOT, NFC, FT, TT and TC ranged from 11.99 to 25.28%; 10.92 to 14.44; 10.64 to 17.19%; 2.95 to 4.77; 54.83 to 63.14%; 39.40 to 46.62%; 49.74 to 57.95; 28.52 to 39.15; 65.40 to 72.73; 5.47 to 12.86%; 0.37 to 0.52%; 0.16 to 0.28%; and from 1.28 to 6.24%, respectively. Potential degradability (%), fraction B (%), fraction C (%/h), fraction A (%), effective degradability and passage rate of 2 and 5%/h ranged from 48.25 to 64.63; 35.77 to 47.78; 4.60 to 13.40; 9.74 to 18.13; 43.28 to 55.71 and 37.60 to 47.27 for dry matter; from 36.43 to 54.34; 33.28 to 50.38; 3.84 to 8.42; 2.16 to 4.41; 29.21 to 36.54; 23.02 to 33.33 for neutral detergent fiber and from 62.13 to 77.24; 35.44 to 56.09; 5.37 to 14.36; 20.21 to 31.49; 55.84 to 67.49; 45.74 to 59.99 for protein, respectively. The chemical composition and in situ digestibilility of diets for sheep in caatinga is influenced by the month of evaluation. The diet for sheep in the caatinga region presented low in situ digestibility of dry matter, neutral detergent fiber and crude protein. Ruminal cannula instead of esophageal cannula can be used to characterize the chemical composition and degradability of diet consumed by small ruminants. © 2009 Sociedade Brasileira de Zootecnia.