Two different drying methods of bovine faeces for estimating n-alkane concentration, intake and digestibility: a comparison.

SÁNCHEZ CHOPA, F., NADIN, L.B. AND GONDA, H.L.

ANIMAL FEED SCIENCE AND TECHNOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 p. 1 - 6

0377-8401

An experiment was completed to evaluate effects of two drying methods applied to faecal and herbage samples on estimation of n-alkane concentration and the calculated dry matter (DM) intake, faecal output (FO) and apparent in vivo DM digestibility (DMD). Four Holstein–Friesian steers (182 ± 12.1 kg initial body weight) housed in individual pens were fed at 8:30 and 16:30 h with ryegrass (Lolium perenne L.) hay for 18 d. Refusals were removed and weighed every day at 8:30 h before morning feeding. From days 9 to 18, the steers were dosed twice a day at feeding time, with cellucotton stoppers containing C32 (88.49 mg/pellet) and C36 (87.12 mg/pellet). During the last 5 d of dosing, total collection of faeces was completed using harnesses. For the n-alkane analysis, faecal (n = 64) and offered hay (n = 4) samples were subdivided into two subsamples and prepared for two alternative drying methods: oven-drying at 60 ◦C (OD) or freeze-drying (FD). The n-alkane profiles of the offered and refused hay oven-dried at 60 ◦C did not differ. In offered hay subsamples, concentrations of n-alkanes were not affected by drying method. In faecal subsamples, drying method affected (P