Effects of forage type, animal characteristics and feed intake on faecal particle size in goat, sheep, llama and cattle

Abstract

Abstract The effect of forage maturity stage at harvest, animal characteristics and neutral detergent fibre (NDF) intake on mean particle size and particle size distribution in faeces from sheep and cattle fed grass silages was studied (Study I). Models for prediction of faeces characteristics from sheep and cattle and feed characteristics established from Study I were tested on faeces samples from goat, sheep, llama and cattle fed other types of forages (Study II). Study I included 112 faeces samples from 5 trials, and Study II included 90 faeces samples from 3 trials. Animals were fed ad libitum or restrictively with or without concentrate supplementation. The NDF content and acid detergent lignin (ADL) to NDF ratio of the forages ranged from 410 to 660 g/kg of dry matter (DM) and from 0.03 to 0.10, respectively, in Study I, and from 320 to 810 g/kg of DM and from 0.05 to 0.18, respectively, in Study II. The faecal samples were washed in nylon bags with a pore size of 0.01 mm and freeze dried before being sorted into 5 sieving fractions with pore sizes of 2.4–0.1 mm; particles less than 0.1 mm were collected in bottom bowl. The faecal particles were characterized by the arithmetic and geometric mean sizes, most frequent, median and the 95 percentile values. In Study I, the mean faecal particle size increased, and the proportion of small particles (SP; C : F ), and NDF intake ( p 1 mm) increased with higher BW and NDF intake ( p p C : F and forage NDF intake on particle size in faeces of grass silage-fed animals in Study I appeared to be valid to predict the geometric mean particle size in faeces from goat, sheep, llama and steers fed other forages e.g., lucerne, dried grass, grass seed straw and whole crop barley silage in Study II.