Rm. Beames et al., A COMPARISON OF METHODS FOR MEASURING THE NUTRITIVE-VALUE FOR PIGS OFA RANGE OF HULLED AND HULLESS BARLEY CULTIVARS, Animal feed science and technology, 62(2-4), 1996, pp. 189-201
Six hulled and three hulless barley cultivars were each divided into a
high and a low density fraction by the use of a gravity table. These
fractions were analyzed for density (wt vol(-1)), 1000 kernel weight,
soluble non-starch polysaccharides (S-NSP), insoluble NSP (I-NSP), lig
nin, total dietary fibre (TDF, S-NSP plus I-NSP plus ligin), beta-gluc
ans, gross energy and crude protein content. Measurements were made on
pigs and rats for apparent energy digestibility (AED) and true protei
n digestibility (TPD, apparent digestibility minus metabolic faecal N)
, apparent dry matter digestibility in pigs by the mobile nylon bag (M
NB) technique, and in vitro digestibility of dry matter and N by simul
ation of enzymatic activity anterior to the terminal ileum and for the
whole gastrointestinal tract. The results obtained were examined for
the reliability of various measurements for predicting AED and TPD in
pigs, Coefficients of determination were assessed for all sets of meas
urements for both the total 18 samples and for the 12 hulled samples o
nly. For most measurements, the predictive values were greater when 18
samples were used than when 12 samples were used, Best predictions fo
r AED in pigs were AED in rats (r(2), 0.97, n = 18; 0.88, n = 12), I-N
SP (r(2), 0.97, n = 18; 0.88, n = 12), in vitro organic matter digesti
bility (r(2), 0.97, n = 18; 0.82, n = 12) and MNB dry matter digestibi
lity (r(2), 0.86, n = 18; 0.85, n = 12). Coefficients of determination
were not so high for the estimation of TPD in pigs, The only values s
howing a strong relationship were obtained for the TPD measurements in
rats (r(2), 0.94, n = 18; 0.88, n = 12).