Author/Editor     Babnik, D
Title     Some environmental effects on relationships between in sacco degradability of protein and dry matter and chemical composition of Italian ryegrass
Type     članek
Source     Arch Tierernahr
Vol. and No.     Letnik 48, št. 3
Publication year     1995
Volume     str. 303-17
Language     eng
Abstract     The environmental effects on chemical composition and the rate and extent of crude protein (CP) and dry matter (DM) degradation of Italian ryegrass (Lolium multiflorum Lam.) in the rumen were studied. More intensive nitrogen (N) fertilizing (40, 80 and 140 kg N/ha) increased the content of the water, CP, true proteins and the effective degradability of CP (P less th. 0.05). Especially in the spring harvest such fertilizing increased the content of acid detergent fibre (ADF), neutral detergent fibre (NDF), cellulose and crude fibre (CF) as well as the rate of DM degradation (P less th. 0.05) and caused lower DM solubility while the content of hemicellulose was not affected. The most rapid changes due to grass ageing occurred in springtime. The content of DM, ADF, NDF, cellulose, hemicellulose and CF increased with maturity while the degradation rate and effective DM degradability decreased. The season and the trial location influenced the chemical composition of grass and the degradability of both DM and CP (P less th. 0.05). The closest multiple regression (the lowest RSD) was between the effective protein degradability and CP, NDF, ADF and and acid detergent lignin (ADL) (R2 = 0.97). Relatively good estimation of effective protein degradability was obtained using an exponential regression equation on the basis of CP content (R2 = 0.72), NDF content (R2 = 0.67) or effective DM degradability (R2 = 0.71) while the effective DM degradability may be estimated on the basis of DM solubility (R2 = 0.94), CF content (R2 = 0.93), ADF content (R2 = 0.94), ADL content (R2 = 0.85) or NDF content (R2 = 0.96). When estimating the effective CP and DM degradability from chemical composition, the error that occurs is most evidently influenced by N fertilizing and by time of harvest.
Descriptors     DIETARY PROTEINS
DIGESTION
LOLIUM
RUMEN
BIODEGRADATION
DIETARY FIBER
ITALY
LOLIUM
REGRESSION ANALYSIS
SEASONS