Abstract

LANDAU, S.; GLASSER, T.; DVASH, L.  and  PEREVOLOTSKY, A.. Faecal NIRS to monitor the diet of Mediterranean goats. S. Afr. j. anim. sci. [online]. 2004, vol.34, n.5, pp.76-80. ISSN 2221-4062.

A method to establish the diet of goats in ligneous environments is needed. Twelve Damascus yearlings were subjected to 12 test periods in which days 1-7 were for adaptation, intake was recorded on days 8-10 and faeces were grab-sampled on days 9-10, resulting in 143 pairs of diets and faeces. Diets consisted of hay and concentrate given in different ratios (n = 60), or combinations of three species browsed by goats (Pistacia lentiscus, Phyllirea latifolia, and Pinus Brutia) and concentrate (n = 83). Faeces were scanned in the 1,100-2,500 nm range by aid of a Near Infrared Spectrometer. Chemical and botanical percentage (% of DM) and actual (g/d) intake values were then fitted to reflectance values. Values for R² and the standard error of cross validation (SECV), used as estimates of calibration quality for component percentages were: CP, 0.98, 0.5; NDF, 0.94, 1.5; in vitro DMD, 0.98, 2.0; PEG-binding tannin, 0.96, 1.0; hay, 0.99, 5.5; concentrate, 0.95, 4.5; total browse, 0.97, 6.1; P. lentiscus, 0.95, 7.1; P. latifolia, 0.94, 7.0; and P. brutia, 0.95, 6.5. Values for R² and SECV of intake (g/d) were: DM, 0.83, 126; CP, 0.75, 12; NDF, 0.79, 56; in vitro digestible DM, 0.74, 58; PEG-binding tannin, 0.92, 20; hay, 0.97, 67; concentrate, 0.95, 41; total browse, 0.87, 180; P. lentiscus, 0.93, 106; P. latifolia, 0.85, 194; and P. brutia, 0.85, 151. Chemical composition (% DM) can be predicted from faeces spectra as accurately as from direct analyses of feeds. Predictions of nutrient and botanical intake (g/d) are less accurate but still relevant for monitoring purposes.

Keywords : Ruminant nutrition; range management; near infrared; Mediterranean pasture; grazing.

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