Effects of fibre source on nutrient digestibility of diets for finishing lambs

Abstract

Inexpensive fibre sources might be used as an alternative to lucerne hay in diets for finishing lambs. Thus, effects of providing fibre from lucerne hay (LH), soyhulls (SH), maize stover (MS) and Eragrostis teff hay (ET) on the nutrient digestibility of diets of finishing lambs with comparable NDF and nutrient concentration were evaluated. Thirty-six individually housed Merino ram lambs (x̄ = 43.03, SD = 3.72 kg) were randomly allocated to four diets (n = 9 lambs/treatment). A digestibility study was conducted to determine the nutrient availability of these diets. Dry matter (DM) intake of SH (1436 g) was lower than ET (1716 g). No differences were recorded between treatments for digestibility of NDF (0.32 - 0.34), acid detergent fibre (ADF) (0.41 - 0.44), and ether extract (EE) (0.67 - 0.75), except that MS (0.23) had lower NDF digestibility. Digestibility of DM, organic matter (OM) and non-structural carbohydrates (NSC) were similar for the LH (0.72; 0.75; 0.96) and SH (0.70; 0.74; 0.95) diets, whereas digestibility of crude protein (CP) (0.71 vs. 0.68), metabolizable energy (ME) (9.49 vs. 8.90 MJ/kg DM), and the available ash fraction (0.39 vs. 0.28) were altered. The SH and ET (8.70 MJ/kg DM) treatments had similar ME concentrations, but ET had lower DM digestibility (0.68). The MS treatment had the lowest ME concentration (8.25 MJ/kg DM). The LH treatment resulted in overall better nutrient availability compared with SH, MS, and ET.