Abstract #T372

# T372
Sources of nonfiber carbohydrate in sugarcane silage based diets.
Viviane B. Ferrari*1, Nara R. B. Consolo1, Rafael T. Sousa1, Frederich D. Rodriguez1, Luís Felipe P. Silva1, 1University of São Paulo, São Paulo, Brazil.

The aim of this study was to evaluate sources of nonfiber carbohydrates (NFC) and levels of concentrate, in sugarcane silage based diets, on intake, ADG, final body weight (FBW) and G:F ratio. The trial was repeated in 2 years: 2012 and 2013, to increase the power of the experiment. In each year, 54 Nellore young bulls, with initial body weight of 365 kg, were randomly distributed in 18 pens, with 3 animals per pen. The experimental design was a randomized block design, with 6 replicates, in a 2 × 3 factorial arrangement of treatments. Treatments were 2 levels of concentrate (diets 60% or 80% concentrate on DM basis) and 3 sources of NFC: steam-flaked corn (SFC), pelleted citrus pulp (PCP), or ground corn (GC). Steam-flaked corn and PCP replaced 70% of the ground corn in the diet, and all diets had sugarcane silage as the roughage source. Animals were weighted at the beginning of the experiment and at the end of each period (4 periods of 21 d). Intake was regulated for pen by daily weighting of diet and orts, allowing for 5 to 10% of orts. Samples of feedstuffs and orts were weekly collected for chemical analyses and determination of nutrients intake. There was a NFC x Diet interaction on DMI (P = 0.01), as substituting GC for SFC and PCP decreased DMI, but only at the 60% concentrate diet (P < 0.01). There was also a NFC × Diet interaction for NDFI (P = 0.02). At the 60% concentrate diet, SFC decreased NDFI when compared with GC and PCP (P < 0.05). At the 80% concentrate diet, NDFI was higher for PCP than for GC and SFC (P < 0.01). Substituting PCP for GC decreased FBW (P < 0.01), with no difference between GC and SFC (P = 0.26). Similarly, PCP decreased ADG compared with GC (1.27 vs. 1.40; P = 0.04), independently of diet. Increasing the concentrate level in the diet improved G:F ratio (0.149 vs. 0.137; P < 0.01), but there was no effect of NFC sources on G:F ratio (P = 0.74), nor there was a NFC × Diet interaction (P = 0.21). Pelleted citrus pulp as main carbohydrate source decreased performance of young bulls compared with ground and steam-flaked corn.

Key Words: average daily gain, steam-flaking, feed intake