689 Effect of increasing levels of babassu mesocarp flour on feed intake, nutrient digestibility, and rumen fermentation in sheep

Abstract

In Northeastern Brazil, an important alternative food source is the babassu palm (Orbignya spp.). The babassu coconut is composed of 11% exocarp, 23% mesocarp, 59% endocarp, and 7% kernels. A low-cost flour can be extracted from the mesocarp. An important feature of babassu byproducts is their availability during the off-seasons of conventional grains, thus making it an important alternative for regional producers. Twenty crossbred lambs were used in a randomized complete block design (29.17 ± 2.23 kg BW) to evaluate the effect of increasing levels of babassu mesocarp flour (BMF; 0, 10, 20 and 30% [DM basis], corresponding to experimental diets 0BMF, 10BMF, 20BMF, and 30BMF, respectively) on feed intake, digestibility of nutrients, and ruminal fermentation. Lambs were individually confined and fed an isonitrogenous diet (16.5 ± 0.2 CP, DM basis) containing 70% of concentrate and 30% of Tifton 85 hay (DM basis) for 21 d, with 15 d for diet adaptation, 5 d for data collection of orts and feces, and 1 d for ruminal content collection ( 0, 2.5, 5.0 and 7.5 h after feeding). A representative sample of ruminal content from each animal was collected via esophageal tube. The first portion of rumen fluid was discarded, and the second portion, after being squeezed through 2 layers of cheesecloth, was used for determining pH, ammonia nitrogen, and short-chain fatty acids (SCFA). Orthogonal polynomials for diet responses were determined by linear and quadratic effects (P <0.05). There was a quadratic effect (P <0.05) on DMI (1,157.6, 1,397.6, 1,171.2, and 815.6 g/d for BMF0, BMF10, BMF20, and BMF30, respectively), nutrients intake, CP digestibility, and nonfiber carbohydrate digestibility. The digestibility of DM, OM, total carbohydrates, and NDF linearly decreased (P <0.05) whereas ether extract digestibility linearly increased (P <0.05) with increasing levels of BMF. There was no effect (P >0.05) of increasing levels of BMF on pH, butyric acid, and total SCFA concentrations. There was a quadratic effect for propionic acid concentration (20.8, 21.5, 19.1, and 19.6 mol/100 mol for BMF0, BMF10, BMF20, and BMF30, respectively). The increasing levels of BMF linearly increased the acetic acid proportion (63.7, 63.8, 67.8, and 68.0 mol/100 mol for BMF0, BMF10, BMF20, and BMF30, respectively) and linearly decreased the A:P ratio, NH3–N, isobutyrate, and valerate concentrations. The BMF is an alternative for energy source in sheep feed and can be added at levels up to 10%.