Effect of Increasing Levels of Babassu Mesocarp Flour on Feed Intake, Nutrient Digestibility and Rumen Fermentation in Sheep

In Northeastern Brazil, an important alternative food source is the babassu palm (Orbignya ssp). 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 confined individually 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 days, with 15 days for diet adaptation, 5 days for data collection of orts and feces and 1 day for ruminal content collection ( 0, 2.5, 5.0 and 7.5 hours 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 dry matter intake (1157.6, 1397.6, 1171.2 and 815.6 g/d for BMF0, BMF10, BMF20 and BMF30, respectively), nutrients intake, crude protein digestibility and non-fiber carbohydrates digestibility. The digestibility of dry matter, organic matter, total carbohydrates, and neutral detergent fiber decreased linearly (P<0.05), while ether extract digestibility increased linearly (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 moles for BMF0, BMF10, BMF20 and BMF30). The increasing levels of BMF linearly increased the acetic acid proportion (63.7, 63.8, 67.8 and 68.0 mol/100 moles for BMF0, BMF10, BMF20 and BMF30) and decreased linearly the A:P ratio, NH3-N, isobutirate, and valerate concentrations. The BMF is an alternative for energy source in sheep feed, and can be added at levels up to 10%.