Effects of Dietary Babassu Oil or Buriti Oil on Nutrient Intake and Total Tract Digestibility, and Abomasal Digesta Fatty Acid Profile of Lambs

SIMPLE SUMMARY: This research tested the effects of adding babassu oil (450 g/kg C12:0 of total fatty acids—FA) or buriti oil (750 g/kg C18:f total FA) to the diet of lambs on intake, nutrient digestibility, FA profile of abomasal digesta content and biohydrogenation patterns in digestive content. Both are widely available in the Northeast of Brazil and Amazon region. Our results provide evidence that the babassu supplemented diet promotes greater stress to the ruminal bacteria (due to the high concentration of C12:0), changing the normal biohydrogenation of polyunsaturated FA (PUFA) in the rumen, and the FA concentration that flows to the abomasum, compared to the buriti oil supplemented diet, which provided similar results to the non-supplemented diet. ABSTRACT: Our current understanding of the effect of medium-chain FA (MCFA) rich vegetable oils on ruminant nutrition is limited. We assessed the effects of babassu or buriti oil addition to the diet of lambs on intake, nutrient digestibility, FA profile of abomasal digesta content and biohydrogenation (BH) patterns in digestion. The experimental diets were defined by the addition of babassu oil or buriti oil to the diet, as follows: (1) non-supplemented diet (CON); (2) 40 g/kg of babassu oil (BAO, rich in C12:0); and (3) 40 g/kg of buriti oil (BUO, rich in c9 18:1), on a dry matter (DM) basis. During the last five days of the feedlot, samples of orts and feces were individually collected to determine the nutrient and FA digestibility. At the end of the experiment, animals were slaughtered, and the abomasal digesta was collected, freeze-dried and used for FA determinations conducted by gas chromatography. The BAO diet decreased the DM (p = 0.014) and nutrient intake. The lambs fed BUO had the greatest FA intake, followed by the BAO and CON diets. However, BAO increased total FA digestibility, compared with CON, but did not differ from BUO. The BAO diet extensively changed the FA composition of abomasal digesta when compared with both the CON and BUO diets. The BAO diet also increased C12:0 and C14:0, the sum of PUFA and the BH intermediates FA, including the t-10-18:1 but decreased the C18:0 in abomasal digesta. The BUO addition had the greatest total-FA and C18:0 and the lowest biohydrogenation intermediate content in abomasal digesta. The BH was less complete with the BAO diet and a large increase in t10-18:1 and of t10-/t11-18:1 ratio was observed, which indicates the occurrence of t10 possibly shifted rumen BH pathways, probably as a response to bacterial membrane stress induced by the greater C12:0 concentration in the rumen.