Effect of Biosurfactant and Oils over the Morphometry of the Rumen and Duodenum of Lambs

Fat is an energy source to be taken into consideration in the diets of feedlot lambs, but an excess can cause metabolic disorders. Biosurfactant acts in the digestion and absorption of these lipids and thus increases energy utilization. The objective of the experiment was to evaluate the inclusion of biosurfactant with two different oil sources in a high concentrate diet for feedlot lambs on the development of ruminal papillae and villi in the duodenum. A 2x2 factorial design was used (soybean or sunflower oil x inclusion or not of biosurfactant). The experiment was conducted at the Faculty of Zootechnics and Food Engineering of USP, Pirassununga, São Paulo, Brazil. Four diets were evaluated: two oil sources (soybean or sunflower) with or without biosurfactant, with 10 animals per treatment. The diet contained 17% crude protein, 2,400 mcal of metabolizable energy, and 5% fat. The initial body weight was 24 kg and the final weight was 42 kg, for a feedlotting period of 60 days. After slaughtering, an area of 5 cm² from the ventral ruminal sac, and duodenum were fixed in formalin, paraffin embedding and sectioned. For morphometric analysis, slides were stained with hematoxylin-eosin. The measurements taken were the area and height of ruminal and intestinal villi and the depth of the intestinal glands. Data was analysed using the GLM of SAS, comparing the means from the Student test with a 5% probability. In the rumen the height of the papilla was not affected (P>0.05), with a mean of 3.47 mm, but the area of the papilla (P=0.0017) was influenced by the interaction of the oils with the inclusion of the biosurfactant, with greater areas for soy without biosurfactant, with a mean of 6.660 mm², and the other treatments having a mean of 5.315 mm². In the intestine the depth of the crypt was not affected by the diet (P>0.05), with a mean of 0.97 mm. There was an interaction for the height of the villus (P=0.0340), this being greater for the diet with sunflower oil and biosurfactant, with a mean value of 1.13 mm. The area of the intestinal crypt (P=0.0009) was greater for the treatments without biosurfactant, with a mean of 293 mm². It is concluded that the different oil sources and the addition of biosurfactant have an effect over rumen papillae and duodenum villi.