Utilització d'oli àcid de soia i destil·lats d'àcids grassos de palma en l'alimentació de pollastres de carn
- Autores: Beatriz Jimenez Moya
- Directores de la Tesis: Ana Cristina Barroeta Lajusticia (dir. tes.), Roser Sala Pallarès (codir. tes.)
- Lectura: En la Universitat Autònoma de Barcelona ( España ) en 2021
- Idioma: catalán
- Tribunal Calificador de la Tesis: Lorena Castillejos (presid.), Pedro Medel de la Torre (secret.), Raquel Rodríguez Sánchez (voc.)
- Programa de doctorado: Programa de Doctorado en Producción Animal por la Universidad Autónoma de Barcelona
- Materias:
- Enlaces
- Tesis en acceso abierto en: TDX
- Resumen
The supplementation of fats and oils in broiler chicken feeds is a common practice to increase the energy content of diets and provide essential fatty acids. Soybean acid oil (SA) and palm fatty acid distillate (PFAD) are by-products derived from the soybean oil (S) and palm oil (P) refining industry, respectively. They have similar fatty acid (FA) composition to their respective crude oil, but different molecular structure (triacylglycerols, TAG; diacylglycerols, DAG; monoacylglycerols, MAG; free fatty acids, FFA). Its high content in FFA, represents a limitation to upcycle these by-products in the animal feed industry. The global aim of this thesis was to investigate the potential use of SA and PFAD in blends with conventional oils with different saturation degree in broiler chicken diets, focusing the study on the fat intestinal absorption in both starter and grower-finisher chickens.
In the first experiment, in vitro methodologies were performed with the aim to evaluate the hydrolysis and bioaccessibility of SA, PFAD, and their respective crude oils. The results supported the findings reported in in vivo studies, the bioaccessibility was the most limiting step in oil digestion, not the hydrolysis. Moreover, the assessment of the bioaccessibility corroborated that the FFA level of dietary fat influences fat utilization less than its saturation degree.
The second and the third trial were conducted in parallel in order to study the effect of the replacement of S by PFAD and P by SA on lipid-class content and FA digestibility along the intestinal tract (upper and lower jejunum, upper and lower ileum) and in the excreta in broiler chickens at 11 and 35 days (d). The assessment of the lipid-class content and the apparent FA digestibility in the different intestinal segments was crucial for a better understanding of the utilization of different fat sources in broiler chickens, being the lower ileum the most important segment to evaluate the final fat utilization. Concerning the absorption dynamics, as the saturated FA (SFA) and FFA dietary content increased, the absorption of dietary fat was reduced and delayed in starter chickens. On the other hand, as the age of the chicken increased, was seen an improvement in the absorption of SFA and FFA in the jejunum and an increase in the contribution of the upper ileum to FA absorption. The results revealed that for 11-d-old broiler chickens the inclusion of PFAD at 6% or blended with S impaired fat utilization, whereas the replacement of P by SA improved FA absorption, although did not reach the fat absorption obtained with S. In broiler chickens at 35 d, the inclusion of PFAD blended with S (2% and 4%, respectively) represented a suitable fat alternative, when the blend has from 2.6 unsaturated FA:SFA ratio and the FFA% does not exceed 30%, which led to adequate fat utilization. Moreover, the use of SA at 6% or the blend between P and SA (2% and 4%, respectively) led to obtaining similar fat utilization than S at 6%. Furthermore, in 35-d-old broiler chickens, the synergism obtained in the apparent metabolizable energy of diets when both by-products were blended with the conventional oils suggested that the increase in both the unsaturated FA:SFA ratio and the proportion of TAG to FFA in the diet is a good way to introduce these by-products in broiler chicken diets. An interesting result was that the dietary FFA digestibility was higher when FFA were provided from unsaturated rather than saturated fat sources. This potential strategy to use SA and PFAD implies a reduction in economic costs of feed and a way to upcycle them decreasing their environmental impact.
