Untitled

Funder

Organizational Unit

Publications

Inclusion of Cistus ladanifer in ruminant diets : an approach to improve the nutritional value of edible fats

Publication . Guerreiro, Olinda Rosa Fragoso das Neves; Bessa, Rui José Branquinho de; Jerónimo, Eliana Alexandra Sousa; Duarte, Maria de Fátima Pereira

Cistus ladanifer is a shrub quite abundant in Mediterranean countries, that when fed to lambs has been associated with changes in rumen biohydrogenation (BH), increasing t11-18:1 concentration in abomasal digesta and meat. The thesis main motivation was to further knowledge regarding C. ladanifer plant and to explore its utilization in nutritional strategies to ruminal BH modulation. In the first two experiments, seasonal variation of C. ladanifer aerial parts, with two ages, was characterized for chemical composition, including proximate composition and total phenols and condensed tannins (CT) contents, for in vitro digestibility, antioxidant activity and fatty acid (FA) profile. Cistus ladanifer was considered a nutritionally unbalanced feed, however, it may be used in ruminant nutrition, but only associated with other feeding resources to complement its nutritional imbalances. In third experiment, C. ladanifer fractions effects were tested on in vitro ruminal BH. Condensed tannins fraction was the most active on ruminal BH modulation, leading to a higher t11-18:1 accumulation and higher disappearance of substrate polyunsaturated FA. Therefore, we intended to determine which CT amount can optimize t11-18:1 ruminal synthesis. However, all CT fraction levels led to a depression of microbial growth without effects on ruminal BH. Last experiment was designed to explore effect of two levels of C. ladanifer CT (1.25% and 2.5%) and two ways of CT supply (C. ladanifer aerial parts and C. ladanifer CT extract) on lamb growth performance, carcass composition, meat quality and FA composition of lamb fat. The highest amount of C. ladanifer aerial part (2.5% of CT) had detrimental effects on growth performance, whereas, C. ladanifer CT extract inclusion in diet (1.25% of CT) led to the highest t11-18:1 increase in fat. So, we can conclude that C. ladanifer CT extract may be a good approach to improve the nutritional value of the ruminant edible fats.

2018-06-11Doctoral thesis

Open access