Use of tannins to improve fatty acids profile of meat and milk quality in ruminants: A review

Abstract

This paper reviews how tannins, through their effects on rumen lipid metabolism, can affect the composition of ruminants' meat and milk fat. Tannins are a heterogeneous group of plant secondary compounds known for both beneficial and detrimental effects on animals' digestive physiology. Tannins supplementation of ruminants' diets alters both in vivo and in vitro unsaturated fatty acids biohydrogenation and hence the profile of fatty acids outflowing the rumen, which can influence milk and meat content of beneficial fatty acids such as linolenic acid (c9,c12,c15-18:3), vaccenic acid (t11-18:1) and rumenic acid (c9,t11-18:2), among others. Published information indicates that tannins could inhibit biohydrogenation though affecting ruminal microorganisms. Some studies found increments in linolenic, rumenic and/or vaccenic acids in meat and milk fat using different sources of tannins; however, the effects of tannins supplementation on milk and meat fatty acid profile are not consistent, and there are contradictory results published in the literature. Effects of tannin supplementation on fatty acids biohydrogenation are affected by the chemical type of tannins, the complexity of their interactions with dietary components, and the potential microbial adaptation to tannins. In addition, the duration of the tannins-feeding period may also affect milk and meat fatty acid profile. Characterizing the effects of each specific tannic compound on different biohydrogenation steps and on the microbial species conducting them, as well as the interaction between specific tannin compounds and other dietary components can help to take greater advantage of tannins potential to contribute to improve human health through promoting beneficial fatty acids in ruminants products.

Framework for life cycle assessment of livestock production systems to account for the nutritional quality of final products

“…From this pool, all abstracts were examined and studies reporting the effect of either diets or production systems on meat fatty acid profiles were shortlisted. Papers focused solely on novel and unconventional feeding strategies such as inclusion of tannins (Morales & Ungerfeld, 2015) or microalgae (Madeira et al., 2017) were excluded. Furthermore, selection was limited to beef, lamb, chicken, and pork—the four most commonly produced meats globally (OECD/FAO, 2017)—and therefore work on other meat (e.g., rabbit) was also excluded.…”

Physicochemical Quality, Fatty Acid Composition, and Sensory Analysis of Nellore Steers Meat Fed with Inclusion of Condensed Tannin in the Diet

“…There is an increase in the ratio of saturated to unsaturated fatty acids and an increase in the intermediates of the BH, such as vaccenic acid (VA; trans‐ 11 18:1) and conjugated linoleic acid (CLA). Many studies have been focusing on decreasing BH as a way to increase the quality of meat and milk of ruminants by increasing the percentage of beneficial fatty acids in ruminant products (Bessa, Portugal, Mendes, & Santos‐Silva, ; Carvalho et al., ; Correia et al., ; Fiorentini et al., ; Morales & Ungerfeld, ). Dietary factors that affect ruminal BH are the amount and type of dietary fatty acid sources (Martin & Jenkins, ), and supplements or additives that change the ruminal ecosystem.…”

PISTACHIO (Pistacia vera) BY-PRODUCTS AS RUMINANT FEED: A REVIEW ON PRODUCTION, MANAGEMENT AND UTILIZATION IN ARID AND SEMI-ARID AREAS IN THE MIDDLE EAST

“…That might increase the influx of essential amino acids to the small intestine which may lead to the improvement in fattening. Tannins might have potential of altering microbial metabolism of proteins and fatty acids which are expected to improve meat content of conjugated fatty acids (Morales & Ungerfeld, 2015). Thus, further studies need to identify the use of pistachio by-products to improve meat quality of ruminants.…”

“…The inclusion of 32% dry PBM in the diet of dairy goats had positive effects on fatty acids profile of milk (increase cis-9 and trans-11 CLA and trans-11 18:1) without negative effects on milk yield (Sedighi-Vesagh et al, 2015). Tannins are expected to alter the biohydrogeneation of fatty acids in the rumen leading to an increase in conjugated fatty acids content in milk (Morales & Ungerfeld, 2015). However, contradictory results have been reported on the effect of using dry pistachio by-products on conjugated linoleic acids in goat milk (Ghaffari et al, 2014b;Sedighi-Vesagh et al, 2015).…”