A critical review on feed value of coffee waste for livestock feeding

The objective of this review is to synthesize information available on the feeding value of coffee waste. In the diets of ruminants, waste and by-products of coffee have successfully used 10 to 30%. It has been claimed that the feeding of Coffee leaves extends the lactation period. Coffee pulp (dried or not), coffee hulls (sticky or dried) and coffee grounds (a by-product of instant coffee manufacture) have an overall deleterious effect on pigs. At certain growth stages, lower weight gain was attributed to phenolics in the coffee pulp. On the contrary, inclusion of dried coffee pulp rations at different levels had no significant influence on the feed intake, growth rate and feed conversion efficiency. Pigs fed with rations containing up to 15% of coffee pulp ensiled with 5% molasses had equal or better total weight gain than those fed commercial concentrates. At levels exceeding 10% in poultry diets, it produces toxic symptoms. Coffee pulp (13%) also did not affect the growth and feed efficiency of the fish Tilapia aurea. On the contrary, Caffeine dietary levels between 2.4 g/kg to 4.6 g/kg tended to reduce fish growth, feed intake and nutrient digestibility in tilapia fingerlings. Limiting the use of waste and byproducts of coffee by the animals is due to their caffeine content which diminishes the palatability and acceptance of husk and pulp by animals. Tannin and alkaloids affect their health and negatively affect the palatability of the diets. But drying, silage, physical (percolation), chemical (alcohol extraction) or microbiological (fermentation with Aspergillus niger) methods contribute to lower levels/ 10% dietary level/ of caffeine and tannins of waste and by-products of coffee.