Chemical Composition, In Vitro Digestibility and Rumen Fermentation Kinetics of Agro-Industrial By-Products

Abstract

Simple SummaryAgro-industrial by-products are the waste from either agricultural crops or vegetable processing industries, and their disposal represents an environmental problem since they are potential pollutants. One of their most promising alternative uses is as feedstuffs in ruminant diets. The aim of this study was to assess the nutritive value of different by-products by analysing their chemical composition, in vitro digestibility and gas production kinetics. The results showed a high variability in chemical composition, in vitro digestibility and rumen fermentation kinetics among different by-products. In addition, samples of the same by-product from a different origin or subjected to different conservation processes showed a certain variability in the evaluated parameters. The variability among by-products was reflected in the results of the cluster analysis, which divided the materials in four groups based on the multivariate analysis. Most by-products showed the potential to be included as alternative ingredients in ruminant rations. They could be used as a source of energy, fibre or protein, replacing part of the ingredients in a conventional diet and therefore, reducing the risk of environmental pollution and contributing to develop a circular economy by recycling these wastes. In addition, their use as feedstuffs might reduce competition between ruminants and humans for food or land.AbstractThe nutritive value of 26 agro-industrial by-products was assessed from their chemical composition, in vitro digestibility and rumen fermentation kinetics. By-products from sugar beet, grape, olive tree, almond, broccoli, lettuce, asparagus, green bean, artichoke, peas, broad beans, tomato, pepper, apple pomace and citrus were evaluated. Chemical composition, in vitro digestibility and fermentation kinetics varied largely across the by-products. Data were subjected to multivariate and principal component analyses (PCA). According to a multivariate cluster analysis chart, samples formed four distinctive groups (A–D). Less degradable by-products were olive tree leaves, pepper skins and grape seeds (group A); whereas the more degradable ones were sugar beet, orange, lemon and clementine pulps (group D). In the PCA plot, component 1 segregated samples of groups A and B from those of groups C and D. Considering the large variability among by-products, most of them can be regarded as potential ingredients in ruminant rations. Depending on the characteristic nutritive value of each by-product, these feedstuffs can provide alternative sources of energy (e.g., citrus pulps), protein (e.g., asparagus rinds), soluble fibre (e.g., sugar beet pulp) or less digestible roughage (e.g., grape seeds or pepper skin).

Effects of Replacing Extruded Maize by Dried Citrus Pulp in a Mixed Diet on Ruminal Fermentation, Methane Production, and Microbial Populations in Rusitec Fermenters

“…Although many studies have investigated the effects of DCP on ruminal fermentation, results have been sometimes contradictory, which can be explained by factors such as the type of citrus pulp, the level of dietary inclusion, the ruminant species, the type of diet, and the conventional feed ingredient that were replaced. The greater NDF and ADF disappearance observed for the DCP diet in the present study is in accordance with previous in vivo [15,18,20] and in vitro [43,44] studies, and agrees with the greater cellulolytic bacteria populations observed by Barrios-Urdaneta et al [20] in the rumen of sheep when DCP replaced barley grains in the diet. Even though results from different studies are contrasting, in most of them, no negative effects of DCP on diet digestibility were reported [19][20][21].…”

Evaluation of Nutritive Values of Agro-Industrial By-Products (AIBPS) and Effect of Their Nano Structural Characteristics on the Kinetics of Biogas Production and Methane Emission

“…Calculated parameters were not in line with those reported by other studies [22,25] these parameters are affected by different factors, beside GP of 24h such as CP, CF and ash, on the other hand as mentioned factors had a variety of ranges due to conservation and cultivation methods, thus these differences were expectable.…”

“…Our ndings about chemical composition of AIBPs are presented in Table 1, variable nutritive values were reported from past to present [9,22,23,25,39]. Different geographical areas, processing type, cultivation and climate differences beside conservation system seems to be the origin of the variant values.…”

“…Per report of Paya et al (2012) nutritive values of dry apple pomace (DAP) and dry orange pulp (DOP) were; crude protein (CP): 7.2% − 7.9%, ether extract (EE): 2.9%-1.8%, neutral-detergent ber (NDF):43.3% − 22.4%, acid detergent ber (ADF): 32.3% − 15.3% and metabolizable energy (ME): 10.8-8.3 MJ/Kg, These values represent suitable capacity of these processed wastes as feedstuff which is not in competing with human food. Not only the nutritive value, but also economically being suitable as an alternative for feedstuff make these agroindustrial by-products useful [19,25]. The hypothesis that we followed in the present study was that; biore ning of agro-industrial byproducts can decrease environmental contaminators beside producing the food for human.…”

Available Pathways for Operationalizing Circular Economy into the Olive Oil Supply Chain: Mapping Evidence from a Scoping Literature Review

“…Olive leaves or solid mill wastes can be fruitfully used in animal feeding experimental studies [98][99][100][101] have shown the beneficial role of dietary administration of such byproducts due to their antioxidative properties for poultry industry. In particular, ref.…”