*3.3.1. Phytochemical-rich forages*

consider alternative home-grown protein-rich forage crops as supplements to grass silage for sustaining production. Ensiling legumes is a good way of providing a cheaper, non-animalbased and traceable home-grown protein that may improve the efficiency of production system in any livestock farms. Also, legume silages with low DM and WSC contents are generally more resistant to aerobic deterioration than cereal silages [6]. There are also some unidentified microbial inhibitors that prevent the growth of spoilage microorganisms [7]. But, most legumes undergo butyric acid fermentation when ensiled without additives at low DM content due to low WSC and high buffering capacity [8]. Furthermore, severe degradation of proteins may

Besides, stage of maturity and DM content of the crop at ensiling, wilting and rate of drying markedly reduce proteolysis in the silo [9]. Rapid and extensive wilting (DM > 500 g/kg) improved protein value and reduced CP degradability. Moreover, due to the reversible proteinbinding properties of tannin, species containing tannin have shown to undergo less protein degradation during ensiling than that do not contain tannin. Since protein degradation in the silo is widely recognized to be the most limiting factor in legume silage, intrinsic protein protection by mixing tannin-containing forages may contribute to reducing the rate and the extent of NPN formation in silages, thereby improving N usage. Fraser et al. [10] compared the nutritive value of a range of ensiled forage legumes from late second-cut lotus (*Lotus corniculatus*), first-cut sainfoin (*Onobrychis viciifolia*) and both early and late second-cut red clover (*Trifolium pratense*) and lucerne and found high intake potential of all the legume silages. The taniferous lotus silage recorded higher intake and N utilization compared to less/non-tannin legumes, clover and lucerne, while low N digestibility appears to limit the nutritional value of sainfoin. In silages made from the beginning of ripening stage, where most of the protein was localized in the seed, the level of proteolysis was reduced and a good fermentation was observed in peas ensiled after a short wilting period [11]. Possible approaches include the adoption of harvesting techniques that reduce field wilting time, the use of protein protection agents during ensiling

devalue the protein quality due to inefficient N utilization.

16 Ruminants - The Husbandry, Economic and Health Aspects

such as tannins or the choice of natural tannin-containing legume species.

Industrialization of food production has produced large quantities of food wastes, viz. (i) crop waste and residues, (ii) grain and legume by-products; (iii) distillery and brewery byproducts; (iv) fruit and vegetables by-products; (v) sugar, starch and confectionary industry by-products and (vi) oil industry by-products. Fruit and vegetable processing by-products/ co-products are promising sources of valuables such as phytochemicals (carotenoids, phenolics, flavonoids), antioxidants, antimicrobials, vitamins or dietary fats that have favorable technological activities or nutritional properties and have traditionally been used as feed ingredients, and their effect on animal performance has been extensively studied [12–14].

**Key determinants while selecting unconventional resources:** Moisture content is the most important factor in silage making, with a recommendation at 65–75% [15] depending on the means of storage, the degree of compression and the amount of water that will be lost in storage. Effluent is produced when moisture is above 75%, with the amount of effluent increasing with increasing silo height due to increasing pressure. In general, forage with high moisture

**3.3. Alternate plant biomass for silage making**

Tannins in ruminants can induce beneficial effects attributable to tannin-protein complexes, which lead to increased rumen escape of dietary protein and increase in microbial protein outflow. High N fertilized grasses are more degradable, which are hydrolyzed extensively during ensiling and are rapidly degraded in rumen resulting in more excretory loss. Decreased proteolysis and slower fermentation of proteins and NPN are particularly important in silages for uniform N availability to ruminal microbial synthesis and thus optimizing its usage. Forage legumes with PSM are considered to be less susceptible to proteolysis than other legumes, which improve silage quality. The legume sainfoin has been shown to contain tannins of particularly beneficial composition for ruminant nutrition. Adding tannins during ensiling holds key both at ensiling and at rumen level to check N degradation and decrease its excretion.

Plant phenolic compounds and flavonoids are the largest and best-studied natural phenols that possess a series of biological properties and act on biological systems, such as antioxidants, antimicrobials and immunostimulants, which in turn, are associated with a reduction in the incidence of various human diseases. The shift in research to feedstuff endogenous factors, which influence proteolysis and lipolysis, may have a significant contribution on ruminant products (meat, milk) and their transmission to human food chain. Any qualitative variation in ruminant food products with naturally rich conjugated linoleic/linolenic acid (CLA) and other ω3 fatty acids (FA) can thus be influenced by animal's diet. Ruminal biohydrogenation is heavily influenced by PSM, which includes polyphenol oxidase (PPO), FA oxidation and tannins, and the effect is a complex set of mechanisms directly affected by PPO or indirectly by passage rate, lipid encapsulation, shift in the ruminal microbial population, modulation of protein and fiber degradation and interactive effect of other PSM [16]. The animal performance with silages from PSM-rich forages attributed not only to differences in their nutritive value but also to interactive effects impacting differently on feeding motivation and digestive efficiency [17].

sainfoin and alfalfa improves fermentation in silos and increases total tract digestibility, suggesting positive associative effects of the two forages [20]. The optimal ensiling and ruminal fermentation for alfalfa and sainfoin were observed at approximately 60:40 ratio (DM basis). It also reduces proteolysis and preserves the nutritive value with sainfoin relative to alfalfa alone. Both total phenol and total tannin contents contributed to the decrease in lactic acid production. Fasuyi et al. [22] found 4% molasses and 14 to 21 days ensiling period optimum and most suitable for effective ensiling of *Tithonia diversifolia* leaves. They also observed a gradual decrease in major anti-nutrients (phytin, tannins, oxalates, alkaloids, flavonoids) with lengthening duration of ensiling. However, there are reports that tannins suppress the production of lactic acid during ensilage [23]. A number of additives that include chemical inhibitors, such as acids, formaldehydes, and various salts, and biological stimulants (LAB and other bacteria) expedite lactic acid production to support ensiling process [24]. The resistance mechanisms of *L. plantarum* include the ability to degrade phenolic compounds [25] such as tannin, by the

Silage for Climate Resilient Small Ruminant Production http://dx.doi.org/10.5772/intechopen.74667 19

action of novel tannin acylhydrolase [26] and gallate decarboxylase enzymes [27].

mixed ration (TMR) silage is a way forward in this direction.

The concept of mixed silage has widen the scope of incorporating grains, protein concentrates, leguminous forage crops, tree forages and other conventional and unconventional tanniniferous forage crops with the conventional one for silage making. Making of mixed silage involving seasonal availability of feed resources allows the farmers to opt for a variety of forages, for example monsoon herbages, tree forages and browses, including that of conventional grasses and cultivated fodder. It also widens the scope of incorporating non-conventional fodder resources like cactus, thorny non-toxic plants/weeds and phytochemical-rich plant resources. Corn and legume silages are commonly fed together in rations for dairy cattle, one complementing the other for the deficit N and energy sources, respectively. Thus, the fermentable carbohydrates in corn silage may complement the rumen degradable N (RDN) in legume silage, which may decrease ruminal N losses. Above all, the N intake affects the amount of N excreted via manure, whereas types of carbohydrate (starch in corn silage vs. sugars in grass silage) and forage species (legume vs. grasses) have greater impacts on the route (fecal or urinary) of excretion. Besides agronomic benefits of grass-legume mixtures, there are positive associative effects contributing to voluntary intake due to a greater motivation of animals to eat mixtures along with decreased urinary N excretion and increased N retention [28]. Thirumurugan et al. [29] evaluated cereal-legume mixed silage to combat feed and water scarcity and sustaining production during hot summer in semi-arid regions of India. Total

Monotonous use of a single fodder (e.g. maize) in silage making limits the farmers to adopt the technologies, particularly in unfavorable geographical and climatic regions (semi-arid and arid regions). Therefore, combination of grasses and legumes is an alternative solution to the success of the ensiling process. The purpose of the addition of legumes to silage is to supply N/protein for microbial protein synthesis, reduce protein degradation in the rumen and

**3.4. Concept of mixed silage**

*3.4.1. Why mixed silage?*
